Prenatal morphine exposure alters estrogen regulation of kappa receptors in the cortex and POA of adult female rats but has no effects on these receptors in adult male rats.

The binding characteristics of kappa receptors were assessed in the frontal cortex (CX), striatum, hypothalamus, preoptic area (POA), cerebellum, and ventral tegmental area of adult male and female rats exposed prenatally to morphine or saline. Prenatal morphine exposure altered estrogen regulation of kappa receptors in the CX and POA of females, but had no effects on kappa receptors in any of the examined brain regions in male rats.