Nap.mod 1.3 KB

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  1. :Comment : mtau deduced from text (said to be 6 times faster than for NaTa)
  2. :Comment : so I used the equations from NaT and multiplied by 6
  3. :Reference : Modeled according to kinetics derived from Magistretti & Alonso 1999
  4. :Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21
  5. NEURON {
  6. SUFFIX Nap
  7. USEION na READ ena WRITE ina
  8. RANGE gbar, g, ina
  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. ena (mV)
  21. ina (mA/cm2)
  22. g (S/cm2)
  23. mInf
  24. mTau
  25. mAlpha
  26. mBeta
  27. hInf
  28. hTau
  29. hAlpha
  30. hBeta
  31. }
  32. STATE {
  33. m
  34. h
  35. }
  36. BREAKPOINT {
  37. SOLVE states METHOD cnexp
  38. g = gbar*m*m*m*h
  39. ina = g*(v-ena)
  40. }
  41. DERIVATIVE states {
  42. rates()
  43. m' = (mInf-m)/mTau
  44. h' = (hInf-h)/hTau
  45. }
  46. INITIAL{
  47. rates()
  48. m = mInf
  49. h = hInf
  50. }
  51. PROCEDURE rates(){
  52. LOCAL qt
  53. qt = 2.3^((34-21)/10)
  54. UNITSOFF
  55. mInf = 1.0/(1+exp((v- -52.6)/-4.6))
  56. if(v == -38){
  57. v = v+0.0001
  58. }
  59. mAlpha = (0.182 * (v- -38))/(1-(exp(-(v- -38)/6)))
  60. mBeta = (0.124 * (-v -38))/(1-(exp(-(-v -38)/6)))
  61. mTau = 6*(1/(mAlpha + mBeta))/qt
  62. if(v == -17){
  63. v = v + 0.0001
  64. }
  65. if(v == -64.4){
  66. v = v+0.0001
  67. }
  68. hInf = 1.0/(1+exp((v- -48.8)/10))
  69. hAlpha = -2.88e-6 * (v + 17) / (1 - exp((v + 17)/4.63))
  70. hBeta = 6.94e-6 * (v + 64.4) / (1 - exp(-(v + 64.4)/2.63))
  71. hTau = (1/(hAlpha + hBeta))/qt
  72. UNITSON
  73. }