The current proposal is designed to investigate the possibility of an altered response of brain catecholamine (CA) neurons to the psychoactive compound d-amphetamine in rats with experimental diabetes mellitus induced by alloxan administration. Prior behavioral research in the investigator's laboratory has indicated that diabetic animals are resistant to the anorexic, stimulatant and stereotype-inducing effects of d-amphetamine. Many lines of evidence now indicate that activity within brain catecholamine-containing neurons is responsible for these behavioral effects of amphetamine. Therefore, I propose to investigate the possibility that the brain CA neurons of diabetic animals do not react to d-amphetamine in a normal manner. Two lines of investigation are proposed: (1) that brain CA cells degenerate during alloxan diabetes; and (2) that elevated synthesis of brain 3H-dopamine and 3H-norepinephrine from 3H-tyrosine normally seem in amphetamine-treated is attenuated in alloxan diabetes.