<?xml version="1.0"?>

<!-- FILE : dokos_model_1996.xml

CREATED : 10th April 2003

LAST MODIFIED : 20th April 2005

AUTHOR : Catherine Lloyd
         Department of Engineering Science
         The University of Auckland
         
MODEL STATUS : This model conforms to the CellML 1.0 Specification released on
10th August 2001, and the 16/01/2002 CellML Metadata 1.0 Specification.

DESCRIPTION : This file contains a CellML description of Dokos et al's 1996 mathematical model of the ion currents underlying sinoatrial node pacemaker activity.

CHANGES: 
  04/06/2003 - CML - Fixed MathML in a couple of components.
  11/08/2003 - CML - Added equations.
  20/04/2005 - PJV - Made MathML id's unique
  
-->


<model name="dokos_model_1996" cmeta:id="dokos_model_1996" xmlns="http://www.cellml.org/cellml/1.0#" xmlns:cellml="http://www.cellml.org/cellml/1.0#" xmlns:cmeta="http://www.cellml.org/metadata/1.0#">
  
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:bqs="http://www.cellml.org/bqs/1.0#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">
    
<!--
      The following RDF block contains metadata that applies to this document
      as a whole, as indicated by the empty about attribute on the 
      <rdf:Description> element.
    -->

    
<rdf:Description rdf:about="">
      
<!--
        The Model Builder Metadata.  The Dublin Core "creator" element is used  
        to indicate the person who translated the model into CellML.
      -->

      
<dc:creator rdf:parseType="Resource">
        
<vCard:N rdf:parseType="Resource">
          
<vCard:Family>Lloyd</vCard:Family>
          
<vCard:Given>Catherine</vCard:Given>
          
<vCard:Other>May</vCard:Other>
        
</vCard:N>
        
<vCard:EMAIL rdf:parseType="Resource">
          
<rdf:value>c.lloyd@auckland.ac.nz</rdf:value>
          
<rdf:type rdf:resource="http://imc.org/vCard/3.0#internet" />
        
</vCard:EMAIL>
        
<vCard:ORG rdf:parseType="Resource">
          
<vCard:Orgname>The University of Auckland</vCard:Orgname>
          
<vCard:Orgunit>The Bioengineering Institute</vCard:Orgunit>
        
</vCard:ORG>
      
</dc:creator>
      
      
<!--
        The Creation Date metadata. This is the date on which the model
        was translated into CellML.
      -->

      
<dcterms:created rdf:parseType="Resource">
        
<dcterms:W3CDTF>2003-04-10</dcterms:W3CDTF>
      
</dcterms:created>
      
      
<!--
        The Modification History metadata. This lists the changes that have been
        made to the document, who made the changes, and when they were made.
      -->

       
<cmeta:modification rdf:parseType="Resource">
        
<rdf:value>
          Made MathML id's unique
        
</rdf:value>
        
<cmeta:modifier rdf:parseType="Resource">
          
<vCard:N rdf:parseType="Resource">
            
<vCard:Family>Villiger</vCard:Family>
            
<vCard:Given>Peter</vCard:Given>
            
<vCard:Other>J</vCard:Other>
          
</vCard:N>
        
</cmeta:modifier>
        
<dcterms:modified rdf:parseType="Resource"> 
          
<dcterms:W3CDTF>2005-04-20</dcterms:W3CDTF>
        
</dcterms:modified>
      
</cmeta:modification> 
      
<cmeta:modification rdf:parseType="Resource">
        
<rdf:value>
          Added equations for k14, k41, di, k34, k21, k23, k32, and do in the sodium-calcium exchange current component. 
        
</rdf:value>
        
<cmeta:modifier rdf:parseType="Resource">
          
<vCard:N rdf:parseType="Resource">
            
<vCard:Family>Lloyd</vCard:Family>
            
<vCard:Given>Catherine</vCard:Given>
            
<vCard:Other>May</vCard:Other>
          
</vCard:N>
        
</cmeta:modifier>
        
<dcterms:modified rdf:parseType="Resource"> 
          
<dcterms:W3CDTF>2002-07-18</dcterms:W3CDTF>
        
</dcterms:modified>
      
</cmeta:modification>
      
<cmeta:modification rdf:parseType="Resource">
        
<rdf:value>
          Corrected equations: i_CaL_calculation in L_type_calcium_current and 
          i_CaT_calculation in T_type_calcium_current.
        
</rdf:value>
        
<cmeta:modifier rdf:parseType="Resource">
          
<vCard:N rdf:parseType="Resource">
            
<vCard:Family>Lloyd</vCard:Family>
            
<vCard:Given>Catherine</vCard:Given>
            
<vCard:Other>May</vCard:Other>
          
</vCard:N>
        
</cmeta:modifier>
        
<dcterms:modified rdf:parseType="Resource"> 
          
<dcterms:W3CDTF>2003-06-04</dcterms:W3CDTF>
        
</dcterms:modified>
      
</cmeta:modification>
      
      
<!-- The Publisher metadata. -->
      
<dc:publisher>
        The University of Auckland, Bioengineering Institute
      
</dc:publisher>
    
</rdf:Description>
    
    
<!--
      The following metadata refers to the model itself, as indicated by the
      reference to the ID "dokos_model_1996", which is declared on the <model>
      element.
    -->

    
<rdf:Description rdf:about="#dokos_model_1996">
      
<!-- A human readable name for the model. -->
      
<dc:title>
        Dokos et al's 1996 mathematical model of the ion currents underlying 
        sinoatrial node pacemaker activity.
      
</dc:title>
      
      
<!-- A comment regarding the model. -->
      
<cmeta:comment rdf:parseType="Resource">
        
<rdf:value>
          This is the CellML description of Dokos et al's 1996 mathematical 
          model of the ion currents underlying sinoatrial node pacemaker 
          activity.  Please note that equations for reversal potentials were not           included in the original published model and have had to be added.  
          Also, a current called i_KACh was included in the equations for 
          external and internal potassium ion concentration calculation.  This 
          current had not been previously mentioned in the paper, and as i_KACh 
          is usually referred to in ischemic tissue, and also the background 
          potassium current i_bK had not been included in the equation, I am 
          assuming that this was a typo.  The model authors have been contacted 
          and we are awaiting their reply. 
        
</rdf:value>
        
<!-- The creator of the comment. -->
        
<dc:creator rdf:parseType="Resource">
          
<vCard:FN>Catherine Lloyd</vCard:FN>
        
</dc:creator>
      
</cmeta:comment>
      
      
<!-- The model is relevant to all mammals. -->
      
<cmeta:species>Mammalia</cmeta:species>
      
      
<cmeta:bio_entity>Sinoatrial Node Cell</cmeta:bio_entity>
      
      
<!--  Keyword(s) -->
      
<bqs:reference rdf:parseType="Resource">
        
<dc:subject rdf:parseType="Resource">
          
<bqs:subject_type>keyword</bqs:subject_type>
          
<rdf:value>
            
<rdf:Bag>
              
<rdf:li>Sinoatrial Node</rdf:li>
              
<rdf:li>cardiac</rdf:li>
              
<rdf:li>electrophysiology</rdf:li>
            
</rdf:Bag>
          
</rdf:value>
        
</dc:subject>
      
</bqs:reference>
      
      
<!-- 
        The CellML Metadata Specification recommends that bibliographic metadata
        is used to provide information about the original model reference.  The 
        "identifier" attribute on the "BibliographicReference" class provides an
        elegant way to identify a cited reference using a database identifier
        such as Pubmed.  All associated data such as author, journal title,     
        date, etc can be looked up on the database.
      -->

