Neurologically active peptides.

This paper reviews recent evidence that a number of small peptides found in the brain are active in the central nervous system and behaviorally. Attention is focused on MSH/ACTH 4-10, alpha- and beta-MSH, and the prohormone beta-LPH, as they produce a syndrome of yawning and stretching. Studies with substance P and mainly with MIF-I are also reviewed. It is shown that substance P is an excitatory transmitter or modulator in the dorsal spinal cord with that MIF-I has antiparkinson properties. It is concluded that many polypeptides have direct actions on the central nervous system independent of their neuroendocrine properties.