Spatial and temporal properties of X and Y cells in the cat lateral geniculate nucleus

J Physiol. 1979 Aug;293:347-64. doi: 10.1113/jphysiol.1979.sp012893.

Abstract

1. Extracellular recordings were obtained from units in the dorsal lateral geniculate nucleus of anaesthetized cats. 2. Of sixty-nine units, sixty-three could be unambiguously identified as either X (n = 33) or Y (n = 30) by testing the presence of a null response to stationary sine wave gratings presented in different spatial phases. 3. In response to stationary gratings flashed on and off, Y cells exhibited bigger, more transient responses than X cells. 4. All Y cells but few X cells exhibited a shift effect (modulated periphery effect). 5. In response to drifting sine wave gratings of different spatial frequencies, X cells preferred higher spatial frequencies and showed smaller peak contrast sensitivities and somewhat narrower tuning curves than Y cells. 6. In response to a sine wave grafting of optimal spatial frequency drifting at different velocities, X and Y cells had similar temporal tuning curves. However, Y cells, largely because they preferred lower spatial frequencies, preferred higher drift velocities than X cells. 7. Our data suggest that X and Y cells can be differentiated objectively on the basis of a number of discharge parameters. These parameters are compared with similar data collected by others from neurones in the visual cortex.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials
  • Animals
  • Cats
  • Geniculate Bodies / cytology
  • Geniculate Bodies / physiology*
  • Motion Perception / physiology
  • Neural Conduction
  • Neurons / classification
  • Neurons / physiology*
  • Space Perception / physiology*