Serotonin Projections, the Dorsal and Median Raphe Nuclei, and Phencyclidine (Also Called Angel Dust or PCP)

Abstract

Phencyclidine (also known as PCP or "angel dust") is a hallucinogen that causes not only euphoria, excitation, and disordered thinking, but also psychotic episodes and violent behavior. Phencyclidine is a noncompetitive antagonist at N-methyl-. d-aspartate (NMDA) receptors, and its effects in animals have been used as a model of the psychotic aspects of schizophrenia. The forebrain serotonin system originates in the raphe nuclei in the midbrain, including the dorsal raphe nucleus (DRN) and median raphe nucleus (MRN). Neurotoxin lesions of the MRN, but not DRN, markedly enhanced the effects of phencyclidine in rats. This enhancement was also observed after serotonin depletion in the dorsal hi..