"Simple cells in layer 4 of the primary visual cortex of the cat show contrast-invariant orientation tuning, in which the amplitude of the
peak response is proportional to the stimulus contrast but the width of the tuning curve hardly changes with contrast.
This study uses a
detailed model of spiny stellate cells (SSCs) from cat area 17 to explain this property.
The model integrates our experimental data,
including morphological and intrinsic membrane properties and the number and spatial distribution of four major synaptic input
sources of the SSC: the dorsal lateral geniculate nucleus (dLGN) and three cortical sources.
...
The model response is in close
agreement with experimental results, in terms of both output spikes and membrane voltage (amplitude and fluctuations), with reasonable
exceptions given that recurrent connections were not incorporated."
Reference:
1 .
Banitt Y, Martin KA, Segev I (2007) A biologically realistic model of contrast invariant orientation tuning by thalamocortical synaptic depression. J Neurosci 27:10230-9 [PubMed]
2 .
Anderson JC, Douglas RJ, Martin KA, Nelson JC (1994) Map of the synapses formed with the dendrites of spiny stellate neurons of cat visual cortex. J Comp Neurol 341:25-38 [PubMed]
3 .
Anderson JC, Douglas RJ, Martin KA, Nelson JC (1994) Synaptic output of physiologically identified spiny stellate neurons in cat visual cortex. J Comp Neurol 341:16-24 [PubMed]
4 .
Banitt Y, Martin KA, Segev I (2005) Depressed responses of facilitatory synapses. J Neurophysiol 94:865-70 [PubMed]
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