Effects of Mixed Gamma-Neutron Radiation on the Activity of Brain Enzymes involved in Neurotransmitter Metabolism

Sprague-Dawley adult male rats were exposed to incapacitating doses (20,000 rads) of mixed gamma-neutron radiation in a single pulse from the AFRRI- TRIGA reactor. The activities of the enzymes choline acetyl transferase, acetylcholinesterase, monoamine oxidase and RNA polymerase were determined in the cerebral cortex, cerebellum and hippocampus. It was found that as early as four minutes after irradiation of the animal the activity of monoamine oxidase was markedly decreased in all three brain areas investigated. Choline acetyl transferase and RNA polymerase activities were also decreased but to a lesser extent. No appreciable changes in the activity of acetylcholinesterase were observed.