I'm working with a model of the amygdala https://senselab.med.yale.edu/modeldb/S ... del=150288
I want to induce gamma oscillations in the model and I'm working with a paper, Koppell, N., Börgers, C., Pervouchine, D., Malerba, P., Tort, A. 2010. ``Gamma and Theta Rhythms in Biophysical Models of Hippocampal Circuits'', in Hippocampal Microcircuits, Springer. According to the paper, one of the conditions for gamma oscillations is that the excitatory cells should receive sufficient input to spike at or above gamma frequency without synaptic interactions. Currently, external input is given to the excitatory neurons as background noise through the BgGen template, which I give below for convenience
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begintemplate BgGen
public noise_freq,noise_start,noise_total_length,refractory_period,tone_netstim,tone_turn,noise_netstim,intfire1,TempNetCon
objref noise_netstim,intfire1,TempNetCon
proc init() {
noise_freq = $1
noise_start = $2
noise_total_length = $3
refractory_period = $4
timestep = $5
refractory_period = refractory_period - timestep
noise_netstim = new NetStim()
noise_netstim.interval = 1000/noise_freq
//noise_netstim.number = 1e100 //noise_total_length*noise_freq/1000
noise_netstim.number = noise_total_length*noise_freq/1000
noise_netstim.start = noise_start
noise_netstim.noise = 1
intfire1 = new IntFire1()
intfire1.tau = 1e9
intfire1.refrac = refractory_period
intfire1.m = 0
intfirewgt = 1+(1e-9)
TempNetCon = new NetCon(noise_netstim,intfire1,0.5,0,intfirewgt)
}
endtemplate BgGen
excitatory cell or even the intfire1 (or even noise_netstim) input to the cell. Why is this so? Any help would be appreciated.
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load_file("nrngui.hoc")
load_file("LAcells_template.hoc")
load_file("BgGen.hoc")
objectvar cell_exc
cell_exc=new Cell_A()
tstop = 1000
dt = 0.01
objref bggen, bg2LAPsyn, bg2LAPcon
bggen = new BgGen(300,0,tstop,30,dt)
//30, 45, 60, 90, 120
cell_exc.dend bg2LAPsyn = new bg2pyr(0.9)
bg2LAPsyn.initW = 6.3
bg2LAPcon = new NetCon(bggen.intfire1,bg2LAPsyn,1,1,1)
objref apc
bggen.intfire1 apc = new APCount(0.5)
apc.thresh=0
objref counts
counts = new Vector()
apc.record(counts)
objref rect, recv
rect = new Vector()
recv = new Vector()
recv.record(&cell_exc.soma.v(0.5))
rect.record(&t)
recv.printf()
run(tstop)
objref f1
f1 = new File()
f1.wopen("counts.txt")
counts.printf(f1)
f1.close()
objref savdata
savdata = new File()
savdata.wopen("voltage.dat")
for i=0,rect.size()-1 {
savdata.printf("%g %g\n", rect.x(i), recv.x(i))
}
savdata.close()