Ca_LVA.mod 1.0 KB

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  1. :Comment : LVA ca channel. Note: mtau is an approximation from the plots
  2. :Reference : : Avery and Johnston 1996, tau from Randall 1997
  3. :Comment: shifted by -10 mv to correct for junction potential
  4. :Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21
  5. NEURON {
  6. SUFFIX Ca_LVA
  7. USEION ca READ eca WRITE ica
  8. RANGE gbar, g, ica
  9. }
  10. UNITS {
  11. (S) = (siemens)
  12. (mV) = (millivolt)
  13. (mA) = (milliamp)
  14. }
  15. PARAMETER {
  16. gbar = 0.00001 (S/cm2)
  17. }
  18. ASSIGNED {
  19. v (mV)
  20. eca (mV)
  21. ica (mA/cm2)
  22. g (S/cm2)
  23. mInf
  24. mTau
  25. hInf
  26. hTau
  27. }
  28. STATE {
  29. m
  30. h
  31. }
  32. BREAKPOINT {
  33. SOLVE states METHOD cnexp
  34. g = gbar*m*m*h
  35. ica = g*(v-eca)
  36. }
  37. DERIVATIVE states {
  38. rates()
  39. m' = (mInf-m)/mTau
  40. h' = (hInf-h)/hTau
  41. }
  42. INITIAL{
  43. rates()
  44. m = mInf
  45. h = hInf
  46. }
  47. PROCEDURE rates(){
  48. LOCAL qt
  49. qt = 2.3^((34-21)/10)
  50. UNITSOFF
  51. v = v + 10
  52. mInf = 1.0000/(1+ exp((v - -30.000)/-6))
  53. mTau = (5.0000 + 20.0000/(1+exp((v - -25.000)/5)))/qt
  54. hInf = 1.0000/(1+ exp((v - -80.000)/6.4))
  55. hTau = (20.0000 + 50.0000/(1+exp((v - -40.000)/7)))/qt
  56. v = v - 10
  57. UNITSON
  58. }