Hi Kamal,
Hopefully someone else will be able to answer your question better
than I... I don't know anything about matlab, but I can vaguely write
stuff for NEURON. But I just had a couple of questions, any maybe when
you answer them, you might see where you problem is.
Firstly... am I right in reading that your time step is 1 ms? That
hardly seems small enough? I would have thought you needed a time step
of 10 micro seconds.
Secondly, this must just be an integrate and fire neuron? I can't see
any hodgkin-huxley type channels. Moreover, what is the mechanism for
generating the "calcium current" needed for the burst firing? I can't
see one.
Finally, you must hyperpolarize a cell to get it to burst, are you
sure you are hyperpolarizing it?
On Feb 19, 7:46 am, "Kamal J. AbuHassan" <kamal.abuhas... from hotmail.com>
wrote:
> Hi,
>> I have started to study Izhikevich's large scale model of mammalian thalamocortical systems, I have tried to simulate the neuronal model : v=(k*(v(i)-vr)*(v(i)-vt)-u(i)+I(i))/C and u=a*(b*(v(i)-vr)-u(i)) using the parameters in fig. 10 of the appendix (for Thalamocortical Neurons: C=200; vr=-60; vt=-50; k=1.6;a=0.1; b=15 or zero depending on v; c=-60; d=10;vpeak=40;) to get the burst firing pattern of Thalamocortical Neurons (see fig.3A of the paper) but the model always generate the results for the tonic firing pattern, I am using the following matlab code from Izhikevich's book, chapter 8:
>> C=200; vr=-60; vt=-50; k=1.6; % parameters used for (TC)
> a=0.1; b=15; c=-60; d=10; %
> vpeak=40; % spike cutoff
> T=1000; tau=1; % time span and step (ms)
> n=round(T/tau); % number of simulation steps
> v=vr*ones(1,n); u=0*v; % initial values
> I=[zeros(1,0.1*n),200*ones(1,0.9*n)];% pulse of input DC current
> for i=1:n-1 % forward Euler method
> if v(i)>=-60
> b=0;
> end;
> v(i+1)=v(i)+tau*(k*(v(i)-vr)*(v(i)-vt)-u(i)+I(i))/C;
> u(i+1)=u(i)+tau*a*(b*(v(i)-vr)-u(i));
> if v(i+1)>=vpeak % a spike is fired!
> v(i)=vpeak; % padding the spike amplitude
> v(i+1)=c; % membrane voltage reset
> u(i+1)=u(i+1)+d; % recovery variable update
> end;
> end;
> plot(tau*(1:n), v); % plot the result
>> Can you help me please ?
>> Thanks,
> Kamal.
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