/******************************************************/
/* A simple model of a single AZ at the calyx of Held */
/*                                                    */
/* Definition of AMPARs                               */
/*                                                    */
/* Matthias Hennig                                    */
/* mhennig@inf.ed.ac.uk                               */
/******************************************************/

/* the transmitter in question */
DEFINE_LIGAND Glu {
  DIFFUSION_CONSTANT = D
}

/* AMPA receptor kinetics */
DEFINE_REACTION AMPAR {
  C0[>C1{  Rb:+Glu,POSITIVE_POLE}]
  C1[>C2{2*Rb:+Glu,POSITIVE_POLE}][>O1{Ro1}]  [>C0{4*Ru1:-Glu,POSITIVE_POLE}][>D1{Rd0}]
  C2[>C3{3*Rb:+Glu,POSITIVE_POLE}][>O2{Ro1*2}][>C1{3*Ru1:-Glu,POSITIVE_POLE}][>D2{Rd1*2}]
  C3[>C4{4*Rb:+Glu,POSITIVE_POLE}][>O3{Ro1*3}][>C2{2*Ru1:-Glu,POSITIVE_POLE}][>D3{Rd1*3}]
  C4                                     [>O4{Ro1*4}][>C3{  Ru1:-Glu,POSITIVE_POLE}][>D4{Rd1*4}]

  O1[>C1{Rc1}]
  O2[>C2{Rc1}]
  O3[>C3{Rc1}]
  O4[>C4{Rc1}]

  D1[>C1{Rr1}][>D2{Rd2:+Glu,POSITIVE_POLE}]
  D2[>C2{Rr1}][>D3{2*Rd2:+Glu,POSITIVE_POLE}][>D1{3*Rr2:-Glu,POSITIVE_POLE}]
  D3[>C3{Rr1}][>D4{3*Rd2:+Glu,POSITIVE_POLE}][>D2{2*Rr2:-Glu,POSITIVE_POLE}]
  D4[>C4{Rr1}]                               [>D3{Rr2:-Glu,POSITIVE_POLE}]

  REFERENCE_STATE C0 {
    Glu
    NUMBER_BOUND = 0
  }
}