//Created by libAntimony v2.4
model zhang_2000__environment(time_)

  // Variable initializations:
  time_ = ;
end

model zhang_2000__membrane(dCell, FCell, V, R, T, F, time_, i_Na, i_Ca_L, i_Ca_T, i_to, i_sus, i_K_r, i_K_s, i_f_Na, i_f_K, i_b_Na, i_b_Ca, i_b_K, i_NaCa, i_p, i_Ca_p)

  // Assignment Rules:
  FCell := (1.07 * (3 * dCell - 0.1)) / (3 * (1 + 0.7745 * exp(-(3 * dCell - 2.05) / 0.295)));
  Cm := CmCentre + FCell * (CmPeriphery - CmCentre);

  // Rate Rules:
  V' = (-(1) / Cm) * (i_Na + i_Ca_L + i_Ca_T + i_to + i_sus + i_K_r + i_K_s + i_f_Na + i_f_K + i_b_Na + i_b_Ca + i_b_K + i_NaCa + i_p + i_Ca_p);

  // Variable initializations:
  dCell = 0;
  V = -39.013558536;
  R = 8314;
  T = 310;
  F = 96845;
  CmCentre = 2e-5;
  CmPeriphery = 6.5e-5;
  time_ = ;
  i_Na = ;
  i_Ca_L = ;
  i_Ca_T = ;
  i_to = ;
  i_sus = ;
  i_K_r = ;
  i_K_s = ;
  i_f_Na = ;
  i_f_K = ;
  i_b_Na = ;
  i_b_Ca = ;
  i_b_K = ;
  i_NaCa = ;
  i_p = ;
  i_Ca_p = ;
end

model zhang_2000__sodium_current_m_gate(m, V, time_)

  // Assignment Rules:
  m_infinity := power(1 / (1 + exp(- V / 5.46)), 1 / 3);
  tau_m := 0.0006247 / (0.832 * exp(-(0.335) * (V + 56.7)) + 0.627 * exp(0.082 * (V + 65.01))) + 4E-5;

  // Rate Rules:
  m' = (m_infinity - m) / tau_m;

  // Variable initializations:
  m = 0.092361701692;
  V = ;
  time_ = ;
end

model zhang_2000__sodium_current_h_gate(h, V, time_)

  // Assignment Rules:
  h := (1 - F_Na) * h1 + F_Na * h2;
  F_Na := (0.0952 * exp(-(0.063) * (V + 34.4))) / (1 + 1.66 * exp(-(0.225) * (V + 63.7))) + 0.0869;
  h1_infinity := 1 / (1 + exp((V + 66.1) / 6.4));
  h2_infinity := h1_infinity;
  tau_h1 := (3.717E-6 * exp(-(0.2815) * (V + 17.11))) / (1 + 0.003732 * exp(-(0.3426) * (V + 37.76))) + 0.0005977;
  tau_h2 := (3.186E-8 * exp(-(0.6219) * (V + 18.8))) / (1 + 7.189E-5 * exp(-(0.6683) * (V + 34.07))) + 0.003556;

  // Rate Rules:
  h1' = (h1_infinity - h1) / tau_h1;
  h2' = (h2_infinity - h2) / tau_h2;

  // Variable initializations:
  h1 = 0.015905380261;
  h2 = 0.01445216109;
  V = ;
  time_ = ;
end

model zhang_2000__sodium_current(FCell, i_Na, E_Na, Na_o, R, F, T, time_, V, m, h)

  // Sub-modules, and any changes to those submodules:
  sodium_current_m_gate: zhang_2000__sodium_current_m_gate(m, V, time_);
  sodium_current_h_gate: zhang_2000__sodium_current_h_gate(h, V, time_);

  // Assignment Rules:
  i_Na := ((((g_Na * power(m, 3) * h * Na_o * power(F, 2)) / (R * T)) * (exp(((V - E_Na) * F) / (R * T)) - 1)) / (exp((V * F) / (R * T)) - 1)) * V;
  g_Na := g_Na_Centre + FCell * (g_Na_Periphery - g_Na_Centre);

