Benzodiazepines prevent kainate-induced loss of GABAergic and cholinergic neurons in the chick retina.

Kainic acid (50 nmol), applied intravitreally to the eyes of chicks, produces within 6 h a loss of more than 50% of biochemical markers for cholinergic and GABAergic neurons in the retina. Repeated peripheral administration of benzodiazepines, such as diazepam and clonazepam, protects from the kainate-induced loss of cholinergic and GABAergic markers in the retina. Histologically diazepam reduces the nuclear pyknosis induced by kainate particularly at the level of the amacrine cell-layer.