Effects of binocular form deprivation on the properties of gamma-aminobutyric acid currents of rat visual cortical neurons

Abstract

To investigate the effects of binocular form deprivation on the properties of inhibitory synaptic transmission of rat visual cortical neurons during the critical period of visual development. We recorded the postsynaptic currents in visual cortex slices of normal, binocular form deprived and deprivation-removed rats at postnatal days 14, 21 and 28 with the use of whole-cell patch recording, and recorded gamma-aminobutyric acid currents by adding D, L-2-amino-5-phosphonovalerate (50 micromol/L) and 6-cyano-7-nitroquinoxaline-2,3-dione (20 micromol/L) to artificial cerebrospinal fluid. The electrophysiological properties were also analysed. The decay time and peak value of inhibitory postsynaptic currents of normal rat visual cortical neurons became larger with age (P < 0.05), but not in binocular form deprived group (P > 0.05). The decay time and peak value of inhibitory postsynaptic currents became large in deprivation-removed rats at postnatal days 28 (P < 0.05). The rise time did not change markedly in all groups. With visual development, the synaptic transmission of visual cortical neurons in normal rats is strengthened, but it can be inhibited by binocular form deprivation and recovered by visual input.