Search found 22 matches

by Hyeon
Mon Apr 08, 2019 3:01 am
Forum: Other questions
Topic: short duration biphasic current stimulation
Replies: 6
Views: 1761

Re: short duration biphasic current stimulation

Thanks for the reply, Ted.
Though I still do not fully understand SEClamp mechanism, it is a good opportunity to understand NEURON detail.
by Hyeon
Wed Apr 03, 2019 4:25 am
Forum: Other questions
Topic: short duration biphasic current stimulation
Replies: 6
Views: 1761

Re: short duration biphasic current stimulation

Thanks for your kind reply, Ted. I understood why the model did not activate, well. The reason why I applied short duration biphasic current pulse is that I want to apply a monophasic square pulse of voltage stimulation. (Since I use the value of the activating function, it is right to use IClamp. A...
by Hyeon
Wed Mar 27, 2019 1:33 am
Forum: Other questions
Topic: short duration biphasic current stimulation
Replies: 6
Views: 1761

short duration biphasic current stimulation

Dear all, Hi, I have a problem to apply current controlled stimulation. Background is, There are animal experiments, which apply epidural cortical stimulation with 0.2 ms rectangular pulses. And I try to explain excitability patterns through simulations. Thus, I constructed a 3D volume conductor mod...
by Hyeon
Tue Jan 08, 2019 2:14 am
Forum: Getting started
Topic: modified HH model with sinusoidal voltage stimulation
Replies: 7
Views: 2985

Re: modified HH model with sinusoidal voltage stimulation

Dear Ted, I really appreciate your help. Through files that you emailed, I can reproduce "extracellular stimulus" results in Mahmud and Vassanelli, and additionally, it is a good opportunity to understand how to stimulate neurons. Now, I can proceed with an investigation related to modeling and expe...
by Hyeon
Fri Jan 04, 2019 3:08 am
Forum: Getting started
Topic: modified HH model with sinusoidal voltage stimulation
Replies: 7
Views: 2985

Re: modified HH model with sinusoidal voltage stimulation

Thanks for your kind reply, Ted. I agree that applied current (I_app) did not explain extracellular stimulation adequately. However, since I am currently interested in sinusoidal stimulation to the excitatory and inhibitory neurons, I try to reproduce this paper results. I am also simulating other m...
by Hyeon
Tue Jan 01, 2019 8:32 pm
Forum: Getting started
Topic: modified HH model with sinusoidal voltage stimulation
Replies: 7
Views: 2985

Re: modified HH model with sinusoidal voltage stimulation

This modified HH equation was from "Differential modulation of excitatory and inhibitory neurons during periodic stimulation", Mahmud et al., 2016 It aims to simulate excitatory and inhibitory neurons (composed of a single compartment) subject to sinusoidal stimulation using varied frequencies and a...
by Hyeon
Fri Dec 28, 2018 1:30 am
Forum: Getting started
Topic: modified HH model with sinusoidal voltage stimulation
Replies: 7
Views: 2985

modified HH model with sinusoidal voltage stimulation

Dear all, I have a simple question. I try to implement a modified HH model using a single compartment, as follows: cm*dV/dt = I_na + I_k + I_l+ I_app where I_app = cm*dVs/dt and Vs is applied voltage. I want to make NMODL for I_app, by modifying IClamp, as follows: COMMENT applied current ENDCOMMENT...
by Hyeon
Wed Oct 14, 2015 6:43 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Thanks always, Ted. Now, I can solve my problem : ) ----------------------------------------------------------------------------------- Dear rth, I also check and fix the Pashut code and found same error what you said before. Even after fixing the Pashut code it induced nothing, it might be due to s...
by Hyeon
Mon Oct 12, 2015 3:17 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Thanks for your kind explanation, ted.

I have one more question.
I found that the NMODL code is similar with 'a passive leak current' in 9.2 Example in book.
Since tms pulse has opposite direction with leak current, is it reasonable to multiply is = (-1)*k*f rather than is = k*f?
by Hyeon
Wed Oct 07, 2015 10:28 pm
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Sorry, I did not answer properly. At each center point of each compartment, applied membrane current is a scalar value. This membrane current is determined by u(x,y,z) which represents axial direction and F(x,y,z) which is electric field at some point p(x,y,z). Then, this membrane current (scalar) w...
by Hyeon
Wed Oct 07, 2015 6:14 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Yes, the u(x,y,z) is assigned by axial direction at each center point of each compartment of neuronal model and F is a scalar that depends only on time which is calculated in finite element head model.

And thanks for recommended papers and I have to keep in mind.
by Hyeon
Tue Oct 06, 2015 1:02 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Thanks for kind explanation. I studied the NEURON book and related paper for this issue, and understand what is the problem of Pashut code that ted mentioned before (apply MS as a nonspecific leak current .. part). What I am trying to do is, I calculate potential/electrical field using finite elemen...
by Hyeon
Thu Aug 06, 2015 11:07 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

I ask my question to the authors, but unfortunately they don't give the answer; because they cannot remember it as it is done almost five years ago. There are some ambiguous things to me, so I will be very pleased if you let me know the answers. First, electric field induced by transcranial magnetic...
by Hyeon
Tue Aug 04, 2015 10:17 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Re: Apply extracellular stimulation using electric field

Thank you for your answer and the recommended paper was very helpful. Since the solution field by transcranial magnetic stimulation (TMS) is electric field, I am decided to use activating function approach. For this, I reference the Pashut 2011 paper and code https://senselab.med.yale.edu/ModelDB/Sh...
by Hyeon
Thu Jul 16, 2015 7:23 am
Forum: Other questions
Topic: Apply extracellular stimulation using electric field
Replies: 16
Views: 10379

Apply extracellular stimulation using electric field

Hi, ted I am interested in the effects of brain stimulation to pyramidal cell. So, previously, I calculated stimulus-induced potential fields using FEM and then applied it to each compartment of pyramidal cells using e_extracellular(x). Similarly, I want to apply extracellular stimulation using elec...