Lack of lateral inhibitory interactions in visual cortex of monocularly deprived cats

To gain new insight into the effects of monocular deprivation, we studied the visual cortex of adult cats deprived of vision in one eye. Local field potentials were recorded in response to contrast reversal of square-wave gratings modulated in time either by pseudorandom, m-sequences or periodically. We have found that: (1) stimulation of the retinotopic locus of the recording site elicits responses with abnormal waveforms and long latencies from the deprived eye; (2) stimulation of a remote, non-retinotopic locus elicits responses from the non-deprived eye but not from the deprived eye; (3) the monocularly deprived cortex lacks lateral inhibitory interactions which are characteristic of the normal cortex; and (4) steady-state responses showed little difference in spatial-frequency tuning and contrast sensitivity between the deprived and non-deprived eye, mostly conforming to earlier field-potential data in monocular deprivation. Functional lateral interactions appear to be greatly reduced in monocularly deprived cortex.