Prenatal stress and emotional response of adult offspring.

Pregnant dams were subjected to REM sleep deprivation during different stages of pregnancy. Pups were reared by their biological mothers and tested as adults for susceptibility to PTZ-induced convulsions, and ambulation and defecation in an open-field arena. Adrenal weights were taken at this time. Those animals whose mothers had been stressed during the first trimester showed a reduction in ambulatory behavior measured in the open field, and a reduction in adrenal weight after open-field exposure. Subjects exposed to prenatal stress (PNS) during the 2nd trimester showed an increased susceptibility to PTZ-induced clonic convulsions, and a reduction in adrenal weight after PTZ administration and open-field exposure. Finally, subjects exposed to PNS during the third trimester showed a reduction in susceptibility to PTZ compared with 2nd week PNS pups. The results showed different patterns of prenatal stress-induced behavioral and physiological changes, depending on the developmental stage in which the stress was applied.