Chronic benzodiazepine treatment increases [3H]muscimol binding in mouse brain.

High affinity [3H]muscimol receptors were analyzed in the forebrain and cerebellum of mice that had been treated on a chronic regimen with chlordiazepoxide and clonazepam. In the forebrain, only clonazepam induced an increase in the number of muscimol binding sites 2 hr after drug treatment. In the cerebellum, both the chlordiazepoxide and clonazepam-treated animals showed an increased number of muscimol binding sites 2 hr after drug treatment. At 26 hr after drug treatment, only the clonazepam-treated animals still revealed an increased number of cerebellar muscimol binding sites. Chronic benzodiazepine administration, therefore, induced an increase in the apparent number of high affinity muscimol binding sites in both the forebrain and cerebellum.