I have a good idea for a very effective way to do this. Let me first ask: will you ever want this to have a biexponential time course, and will you ever want it to occur more than once during a simulation, or at random times, or in response to some other phenomenon e.g. a cell firing a spike?jjnaylor wrote:My current goal is to model an alpha synapse with conductance normally distributed over the dendrite.
Am I correct to guess that you meant "conductance density"? Also, I would guess that you are either starting with an experimental estimate of some total conductance, or trying to implement in NEURON a model that was previously implemented in C, Matlab, FORTRAN etc. using "absolute biophysical parameters."if I know the desired total conductance of a certain current then how do I convert that to a current density?
Yes and yes. Assuming that the original model implementation provided enough information for you to discover the surface area of the thing that has the total conductance in question. Typical conversions are between mm2 and cm2 (clearly 100 mm2 = 1 cm2), or um2 and cm2 (1e8 um2 = 1 cm2).Should I just divide by the total area (ie. set g = gbar/area perhaps with a dimensional adjustment)?
Actually that's not the case. The problem is really that, when adaptive integration is used, statements in the BREAKPOINT block are not executed because this mechanism does not WRITE a current. So x starts out at 0 andjjnaylor wrote:One small issue is that if I use the variable step integrator, it misses the event of the netstim and so it seems as if nothing happened
I'm not sure I understand this. Can you send me a toy model with just enough code to reproduce this, so I can see what you are describing?The other issue is that a very large, delayed capacitive current seems to drive uniform depolarization across the entire cell (when I want the postsynaptic current to originate in the dendrite and then spread to the soma). It might just be how I coded my cell, but I only put the dsyn on the dendrites.
Users browsing this forum: No registered users and 0 guests