Search found 50 matches

by vladimirov
Mon Apr 30, 2012 2:18 pm
Forum: Getting started
Topic: Fitting time constants for EPSPs
Replies: 6
Views: 8672

Re: Fitting time constants for EPSPs

Dear Ted, Thank you very much for the detailed answer. The rise time is 10-90, and the available data are both current clamp and voltage clamp of soma not far from the synapse. Does it make any sense to try to fit the given experimental IPSC amplitude (22 pA in my case), or it is hopeless due to flu...
by vladimirov
Tue Apr 24, 2012 5:05 pm
Forum: Getting started
Topic: Fitting time constants for EPSPs
Replies: 6
Views: 8672

Fitting time constants for EPSPs

Hi, How do you fit the experimental data on EPSP/IPSP kinetics? I have two time constants from experiment: "rise time" (3 ms) and "half-duration (width at half-amplitude)" (21 ms). I guess using Exp2Syn() mechanism should suffice? It also has two time constants tau1, tau2, but their meaning is sligh...
by vladimirov
Mon Apr 16, 2012 7:17 pm
Forum: NEURON + Python
Topic: PyNEURON simplify NEURON usage from Python on Windows
Replies: 12
Views: 11833

Re: PyNEURON simplify NEURON usage from Python on Windows

Hi, Uri,
Thanks a lot for the PyNEURON. I just noticed on PyNEURON site that the link to installation instructions is broken due to a typo (https://bitbucket.org/uric/pyneuron/wiki/Instalation), double "l" in "Installation" is missing.
by vladimirov
Wed Mar 14, 2012 10:22 am
Forum: Getting started
Topic: Lambda rule for fast spiking axon
Replies: 2
Views: 3292

Re: Lambda rule for fast spiking axon

Ok, thanks!
by vladimirov
Tue Mar 13, 2012 11:30 am
Forum: Getting started
Topic: Lambda rule for fast spiking axon
Replies: 2
Views: 3292

Lambda rule for fast spiking axon

Hi,
Would the standard d_lambda rule still applicable for a fast spiking axon, when interspike intervals are ~1.5-2 ms? The generic formula suggests

Code: Select all

nseg = int((L/(0.1*lambda_f(100))+.9)/2)*2 + 1
is it still good for an axon which conducts trains of high-frequency spikes (>300 Hz)?
Thank you!
by vladimirov
Tue Mar 06, 2012 3:53 pm
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

Your help is greatly appreciated!
by vladimirov
Fri Mar 02, 2012 4:49 pm
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

Wow, Ted, many thanks for the code. It would take me days to figure out how to write this thing properly. In case any beginner needs complete code: after defining ns in Ted's code, just add objref nc axon nc = new NetCon(ns,ip) nc.threshold = 0 nc.weight = 1 nc.delay = 0 and enjoy the random spikes....
by vladimirov
Thu Mar 01, 2012 1:03 pm
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

So, an external random number generator can stimulate axons via their NetStim's? I don't need to build in random numbers into NMODL file of the (synaptic) stimulation mechanism?
by vladimirov
Wed Feb 29, 2012 6:06 pm
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

Hi, Ted, I am actually interested primarily in what happens in axons, with propagation failures and antidromic spikes. In principle, my model is all around axons, rather than soma and dendrites. Is there any way to implement the random drive to axons? I keep posting here because maybe our discussion...
by vladimirov
Tue Feb 28, 2012 11:25 am
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

These should be current pulses, delivered to distal axons and making them to spike 1 or more times, depending on pulse duration or amplitude. Waveform can be square, with parameters ton, amp as in generic Ipulse1 mechanism, and toff being a random exp. distributed variable. Any ideas to how implemen...
by vladimirov
Mon Feb 27, 2012 11:03 am
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Re: Random pulses

Hi, Ted,
I need some hundreds of pulses per network, pulses delivered to random cells at random times. Kind of Poisson noisy input for a network (100 cells or more, anatomically reconstructed).
Thanks,
Nik
by vladimirov
Fri Feb 24, 2012 5:57 pm
Forum: Getting started
Topic: Random pulses
Replies: 12
Views: 3991

Random pulses

I need a random time series of current pulses delivered to axon, with exponentially distributed times between successive pulses. How could I possibly do this?
Thank you!
Nik
by vladimirov
Thu Dec 01, 2011 10:43 pm
Forum: Anatomically detailed models
Topic: Reconstruction cookbook?
Replies: 1
Views: 2093

Reconstruction cookbook?

Dear colleagues, Does anybody know a good manual for reconstruction of anatomically detailed models? I am new in the field, and there are some immediate questions to the topic: 1) After I open the swc file in import3D and save it as Neuron hoc file, is it good enough to populate with ion channels an...
by vladimirov
Wed Nov 30, 2011 6:19 pm
Forum: Anatomically detailed models
Topic: SWC files with a single "soma" point
Replies: 13
Views: 12994

Re: SWC files with a single "soma" point

This seems to be a common issue. I got same problem in swc file for cell http://neuromorpho.org/neuroMorpho/neuron_info.jsp?neuron_name=ca1a 1 1 2413. 1468. 1755. 5. -1 2 3 2412. 1468. 1755. 0.3 1 3 3 2411. 1469. 1755. 0.3 2 Maybe trivial, but worth mentioning: both diameter of soma apex and *its co...
by vladimirov
Mon Sep 19, 2011 8:01 am
Forum: Modeling networks
Topic: Rasterogramm of two overlapping rings
Replies: 5
Views: 2819

Re: Rasterogramm of two overlapping rings

Oh, that's what is symbolic constants. I always try to use this style, of course, and put all (most) controls at the top of code. I thought "symbolic constants" is something special :)
Thanks a lot, Ted!