Effect on neuronal and non-neuronal benzodiazepine binding sites.

The frontal cortex, hippocampus, and cerebellum of the Fischer 344 rat were examined for an age-dependent change in neuronal and non-neuronal binding. Clonazepam and Ro5-6669 displaceable [3H]diazepam binding were used as indicators of [3H]diazepam binding on neuronal and non-neuronal membranes, respectively. In both the frontal cortex and the hippocampus, clonazepam displaceable [3H]diazepam binding in the senescent rat was significantly less than the young and mature rat. In the frontal cortex, Ro5-6669 did not significantly displace [3H]diazepam binding in any age group. The Ro5-6669 displaceable [3H]diazepam binding in the hippocampus was not altered with age. In the cerebellum clonazepam and Ro5-6669 displaceable binding in the old rat was significantly less and more, respectively, compared to the young rat.