      
<bqs:reference rdf:parseType="Resource">
        
<bqs:Pubmed_id>8869126</bqs:Pubmed_id>
        
<bqs:JournalArticle rdf:parseType="Resource">
          
<dc:creator>
            
<rdf:Seq>
              
<rdf:li rdf:parseType="Resource">
                
<bqs:Person rdf:parseType="Resource">
                  
<vCard:N rdf:parseType="Resource">
                    
<vCard:Family>Dokos</vCard:Family>
                    
<vCard:Given>Socrates</vCard:Given>
                  
</vCard:N>
                
</bqs:Person>
              
</rdf:li>
              
<rdf:li rdf:parseType="Resource">
                
<bqs:Person rdf:parseType="Resource">
                  
<vCard:N rdf:parseType="Resource">
                    
<vCard:Family>Celler</vCard:Family>
                    
<vCard:Given>Branko</vCard:Given>
                  
</vCard:N>
                
</bqs:Person>
              
</rdf:li>
              
<rdf:li rdf:parseType="Resource">
                
<bqs:Person rdf:parseType="Resource">
                  
<vCard:N rdf:parseType="Resource">
                    
<vCard:Family>Lovell</vCard:Family>
                    
<vCard:Given>Nigel</vCard:Given>
                  
</vCard:N>
                
</bqs:Person>
              
</rdf:li>
            
</rdf:Seq>
          
</dc:creator>
          
<dc:title>
            Ion Currents Underlying Sinoatrial Node Pacemaker Activity: A New 
            Single Cell Mathematical Model
          
</dc:title>
          
<dcterms:issued rdf:parseType="Resource">
            
<dcterms:W3CDTF>1996-08-07</dcterms:W3CDTF>
          
</dcterms:issued>
          
<bqs:Journal rdf:parseType="Resource">
            
<dc:title>Journal of Theoretical Biology</dc:title>
          
</bqs:Journal>
          
<bqs:volume>181</bqs:volume>
          
<bqs:first_page>245</bqs:first_page>
          
<bqs:last_page>272</bqs:last_page>
        
</bqs:JournalArticle>
      
</bqs:reference>
    
</rdf:Description>
  
</rdf:RDF>
  
  
<!--
    Below, are defined some additional units for association with variables and
    constants within the model.
  -->

  
  
<units name="first_order_rate_constant">
    
<unit units="second" exponent="-1" />
  
</units>
  
  
<units name="second_order_rate_constant">
    
<unit units="second" exponent="-1" />
    
<unit units="millimolar" exponent="-1" />
  
</units>

  
<units name="millivolt">
    
<unit prefix="milli" units="volt" />
  
</units>

  
<units name="per_millivolt">
    
<unit prefix="milli" units="volt" exponent="-1" />
  
</units>
  
  
<units name="per_millivolt_second">
    
<unit units="millivolt" exponent="-1" />
    
<unit units="second" exponent="-1" />
  
</units>
  
  
<units name="nanoS">
    
<unit prefix="nano" units="siemens" />
  
</units>
  
  
<units name="picoF">
    
<unit prefix="pico" units="farad" />
  
</units>

  
<units name="picoA_per_millimolar">
    
<unit prefix="pico" units="ampere" />
    
<unit units="millimolar" exponent="-1.59" />
  
</units>
  
  
<units name="picoA">
    
<unit prefix="pico" units="ampere" />
  
</units>
  
  
<units name="millimolar">
    
<unit prefix="milli" units="mole" />
    
<unit units="litre" exponent="-1" />
  
</units>
  
  
<units name="joule_per_mole_kelvin">
    
<unit units="joule" />
    
<unit units="mole" exponent="-1" />
    
<unit units="kelvin" exponent="-1" />
  
</units>
  
  
<units name="coulomb_per_millimole">
    
<unit units="coulomb" exponent="-1" />
    
<unit prefix="milli" units="mole" />
  
</units>
  
  
<units name="picolitre">
    
<unit prefix="pico" units="litre" />
  
</units>
    
  
  
<component name="environment">
    
<variable name="time" public_interface="out" units="second" />
  
</component>
  
  
<component name="constants">
    
<variable name="R" public_interface="out" initial_value="8.32" units="joule_per_mole_kelvin" />
    
<variable name="T" public_interface="out" initial_value="310.0" units="kelvin" />
    
<variable name="F" public_interface="out" initial_value="96.49" units="coulomb_per_millimole" />
  
</component>
  
  
<component name="membrane">
    
<variable name="E" public_interface="out" initial_value="-64.9" units="millivolt" />
    
    
<variable name="C" initial_value="32.0" units="picoF" />
    
<variable name="i_tot" units="picoA" />
    
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="i_CaL" public_interface="in" units="picoA" />
    
<variable name="i_CaT" public_interface="in" units="picoA" />
    
<variable name="i_Na" public_interface="in" units="picoA" />
    
<variable name="i_K" public_interface="in" units="picoA" />
    
<variable name="i_f" public_interface="in" units="picoA" />
    
<variable name="i_p" public_interface="in" units="picoA" />
    
<variable name="i_NaCa" public_interface="in" units="picoA" />
    
<variable name="i_bNa" public_interface="in" units="picoA" />
    
<variable name="i_bK" public_interface="in" units="picoA" />
     
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="membrane_voltage_diff_eq"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> E </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> i_tot </ci>
          
</apply>
          
<ci> C </ci>
        
</apply>
      
</apply>
      
      
<apply id="i_tot_calculation"><eq />
        
<ci> i_tot </ci>
        
<apply><plus />
          
<ci> i_CaL </ci>
          
<ci> i_CaT </ci>
          
<ci> i_Na </ci>
          
<ci> i_K </ci>
          
<ci> i_f </ci>
          
<ci> i_p </ci>
          
<ci> i_NaCa </ci>
          
<ci> i_bNa </ci>
          
<ci> i_bK </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="reversal_potentials">
    
<variable name="E_Ca" public_interface="out" units="millivolt" />
    
<variable name="E_Na" public_interface="out" units="millivolt" />
    
<variable name="E_K" public_interface="out" units="millivolt" />
    
    
<variable name="R" public_interface="in" units="joule_per_mole_kelvin" />
    
<variable name="T" public_interface="in" units="kelvin" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="Cai" public_interface="in" units="millimolar" />
    
<variable name="Cao" public_interface="in" units="millimolar" />
    
<variable name="Nai" public_interface="in" units="millimolar" />
    
<variable name="Nao" public_interface="in" units="millimolar" />
    
<variable name="Ki" public_interface="in" units="millimolar" />
    
<variable name="Ko" public_interface="in" units="millimolar" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="E_Ca_calculation"><eq />
        
<ci> E_Ca </ci>
        
<apply><times />
          
<apply><divide />
            
<apply><times />
              
<ci> R </ci>
              
<ci> T </ci>
            
</apply>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 2.0 </cn>
              
<ci> F </ci>
            
</apply>
          
</apply>
          
<apply><ln />
            
<apply><divide />
              
<ci> Cao </ci>
              
<ci> Cai </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
     
      
<apply id="E_Na_calculation"><eq />
        
<ci> E_Na </ci>
        
<apply><times />
          
<apply><divide />
            
<apply><times />
              
<ci> R </ci>
              
<ci> T </ci>
            
</apply>
            
<ci> F </ci>
          
</apply>
          
<apply><ln />
            
<apply><divide />
              
<ci> Nao </ci>
              
<ci> Nai </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="E_K_calculation"><eq />
        
