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 γ-aminobutyric acid (GABA). The purpose of the current study was to determine whether reproductive experience alters the mRNA expression of selective GABAA 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®. Results: Increased α1 mRNA expression was found in proestrus within both medial preoptic area (MPOA) and medial amygdala (MeA) in nulliparous and primiparous females. The expression of α2 mRNA was also increased within the MPOA in proestrus in both nulliparous and primiparous females; however, within the MeA, an increased α2 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 α2 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 GABAA α2 mRNA expression in the MeA.

Keywords:
Primiparous rats, Proestrus, Medial amygdala, Periaqueductal gray, Medial preoptic area, Anxiety
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2007
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