Age-Related Peculiarities in Steroid Hormone Secretion and Behavior in Prenatally Stressed Female Rats in Novel Environment

Abstract

We studied the effects of immobilization of female rat during days 15-18 of pregnancy on the behavior in novel environment (open field test) and blood level of steroid hormones in their female offspring depending on the cycle phase and age. The rats were tested at the age of 3, 12, and 24 months. Locomotor and exploratory activity and anxiety of control rats depended on the phase of estrous cycle. Age-related changes in the studied parameters were noted: locomotor and exploratory activity decreased and anxiety increased against the background of reduced secretion of the main ovarian hormones with age. In addition, blood estradiol level and behavior in novel environment virtually did not depend on age and estrous cycle phase in prenatally stressed females. Our findings suggest that maternal stress has a modulatory effect on relationship between behavioral type and estrous cycle stage, as well as on age-related pattern of behavioral reactions.