[Raphe nucleus and corticorophic activity in pigeons].

Multiple electrolytic lesions were placed in the raphe area of pigeons. Basal plasma corticosterone level (B) was found not to be altered. Stress-induced adrenocortical activation was markedly reduced in raphe lesioned pigeons as compared to controls. Electrical stimulation of the nucleus raphes in permanently implanted, unrestrained and unanesthetized birds induced a significant rise in B. However the magnitude of the response to raphe stimulating was lower (1/2 approximately) and especially later than after hypothalamic stimulation since it paralleled exactly the pattern of stress induced activation.