Relationships between the epiphysis and hippocampus during formation of a stress response.

Lesions to the dorsal hippocampus and removal of the epiphysis had differently-directed effects on behavior in rats in conditions of a conflict situation and on the temporal dynamics of forced swimming. The combination of both operative procedures resulted in weakening of the behavioral changes typical of hippocampus deficiency. It is suggested that the anti-stress properties of epiphyseal factors may be mediated by changes in the functional state of the hippocampus.