30 Dec
2020
30 Dec
'20
11:15 a.m.
Dear Enguang,
When a neuron receives a spike, its handle() method for SpikeEvents is invoked. Typically,
this method just files the incoming spike into a temporary buffer. Some neuron models put
spikes into different buffers depending on the sign of the weight: spikes with negative
weight are interpreted as inhibitory, and positive weight as excitatory. For
iaf_psc_alpha, this is done here:
https://github.com/nest/nest-simulator/blob/2869b6364ccd85edf69246deb12c03c…
Note that the weight is read out by calling get_weight() on the spike event, and is stored
in the buffer.
The actual numerical integration then happens in the update() method, which is called once
every simulation timestep. Here, the spikes are read out again from the buffer, and their
contribution added to synaptic current (and via there, membrane potential). For
iaf_psc_alpha, this is at:
https://github.com/nest/nest-simulator/blob/2869b6364ccd85edf69246deb12c03c…
The integration of excitatory spikes, for example, happens on lines 345-346.
Hope this helps, if anything's unclear please don't hesitate to get back in
touch.
Best regards,
Charl
On Tue, Dec 29, 2020, at 13:36, enguang zhou wrote:
> Hello everyone,
> As the title says, can someone help me answer this? I am really
> confused about this. Because I need to know how to control the neuron
> spiking from the mathematical formula, and I check out the
> iaf_psc_alpha.cpp and its .h file, and I can't get a clue how does the
> synapse weight value influence the neuron spiking. I would be
> appreciate if you can tell me how to check out the code in
> nest_simualator.
> Thank you.
> Enguang
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