Effects of prenatal cocaine on behavioral adaptation to chronic stress in adult rats.

Prenatal exposure to cocaine in rats has previously been shown to alter the behavioral and hormonal responses to acute stressors, although no work has yet examined stress adaptation in these animals in adulthood, a possibility examined in this experiment. Male and female offspring of Sprague-Dawley rat dams given 40 mg/kg/3 ml subcutaneously daily from gestational days 8-20 (C40), saline injected and pair-fed dams (PF), and non-treated dams (NT) were tested in adulthood (90-120 days). Offspring were given a 5-min open field test 24 h following the last of 1 (Acute), 9 (Chronic) or 0 (control) daily 15-min intermittent footshock sessions. Substantially more behavioral adaptation was evident in NT offspring than in C40 and PF animals. The attenuated stress adaptation seen in C40 offspring extends prior work showing altered stress responsiveness in these animals, although the PF data caution against the conclusion that this lack of stress adaptation necessarily reflects gestational exposure to cocaine per se.