Martin D L, Barke K E
Wadsworth Center, New York State Department of Health, Albany 12201-0509, USA.
Perspect Dev Neurobiol. 1998;5(2-3):119-29.
Brain contains at least two pools of gamma-aminobutyric acid (GABA), the transmitter pool and the so-called metabolic pool. To a large extent these pools may reflect the presence of GABA in different intracellular compartments, as immunocytochemical studies show that GABA is not localized mainly in terminals but is distributed throughout neurons. An interesting issue is the extent to which the two major forms of glutamate decarboxylase (GAD65 and GAD67) are specialized to synthesize GABA for these pools. Although GAD65 and GAD67 differ significantly in several characteristics, they also have substantial similarities and interactions, and the presence of individual forms of GAD in certain cell types is consistent with the idea that GAD65 and GAD67 can each synthesize GABA for both pools. Substantial progress has been made in understanding the regulatory properties of GAD, but the available data provide little indication of how differences between the forms might enable each to serve the demands for GABA synthesis in a specific pool.
大脑中至少存在两种γ-氨基丁酸（GABA）池，即递质池和所谓的代谢池。免疫细胞化学研究表明，GABA并非主要定位于终末，而是分布于整个神经元，在很大程度上，这些池可能反映了GABA在不同细胞内区室中的存在。一个有趣的问题是，两种主要形式的谷氨酸脱羧酶（GAD65和GAD67）在何种程度上专门为这些池合成GABA。尽管GAD65和GAD67在几个特征上有显著差异，但它们也有大量的相似性和相互作用，并且某些细胞类型中个别形式的GAD的存在与GAD65和GAD67均可为两个池合成GABA的观点一致。在理解GAD的调节特性方面已经取得了实质性进展，但现有数据几乎没有表明这些形式之间的差异如何使每种形式能够满足特定池中GABA合成的需求。
