AN ELECTROENCEPHALOGRAPHIC AND CHEMICAL RE-EVALUATION OF THE CENTRAL ACTION OF RESERPINE IN THE RABBIT

¹ Thudichum Psychiatric Research Laboratory, Galesburg State Research Hospital, Galesburg, Illinois

EEG recordings were made in three groups of animals—nonreserpinized control rabbits, rabbits injected with reserpine after preparatory surgical procedures for EEG recording, and rabbits injected with reserpine before surgical procedures prior to electrode placement. Normal resting rhythms were obtained from the unmedicated control animals for a period of 2 hours but by the third hour persistent EEG activation appeared. In both the pre- and postsurgical injected animals EEG activation appeared 30 to 60 minutes after reserpine injection. However, the postsurgically injected rabbits maintained EEG activation throughout the recording period. The presurgically injected animals, in contrast, displayed EEG rhythms characteristic of sedation at 5 hours when the EEG recordings were made. It was concluded that reserpine has a dual action on the EEG, a short initial arousal followed by an enhancement of resting rhythms. The initial arousal occurred at a time when the brain amines (norepinephrine and serotonin) were being depleted by reserpine and may be related to the transitory presence of free amine. The persistent arousal continuing for several hours in the postsurgically injected rabbits was viewed as an artifact inasmuch as it was also observed in unmedicated control animals. The different procedures employed did not impair the ability of reserpine to deplete either serotonin or norepinephrine from the brain.