1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
"""
Executes one simulation with specified stimulus.
Displays response and reports spike frequency
"""
from neuron import h, gui
# simulation parameter
h.tstop = 500 # ms, more than long enough for 15 spikes at ISI = 25 ms
# model specification
from cell import Cell
cell = Cell()
# instrumentation
# experimental manipulations
stim = h.IClamp(cell.soma(0.5))
stim.delay = 1 # ms
stim.dur = 1e9
stim.amp = 0.1 # nA
# data recording and analysis
# count only those spikes that get to distal end of dend
nc = h.NetCon(cell.dend(1)._ref_v, None, sec=cell.dend)
nc.threshold = -10 # mV
spvec = h.Vector()
nc.record(spvec)
NSETTLE = 5 # ignore the first NSETTLE ISI (allow freq to stablize)
NINVL = 10 # num ISI from which frequency will be calculated
NMIN = NSETTLE + NINVL # ignore recordings with fewer than this num of ISIs
def get_frequency():
nspikes = spvec.size()
if nspikes > NMIN:
t2 = spvec[-1] # last spike
t1 = spvec[-(1 + NINVL)] # NINVL prior to last spike
return NINVL * 1.0e3 / (t2 - t1)
else:
return 0
# Simulation control and reporting of results
def onerun(amp):
# amp = amplitude of stimulus current
g = h.Graph(0)
g.size(0, 500, -80, 40)
g.view(0, -80, 500, 120, 2, 105, 300.48, 200.32)
# update graph throughout the simulation
h.graphList[0].append(g)
# plot v at distal end of dend
g.addvar("dend(1).v", cell.dend(1)._ref_v)
stim.amp = amp
h.run()
freq = get_frequency()
print("stimulus %g frequency %g" % (amp, freq))
onerun(0.15)
|
