1 Department of Biology, Karaj branch, Islamic Azad University, Karaj, Iran.
2 Department of Child and Adolescent Mental Health, University of Erlangen-Nuremberg.
Acta Neuropsychiatr. 2013 Aug;25(4):221-6. doi: 10.1111/acn.12016.
There has been increasing evidence that the γ-aminobutyric acid (GABA)ergic system is involved in the neurobiology of anxiety. The present study aimed to investigate the role of GABAergic systems in the modulation of anxiety in the medial prefrontal cortex (mPFC) of rats using the elevated plus maze test.
Rats were anaesthetised with a mixture of ketamine and xylazine, and then special cannulae were inserted stereotaxically into the mPFC. After 5-7 days of recovery, the effects of intra-mPFC administration of GABAergic agents were studied.
Bilateral injection of the GABAA receptor agonist muscimol (0.25, 0.5 and 1 μg/rat) produces an anxiolytic-like effect, shown by significant increases in the percentage of open-arm time (%OAT) and percentage of open-arm entries (%OAE). Intra-mPFC administration of the GABAA receptor antagonist bicuculline (0.25, 0.5 and 1 μg/rat) produces significant anxiogenic-like behaviour. However, intra-mPFC injection of the GABAB receptor agonist baclofen (0.05, 0.1 and 0.2 μg/rat) and the GABAB receptor antagonist CGP35348 (5, 10 and 15 μg/rat) did not alter %OAT and %OAE significantly.
The results of the present study demonstrate that the GABAergic system of the mPFC modulates anxiety-related behaviours of rats through GABAA receptors.
越来越多的证据表明γ-氨基丁酸（GABA）能系统参与了焦虑的神经生物学过程。本研究旨在通过高架十字迷宫实验，研究大鼠前额皮质（mPFC）中 GABA 能系统在调节焦虑中的作用。
用氯胺酮和甲苯噻嗪的混合物麻醉大鼠，然后立体定向插入 mPFC 的特殊套管。恢复 5-7 天后，研究了 mPFC 内给予 GABA 能药物的效果。
双侧注射 GABAA 受体激动剂 muscimol（0.25、0.5 和 1μg/只）产生类似抗焦虑的作用，表现为开放臂时间百分比（%OAT）和开放臂进入次数百分比（%OAE）显著增加。mPFC 内注射 GABAA 受体拮抗剂 bicuculline（0.25、0.5 和 1μg/只）产生明显的类焦虑样行为。然而，mPFC 内注射 GABAB 受体激动剂 baclofen（0.05、0.1 和 0.2μg/只）和 GABAB 受体拮抗剂 CGP35348（5、10 和 15μg/只）对%OAT 和%OAE 没有显著影响。
本研究结果表明，mPFC 的 GABA 能系统通过 GABAA 受体调节大鼠的焦虑相关行为。