  // Variable initializations:
  FCell = ;
  g_Na_Centre = 0;
  g_Na_Periphery = 1.2e-6;
  E_Na = ;
  Na_o = ;
  R = ;
  F = ;
  T = ;
end

model zhang_2000__L_type_Ca_channel_d_gate(FCell, d_L, V, time_)

  // Assignment Rules:
  alpha_d_L := (-(28.38) * (V + 35)) / (exp(-(V + 35) / 2.5) - 1) - (84.9 * V) / (exp(-(0.208) * V) - 1);
  beta_d_L := (11.42 * (V - 5)) / (exp(0.4 * (V - 5)) - 1);
  d_L_infinity := 1 / (1 + exp(-(V + 23.1) / 6));
  tau_d_L := 2 / (alpha_d_L + beta_d_L);

  // Rate Rules:
  d_L' = (d_L_infinity - d_L) / tau_d_L;

  // Variable initializations:
  FCell = ;
  d_L = 0.04804900895;
  V = ;
  time_ = ;
end

model zhang_2000__L_type_Ca_channel_f_gate(FCell, f_L, V, time_)

  // Assignment Rules:
  alpha_f_L := (3.12 * (V + 28)) / (exp((V + 28) / 4) - 1);
  beta_f_L := 25 / (1 + exp(-(V + 28) / 4));
  f_L_infinity := 1 / (1 + exp((V + 45) / 5));
  tau_f_L := 1 / (alpha_f_L + beta_f_L);

  // Rate Rules:
  f_L' = (f_L_infinity - f_L) / tau_f_L;

  // Variable initializations:
  FCell = ;
  f_L = 0.48779845203;
  V = ;
  time_ = ;
end

model zhang_2000__L_type_Ca_channel(FCell, i_Ca_L, time_, V, d_L, f_L)

  // Sub-modules, and any changes to those submodules:
  L_type_Ca_channel_d_gate: zhang_2000__L_type_Ca_channel_d_gate(FCell, d_L, V, time_);
  L_type_Ca_channel_f_gate: zhang_2000__L_type_Ca_channel_f_gate(FCell, f_L, V, time_);

  // Assignment Rules:
  i_Ca_L := g_Ca_L * (f_L * d_L + 0.006 / (1 + exp(-(V + 14.1) / 6))) * (V - E_Ca_L);
  g_Ca_L := g_Ca_L_Centre + FCell * (g_Ca_L_Periphery - g_Ca_L_Centre);

  // Variable initializations:
  g_Ca_L_Centre = 0.0058;
  g_Ca_L_Periphery = 0.0659;
  E_Ca_L = 46.4;
end

model zhang_2000__T_type_Ca_channel_d_gate(d_T, V, time_)

  // Assignment Rules:
  alpha_d_T := 1068 * exp((V + 26.3) / 30);
  beta_d_T := 1068 * exp(-(V + 26.3) / 30);
  d_T_infinity := 1 / (1 + exp(-(V + 37) / 6.8));
  tau_d_T := 1 / (alpha_d_T + beta_d_T);

  // Rate Rules:
  d_T' = (d_T_infinity - d_T) / tau_d_T;

  // Variable initializations:
  d_T = 0.42074047435;
  V = ;
  time_ = ;
end

model zhang_2000__T_type_Ca_channel_f_gate(FCell, f_T, V, time_)

  // Assignment Rules:
  alpha_f_T := 15.3 * exp(-(V + 71.7) / 83.3);
  beta_f_T := 15 * exp((V + 71.7) / 15.38);
  f_T_infinity := 1 / (1 + exp((V + 71) / 9));
  tau_f_T := 1 / (alpha_f_T + beta_f_T);

  // Rate Rules:
  f_T' = (f_T_infinity - f_T) / tau_f_T;

  // Variable initializations:
  FCell = ;
  f_T = 0.038968420558;
  V = ;
  time_ = ;
end

model zhang_2000__T_type_Ca_channel(FCell, i_Ca_T, time_, V, d_T, f_T)

