Lecture 11 Notes, Thursday 29 September 2005

  • Hille. Chap. 2, pp. 25-60
  • Homework due: Thur 06 Oct 2005
  • This is part 2 of the Hodgkin-Huxley theory and modeling work.


    Homework (Due Thur 06 Oct 2005)

    Below are the Hodgkin-Huxley equations for membrane excitability. Create an *.ode file to implement these equations. Run some simulations varying the applied current, hand in a print out showing the working model. We will make use of this *.ode file more after the mid-term.

    v′ = (-1/C)*(INa + IK + IL - Iapp)
    m′ = αm(V)*(1 - m) - βm(V)*m
    h′ = αh(V)*(1 - h) - βh(V)*h
    n′ = αn(V)*(1 - n) - βn(V)*n

    initial V = -65.08
    initial m = 0.0568
    initial h= 0.568
    initial n = 0.318

    αh(V) = 0.0027*e-v/20
    αm(V) = 0.1*(V + 40)/(1 - e-(v+40)/10)
    αn(V) = 0.01*(V + 55)/(1-e-(v+55)/10)
    βh(V) = 1/(1+e-(v+35)/10)
    βm(V) = 0.108*e-v/18
    βn(V) = 0.055*e-v/80

    INa = gNa-max*m3*h*(V - ENa)
    IK = gK-max*n4*(V - EK)
    IL = gL*(V - EL)

    C = 1
    gK-max = 36
    gL = 0.3
    gNa-max = 120
    EK = -77
    EL = -54.4
    ENa = 50

    You have several options for Iapp; you can implement a heavyside step function or a simple steady current. At first just make Iapp a parameter and try values from 0 to 10 and see how the HH system responds.


    Lecture 11 Top - Cellular Biophysics and Modeling - Del Negro Homepage - Applied Science - The College of William and Mary