42
Figure 2.8: Simulations demonstrate converging accuracy for the quasi-active versus reduced
system. We used the neuron of Figure 2.6B with the nonuniform channel model of Table B.2. The
discretized neuron had 1121 compartments, leading to a 6726-dimensional system. For each reduced
system size k, we performed 10 simulations of 50 ms each with 35 random alpha-function synaptic
inputs for which gt,s ∈ [0, 2].
onto synapse s of branch b as
~ /, ∖ ʌ t Utart / 1 t Utart ʌ
дъЛ.4 = 9bs-------exp I 1------- I ,
(2.41)
where fstart is the time (in ms) of stimulus onset, and the time constant τ = 1 ms
is the time at which the conductance reaches its maximum value of ‰. In order to
know the strength required for a single synaptic input at a given location to produce
a peak target depolarization at the soma, we need to run a parameter sweep for gt>s-
Using the reduced system on the forked neuron with the uniform channels of Table
B.l, we execute the bisection method with a tolerance of IO-8 to obtain values for