  // Sub-modules, and any changes to those submodules:
  T_type_Ca_channel_d_gate: zhang_2000__T_type_Ca_channel_d_gate(d_T, V, time_);
  T_type_Ca_channel_f_gate: zhang_2000__T_type_Ca_channel_f_gate(FCell, f_T, V, time_);

  // Assignment Rules:
  i_Ca_T := g_Ca_T * d_T * f_T * (V - E_Ca_T);
  g_Ca_T := g_Ca_T_Centre + FCell * (g_Ca_T_Periphery - g_Ca_T_Centre);

  // Variable initializations:
  g_Ca_T_Centre = 0.0043;
  g_Ca_T_Periphery = 0.0139;
  E_Ca_T = 45;
end

model zhang_2000__four_AP_sensitive_currents_q_gate(FCell, q, V, time_)

  // Assignment Rules:
  q_infinity := 1 / (1 + exp((V + 59.37) / 13.1));
  tau_q := 0.0101 + 0.06517 / (0.57 * exp(-(0.08) * (V + 49))) + 2.4E-5 * exp(0.1 * (V + 50.93));

  // Rate Rules:
  q' = (q_infinity - q) / tau_q;

  // Variable initializations:
  FCell = ;
  q = 0.29760539675;
  V = ;
  time_ = ;
end

model zhang_2000__four_AP_sensitive_currents_r_gate(r, V, time_)

  // Assignment Rules:
  r_infinity := 1 / (1 + exp(-(V - 10.93) / 19.7));
  tau_r := 0.001 * (2.98 + 15.59 / (1.037 * exp(0.09 * (V + 30.61)) + 0.369 * exp(-(0.12) * (V + 23.84))));

  // Rate Rules:
  r' = (r_infinity - r) / tau_r;

  // Variable initializations:
  r = 0.064402950262;
  V = ;
  time_ = ;
end

model zhang_2000__four_AP_sensitive_currents(FCell, i_to, i_sus, E_K, V, time_, q, r)

  // Sub-modules, and any changes to those submodules:
  four_AP_sensitive_currents_q_gate: zhang_2000__four_AP_sensitive_currents_q_gate(FCell, q, V, time_);
  four_AP_sensitive_currents_r_gate: zhang_2000__four_AP_sensitive_currents_r_gate(r, V, time_);

  // Assignment Rules:
  i_to := g_to * q * r * (V - E_K);
  i_sus := g_sus * r * (V - E_K);
  g_to := g_to_Centre + FCell * (g_to_Periphery - g_to_Centre);
  g_sus := g_sus_Centre + FCell * (g_sus_Periphery - g_sus_Centre);

  // Variable initializations:
  g_to_Centre = 0.00491;
  g_to_Periphery = 0.03649;
  g_sus_Centre = 6.65e-5;
  g_sus_Periphery = 0.0114;
  E_K = ;
end

model zhang_2000__rapid_delayed_rectifying_potassium_current_P_af_gate(P_af, P_af_infinity, V, time_)

  // Assignment Rules:
  P_af_infinity := 1 / (1 + exp(-(V + 14.2) / 10.6));
  tau_P_af := 1 / (37.2 * exp((V - 9) / 15.9) + 0.96 * exp(-(V - 9) / 22.5));

  // Rate Rules:
  P_af' = (P_af_infinity - P_af) / tau_P_af;

  // Variable initializations:
  P_af = 0.13034201158;
  V = ;
  time_ = ;
end

model zhang_2000__rapid_delayed_rectifying_potassium_current_P_as_gate(P_as, P_af_infinity, V, time_)

  // Assignment Rules:
  P_as_infinity := P_af_infinity;
  tau_P_as := 1 / (4.2 * exp((V - 9) / 17) + 0.15 * exp(-(V - 9) / 21.6));

  // Rate Rules:
  P_as' = (P_as_infinity - P_as) / tau_P_as;

