Alterations in GABAA receptor α2 subunit mRNA expression following reproductive experience in rats

Background/Aim: Reproductive experience (i.e., pregnancy and lactation) alters anxiety-like behavior. One neurotransmitter system that may mediate the effects of reproductive experience on anxiety-like behavior is gamma-aminobutyric acid (GABA). The purpose of the current study was to determine whether reproductive experience alters the mRNA expression of selective GABA A receptor subunits in brain regions associated with anxiety-like behaviors. Methods: Brains were collected from age-matched nulliparous and primiparous female rats in either diestrus or proestrus, and the subunit mRNA expression was determined using real-time reverse transcription-polymerase chain reaction with Taqman ((R)). Results: Increased alpha 1 mRNA expression was found in proestrus within both medial preoptic area (MPOA) and medial amygdala (MeA) in nulliparous and primiparous females. The expression of alpha 2 mRNA was also increased within the MPOA in proestrus in both nulliparous and primiparous females; however, within the MeA, an increased alpha 2 mRNA expression in proestrus was only observed in nulliparous females, with primiparous females having a significantly reduced expression when compared to nulliparous controls. In addition, a significant increase in the expression of alpha 2 mRNA expression was observed within the periaqueductal gray of reproductively experienced female rats. Conclusion: These results indicate that reproductive experience results in significant shifts in the expression of GABA A alpha 2 mRNA expression in the MeA. Copyright (c) 2007 S. Karger AG, Basel