Differential expression of gamma-aminobutyric acid type B receptor-1a and -1b mRNA variants in GABA and non-GABAergic neurons of the rat brain.
Differential expression of gamma-aminobutyric acid type B receptor-1a and -1b mRNA variants in GABA and non-GABAergic neurons of the rat brain.
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大鼠脑 GABA 和非 GABA 能神经元中 γ-氨基丁酸 B 型受体-1a 和 -1b mRNA 变体的差异表达。
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
T. Hashikawa
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作者：
F. Liang;Y. Hatanaka;H. Saito;T. Yamamori;T. Hashikawa
为了了解γ-氨基丁酸B型受体（GABABR）介导的事件的异质性，我们采用非放射性原位杂交组织化学和结合GABA免疫细胞化学的双标记方法，研究了大鼠中枢神经系统（CNS）GABA和非GABA能神经元中GABABR 1 a和1 B mRNA变体的表达。原位杂交与泛探针，它可以识别一个共同的序列GABABR 1a和GABABR 1b mRNA的变体，证明了广泛的表达GABABR 1 mRNA在中枢神经系统中的各种水平。GABABR 1a和GABABR 1b都在新皮质、海马、背侧丘脑、缰核和隔中表达，但在小脑颗粒细胞、尾壳核和大多数后脑结构中仅检测到GABABR 1a。大脑皮层中的大多数GABA神经元显示出GABABR 1a和GABABR 1b的杂交信号，而大多数皮层下结构中的GABA神经元表达这两种信号中的一种或两种都不表达。丘脑网状核和尾壳核的GABA神经元主要与GABABR 1a杂交。小脑皮质的浦肯野细胞主要表达GABABR 1b。外侧膝状体背侧核GABA神经元中GABABR 1a和GABABR 1b mRNA水平均不显著。这些数据表明GABABR介导的抑制作用在CNS中广泛存在。GABABR 1 mRNA变体在不同神经元和脑结构中的差异但重叠的表达可能有助于GABABR介导的抑制的异质性。一些GABA神经元拥有，但其他人可能缺乏GABABR介导的去抑制，自抑制，或两者兼而有之的分子机制。
To understand the heterogeneity of gamma-aminobutyric acid type B receptor (GABABR)-mediated events, we investigated expression of GABABR1a and 1b mRNA variants in GABA and non-GABAergic neurons of the rat central nervous system (CNS), by using nonradioactive in situ hybridization histochemistry and, in combination with GABA immunocytochemistry, double labeling. In situ hybridization with a pan probe, which recognizes a common sequence of both GABABR1a and GABABR1b mRNA variants, demonstrated widespread expression of GABABR1 mRNA at various levels in the CNS. Both GABABR1a and GABABR1b were expressed in the neocortex, hippocampus, dorsal thalamus, habenula, and septum, but only GABABR1a was detected in cerebellar granule cells, in caudate putamen, and most hindbrain structures. A majority of GABA neurons in cerebral cortex showed hybridization signals for both GABABR1a and GABABR1b, whereas those in most subcortical structures expressed either or neither of the two. GABA neurons in thalamic reticular nucleus and caudate putamen hybridized primarily for GABABR1a. Purkinje cells in the cerebellar cortex expressed predominantly GABABR1b. GABA neurons in dorsal lateral geniculate nucleus did not display significant levels of either GABABR1a or GABABR1b mRNAs. These data suggested widespread availability of GABABR-mediated inhibition in the CNS. The differential but overlapping expression of GABABR1 mRNA variants in different neurons and brain structures may contribute to the heterogeneity of GABABR-mediated inhibition. Some GABA neurons possessed, but others might lack the molecular machinery for GABABR-mediated disinhibition, autoinhibition, or both.