This study employed immunocytochemistry to visualize the neurotoxic effects of methylenedioxyamphetamine hydrochloride (MDA) on serotonergic projections to brainstem structures. Separate groups of animals were injected twice a day, for 4 consecutive days, with: saline; MDA (40 mg/kg/day); or fluoxetine hydrochloride (10 mg/kg) prior to each injection of MDA. In agreement with previous reports,...