K_P.mod 1.2 KB

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  1. :Comment : The persistent component of the K current
  2. :Reference : : Voltage-gated K+ channels in layer 5 neocortical pyramidal neurones from young rats:subtypes and gradients,Korngreen and Sakmann, J. Physiology, 2000
  3. :Comment : shifted -10 mv to correct for junction potential
  4. :Comment: corrected rates using q10 = 2.3, target temperature 34, orginal 21
  5. NEURON {
  6. SUFFIX K_P
  7. USEION k READ ek WRITE ik
  8. RANGE gbar, g, ik
  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. ek (mV)
  21. ik (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. ik = g*(v-ek)
  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/(1 + exp(-(v+1)/12)))
  53. if(v<-50){
  54. mTau = (1.25+175.03*exp(-v * -0.026))/qt
  55. }else{
  56. mTau = ((1.25+13*exp(-v*0.026)))/qt
  57. }
  58. hInf = 1/(1 + exp(-(v+54)/-11))
  59. hTau = (360+(1010+24*(v+55))*exp(-((v+75)/48)^2))/qt
  60. v = v - 10
  61. UNITSON
  62. }