<ci> E_K </ci>
        
<apply><times />
          
<apply><divide />
            
<apply><times />
              
<ci> R </ci>
              
<ci> T </ci>
            
</apply>
            
<ci> F </ci>
          
</apply>
          
<apply><ln />
            
<apply><divide />
              
<ci> Ko </ci>
              
<ci> Ki </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="L_type_calcium_current">
    
<variable name="i_CaL" public_interface="out" units="picoA" />

    
<variable name="g_CaL" initial_value="400.0" units="nanoS" />
    
    
<variable name="E_Ca" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" private_interface="out" units="second" />
    
<variable name="E" public_interface="in" private_interface="out" units="millivolt" />
    
<variable name="Cai" public_interface="in" private_interface="out" units="millimolar" />
    
    
<variable name="d" private_interface="in" units="dimensionless" />
    
<variable name="f" private_interface="in" units="dimensionless" />
    
<variable name="f2" private_interface="in" units="dimensionless" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_CaL_calculation"><eq />
        
<ci> i_CaL </ci>
        
<apply><times />
          
<ci> g_CaL </ci>
          
<ci> d </ci>
          
<ci> f </ci>
          
<ci> f2 </ci>
          
<apply><plus />
            
<ci> E </ci>
            
<apply><minus />
              
<ci> E_Ca </ci>
            
</apply>
            
<cn cellml:units="millivolt"> 75.0 </cn>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="L_type_calcium_current_d_gate">
    
<variable name="d" public_interface="out" initial_value="0.0001" units="dimensionless" />
        
    
<variable name="d_infinity" units="dimensionless" />
    
<variable name="tau_d" initial_value="0.002" units="second" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="L_type_calcium_current_d_gate_d_infinity_calculation"><eq />
        
<ci> d_infinity </ci>
        
<apply><divide />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><divide />
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 6.6 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> -6.6 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="L_type_calcium_current_d_gate_dd_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> d </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> d_infinity </ci>
            
<ci> d </ci>
          
</apply>
          
<ci> tau_d </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="L_type_calcium_current_f_gate">
    
<variable name="f" public_interface="out" initial_value="0.1505" units="dimensionless" />
        
    
<variable name="f_infinity" units="dimensionless" />
    
<variable name="tau_f" units="second" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="L_type_calcium_current_f_gate_f_infinity_calculation"><eq />
        
<ci> f_infinity </ci>
        
<apply><divide />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><divide />
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 25.0 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> 6.0 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="L_type_calcium_current_f_gate_tau_f_calculation"><eq />
        
<ci> tau_f </ci>
        
<apply><plus />
          
<cn cellml:units="second"> 0.031 </cn>
          
<apply><divide />
            
<cn cellml:units="second"> 1.0 </cn>
            
<apply><plus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<apply><exp />
                
<apply><divide />
                  
<apply><plus />
                    
<ci> E </ci>
                    
<cn cellml:units="millivolt"> 37.6 </cn>
                  
</apply>
                  
<cn cellml:units="millivolt"> 8.1 </cn>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="L_type_calcium_current_f_gate_df_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> f </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> f_infinity </ci>
            
<ci> f </ci>
          
</apply>
          
<ci> tau_f </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="L_type_calcium_current_f2_gate">
    
<variable name="f2" public_interface="out" initial_value="0.2190" units="dimensionless" />
        
    
<variable name="alpha_f2" initial_value="3.0" units="first_order_rate_constant" />
    
<variable name="beta_f2" initial_value="40000.0" units="second_order_rate_constant" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="Cai" public_interface="in" units="millimolar" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="df2_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> f2 </ci>
        
</apply>
        
<apply><minus />
          
<apply><times />
            
<ci> alpha_f2 </ci>
            
<apply><minus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<ci> f2 </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> beta_f2 </ci>
            
<ci> Cai </ci>
            
<ci> f2 </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="T_type_calcium_current">
    
<variable name="i_CaT" public_interface="out" units="picoA" />
    
    
<variable name="g_CaT" initial_value="85.0" units="nanoS" />
    
    
<variable name="E_Ca" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" private_interface="out" units="second" />
    
<variable name="E" public_interface="in" private_interface="out" units="millivolt" />
    
    
<variable name="d" private_interface="in" units="dimensionless" />
    
<variable name="f" private_interface="in" units="dimensionless" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_CaT_calculation"><eq />
        
<ci> i_CaT </ci>
        
<apply><times />
          
<ci> g_CaT </ci>
          
<ci> d </ci>
          
<ci> f </ci>
          
<apply><plus />
            
<ci> E </ci>
            
<apply><minus />
              
<ci> E_Ca </ci>
            
</apply>
            
<cn cellml:units="millivolt"> 75.0 </cn>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="T_type_calcium_current_d_gate">
    
<variable name="d" public_interface="out" initial_value="0.0010" units="dimensionless" />
        
    
<variable name="d_infinity" units="dimensionless" />
    
<variable name="tau_d" units="second" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="T_type_calcium_current_d_gate_d_infinity_calculation"><eq />
        
<ci> d_infinity </ci>
        
<apply><divide />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><divide />
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 23.0 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> -6.1 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="tau_d_calculation"><eq />
        
<ci> tau_d </ci>
        
<apply><plus />
          
<cn cellml:units="second"> 0.0006 </cn>
          
<apply><divide />
            
<cn cellml:units="second"> 0.0054 </cn>
            
<apply><plus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<apply><exp />
                
<apply><times />
                  
<cn cellml:units="dimensionless"> 0.03 </cn>
                  
<apply><plus />
                    
<ci> E </ci>
                    
<cn cellml:units="millivolt"> 100.0 </cn>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="T_type_calcium_current_d_gate_dd_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> d </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> d_infinity </ci>
            
<ci> d </ci>
          
</apply>
          
<ci> tau_d </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="T_type_calcium_current_f_gate">
    
<variable name="f" public_interface="out" initial_value="0.1328" units="dimensionless" />
        
    
<variable name="f_infinity" units="dimensionless" />
    
<variable name="tau_f" units="second" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="T_type_calcium_current_f_gate_f_infinity_calculation"><eq />
        
<ci> f_infinity </ci>
        
<apply><divide />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><divide />
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 75.0 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> 6.6 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="T_type_calcium_current_f_gate_tau_f_calculation"><eq />
        
<ci> tau_f </ci>
        
<apply><plus />
          
<cn cellml:units="second"> 0.001 </cn>
          
<apply><divide />
            
<cn cellml:units="second"> 0.04 </cn>
            
<apply><plus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<apply><exp />
                
<apply><times />
                  
<cn cellml:units="dimensionless"> 0.08 </cn>
                  
<apply><plus />
                    
<ci> E </ci>
                    
<cn cellml:units="millivolt"> 65.0 </cn>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="T_type_calcium_current_f_gate_df_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> f </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> f_infinity </ci>
            
<ci> f </ci>
          
</apply>
          
<ci> tau_f </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="fast_sodium_current">
    
<variable name="i_Na" public_interface="out" units="picoA" />
    
    
<variable name="g_Na" initial_value="250.0" units="nanoS" />
    
    
<variable name="E_Na" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" private_interface="out" units="second" />
    
<variable name="E" public_interface="in" private_interface="out" units="millivolt" />
    
    
<variable name="m" private_interface="in" units="dimensionless" />
    
<variable name="h" private_interface="in" units="dimensionless" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_Na_calculation"><eq />
        
<ci> i_Na </ci>
        
<apply><times />
          
<ci> g_Na </ci>
          
<apply><power />
            
<ci> m </ci>
            
<cn cellml:units="dimensionless"> 3.0 </cn>
          
</apply>
          
<ci> h </ci>
          
<apply><minus />
            
<ci> E </ci>
            
<ci> E_Na </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="fast_sodium_current_m_gate">
    
