6.021/Notes/2006-11-03

Hodgkin-Huxley

 * Each factor can also be written as rates $$\alpha,\beta$$
 * $$x_\infty=\frac{\alpha_x}{\alpha_x+\beta_x}, \tau_x=\frac{1}{\alpha_x+\beta_x}$$
 * The effect of temperature is to multiple rates by $$K_T = 3^{T_c-6.3}$$
 * An increase in temperature decreases all 3 time constants but has no effect on the final values.
 * At high temperature, no action potential is seen
 * There's another time constant due to capacitance in membrance
 * Changes in conductances have time delay before membrane potential changes
 * $$\tau_M$$ (membrane "RC" time constant) is about 1-2 ms.
 * $$\tau_m \approx 1-2 ms, \tau_n \approx 3-4 ms, \tau_h \approx 3-4 ms$$
 * increase in temperature causes the $$G_K$$ wave to catch up with the $$G_{Na}$$ wave
 * As increase temperature, both approach $$\tau_M$$. If waves go at same speed, cannot have action potential.