LONG-TERM EFFECTS OF PRENATAL STRESS ON HPA AXIS ACTIVITY IN JUVENILERHESUS-MONKEYS

The effect of stress to the pregnant mother on hormonal responses of t he offspring to stressful events was investigated in juvenile rhesus m onkeys. Six pregnant monkeys were repeatedly removed from their home c ages and exposed to unpredictable noise during mid- to late gestation (Days 90-145 postconception), while six undisturbed pregnant mothers s erved as controls. Blood samples were collected from the juvenile offs pring under anesthesia on four occasions and assayed for ACTH and cort isol. In a second experiment, blood samples were collected from the aw ake offspring under a baseline and four progressively stressful condit ions. Offspring of stressed mothers showed higher ACTH and cortisol le vels than control offspring at all four anesthesia samples and at a no nanesthesized home cage baseline. Prenatally stressed offspring also s howed higher ACTH values in all four stress conditions. Cortisol value s were similar for the two groups under the stress conditions. The dis parity between the two groups in the relationship between ACTH and cor tisol was greatest in the most stressful condition, suggesting regulat ory differences between the two groups. These results indicate that of fspring of primate mothers stressed during pregnancy show enhanced HPA axis responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on HPA axis regulation. (C) 1994 John Wiley and Sons, Inc.