<variable name="m" public_interface="out" initial_value="0.0139" units="dimensionless" />
        
    
<variable name="alpha_m" units="first_order_rate_constant" />
    
<variable name="beta_m" units="first_order_rate_constant" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="alpha_m_calculation"><eq />
        
<ci> alpha_m </ci>
        
<apply><divide />
          
<apply><times />
            
<cn cellml:units="per_millivolt_second"> 200.0 </cn>
            
<apply><plus />
              
<ci> E </ci>
              
<cn cellml:units="millivolt"> 34.3 </cn>
            
</apply>
          
</apply>
          
<apply><minus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><times />
                
<cn cellml:units="dimensionless"> -0.09 </cn>
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 34.3 </cn>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="beta_m_calculation"><eq />
        
<ci> beta_m </ci>
        
<apply><times />
          
<cn cellml:units="first_order_rate_constant"> 8000.0 </cn>
          
<apply><exp />
            
<apply><times />
              
<cn cellml:units="dimensionless"> -0.15 </cn>
              
<apply><plus />
                
<ci> E </ci>
                
<cn cellml:units="millivolt"> 56.2 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dm_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> m </ci>
        
</apply>
        
<apply><minus />
          
<apply><times />
            
<ci> alpha_m </ci>
            
<apply><minus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<ci> m </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> beta_m </ci>
            
<ci> m </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="fast_sodium_current_h_gate">
    
<variable name="h" public_interface="out" initial_value="0.0087" units="dimensionless" />
        
    
<variable name="alpha_h" units="first_order_rate_constant" />
    
<variable name="beta_h" units="first_order_rate_constant" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="alpha_h_calculation"><eq />
        
<ci> alpha_h </ci>
        
<apply><times />
          
<cn cellml:units="first_order_rate_constant"> 32.4 </cn>
          
<apply><exp />
            
<apply><times />
              
<cn cellml:units="dimensionless"> -0.14 </cn>
              
<apply><plus />
                
<ci> E </ci>
                
<cn cellml:units="millivolt"> 93.4 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="beta_h_calculation"><eq />
        
<ci> beta_h </ci>
        
<apply><divide />
          
<cn cellml:units="first_order_rate_constant"> 709.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 4.2 </cn>
              
<apply><exp />
                
<apply><times />
                  
<cn cellml:units="dimensionless"> -0.06 </cn>
                  
<apply><plus />
                    
<ci> E </ci>
                    
<cn cellml:units="millivolt"> 45.4 </cn>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dh_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> h </ci>
        
</apply>
        
<apply><minus />
          
<apply><times />
            
<ci> alpha_h </ci>
            
<apply><minus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<ci> h </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> beta_h </ci>
            
<ci> h </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="delayed_rectifying_potassium_current">
    
<variable name="i_K" public_interface="out" units="picoA" />
    
<variable name="i_KK" public_interface="out" units="picoA" />
    
<variable name="i_KNa" public_interface="out" units="picoA" />
    
    
<variable name="Kk" initial_value="0.26" units="picoA_per_millimolar" />
    
<variable name="P_KNa" initial_value="0.035" units="dimensionless" />
    
    
<variable name="R" public_interface="in" units="joule_per_mole_kelvin" />
    
<variable name="T" public_interface="in" units="kelvin" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="Ko" public_interface="in" units="millimolar" />
    
<variable name="Ki" public_interface="in" units="millimolar" />
    
<variable name="Nao" public_interface="in" units="millimolar" />
    
<variable name="Nai" public_interface="in" units="millimolar" />
    
<variable name="time" public_interface="in" private_interface="out" units="second" />
    
<variable name="E" public_interface="in" private_interface="out" units="millivolt" />
    
    
<variable name="x" private_interface="in" units="dimensionless" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML"> 
      
<apply id="i_K_calculation"><eq />
        
<ci> i_K </ci>
        
<apply><plus />
          
<ci> i_KK </ci>
          
<ci> i_KNa </ci>
        
</apply>
      
</apply>
      
      
<apply id="i_KK_calculation"><eq />
        
<ci> i_KK </ci>
        
<apply><times />
          
<ci> x </ci>
          
<ci> Kk </ci>
          
<apply><power />
            
<ci> Ko </ci>
            
<cn cellml:units="dimensionless"> 0.59 </cn>
          
</apply>
          
<apply><minus />
            
<ci> Ki </ci>
            
<apply><times />
              
<ci> Ko </ci>
              
<apply><exp />
                
<apply><divide />
                  
<apply><times />
                    
<apply><minus />
                      
<ci> E </ci>
                    
</apply>
                    
<ci> F </ci>
                  
</apply>
                  
<apply><times />
                    
<ci> R </ci>
                    
<ci> T </ci>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="i_KNa_calculation"><eq />
        
<ci> i_KNa </ci>
        
<apply><times />
          
<ci> x </ci>
          
<ci> Kk </ci>
          
<ci> P_KNa </ci>
          
<apply><power />
            
<ci> Ko </ci>
            
<cn cellml:units="dimensionless"> 0.59 </cn>
          
</apply>
          
<apply><minus />
            
<ci> Nai </ci>
            
<apply><times />
              
<ci> Nao </ci>
              
<apply><exp />
                
<apply><divide />
                  
<apply><times />
                    
<apply><minus />
                      
<ci> E </ci>
                    
</apply>
                    
<ci> F </ci>
                  
</apply>
                  
<apply><times />
                    
<ci> R </ci>
                    
<ci> T </ci>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="delayed_rectifying_potassium_current_x_gate">
    
<variable name="x" public_interface="out" initial_value="0.5682" units="dimensionless" />
              
    
<variable name="x_infinity" units="dimensionless" />
    
<variable name="tau_x" units="second" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="x_infinity_calculation"><eq />
        
<ci> x_infinity </ci>
        
<apply><divide />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><plus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><divide />
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 25.1 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> -7.4 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="tau_x_calculation"><eq />
        
<ci> tau_x </ci>
        
<apply><divide />
          
<cn cellml:units="second"> 1.0 </cn>
          
<apply><plus />
            
<apply><times />
              
<cn cellml:units="dimensionless"> 17.0 </cn>
              
<apply><exp />
                
<apply><times />
                  
<cn cellml:units="dimensionless"> 0.0398 </cn>
                  
<ci> E </ci>
                
</apply>
              
</apply>
            
</apply>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 0.211 </cn>
              
<apply><exp />
                
<apply><times />
                  
<cn cellml:units="dimensionless"> -0.051 </cn>
                  
<ci> E </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dx_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> x </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> x_infinity </ci>
            
<ci> x </ci>
          
</apply>
          
<ci> tau_x </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="hyperpolarising_activated_current">
    
<variable name="i_f" public_interface="out" units="picoA" />
    
<variable name="i_fNa" public_interface="out" units="picoA" />
    
<variable name="i_fK" public_interface="out" units="picoA" />
    
    
<variable name="Kmf" initial_value="10.3" units="millimolar" />
    
<variable name="g_fNa" initial_value="8.1" units="nanoS" />
    
<variable name="g_fK" initial_value="13.5" units="nanoS" />
    
    
<variable name="E_Na" public_interface="in" units="millivolt" />
    
<variable name="E_K" public_interface="in" units="millivolt" />
    
<variable name="Ko" public_interface="in" units="millimolar" />
    
<variable name="time" public_interface="in" private_interface="out" units="second" />
    
<variable name="E" public_interface="in" private_interface="out" units="millivolt" />
    
    
<variable name="y" private_interface="in" units="dimensionless" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML"> 
      
