IAF Neuron simulation [Resolved]

volt_rest = -70; % resting potential (mV) 
volt_thresh = -50; % action potential thresh. (mV) 
volt_reset = -75; % post-spike reset voltage 

% membrane parameters 
R_m = 10; % neuron membrane resistance (MOhm)
 tau = 10; % time constant of decay (ms)

srate = 10000; % sampling rate in Hz 
sim_dur = 1; % stimulus duration in seconds 
time = 0:1/srate:sim_dur - 1/srate; 
input = zeros(1,length(time));
 input(dsearchn(time',.3):dsearchn(time',.7)) = 3;

neuronV = volt_rest + zeros(size(timevec));
spiketimes = [];

if neuronV(ti) > volt_thresh 
neuronV(ti) = volt_reset; 
spiketimes = cat(1,spiketimes,ti); 
end

r_i = volt_rest + input(ti)*R_m; 
neuronV(ti+1) = r_i + (neuronV(ti) - r_i) * exp(-1000/srate/tau);

neuronV(neuronV==volt_reset) = 40;

Answer 1

[Ameer Hamza]

I cannot tell you what is exactly written in that book, but a quick view of the code shows that timevec is same is time in your case. As for ti it is an index of the matrix so it can be defined in the following way.

• For timevec change as follow:

neuronV = volt_rest + zeros(size(time));

• For the issue with ti do the following:

for ti=1:numel(time)
    if neuronV(ti) > volt_thresh
        neuronV(ti) = volt_reset;
        spiketimes = cat(1,spiketimes,ti);
    end
end

This will remove all error.