Chronic bifemelane hydrochloride administration enhances muscarinic cholinergic receptor binding in the senescent rat brain.

In senescent rats, the binding ability of muscarinic cholinergic receptors (MCR) was markedly decreased in the cerebral cortex, hippocampus, thalamus, and the striatum compared with young adult rats. This decrease was markedly improved by chronic administration of bifemelane hydrochloride (bifemelane). In view of the findings that bifemelane markedly inhibits the decrease in acetylcholine (ACh) associated with cerebral ischemia, and that it improves amnesia induced by scopalamine, it may be inferred that bifemelane acts on the pre- and post-synaptic ACh neuronal systems. It may improve memory disturbance due to aging or cerebral ischemia, decreased conscious level, and decreased motor function.