hhode.m

利用Matlab模拟细胞HH 模型中的所有参数变化和动态Action Potential 生成过程

function varargout=hhode(t, y, flag)

% HHODE - ODE file for HH equations. State vector is [V,n,m,h]'. External
% current injected by function iexthh(t). Model parameters returned using
% hhpars = [gnamx; Ena; gkmx; Ek; gleak; El; C] = gethhparms.
% flag='': returns ydot (column)
%     ='init': returns [tsp,y0,opt], time span, initial values, options.

if nargin<3							% Catch for numjac the dumbjack
	varargout{1} = hhdot(t,y);
else
	switch flag
		case ''                % Return ydot vector
			varargout{1} = hhdot(t,y);
		case 'init'             % Return default tspan, y0, and options
			[varargout{1:3}] = init;
	%	case 'jacobian'         % Return Jacobian matrix
	%		varargout{1} = hhjac(t,y);
		otherwise
			error(strcat('***Unknown flag=''',flag,''' in HHODE.***'))
	end
end
return


function ydot = hhdot(t,y)

% Note the external current is provided by function iexthh(t)

% Parameters (mS/cm^2, mV, uFd/cm^2)
% hps = [gnamx=120; Ena=55; gkmx=36; Ek=-72; gleak=0.3; El=-49.4; C=1]
    hps = gethhparms;

	ydot=zeros(4,1);
	
% Membrane potential:
	ydot(1) = (iexthh(t) - hps(1)*y(3)^3*y(4)*(y(1)-hps(2)) - ...
	      hps(3)*y(2)^4*(y(1)-hps(4)) - hps(5)*(y(1)-hps(6)))/hps(7);
% n
	ydot(2) = (1-y(2))*alphn(y(1)) - y(2)*betan(y(1));
% m
	ydot(3) = (1-y(3))*alphm(y(1)) - y(3)*betam(y(1));
% h
	ydot(4) = (1-y(4))*alphh(y(1)) - y(4)*betah(y(1));
return


function [tsp,y0,opt]=init
   tsp = [0; 50];
   y0 = [-60., 0.318, 0.053, 0.596]';
   opt = odeset('OutputFcn','odeplot', 'jacobian','off', 'RelTol',1e-4);
return