The Effect of Treatment with Tryptophan and/or Imipramine on the Serotonergic Immunoreactivity in Raphe Nucleus of Midbrain of the Rats / 대한해부학회지

ABSTRACT

These experiments were performed to investigate the effect of saline, tryptophan, tryptophan-imipramine and/or imipramine on serotonin immunoreactivity in raphe nucleus of midbrain of the rats (180~200 g, body weight). The animals were injected i.p. with tryptophan (15 mg/kg) and imipramine (15 mg/kg) for 20 days. The result by immunohistochemical methods were as follows; 1. Serotonin-immunoreactive neurons in the raphe of midbrain were significantly increased in tryptophan treated group compared to imipramine treated group. 2. Serotonin-immunoreactive neurons in the raphe of midbrain were decreased in imipramine treated group compared all the other group. 3. Serotonin-immunoreactive neurons in the raphe of midbrain were significantly decreased in tryptophanimipramine treated group compared to imipramine treated group. These experiments indicated that serotonin immunoreactive neurons in raphe of midbrain were increased due to the activation of tryptophan and decreased by suppresing activation of tryptophan through imipramine treatment.