title: An "antagonistic" surround facilitates central responses by retinal ganglion cells.
abstract: Ganglion cells in the turtle retina respond to increments of saturating illumination of the receptive field centre by progressively decreasing the number of spikes of the responses, perhaps as a result of membrane inactivation. Intracellular recording indicates that a simultaneous illumination of the receptive field surround greatly facilitates the "suprasaturated" central responses, while the expected centre-surround antagonism is still present between photoresponses below saturation. It is suggested that both pre- and post-synaptic mechanisms provide the ganglion cells with the unique possibility, among other retinal cells, to shift their full dynamic range across more than 3 log units of illumination intensity.
mesh_terms: D000200:Action Potentials; D000221:Adaptation, Ocular; D000818:Animals; D066298:In Vitro Techniques; D008564:Membrane Potentials; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D014426:Turtles