Geniculate Neural Plasticity in Kittens after Exposure to Periodic Gratings

Abstract

Kittens were exposed for 2 hours a day to a periodic vertical grating during the first 10 weeks after birth, and otherwise kept in darkness. The spatial frequency of the grating fell in the range of highest contrast sensitivity of normal cats. After the 10-week exposure period, cortical evoked potentials and lateral geniculate mass responses to alternating gratings showed a reduced amplitude for the spatial frequency of exposure. This reduction was independent of grating orientation. An analysis of orientational sensitivity of cortical units did not show any bias in favor of the vertical orientation.