Relationship of brain dopamine to stress-induced changes in seizure succeptibility

Abstract

Mice stressed in a revolving drum exhibited a biphasic increase in the latency to tonic extension following maximal electroshock. The prolonged increase in seizure latency was paralleled by an increase in brain dopamine levels. These alterations were prevented in mice given a- ethyltyrosine prior to stress. No changes in the levels or turnover rates of brain norepinephrine and serotonin were obtained in stressed animals. When the tyrosine hydroxylase inhibitor, a- methyltyrosine , was given after stress and the rate of dopamine decline measureed, there was an apparent increase in the synthesis rate as reflected by an increase in dopamine levels due to stress. When a- methyltyrosine was given before stress, a decrease in turnover rate was observed. It is suggested that stress may possibly result in decreased utilization of dopamine in brain.