  // Variable initializations:
  P_as = 0.46960956028;
  P_af_infinity = ;
  V = ;
  time_ = ;
end

model zhang_2000__rapid_delayed_rectifying_potassium_current_P_i_gate(P_i, V, time_)

  // Assignment Rules:
  P_i_infinity := 1 / (1 + exp((V + 18.6) / 10.1));

  // Rate Rules:
  P_i' = (P_i_infinity - P_i) / tau_P_i;

  // Variable initializations:
  P_i = 0.87993375273;
  tau_P_i = 0.002;
  V = ;
  time_ = ;
end

model zhang_2000__rapid_delayed_rectifying_potassium_current(FCell, i_K_r, E_K, time_, V, P_af, P_as, P_i)

  // Sub-modules, and any changes to those submodules:
  rapid_delayed_rectifying_potassium_current_P_af_gate: zhang_2000__rapid_delayed_rectifying_potassium_current_P_af_gate(P_af, P_af_infinity, V, time_);
  rapid_delayed_rectifying_potassium_current_P_as_gate: zhang_2000__rapid_delayed_rectifying_potassium_current_P_as_gate(P_as, P_af_infinity, V, time_);
  rapid_delayed_rectifying_potassium_current_P_i_gate: zhang_2000__rapid_delayed_rectifying_potassium_current_P_i_gate(P_i, V, time_);

  // Assignment Rules:
  i_K_r := g_K_r * P_a * P_i * (V - E_K);
  g_K_r := g_K_r_Centre + FCell * (g_K_r_Periphery - g_K_r_Centre);
  P_a := 0.6 * P_af + 0.4 * P_as;

  // Variable initializations:
  FCell = ;
  g_K_r_Centre = 0.000797;
  g_K_r_Periphery = 0.016;
  E_K = ;
end

model zhang_2000__slow_delayed_rectifying_potassium_current_xs_gate(xs, V, time_)

  // Assignment Rules:
  alpha_xs := 14 / (1 + exp(-(V - 40) / 9));
  beta_xs := 1 * exp(- V / 45);

  // Rate Rules:
  xs' = alpha_xs * (1 - xs) - beta_xs * xs;

  // Variable initializations:
  xs = 0.082293827208;
  V = ;
  time_ = ;
end

model zhang_2000__slow_delayed_rectifying_potassium_current(FCell, i_K_s, E_K_s, time_, V, xs)

  // Sub-modules, and any changes to those submodules:
  slow_delayed_rectifying_potassium_current_xs_gate: zhang_2000__slow_delayed_rectifying_potassium_current_xs_gate(xs, V, time_);

  // Assignment Rules:
  i_K_s := g_K_s * power(xs, 2) * (V - E_K_s);
  g_K_s := g_K_s_Centre + FCell * (g_K_s_Periphery - g_K_s_Centre);

  // Variable initializations:
  FCell = ;
  g_K_s_Centre = 0.000518;
  g_K_s_Periphery = 0.0104;
  E_K_s = ;
end

model zhang_2000__hyperpolarisation_activated_current_y_gate(y, V, time_)

  // Assignment Rules:
  alpha_y := 1 * exp(-(V + 78.91) / 26.62);
  beta_y := 1 * exp((V + 75.13) / 21.25);

  // Rate Rules:
  y' = alpha_y * (1 - y) - beta_y * y;

  // Variable initializations:
  y = 0.03889291759;
  V = ;
  time_ = ;
end

model zhang_2000__hyperpolarisation_activated_current(FCell, i_f_Na, i_f_K, E_K, E_Na, time_, V, y)

  // Sub-modules, and any changes to those submodules:
  hyperpolarisation_activated_current_y_gate: zhang_2000__hyperpolarisation_activated_current_y_gate(y, V, time_);

  // Assignment Rules:
  i_f_Na := g_f_Na * y * (V - E_Na);
  i_f_K := g_f_K * y * (V - E_K);
  g_f_Na := g_f_Na_Centre + FCell * (g_f_Na_Periphery - g_f_Na_Centre);
  g_f_K := g_f_K_Centre + FCell * (g_f_K_Periphery - g_f_K_Centre);