<apply id="i_f_calculation"><eq />
        
<ci> i_f </ci>
        
<apply><plus />
          
<ci> i_fK </ci>
          
<ci> i_fNa </ci>
        
</apply>
      
</apply>
      
      
<apply id="i_fNa_calculation"><eq />
        
<ci> i_fNa </ci>
        
<apply><times />
          
<ci> y </ci>
          
<apply><divide />
            
<apply><power />
              
<ci> Ko </ci>
              
<cn cellml:units="dimensionless"> 1.83 </cn>
            
</apply>
            
<apply><plus />
              
<apply><power />
                
<ci> Ko </ci>
                
<cn cellml:units="dimensionless"> 1.83 </cn>
              
</apply>
              
<apply><power />
                
<ci> Kmf </ci>
                
<cn cellml:units="dimensionless"> 1.83 </cn>
              
</apply>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> g_fNa </ci>
            
<apply><times />
              
<ci> Ko </ci>
              
<apply><minus />
                
<ci> E </ci>
                
<ci> E_Na </ci>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="i_fK_calculation"><eq />
        
<ci> i_fK </ci>
        
<apply><times />
          
<ci> y </ci>
          
<apply><divide />
            
<apply><power />
              
<ci> Ko </ci>
              
<cn cellml:units="dimensionless"> 1.83 </cn>
            
</apply>
            
<apply><plus />
              
<apply><power />
                
<ci> Ko </ci>
                
<cn cellml:units="dimensionless"> 1.83 </cn>
              
</apply>
              
<apply><power />
                
<ci> Kmf </ci>
                
<cn cellml:units="dimensionless"> 1.83 </cn>
              
</apply>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> g_fK </ci>
            
<apply><times />
              
<ci> Ko </ci>
              
<apply><minus />
                
<ci> E </ci>
                
<ci> E_K </ci>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="hyperpolarising_activated_current_y_gate">
    
<variable name="y" public_interface="out" initial_value="0.0287" units="dimensionless" />
              
    
<variable name="alpha_y" units="first_order_rate_constant" />
    
<variable name="beta_y" units="first_order_rate_constant" />

    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="time" public_interface="in" units="second" />
   
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
     
<apply id="alpha_y_calculation"><eq />
        
<ci> alpha_y </ci>
        
<apply><divide />
          
<apply><times />
            
<cn cellml:units="per_millivolt_second"> 0.36 </cn>
            
<apply><plus />
              
<ci> E </ci>
              
<cn cellml:units="millivolt"> 137.8 </cn>
            
</apply>
          
</apply>
          
<apply><minus />
            
<apply><exp />
              
<apply><times />
                
<cn cellml:units="dimensionless"> 0.0666 </cn>
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 137.8 </cn>
                
</apply>
              
</apply>
            
</apply>
            
<cn cellml:units="dimensionless"> 1.0 </cn>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="beta_y_calculation"><eq />
        
<ci> beta_y </ci>
        
<apply><divide />
          
<apply><times />
            
<cn cellml:units="per_millivolt_second"> 0.1 </cn>
            
<apply><plus />
              
<ci> E </ci>
              
<cn cellml:units="millivolt"> 76.3 </cn>
            
</apply>
          
</apply>
          
<apply><minus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><exp />
              
<apply><times />
                
<cn cellml:units="dimensionless"> -0.21 </cn>
                
<apply><plus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 76.3 </cn>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dy_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> y </ci>
        
</apply>
        
<apply><minus />
          
<apply><times />
            
<ci> alpha_y </ci>
            
<apply><minus />
              
<cn cellml:units="dimensionless"> 1.0 </cn>
              
<ci> y </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> beta_y </ci>
            
<ci> y </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="sodium_potassium_pump">
    
<variable name="i_p" public_interface="out" units="picoA" />
    
    
<variable name="KmNa" initial_value="40.0" units="millimolar" />
    
<variable name="KmK" initial_value="1.0" units="millimolar" />
    
<variable name="i_pmax" initial_value="226.0" units="picoA" />
    
    
<variable name="Ko" public_interface="in" units="millimolar" />
    
<variable name="Nai" public_interface="in" units="millimolar" />
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="E" public_interface="in" units="millivolt" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_p_calculation"><eq />
        
<ci> i_p </ci>
        
<apply><times />
          
<ci> i_pmax </ci>
          
<apply><divide />
            
<ci> Nai </ci>
            
<apply><plus />
              
<ci> Nai </ci>
              
<ci> KmNa </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<ci> Ko </ci>
            
<apply><plus />
              
<ci> Ko </ci>
              
<ci> KmK </ci>
            
</apply>
          
</apply>
          
<apply><minus />
            
<cn cellml:units="dimensionless"> 1.0 </cn>
            
<apply><power />
              
<apply><divide />
                
<apply><minus />
                  
<ci> E </ci>
                  
<cn cellml:units="millivolt"> 40.0 </cn>
                
</apply>
                
<cn cellml:units="millivolt"> 211.0 </cn>
              
</apply>
              
<cn cellml:units="dimensionless"> 2.0 </cn>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component> 
  
  
<component name="sodium_calcium_exchange_current">
    
<variable name="i_NaCa" public_interface="out" units="picoA" />
    
    
<variable name="kNaCa" initial_value="4000.0" units="picoA" />
    
<variable name="x1" units="dimensionless" />
    
<variable name="x2" units="dimensionless" />
    
<variable name="x3" units="dimensionless" />
    
<variable name="x4" units="dimensionless" />
    
<variable name="k41" units="dimensionless" />
    
<variable name="k34" units="dimensionless" />
    
<variable name="k23" units="dimensionless" />
    
<variable name="k21" units="dimensionless" />
    
<variable name="k32" units="dimensionless" />
    
<variable name="k43" units="dimensionless" />
    
<variable name="k12" units="dimensionless" />
    
<variable name="k14" units="dimensionless" />
    
<variable name="Qci" initial_value="0.1369" units="dimensionless" />
    
<variable name="Qn" initial_value="0.4315" units="dimensionless" />
    
<variable name="Qco" initial_value="0.0" units="dimensionless" />
    
<variable name="K3ni" initial_value="26.44" units="millimolar" />
    
<variable name="Kci" initial_value="0.0207" units="millimolar" />
    
<variable name="K1ni" initial_value="395.3" units="millimolar" />
    
<variable name="K2ni" initial_value="2.289" units="millimolar" />
    
<variable name="Kcni" initial_value="26.44" units="millimolar" />
    
<variable name="K3no" initial_value="4.663" units="millimolar" />
    
<variable name="K1no" initial_value="1628.0" units="millimolar" />
    
<variable name="K2no" initial_value="561.4" units="millimolar" />
    
<variable name="Kco" initial_value="3.663" units="millimolar" />
    
<variable name="do" units="dimensionless" />
    
<variable name="di" units="dimensionless" />
    
    
<variable name="Cao" public_interface="in" units="millimolar" />
    
<variable name="Nao" public_interface="in" units="millimolar" />
    
<variable name="Cai" public_interface="in" units="millimolar" />
    
<variable name="Nai" public_interface="in" units="millimolar" />
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="R" public_interface="in" units="joule_per_mole_kelvin" />
    
<variable name="T" public_interface="in" units="kelvin" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="E" public_interface="in" units="millivolt" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_NaCa_calculation"><eq />
        
