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This Article Full Text Full Text (PDF) All Versions of this Article: 586/18/4371    most recent jphysiol.2008.159020v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Zhou, Z. J. Articles by Lee, S. PubMed PubMed Citation Articles by Zhou, Z. J. Articles by Lee, S. Related Collections Perspectives Neuroscience

¹ Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA

Detection of the direction of image movement is accomplished first in the retina by an elegant neuronal circuit, which integrates multiple levels of spatially asymmetric synaptic interactions among subsets of bipolar, amacrine and ganglion cells. Central to these interactions is the asymmetric GABAergic inhibition exerted by the starburst amacrine cell (SAC), a cholinergic and GABAergic interneuron with a radially symmetric dendritic tree. SACs make reciprocal GABAergic synapses on each other to create a direct inhibitory receptive field surround, which suppresses the response of each SAC to centripetal image movement. Each radially projecting branch of a SAC responds to image movement with a centrifugal bias and, through directionally asymmetric synaptic connections with the dendrites of direction-selective ganglion cells (DSGCs), exerts a spatially offset inhibition that vetoes the response of DSGCs to image movement in a specific (null) direction. Recent physiological studies have greatly advanced our understanding of the mechanism of direction selectivity and also revealed a new level of complexity that remains to be understood.

(Received 2 July 2008; accepted after revision 7 July 2008; first published online 10 July 2008)
Corresponding author Z. J. Zhou: Department of Ophthalmology and Visual Science Yale University School of Medicine, 300 George Street, Rm 8100D, New Haven, CT, USA.  Email: jimmy.zhou{at}yale.edu

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				Z. J. Zhou and M. A. McCall Retinal ganglion cells in model organisms: development, function and disease J. Physiol., September 15, 2008; 586(18): 4343 - 4345. [Full Text] [PDF]