title: Macaque ganglion cells, light adaptation, and the Westheimer paradigm.
abstract: Retinal adaptation mechanisms are considered relative to the Westheimer paradigm. Responses to a probe presented upon pedestals were obtained from macaque ganglion cells. On-center magnocellular (MC) cell responses decreased to a plateau as pedestal diameter increased, consistent with operation of a local adaptation pool. Off-center cells also demonstrated a vigorous response with small pedestals, but as pedestal size increased, responsivity decreased and then partially recovered as pedestals encroached upon the surround. The response trough was due to a profound suppression of maintained activity. Comparison with psychophysical data suggests a multiple physiological substrate for the Westheimer paradigm, involving an interaction between adaptation pools, changes in maintained firing due to center-surround mechanisms and a cortical component.
authors.affiliation: Department of Vision Sciences, SUNY State College of Optometry, 33 West 42nd Street, NY 10036, USA. jkunken@sunyopt.edu
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Kunken
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Barry B
authors.initials: BB
authors.lastname: Lee
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology*; D000328:Adult; D000818:Animals; D004594:Electrophysiology; D006801:Humans; D008252:Macaca fascicularis / Q000502:physiology; D008255:Macaca radiata / Q000502:physiology; D008839:Microelectrodes; D010775:Photic Stimulation; D011323:Primates / Q000502:physiology*; D011601:Psychophysics; D012165:Retinal Ganglion Cells / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*