Spatial and temporal sensitivity of lateral geniculate cells in dark-reared cats.
Electrophysiological recordings were made from single-units in the dorsal lateral geniculate nucleus of normally-reared and dark-reared cats. In agreement with previous studies, significantly fewer Y-cells were encountered in dark-reared cats than in normally-reared cats. In addition, a large number of cells having abnormal receptive field and/or response properties were observed in the dark-reared animals. Included in this latter group were a number of cells that had short latencies to electrical stimulation of the optic chiasm, which is indicative of Y-cells, but did not display the nonlinear response component usually observed in Y-cells. Measures of contrast sensitivity across a wide range of spatial and temporal modulation frequencies were made with counterphased grating stimuli. No differences were observed for these measures between X-cells in normally-reared and dark-reared cats. In addition no differences were observed between Y-cells in normally-reared cats and the few Y-cells in dark-reared cats. While previously reported data from monocularly deprived cats indicate that geniculate X-cells can be affected by an abnormal visual environment created through lid-suture, the present data indicate that the X-system can develop normal electrophysiological properties in the absence of light. This observation suggests that the development of the X-system is not necessarily dependent on the influence of normal visual experience. In contrast, it appears that the cat must experience a normal visual environment in order for all of its Y-system to develop properly.
D000818:Animals; D002415:Cats; D003624:Darkness; D005829:Geniculate Bodies / Q000166:cytology / Q000502:physiology*; D012683:Sensory Deprivation; D014785:Vision, Ocular; D014796:Visual Perception