The role of the visual cortex in response properties of lateral geniculate cells in rats

Exp Brain Res. 1984;53(2):223-32. doi: 10.1007/BF00238152.

Abstract

Unitary discharges of the lateral geniculate nucleus (LGN) were analyzed in anesthetized and paralyzed rats after inactivation of visual cortical areas (VC) by cryoblockade or by depositing a cotton wick soaked in KCl (3 M). The receptive fields were mapped prior to and following the interruption of the cortico-geniculate feedback. The responsiveness of the VC was controlled by monitoring evoked potentials and the EEG. In most off-center and about half on-center cells the surround excitatory responses were markedly reduced and even totally abolished. In contrast, the center excitation remained unchanged or increased suggesting a parallel decline of the inhibitory surround. This differential influence of cortical blockade on on- or off-responses failed to appear in on-off cells whose receptive field was nonconcentrically organized. It is proposed that the VC exerts a complex influence upon geniculate physiology while the spatial center-surround relationships are under the control of the VC. The results of this investigation are comparable to those obtained in rabbits and cats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Cortical Spreading Depression / drug effects
  • Evoked Potentials / drug effects
  • Geniculate Bodies / physiology*
  • Optic Chiasm / physiology
  • Potassium Chloride / pharmacology
  • Rabbits
  • Rats
  • Species Specificity
  • Visual Cortex / physiology*
  • Visual Perception

Substances

  • Potassium Chloride