  // Variable initializations:
  FCell = ;
  g_f_Na_Centre = 0.000548;
  g_f_Na_Periphery = 0.0069;
  g_f_K_Centre = 0.000548;
  g_f_K_Periphery = 0.0069;
  E_K = ;
  E_Na = ;
end

model zhang_2000__sodium_background_current(FCell, i_b_Na, E_Na, V)

  // Assignment Rules:
  i_b_Na := g_b_Na * (V - E_Na);
  g_b_Na := g_b_Na_Centre + FCell * (g_b_Na_Periphery - g_b_Na_Centre);

  // Variable initializations:
  FCell = ;
  g_b_Na_Centre = 5.8e-5;
  g_b_Na_Periphery = 0.000189;
  E_Na = ;
  V = ;
end

model zhang_2000__potassium_background_current(FCell, i_b_K, E_K, V)

  // Assignment Rules:
  i_b_K := g_b_K * (V - E_K);
  g_b_K := g_b_K_Centre + FCell * (g_b_K_Periphery - g_b_K_Centre);

  // Variable initializations:
  FCell = ;
  g_b_K_Centre = 2.52e-5;
  g_b_K_Periphery = 8.19e-5;
  E_K = ;
  V = ;
end

model zhang_2000__calcium_background_current(FCell, i_b_Ca, E_Ca, V)

  // Assignment Rules:
  i_b_Ca := g_b_Ca * (V - E_Ca);
  g_b_Ca := g_b_Ca_Centre + FCell * (g_b_Ca_Periphery - g_b_Ca_Centre);

  // Variable initializations:
  FCell = ;
  g_b_Ca_Centre = 1.32e-5;
  g_b_Ca_Periphery = 4.3e-5;
  E_Ca = ;
  V = ;
end

model zhang_2000__sodium_calcium_exchanger(FCell, i_NaCa, Na_i, Na_o, Ca_i, Ca_o, V)

  // Assignment Rules:
  i_NaCa := (k_NaCa * (power(Na_i, 3) * Ca_o * exp(0.03743 * V * gamma_NaCa) - power(Na_o, 3) * Ca_i * exp(0.0374 * V * (gamma_NaCa - 1)))) / (1 + d_NaCa * (Ca_i * power(Na_o, 3) + Ca_o * power(Na_i, 3)));
  k_NaCa := k_NaCa_Centre + FCell * (k_NaCa_Periphery - k_NaCa_Centre);

  // Variable initializations:
  FCell = ;
  k_NaCa_Centre = 2.7e-6;
  k_NaCa_Periphery = 8.8e-6;
  d_NaCa = 0.0001;
  gamma_NaCa = 0.5;
  Na_i = ;
  Na_o = ;
  Ca_i = ;
  Ca_o = ;
  V = ;
end

model zhang_2000__sodium_potassium_pump(FCell, i_p, Na_i, K_o, V)

  // Assignment Rules:
  i_p := (i_p_max * power(Na_i / (K_m_Na + Na_i), 3) * power(K_o / (K_m_K + K_o), 2) * 1.6) / (1.5 + exp(-(V + 60) / 40));
  i_p_max := i_p_max_Centre + FCell * (i_p_max_Periphery - i_p_max_Centre);

  // Variable initializations:
  FCell = ;
  K_m_Na = 5.64;
  K_m_K = 0.621;
  i_p_max_Centre = 0.0478;
  i_p_max_Periphery = 0.16;
  Na_i = ;
  K_o = ;
  V = ;
end

model zhang_2000__persistent_calcium_current(FCell, i_Ca_p, Ca_i, V)

  // Assignment Rules:
  i_Ca_p := (i_Ca_p_max * Ca_i) / (Ca_i + 0.0004);
  i_Ca_p_max := i_Ca_p_max_Centre + FCell * (i_Ca_p_max_Periphery - i_Ca_p_max_Centre);

