Effect of diazepam on mouse whole brain and brain area acetylcholine and choline levels

A single i.v. dose of diazepam, 5 mg/kg, increased mouse whole brain acetylcholine levels. Choline levels, choline acetyltransferase and acetylcholinesterase activities were not affected, which is consistent with the hypothesis that diazepam blocks release of acetylcholine. Diazepam increased acetylcholine levels in the hemispheres and diencephalon but not in the cerebellum or mesencephalon. The effect lasted for 4 hr in the hemispheres and for 30 min in the diencephalon. This short-lastig biochemical action precludes a correlation with the long-lasting action of diazepam against pentylenetetrazole.