Paper available: Review of Orientation Selectivity Development and Models

[Ken Miller]

The following paper is now available at
    ftp://ftp.keck.ucsf.edu/pub/ken/or-review.ps.gz (compressed postscript)
or  http://www.keck.ucsf.edu/~ken                (click on 'Publications')

This is a preprint of an article that appeared as Journal of
Neurobiology 41:44-57 (1999):
http://www3.interscience.wiley.com/cgi-bin/abstract?ID=66000451

------------------------------

 Is the Development of Orientation Selectivity Instructed by Activity?
           Kenneth D. Miller, Ed Erwin and Andrew Kayser
                    Dept. of Physiology, UCSF

ABSTRACT:

Is the development of orientation selectivity in visual cortex
instructed by the patterns of neural activity of input neurons?  We
review evidence as to the role of activity, review models of
activity-instructed development, and discuss how these models can be
tested.  The models can explain the normal development of simple cells
with binocularly matched orientation preferences, the effects of
monocular deprivation and reverse suture on the orientation map, and
the development of a full intracortical circuit sufficient to explain
mature response properties including the contrast-invariance of
orientation tuning.  Existing experiments are consistent with the
models, in that (1) selective blockade of ON-center ganglion cells,
which will degrade or eliminate the information predicted to drive
development of orientation selectivity, in fact prevents development
of orientation selectivity; and (2) the spontaneous activities of
inputs serving the two eyes are correlated in the lateral geniculate
nucleus at appropriate developmental times, as was predicted to be
required to achieve binocular matching of preferred orientations.
However, definitive tests remain to be done to (1) firmly establish
the instructive rather than simply permissive role of activity and (2)
determine whether the retinotopically- and center-type-specific
patterns of activity predicted by the models actually exist.  We
conclude by critically examining alternative scenarios for the
development of orientation selectivity and maps, including the idea
that maps are genetically pre-specified.


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