<ci> i_NaCa </ci>
        
<apply><times />
          
<ci> kNaCa </ci>
          
<apply><divide />
            
<apply><minus />
              
<apply><times />
                
<ci> x2 </ci>
                
<ci> k21 </ci>
              
</apply>
              
<apply><times />
                
<ci> x1 </ci>
                
<ci> k12 </ci>
              
</apply>
            
</apply>
            
<apply><plus />
              
<ci> x1 </ci>
              
<ci> x2 </ci>
              
<ci> x3 </ci>
              
<ci> x4 </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
     
      
<apply id="x1_calculation"><eq />
        
<ci> x1 </ci>
        
<apply><plus />
          
<apply><times />
            
<ci> k41 </ci>
            
<ci> k34 </ci>
            
<apply><plus />
              
<ci> k23 </ci>
              
<ci> k21 </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> k21 </ci>
            
<ci> k32 </ci>
            
<apply><plus />
              
<ci> k43 </ci>
              
<ci> k41 </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="x2_calculation"><eq />
        
<ci> x2 </ci>
        
<apply><plus />
          
<apply><times />
            
<ci> k32 </ci>
            
<ci> k43 </ci>
            
<apply><plus />
              
<ci> k14 </ci>
              
<ci> k12 </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> k41 </ci>
            
<ci> k12 </ci>
            
<apply><plus />
              
<ci> k34 </ci>
              
<ci> k32 </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="x3_calculation"><eq />
        
<ci> x3 </ci>
        
<apply><plus />
          
<apply><times />
            
<ci> k14 </ci>
            
<ci> k43 </ci>
            
<apply><plus />
              
<ci> k23 </ci>
              
<ci> k21 </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> k12 </ci>
            
<ci> k23 </ci>
            
<apply><plus />
              
<ci> k43 </ci>
              
<ci> k41 </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="x4_calculation"><eq />
        
<ci> x4 </ci>
        
<apply><plus />
          
<apply><times />
            
<ci> k23 </ci>
            
<ci> k34 </ci>
            
<apply><plus />
              
<ci> k14 </ci>
              
<ci> k12 </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> k14 </ci>
            
<ci> k21 </ci>
            
<apply><plus />
              
<ci> k34 </ci>
              
<ci> k32 </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="k43_calculation"><eq />
        
<ci> k43 </ci>
        
<apply><divide />
          
<ci> Nai </ci>
          
<apply><plus />
            
<ci> K3ni </ci>
            
<ci> Nai </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="k12_calculation"><eq />
        
<ci> k12 </ci>
        
<apply><divide />
          
<apply><times />
            
<apply><divide />
              
<ci> Cai </ci>
              
<ci> Kci </ci>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><times />
                  
<apply><minus />
                    
<ci> Qci </ci>
                  
</apply>
                  
<ci> E </ci>
                  
<ci> F </ci>
                
</apply>
                
<apply><times />
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<ci> di </ci>
        
</apply>
      
</apply>
      
      
<apply id="k14_calculation"><eq />
        
<ci> k14 </ci>
        
<apply><divide />
          
<apply><times />
            
<apply><plus />
              
<apply><divide />
                
<apply><power />
                  
<ci> Nai </ci>
                  
<cn cellml:units="dimensionless"> 2.0 </cn>
                
</apply>
                
<apply><times />
                  
<ci> K1ni </ci>
                  
<ci> K2ni </ci>
                
</apply>
              
</apply>
              
<apply><divide />
                
<apply><power />
                  
<ci> Nai </ci>
                  
<cn cellml:units="dimensionless"> 3.0 </cn>
                
</apply>
                
<apply><times />
                  
<ci> K1ni </ci>
                  
<ci> K2ni </ci>
                  
<ci> K3ni </ci>
                
</apply>
              
</apply>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><times />
                  
<ci> Qn </ci>
                  
<ci> E </ci>
                  
<ci> F </ci>
                
</apply>
                
<apply><times />
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<ci> di </ci>
        
</apply>
      
</apply>
      
      
<apply id="k41_calculation"><eq />
        
<ci> k41 </ci>
        
<apply><exp />
          
<apply><divide />
            
<apply><minus />
              
<apply><times />
                
<ci> Qn </ci>
                
<ci> E </ci>
                
<ci> F </ci>
              
</apply>
            
</apply>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 2.0 </cn>
              
<ci> R </ci>
              
<ci> T </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="di_calculation"><eq />
        
<ci> di </ci>
        
<apply><plus />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><divide />
            
<ci> Cai </ci>
            
<ci> Kci </ci>
          
</apply>
          
<apply><times />
            
<apply><divide />
              
<ci> Cai </ci>
              
<ci> Kci </ci>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><minus />
                  
<apply><times />
                    
<ci> Qci </ci>
                    
<ci> E </ci>
                    
<ci> F </ci>
                  
</apply>
                
</apply>
                
<apply><times />
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><times />
              
<ci> Cai </ci>
              
<ci> Nai </ci>
            
</apply>
            
<apply><times />
              
<ci> Kci </ci>
              
<ci> Kcni </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<ci> Nai </ci>
            
<ci> K1ni </ci>
          
</apply>
          
<apply><divide />
            
<apply><power />
              
<ci> Nai </ci>
              
<cn cellml:units="dimensionless"> 2.0 </cn>
            
</apply>
            
<apply><times />
              
<ci> K1ni </ci>
              
<ci> K2ni </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><power />
              
<ci> Nai </ci>
              
<cn cellml:units="dimensionless"> 3.0 </cn>
            
</apply>
            
<apply><times />
              
<ci> K1ni </ci>
              
<ci> K2ni </ci>
              
<ci> K3ni </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="k34_calculation"><eq />
        
<ci> k34 </ci>
        
<apply><divide />
          
<ci> Nao </ci>
          
<apply><plus />
            
<ci> K3no </ci>
            
<ci> Nao </ci>
          
</apply>
        
</apply>
      
</apply> 
      
      
<apply id="k21_calculation"><eq />
        
<ci> k21 </ci>
        
<apply><divide />
          
<apply><times />
            
<apply><divide />
              
<ci> Cao </ci>
              
<ci> Kco </ci>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><times />
                  
<ci> Qco </ci>
                  
<ci> E </ci>
                  
<ci> F </ci>
                
</apply>
                
<apply><times />
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<ci> do </ci>
        
</apply>
      
</apply>   
      
      
<apply id="k23_calculation"><eq />
        
<ci> k23 </ci>
        
<apply><divide />
          
<apply><times />
            
<apply><divide />
              
<apply><power />
                
<ci> Nao </ci>
                
<cn cellml:units="dimensionless"> 2.0 </cn>
              
</apply>
              
<apply><times />
                
<ci> K1no </ci>
                
<ci> K2no </ci>
              
</apply>
            
</apply>
            
<apply><divide />
              
<apply><power />
                
<ci> Nao </ci>
                
<cn cellml:units="dimensionless"> 3.0 </cn>
              
</apply>
              
<apply><times />
                
<ci> K1no </ci>
                
<ci> K2no </ci>
                
<ci> K3no </ci>
              
</apply>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><minus />
                  
<apply><times />
                    
<ci> Qn </ci>
                    
<ci> E </ci>
                    
<ci> F </ci>
                  
</apply>
                
</apply>
                
<apply><times />
                  
<cn cellml:units="dimensionless"> 2.0 </cn>
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<ci> do </ci>
        
</apply>
      
</apply>
      
      
<apply id="k32_calculation"><eq />
        
<ci> k32 </ci>
        
<apply><exp />
          
<apply><divide />
            
<apply><times />
              
<ci> Qn </ci>
              
<ci> E </ci>
              
<ci> F </ci>
            
</apply>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 2.0 </cn>
              
<ci> R </ci>
              
<ci> T </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="do_calculation"><eq />
        
