Abstract For:
Chance, F.S., Nelson, S.B. and Abbott, L.F. (1998) Synaptic Depression
and the Temporal Response Characteristics of V1 Simple Cells. J. Neurosci.
18: 4785-4799.
We explore the effects of short-term synaptic depression on the temporal
dynamics of V1 responses to visual images by constructing a model simple
cell. Synaptic depression is modeled on the basis of previous detailed fits
to experimental data. A component of synaptic depression operating in the
range of 100's of ms can account for a number of the unique temporal characteristics
of cortical neurons including the band-pass nature of frequency response
curves, increases in response amplitude and cut-off frequency for transient
stimuli, nonlinear temporal summation, and contrast-dependent shifts in
response phase. Synaptic depression also provides a mechanism for generating
the temporal phase shifts needed to produce direction selectivity, and a
model constructed along these lines matches both extracellular and intracellular
data. A slower component of depression can reproduce the effects of contrast
adaptation.
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