Effect of ethanol administration and withdrawal on benzodiazepine receptor binding in the rat brain

Administration of single doses of ethanol or presence of ethanol in the incubation medium does not change 3H-flunitrazepam binding in rat cerebral cortex, hippocampus and cerebellum. In rats made dependent on ethanol by three daily ethanol administrations for six days and sacrifices 1 hr after the last ethanol dose 3H-flunitrazepam binding is decreased in the cerebral cortex and cerebellum. This decrease is present only in membranes preincubated with Triton X-100 and is due to decreased number of binding sites. In rats sacrificed 16 hours after the last chronic ethanol dose the 3H-flunitrazepam binding returns to control levels.