Byrnes Elizabeth M, Lee Jong O, Bridges Robert S
Department of Biomedical Sciences, Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA.
Neuroendocrinology. 2007;85(3):148-56. doi: 10.1159/000102535. Epub 2007 May 7.
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.
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.
Increased alpha1 mRNA expression was found in proestrus within both medial preoptic area (MPOA) and medial amygdala (MeA) in nulliparous and primiparous females. The expression of alpha2 mRNA was also increased within the MPOA in proestrus in both nulliparous and primiparous females; however, within the MeA, an increased alpha2 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 alpha2 mRNA expression was observed within the periaqueductal gray of reproductively experienced female rats.
These results indicate that reproductive experience results in significant shifts in the expression of GABA(A) alpha2 mRNA expression in the MeA.
背景/目的：生殖经历（即怀孕和哺乳）会改变焦虑样行为。γ-氨基丁酸（GABA）可能是介导生殖经历对焦虑样行为影响的一种神经递质系统。本研究的目的是确定生殖经历是否会改变与焦虑样行为相关脑区中选择性GABA(A)受体亚基的mRNA表达。
收集处于动情间期或动情前期、年龄匹配的未生育和经产雌性大鼠的大脑，使用Taqman实时逆转录-聚合酶链反应测定亚基mRNA表达。
在未生育和经产雌性大鼠的内侧视前区（MPOA）和杏仁核内侧（MeA）中，动情前期的α1 mRNA表达均增加。未生育和经产雌性大鼠在动情前期MPOA内的α2 mRNA表达也增加；然而，在MeA内，仅在未生育雌性大鼠中观察到动情前期α2 mRNA表达增加，与未生育对照组相比，经产雌性大鼠的表达显著降低。此外，在有生殖经历的雌性大鼠的导水管周围灰质中观察到α2 mRNA表达显著增加。
这些结果表明，生殖经历会导致MeA中GABA(A)α2 mRNA表达发生显著变化。
