DRUG INDUCED REVERSAL OF BRAIN DAMAGE IN RAT

Lesions in the medial forebrain bundle of the rat produced both an increased sensitivity to electric-foot shock and a decrease in the telencephalic content of serotonin. Administration of dl-5-hydroxytryptophan reversed the effects of the lesion on shock sensitivity. Only l-5-hydroxytryptophan, the immediate precursor of serotonin in brain, was effective. Equimolar dosages of either d-5-hydroxytryptophan or l-dihydroxyphenylalanine had no effect. It was suggested that sensitivity to a painful stimulus is in part determined by the telencephalic content of serotonin. © 1969.