Khoshdel-Sarkarizi Hoda, Hami Javad, Mohammadipour Abbas, Sadr-Nabavi Ariane, Mahmoudi Mahmoud, Kheradmand Hamed, Peyvandi Mostafa, Nourmohammadi Esmail, Haghir Hossein
Department of Anatomy and cell Biology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Department of Anatomical Sciences, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran.
Int J Dev Neurosci. 2019 Aug;76:86-94. doi: 10.1016/j.ijdevneu.2019.07.006. Epub 2019 Jul 17.
GABA is the chief inhibitory neurotransmitter in the adult brain. However, in the developing brain it acts as an excitatory transmitter causing depolarization. Thereby, activates calcium-dependent processes that are crucial for brain development. Accordingly, GABA receptors have the great role in the brain development, especially in the area with persisting neurogenesis such as hippocampus. The present study investigated the development and lateralization of two important subunits of GABA receptors, GABA and GABA, in the developing rat hippocampus during the neurogenesis-active period, at the first two postnatal weeks. Real-time PCR, western blot and immunohistochemistry were used. We found that the mRNA and protein of these GABA receptor subunits have already been expressed at birth and significantly increased at postnatal day (P) 7, and also at P14. Also, regarding the optical densities of GABA and GABA expressing hippocampal cells, we found a significant increase in the distribution pattern of these subunits in the all hippocampal subregions on day 14 after birth. The highest optical density of GABA was observed in the CA3, and GABA in the CA2. Nevertheless, our results did not show a significant laterality differences in the expression of these subunits. Regarding the crucial role of GABA receptors in the hippocampus development; they probably have the same effects on development of the rat hippocampus on both sides.
γ-氨基丁酸（GABA）是成人大脑中主要的抑制性神经递质。然而，在发育中的大脑中，它作为一种兴奋性递质引起去极化。从而激活对大脑发育至关重要的钙依赖过程。因此，GABA受体在大脑发育中起着重要作用，尤其是在海马体等持续存在神经发生的区域。本研究调查了在出生后前两周神经发生活跃期发育中的大鼠海马体中GABA受体的两个重要亚基GABA和GABA的发育及侧化情况。采用了实时定量聚合酶链反应（Real-time PCR）、蛋白质免疫印迹法（western blot）和免疫组织化学方法。我们发现这些GABA受体亚基的信使核糖核酸（mRNA）和蛋白质在出生时就已表达，并在出生后第7天以及第14天显著增加。此外，关于表达GABA和GABA的海马体细胞的光密度，我们发现在出生后第14天这些亚基在所有海马亚区的分布模式有显著增加。在CA3区观察到GABA的光密度最高，在CA2区GABA的光密度最高。然而，我们的结果并未显示这些亚基表达存在显著的侧化差异。鉴于GABA受体在海马体发育中的关键作用，它们可能对大鼠两侧海马体的发育具有相同的影响。