<ci> do </ci>
        
<apply><plus />
          
<cn cellml:units="dimensionless"> 1.0 </cn>
          
<apply><divide />
            
<ci> Cao </ci>
            
<ci> Kco </ci>
          
</apply>
          
<apply><times />
            
<apply><divide />
              
<ci> Cao </ci>
              
<ci> Kco </ci>
            
</apply>
            
<apply><exp />
              
<apply><divide />
                
<apply><minus />
                  
<apply><times />
                    
<ci> Qco </ci>
                    
<ci> E </ci>
                    
<ci> F </ci>
                  
</apply>
                
</apply>
                
<apply><times />
                  
<ci> R </ci>
                  
<ci> T </ci>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
          
<apply><divide />
            
<ci> Nao </ci>
            
<ci> K1no </ci>
          
</apply>
          
<apply><divide />
            
<apply><power />
              
<ci> Nao </ci>
              
<cn cellml:units="dimensionless"> 2.0 </cn>
            
</apply>
            
<apply><times />
              
<ci> K1no </ci>
              
<ci> K2no </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><power />
              
<ci> Nao </ci>
              
<cn cellml:units="dimensionless"> 3.0 </cn>
            
</apply>
            
<apply><times />
              
<ci> K1no </ci>
              
<ci> K2no </ci>
              
<ci> K3no </ci>
            
</apply>
          
</apply>
        
</apply>
      
</apply>     
    
</math>
  
</component>
  
  
<component name="background_sodium_current">
    
<variable name="i_bNa" public_interface="out" units="picoA" />
    
    
<variable name="g_Nab" initial_value="0.24" units="nanoS" />
      
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="E_Na" public_interface="in" units="millivolt" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_bNa_calculation"><eq />
        
<ci> i_bNa </ci>
        
<apply><times />
          
<ci> g_Nab </ci>
          
<apply><minus />
            
<ci> E </ci>
            
<ci> E_Na </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component> 
  
  
<component name="background_potassium_current">
    
<variable name="i_bK" public_interface="out" units="picoA" />
    
    
<variable name="KbK" initial_value="0.07" units="picoA_per_millimolar" />
      
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="E" public_interface="in" units="millivolt" />
    
<variable name="R" public_interface="in" units="joule_per_mole_kelvin" />
    
<variable name="T" public_interface="in" units="kelvin" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="Ki" public_interface="in" units="millimolar" />
    
<variable name="Ko" public_interface="in" units="millimolar" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_bK_calculation"><eq />
        
<ci> i_bK </ci>
        
<apply><times />
          
<ci> KbK </ci>
          
<apply><power />
            
<ci> Ko </ci>
            
<cn cellml:units="dimensionless"> 0.41 </cn>
          
</apply>
          
<apply><minus />
            
<ci> Ki </ci>
            
<apply><times />
              
<ci> Ko </ci>
              
<apply><exp />
                
<apply><divide />
                  
<apply><times />
                    
<apply><minus />
                      
<ci> E </ci>
                    
</apply>
                    
<ci> F </ci>
                  
</apply>
                  
<apply><times />
                    
<ci> R </ci>
                    
<ci> T </ci>
                  
</apply>
                
</apply>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="sarcoplasmic_reticulum_kinetics">
    
<variable name="i_up" public_interface="out" units="picoA" />
    
<variable name="i_tr" public_interface="out" units="picoA" />
    
<variable name="i_rel" public_interface="out" units="picoA" />
    
<variable name="V_rel" public_interface="out" initial_value="0.015" units="picolitre" />
    
<variable name="V_up" public_interface="out" initial_value="0.035" units="picolitre" />
    
    
<variable name="i_up_max" initial_value="21.2" units="picoA" />
    
<variable name="alpha_rel" units="first_order_rate_constant" />
    
<variable name="alpha_tr" units="first_order_rate_constant" />
    
<variable name="KmCaup" initial_value="0.0005" units="millimolar" />
    
<variable name="KmCarel" initial_value="0.001" units="millimolar" />
    
<variable name="tau_rel" initial_value="0.005" units="second" />
    
<variable name="tau_tr" initial_value="0.4" units="second" />
    
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="Cai" public_interface="in" units="millimolar" />
    
<variable name="Caup" public_interface="in" units="millimolar" />
    
<variable name="Carel" public_interface="in" units="millimolar" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="i_up_calculation"><eq />
        
<ci> i_up </ci>
        
<apply><times />
          
<ci> i_up_max </ci>
          
<apply><divide />
            
<apply><power />
              
<ci> Cai </ci>
              
<cn cellml:units="dimensionless"> 2.0 </cn>
            
</apply>
            
<apply><plus />
              
<apply><power />
                
<ci> Cai </ci>
                
<cn cellml:units="dimensionless"> 2.0 </cn>
              
</apply>
              
<apply><power />
                
<ci> KmCaup </ci>
                
<cn cellml:units="dimensionless"> 2.0 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="i_tr_calculation"><eq />
        
<ci> i_tr </ci>
        
<apply><times />
          
<ci> alpha_tr </ci>
          
<ci> Caup </ci>
        
</apply>
      
</apply>
      
      
<apply id="i_rel_calculation"><eq />
        
<ci> i_rel </ci>
        
<apply><times />
          
<ci> alpha_rel </ci>
          
<ci> Carel </ci>
          
<apply><divide />
            
<apply><power />
              
<ci> Cai </ci>
              
<cn cellml:units="dimensionless"> 2.0 </cn>
            
</apply>
            
<apply><plus />
              
<apply><power />
                
<ci> Cai </ci>
                
<cn cellml:units="dimensionless"> 2.0 </cn>
              
</apply>
              
<apply><power />
                
<ci> KmCarel </ci>
                
<cn cellml:units="dimensionless"> 2.0 </cn>
              
</apply>
            
</apply>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="alpha_rel_calculation"><eq />
        
<ci> alpha_rel </ci>
        
<apply><divide />
          
<apply><times />
            
<cn cellml:units="dimensionless"> 2.0 </cn>
            
<ci> V_rel </ci>
            
<ci> F </ci>
          
</apply>
          
<ci> tau_rel </ci>
        
</apply>
      
</apply>
      
      
<apply id="alpha_tr_calculation"><eq />
        
<ci> alpha_tr </ci>
        
<apply><divide />
          
<apply><times />
            
<cn cellml:units="dimensionless"> 2.0 </cn>
            
<ci> V_rel </ci>
            
<ci> F </ci>
          
</apply>
          
<ci> tau_rel </ci>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<component name="ion_concentrations">
    
<variable name="Cai" public_interface="out" initial_value="0.000034" units="millimolar" />
    
<variable name="Cao" public_interface="out" initial_value="2.0004" units="millimolar" />
    
<variable name="Caup" public_interface="out" initial_value="0.5832" units="millimolar" />
    
<variable name="Carel" public_interface="out" initial_value="0.1101" units="millimolar" />
    
<variable name="Nai" public_interface="out" initial_value="7.4994" units="millimolar" />
    
<variable name="Nao" public_interface="out" initial_value="139.9929" units="millimolar" />
    
<variable name="Ki" public_interface="out" initial_value="140.0073" units="millimolar" />
    
<variable name="Ko" public_interface="out" initial_value="5.4243" units="millimolar" />
    
