Immunohistochemical investigations of the influence of reserpine on the serotonin neuron system in the rat brain.

A peroxidase-antiperoxidase immunohistochemical method with serotonin antiserum was employed to investigate the influence of reserpine on serotonin neurons of rats which were sacrificed at various times after injection (10 mg/kg i.p.). The disappearance of serotonin immunoreactivity induced by reserpine was detected only in the perikarya after 15 min, and then rapidly proceeded to the terminals. Between 2 and 4 h, immunoreactivity completely disappeared throughout the brain. The immunoreactivity reappeared in the perikarya after 6 h, and progressed toward the terminals gradually. However, there was an obvious difference in the rate of recovery of immunoreactivity between areas. After 7 days, the immunoreactivity returned to control levels.