Search found 38 matches

by Qroid_montreal
Mon Apr 09, 2012 1:23 pm
Forum: Adding new mechanisms and functions to NEURON
Topic: Modeling dynamic extracellular fields
Replies: 19
Views: 9755

Re: Modeling dynamic extracellular fields

My equation predicts Vm can change without ionic currents.

But why is this wrong? If Vm=Vi-Ve, doesn't Vm change whenever the extracellular potential changes, regardless of currents?
by Qroid_montreal
Fri Apr 06, 2012 11:34 am
Forum: Adding new mechanisms and functions to NEURON
Topic: Modeling dynamic extracellular fields
Replies: 19
Views: 9755

Re: Modeling dynamic extracellular fields

Try this thought experiment: suppose you block all ionic currents in a real cell. What will happen to membrane potential? How does this differ from what your modified equation would predict? Hmm. Excuse my density... From the original Hodgkin-Huxley equations, the membrane potential can't change wi...
by Qroid_montreal
Thu Mar 29, 2012 11:58 pm
Forum: Adding new mechanisms and functions to NEURON
Topic: Modeling dynamic extracellular fields
Replies: 19
Views: 9755

Re: Modeling dynamic extracellular fields

That's great to hear. I'll play with this tomorrow.

Just so I'm clear, what would happen if I implemented the modified hh equation as written? If I don't see the error, am I missing something on the math/conceptual or the NEURON level?

edit: Thank you!
by Qroid_montreal
Wed Mar 28, 2012 4:00 pm
Forum: Adding new mechanisms and functions to NEURON
Topic: Modeling dynamic extracellular fields
Replies: 19
Views: 9755

Modeling dynamic extracellular fields

Hi, This is my second project with NEURON, and my first time really generating code. I'd like to model the effects of a temporally and spatially dynamic extracellular voltage on transmembrane currents in a spatially distributed neuron. Membrane voltage "v" is internal potential minus extracellular v...
by Qroid_montreal
Wed Oct 19, 2011 10:39 pm
Forum: Getting started
Topic: Modifying Mainen & Sejnowski a la Holt and Koch 1999
Replies: 6
Views: 2675

Re: Modifying Mainen & Sejnowski a la Holt and Koch 1999

Yes it is. Thanks for your help. I'll get started with the basics.

Thanks again.
by Qroid_montreal
Tue Oct 18, 2011 1:06 pm
Forum: Getting started
Topic: Modifying Mainen & Sejnowski a la Holt and Koch 1999
Replies: 6
Views: 2675

Re: Modifying Mainen & Sejnowski a la Holt and Koch 1999

Thanks so much. What do you mean by pas mechanism? Is this the passive i.e. leak current? Do you know where this is found in the code?
by Qroid_montreal
Tue Oct 18, 2011 10:22 am
Forum: Getting started
Topic: Modifying Mainen & Sejnowski a la Holt and Koch 1999
Replies: 6
Views: 2675

Re: Modifying Mainen & Sejnowski a la Holt and Koch 1999

Holt and Koch removed the somatic stimulation and "scattered synaptic input uniformly throughout the dendrites". From their paper: "We used the same approximation as Bernander et al. (1991): synapses were not explicitly modeled, but the leak resistance and reversal potential was changed to reflect t...
by Qroid_montreal
Sun Oct 16, 2011 2:13 pm
Forum: Getting started
Topic: Modifying Mainen & Sejnowski a la Holt and Koch 1999
Replies: 6
Views: 2675

Modifying Mainen & Sejnowski a la Holt and Koch 1999

Hello, First of all, I'm entirely new to NEURON. I'm trying to implement Holt and Koch's modification of Mainen and Sejnowski's model i.e. remove the electrode and distribute synaptic input uniformly throughout the dendrites. I have the original model working (http://senselab.med.yale.edu/ModelDb/sh...