Paper available: Origins of cortical temporal tuning

[Ken Miller]

A preprint of the following article is now available, from 

http://www.keck.ucsf.edu/~ken
(click on 'publications', then on 'Models of Neuronal Integration and Circuitry')

or directly from

ftp://ftp.keck.ucsf.edu/pub/ken/krukowski-miller01.pdf
(there is also a web supplement to the article, 
ftp://ftp.keck.ucsf.edu/pub/ken/krukowski-miller01-websupp.pdf)


Krukowski, A.E. and K.D. Miller (2001).  ``Thalamocortical NMDA
conductances and intracortical inhibition can explain cortical
temporal tuning.''  Nature Neuroscience 4, 424-430.

Abstract:

Cells in cerebral cortex fail to respond to fast-moving stimuli that
evoke strong responses in the thalamic nuclei that provide input to
cortex.  The reason for this behavior has remained a mystery.  We
study an experimentally-motivated model of the thalamic
input-recipient layer of cat primary visual cortex that we have
previously shown accounts for many aspects of cortical orientation
tuning.  In this circuit, inhibition dominates over excitation, but
temporal modulations of excitation and inhibition occur out of phase
with one another, allowing excitation to transiently drive cells.  We
show that this circuit provides a natural explanation of cortical
low-pass temporal frequency tuning, provided N-methyl-D-aspartate
(NMDA) receptors are present in thalamocortical synapses in
proportions measured experimentally.  This suggests a new and
unanticipated role for NMDA conductances in shaping the temporal
response properties of cortical cells, and suggests that common
cortical circuit mechanisms underly both spatial and temporal response
tuning.


Ken
 
        Kenneth D. Miller               telephone: (415) 476-8217
	Associate Professor		fax: (415) 476-4929
        Dept. of Physiology, UCSF	internet: ken at phy.ucsf.edu
        513 Parnassus			www: http://www.keck.ucsf.edu/~ken
        San Francisco, CA 94143-0444