Reproductive experience alters prolactin receptor expression in mammary and hepatic tissues in female rats.

Recent studies have reported that reproductive experience in female rats alters prolactin (PRL) receptor gene expression in the brain as well as neural sensitivity to PRL. Given PRL's actions in nonneural tissues, that is, mammary tissue and liver, it was asked whether reproductive experience may also alter prolactin receptor (Prlr) gene expression in these tissues. Groups of age-matched female rats were generated with varying reproductive histories.

Adolescent opioid exposure in female rats: transgenerational effects on morphine analgesia and anxiety-like behavior in adult offspring.

The use of narcotics by adolescent females is a growing problem, yet very little is known about the long-term consequences for either the user or her future offspring. In the current study, we utilized an animal model to examine the transgenerational consequences of opiate exposure occurring during this sensitive period. Female rats were exposed to increasing doses of morphine or its saline vehicle twice daily during adolescent development (postnatal days 30-40), after which they remained drug free.

Sensorimotor gating and dopamine function in postpartum rats.

There is much speculation regarding the effects of estrogen withdrawal at the end of pregnancy on forebrain dopamine, however, few studies have directly examine changes in this system postpartum. The present work sought to determine what changes in forebrain dopamine function occur in the postpartum rat. Specifically, prepulse inhibition of the acoustic startle response (PPI) was measured in primiparous female rats on postpartum day 2 (PPD2) or 14 (PPD14) following treatment with saline or the dopamine D2 agonist, quinpirole.

Reproductive experience and activation of maternal memory.

The maternal and neurobiological responses of biological mothers and pup-induced maternal virgin rats were compared 55 and 80 days after an initial 2-day maternal experience. When tested for home cage responsiveness after prolonged isolation from young, the biological, primiparous rats displayed shorter maternal latencies. Primiparous females tested in the presence of pups on the elevated plus-maze displayed increased exploration of the open arms and increased c-Fos expression in the cortical nucleus of the amygdala.

Maternal memory in adult, nulliparous rats: effects of testing interval on the retention of maternal behavior.

The retention of maternal behavior (i.e., maternal memory) was measured in adult, nulliparous rats induced to respond maternally by continuous exposure to foster pups.