Effect of enriched environment on the volume of the adrenal gland in prenatally stressed rat

Studies show that prenatal stress causes an increase in the volumes of the adrenal gland in young prenatally stressed rats. The purpose of this study was to investigate the effects of environmental condition during adolescence on reversibility of prenatal stress-induced alterations at adrenal function and structure. 2-month-old Wistar male prenatally restraint stressed rats were maintained in either an enriched-environment or standard living cages throughout the third month of life. At the end of housing period, blood corticosterone levels were measured before, after the acute stress. Also, the volume of adrenal gland was estimated using sterological techniques. Statistical analysis of data showed that corticosterone levels after the acute stress were not significantly different among control and prenatally stressed rats exposed to enrichment environment. However, these levels were significantly higher in prenatally stressed rats exposed to standard environment in comparison to other groups. The total volume and the volume of zona fasciculate of the adrenal cortex in prenatally stressed adult rats significantly decreased following enrichment of environment while it had no effect on these parameters among other animal groups. Discussion & This experimental study showed that the enrichment of living environment could normalize the response of Hypothalamic-Pituitary-Adrenal axis to acute stress together with decreasing the volume of cortex of adrenal gland in adult male rats whose mothers exposed to restraint stress during the last week of gestation.