  // Variable initializations:
  FCell = ;
  i_Ca_p_max_Centre = 0;
  i_Ca_p_max_Periphery = 0;
  Ca_i = ;
  V = ;
end

model zhang_2000__ionic_concentrations(Na_i, Na_o, Ca_i, Ca_o, K_i, K_o)

  // Variable initializations:
  Na_i = 8;
  Na_o = 140;
  Ca_i = 0.0001;
  Ca_o = 2;
  K_i = 140;
  K_o = 5.4;
end

model zhang_2000__reversal_and_equilibrium_potentials(E_Na, E_K, E_K_s, E_Ca, K_o, Na_o, K_i, Na_i, Ca_o, Ca_i, R, F, T)

  // Assignment Rules:
  E_Na := ((R * T) / F) * ln(Na_o / Na_i);
  E_K := ((R * T) / F) * ln(K_o / K_i);
  E_K_s := ((R * T) / F) * ln((K_o + 0.12 * Na_o) / (K_i + 0.12 * Na_i));
  E_Ca := ((R * T) / (2 * F)) * ln(Ca_o / Ca_i);

  // Variable initializations:
  K_o = ;
  Na_o = ;
  K_i = ;
  Na_i = ;
  Ca_o = ;
  Ca_i = ;
  R = ;
  F = ;
  T = ;
end

model *zhang_2000____main()

  // Sub-modules, and any changes to those submodules:
  environment: zhang_2000__environment(time_);
  membrane: zhang_2000__membrane(dCell, FCell, V, R, T, F, time_, i_Na, i_Ca_L, i_Ca_T, i_to, i_sus, i_K_r, i_K_s, i_f_Na, i_f_K, i_b_Na, i_b_Ca, i_b_K, i_NaCa, i_p, i_Ca_p);
  sodium_current: zhang_2000__sodium_current(FCell, i_Na, E_Na, Na_o, R, F, T, time_, V, m, h);
  L_type_Ca_channel: zhang_2000__L_type_Ca_channel(FCell, i_Ca_L, time_, V, d_L, f_L);
  T_type_Ca_channel: zhang_2000__T_type_Ca_channel(FCell, i_Ca_T, time_, V, d_T, f_T);
  four_AP_sensitive_currents: zhang_2000__four_AP_sensitive_currents(FCell, i_to, i_sus, E_K, V, time_, q, r);
  rapid_delayed_rectifying_potassium_current: zhang_2000__rapid_delayed_rectifying_potassium_current(FCell, i_K_r, E_K, time_, V, P_af, P_as, P_i);
  slow_delayed_rectifying_potassium_current: zhang_2000__slow_delayed_rectifying_potassium_current(FCell, i_K_s, E_K_s, time_, V, xs);
  hyperpolarisation_activated_current: zhang_2000__hyperpolarisation_activated_current(FCell, i_f_Na, i_f_K, E_K, E_Na, time_, V, y);
  sodium_background_current: zhang_2000__sodium_background_current(FCell, i_b_Na, E_Na, V);
  potassium_background_current: zhang_2000__potassium_background_current(FCell, i_b_K, E_K, V);
  calcium_background_current: zhang_2000__calcium_background_current(FCell, i_b_Ca, E_Ca, V);
  sodium_calcium_exchanger: zhang_2000__sodium_calcium_exchanger(FCell, i_NaCa, Na_i, Na_o, Ca_i, Ca_o, V);
  sodium_potassium_pump: zhang_2000__sodium_potassium_pump(FCell, i_p, Na_i, K_o, V);
  persistent_calcium_current: zhang_2000__persistent_calcium_current(FCell, i_Ca_p, Ca_i, V);
  ionic_concentrations: zhang_2000__ionic_concentrations(Na_i, Na_o, Ca_i, Ca_o, K_i, K_o);
  reversal_and_equilibrium_potentials: zhang_2000__reversal_and_equilibrium_potentials(E_Na, E_K, E_K_s, E_Ca, K_o, Na_o, K_i, Na_i, Ca_o, Ca_i, R, F, T);
end