Biomedical Engineering Reference
In-Depth Information
Figure 1
. Comparison of multicompartment and composite modeling results with experimental
data for a guinea pig cerebellar Purkinje cell stimulated by rectangular current pulses. The
dashed vertical lines indicate the offset time of the stimulus pulses. (
A
) Data from a cerebellar
slice preparation studied by Llinás and Sugimori (78), reproduced with permission. Note the
"plateau" response of the cell with discharge at an increasing rate under 1.25-nA injected cur-
rent after the stimulus pulse has been turned off (bottom left). (
B
) Data from DeSchutter and
Bower (79), reproduced with permission. The spiking response following stimulus offset actu-
ally occurs at lower stimulating currents (stimulating current value for bottom panel not given
in the original reference). (
C
) Data from a one-compartment version of the composite model of
Coop and Reeke (34), reproduced with permission.
fire" (I&F) neuron (15,16), which is easy to simulate but omits most details of
cell dynamics. The simplest version of this model eliminates the action potential
altogether, replacing it with a simple voltage step on the idea that all action po-
tentials are much alike and already well enough understood. One then has:
dV
C
dt
=
G V
+
I
,
[3]
L
where the variables are as above, omitting the subscript
m
, and the voltage scale
is chosen such that
V
= 0 is the resting potential.
G
L
is a leak conductance that
allows the voltage to decay to 0 in the absence of input. When the voltage,
V
,
