Retinal benzodiazepine receptors are destroyed by kainic acid lesions

[3H]Diazepam binds to preparations of membranes from chicken retina. Two binding sites were detected; a high affinity site (KD, 1.8 nM and Bmax, 0.17 pmol/mg retina protein) and a low affinity site (KD, 132 nM and Bmax, 1.46 pmol/mg retinal protein). GABA stimulated [3H]diazepam binding to these retinal membranes. One week after injection of kainic acid into the eye, which destroys the horizontal and amacrine cells of the retina, the low affinity site disappeared, while the level of the high affinity site was hardly affected. These results establish that chicken retina contains benzodiazepine receptors, which are closely associated with GABA receptors. The benzodiazepine receptors are probably associated with horizontal and/or amacrine cell synapses which use GABA as a transmitter.