54
10--------------------ɪ--------------------1--------------------1--------------------1--------------------1--------------------1--------------------i--------------------1--------------------1--------------------1
О 50 100 150 200 250 300 350 400 450 500
Time (ms)
Second half of Simulation 1 of forked neuron with 1250 weak inputs, Vu = 10 mV
R
20r b
15
10
-5
‰ 550 600 650 700 750 800 850 900 950 1000
Time (ms)
Figure 2.15: A-В) Soma potentials corresponding to the first and second halves of simulation
1 of the “weak” input case using Vth — Ю mV. Note that the reduced system spikes are drawn
for clarification, and that the voltage axis has been scaled so that subthreshold behavior is more
easily seen. Subthreshold behavior is of the nonlinear model is captured well by the reduced model,
especially when less firing occurs, and stars below spikes in (A) indicate that four spikes have been
captured by the reduced model.
the reduced system tend to be very close to the actual spike times.
2.7.2 Thresholding at Multiple Sites
Of course one has no right to expect high accuracy when applying supra-threshold
stimuli to a sub-threshold model. Nonetheless, there are a number of means by which
our crude mechanism may be improved. If we fail to detect a somatic spike because
it was generated in the dendrite, then it may pay to build the reduction in order that