KAINIC-ACID INDUCED LESION OF RAT RETINA DIFFERENTIAL EFFECT ON CYCLIC GMP AND BENZODIAZEPINE AND GAMMA AMINO BUTYRIC-ACID RECEPTORS

Intraocular injection of kainic acid caused a marked decrease in GABA [.gamma.-aminobutyric acid] content in the rat retina and the almost complete loss of GAD [glutamate decarboxylase] activity in this tissue, within 3 days. Moreover, kainic acid produced a decrease of .apprx. 65% in the number of [3H]diazepam and [3H]GABA binding sites without changing the apparent Kd for their ligands. In contrast to that in brain areas, cGMP content in the retina is neither influenced by kainic acid nor by the systemic administration of diazepam and muscimol.