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Curr Opin Neurobiol. 1992 Aug;2(4):462-8.

Feedback connections and operation of the outer plexiform layer of the retina.

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Baylor College of Medicine, Houston, Texas.


The primary feedback control apparatus in the outer retina is the sign-inverting feedback synapse between horizontal cells and cones. In many lower vertebrates horizontal cells release GABA in darkness, which opens Cl- channels in cones. Input-output relations of the feedback synapse reveal that the synaptic gain is light-dependent with the highest negative gain near the dark horizontal cell potential. The horizontal cell-cone feedback synapse improves the reliability of the photoreceptor output synapses. It also modulates the dynamic range and mediates color opponency and surround responses in second-order retinal neurons.

[Indexed for MEDLINE]

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