    
<variable name="V_i" initial_value="2.5" units="picolitre" />
    
<variable name="V_e" initial_value="0.5" units="picolitre" />
    
<variable name="tau_b" initial_value="0.1" units="second" />
    
<variable name="Nab" initial_value="140.0" units="millimolar" />
    
<variable name="Cab" initial_value="2.0" units="millimolar" />
    
<variable name="Kb" initial_value="5.4" units="millimolar" />
    
    
<variable name="time" public_interface="in" units="second" />
    
<variable name="F" public_interface="in" units="coulomb_per_millimole" />
    
<variable name="i_bNa" public_interface="in" units="picoA" />
    
<variable name="i_fNa" public_interface="in" units="picoA" />
    
<variable name="i_Na" public_interface="in" units="picoA" />
    
<variable name="i_p" public_interface="in" units="picoA" />
    
<variable name="i_NaCa" public_interface="in" units="picoA" />
    
<variable name="i_KNa" public_interface="in" units="picoA" />
    
<variable name="i_KK" public_interface="in" units="picoA" />
    
<variable name="i_fK" public_interface="in" units="picoA" />
    
<variable name="i_bK" public_interface="in" units="picoA" />
    
<variable name="i_CaL" public_interface="in" units="picoA" />
    
<variable name="i_CaT" public_interface="in" units="picoA" />
    
<variable name="i_up" public_interface="in" units="picoA" />
    
<variable name="i_rel" public_interface="in" units="picoA" />
    
<variable name="i_tr" public_interface="in" units="picoA" />
    
<variable name="V_rel" public_interface="in" units="picolitre" />
    
<variable name="V_up" public_interface="in" units="picolitre" />
    
    
<math xmlns="http://www.w3.org/1998/Math/MathML">
      
<apply id="dNai_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Nai </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<apply><plus />
              
<ci> i_bNa </ci>
              
<ci> i_fNa </ci>
              
<ci> i_Na </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> 3.0 </cn>
                
<ci> i_p </ci>
              
</apply>
              
<apply><times />
                
<cn cellml:units="dimensionless"> 3.0 </cn>
                
<ci> i_NaCa </ci>
              
</apply>
              
<ci> i_KNa </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> F </ci>
            
<ci> V_i </ci>
          
</apply>
        
</apply>
      
</apply> 
      
      
<apply id="dNao_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Nao </ci>
        
</apply>
        
<apply><plus />
          
<apply><divide />
            
<apply><plus />
              
<ci> i_bNa </ci>
              
<ci> i_fNa </ci>
              
<ci> i_Na </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> 3.0 </cn>
                
<ci> i_p </ci>
              
</apply>
              
<apply><times />
                
<cn cellml:units="dimensionless"> 3.0 </cn>
                
<ci> i_NaCa </ci>
              
</apply>
              
<ci> i_KNa </ci>
            
</apply>
            
<apply><times />
              
<ci> F </ci>
              
<ci> V_e </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><minus />
              
<ci> Nab </ci>
              
<ci> Nao </ci>
            
</apply>
            
<ci> tau_b </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dKi_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Ki </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<apply><plus />
              
<ci> i_KK </ci>
              
<ci> i_fK </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> -2.0 </cn>
                
<ci> i_p </ci>
              
</apply>
              
<ci> i_bK </ci>
            
</apply>
          
</apply>
          
<apply><times />
            
<ci> F </ci>
            
<ci> V_i </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dKo_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Ko </ci>
        
</apply>
        
<apply><plus />
          
<apply><divide />
            
<apply><plus />
              
<ci> i_KK </ci>
              
<ci> i_fK </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> -2.0 </cn>
                
<ci> i_p </ci>
              
</apply>
              
<ci> i_bK </ci>
            
</apply>
            
<apply><times />
              
<ci> F </ci>
              
<ci> V_e </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><minus />
              
<ci> Kb </ci>
              
<ci> Ko </ci>
            
</apply>
            
<ci> tau_b </ci>
          
</apply>
        
</apply>
      
</apply>  
      
      
<apply id="dCai_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Cai </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<apply><plus />
              
<ci> i_CaL </ci>
              
<ci> i_CaT </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> -2.0 </cn>
                
<ci> i_NaCa </ci>
              
</apply>
              
<ci> i_up </ci>
              
<apply><minus />
                
<ci> i_rel </ci>
              
</apply>
            
</apply>
          
</apply>
          
<apply><times />
            
<cn cellml:units="dimensionless"> 2.0 </cn>
            
<ci> F </ci>
            
<ci> V_i </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="dCao_dt"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Cao </ci>
        
</apply>
        
<apply><plus />
          
<apply><divide />
            
<apply><plus />
              
<ci> i_CaL </ci>
              
<ci> i_CaT </ci>
              
<apply><times />
                
<cn cellml:units="dimensionless"> -2.0 </cn>
                
<ci> i_NaCa </ci>
              
</apply>
            
</apply>
            
<apply><times />
              
<cn cellml:units="dimensionless"> 2.0 </cn>
              
<ci> F </ci>
              
<ci> V_e </ci>
            
</apply>
          
</apply>
          
<apply><divide />
            
<apply><minus />
              
<ci> Cab </ci>
              
<ci> Cao </ci>
            
</apply>
            
<ci> tau_b </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="Caup_diff_eq"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Caup </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> i_up </ci>
            
<ci> i_tr </ci>
          
</apply>
          
<apply><times />
            
<cn cellml:units="dimensionless"> 2.0 </cn>
            
<ci> V_up </ci>
            
<ci> F </ci>
          
</apply>
        
</apply>
      
</apply>
      
      
<apply id="Carel_diff_eq"><eq />
        
<apply><diff />
          
<bvar><ci> time </ci></bvar>
          
<ci> Carel </ci>
        
</apply>
        
<apply><divide />
          
<apply><minus />
            
<ci> i_tr </ci>
            
<ci> i_rel </ci>
          
</apply>
          
<apply><times />
            
<cn cellml:units="dimensionless"> 2.0 </cn>
            
<ci> V_rel </ci>
            
<ci> F </ci>
          
</apply>
        
</apply>
      
</apply>
    
</math>
  
</component>
  
  
<group>
    
<relationship_ref relationship="containment" />
    
<component_ref component="membrane">
      
<component_ref component="L_type_calcium_current">
        
<component_ref component="L_type_calcium_current_d_gate" />
        
<component_ref component="L_type_calcium_current_f_gate" />
        
<component_ref component="L_type_calcium_current_f2_gate" />
      
</component_ref>
      
<component_ref component="T_type_calcium_current">
        
<component_ref component="T_type_calcium_current_d_gate" />
        
<component_ref component="T_type_calcium_current_f_gate" />
      
</component_ref>
      
<component_ref component="fast_sodium_current">
        
<component_ref component="fast_sodium_current_m_gate" />
        
<component_ref component="fast_sodium_current_h_gate" />
      
</component_ref>
      
<component_ref component="delayed_rectifying_potassium_current">
        
<component_ref component="delayed_rectifying_potassium_current_x_gate" />
      
</component_ref>
      
<component_ref component="hyperpolarising_activated_current">
        
<component_ref component="hyperpolarising_activated_current_y_gate" />
      
</component_ref>
      
<component_ref component="sodium_potassium_pump" />
      
<component_ref component="sodium_calcium_exchange_current" />
      
<component_ref component="background_sodium_current" />
      
<component_ref component="background_potassium_current" />
      
<component_ref component="sarcoplasmic_reticulum_kinetics" />
      
<component_ref component="ion_concentrations" />
    
</component_ref>
  
</group>
  
  
<group>
    
<relationship_ref relationship="encapsulation" />
    
<component_ref component="L_type_calcium_current">
      
<component_ref component="L_type_calcium_current_d_gate" />
      
<component_ref component="L_type_calcium_current_f_gate" />
      
<component_ref component="L_type_calcium_current_f2_gate" />
    
</component_ref>
    
<component_ref component="T_type_calcium_current">
      
<component_ref component="T_type_calcium_current_d_gate" />
      
<component_ref component="T_type_calcium_current_f_gate"