Frequency specific effects of stroboscopic rearing in the visual cortex of the rabbit.

Rearing animals in stroboscopic illumination deprives those animals of the experience of visual motion. In the rabbit, stroboscopic rearing produces a significant alteration in the response properties of cells in the visual cortex, demonstrating that the rabbit visual system is susceptible to environmental manipulation during early postnatal life. Response properties were determined for single units recorded in the primary visual cortex of 3 groups of rabbits. One group had been reared from birth to 2 months of age at a stroboscopic flash frequency of 8 Hz, a second group was raised at a flash frequency of 4 Hz and a third was reared normally. Compared to normal rabbits, rabbits reared at 8 Hz showed a reduction in the proportion of orientation selective cells which were also direction-selective, and there was an increase in the proportion of cells responsive to stroboscopic flashes. There was no reduction, however, in the overall proportion of orientation-selective cells. This contrasts with the finding for the rabbits raised at a flash frequency of 4 Hz. In addition, cortical cells in the rabbits raised at 8 Hz responded to frequencies of stroboscopic flashes which were significantly higher than the frequencies found for cells in the rabbits raised at 4 Hz. The effects of stroboscopic rearing on the rabbit visual cortex are dependent, therefore, on the flash frequency experienced by the rabbits during development.