Laboratório de Psicobiologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
J Psychopharmacol. 2012 Apr;26(4):543-54. doi: 10.1177/0269881110389209. Epub 2010 Dec 8.
The role of the amygdala in the mediation of fear and anxiety has been extensively investigated. However, how the amygdala functions during the organization of the anxiety-like behaviors generated in the elevated plus maze (EPM) is still under investigation. The basolateral (BLA) and the central (CeA) nuclei are the main input and output stations of the amygdala. In the present study, we ethopharmacologically analyzed the behavior of rats subjected to the EPM and the tissue content of the monoamines dopamine (DA) and serotonin (5-HT) and their metabolites in the nucleus accumbens (NAc), dorsal hippocampus (DH), and dorsal striatum (DS) of animals injected with saline or midazolam (20 and 30 nmol/0.2 µL) into the BLA or CeA. Injections of midazolam into the CeA, but not BLA, caused clear anxiolytic-like effects in the EPM. These treatments did not cause significant changes in 5-HT or DA contents in the NAc, DH, or DS of animals tested in the EPM. The data suggest that the anxiolytic-like effects of midazolam in the EPM also appear to rely on GABA-benzodiazepine mechanisms in the CeA, but not BLA, and do not appear to depend on 5-HT and DA mechanisms prevalent in limbic structures.
杏仁核在恐惧和焦虑的调节中起着重要作用，这已经得到了广泛的研究。然而，杏仁核在高架十字迷宫（EPM）中产生的焦虑样行为的组织过程中是如何发挥作用的，仍在研究之中。杏仁核的基底外侧核（BLA）和中央核（CeA）是其主要的输入和输出站。在本研究中，我们通过行为学方法分析了在 EPM 中注射生理盐水或咪达唑仑（BLA 或 CeA 中的 20 和 30 nmol/0.2 µL）的大鼠的行为，以及这些动物在伏隔核（NAc）、背海马（DH）和背纹状体（DS）中的单胺递质多巴胺（DA）和 5-羟色胺（5-HT）及其代谢产物的含量。咪达唑仑注射到 CeA 而非 BLA 会导致 EPM 中的明显抗焦虑样作用。这些处理方法在 EPM 中测试的动物的 NAc、DH 或 DS 中并未引起 5-HT 或 DA 含量的显著变化。数据表明，咪达唑仑在 EPM 中的抗焦虑样作用似乎也依赖于 CeA 中的 GABA-苯二氮䓬机制，而不是 BLA，并且似乎不依赖于在边缘结构中占主导地位的 5-HT 和 DA 机制。
