COMPARATIVE LOCALIZATION OF MESSENGER-RNAS ENCODING 2 FORMS OF GLUTAMIC-ACID DECARBOXYLASE WITH NONRADIOACTIVE INSITU HYBRIDIZATION METHODS
COMPARATIVE LOCALIZATION OF MESSENGER-RNAS ENCODING 2 FORMS OF GLUTAMIC-ACID DECARBOXYLASE WITH NONRADIOACTIVE INSITU HYBRIDIZATION METHODS
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DOI：
10.1002/cne.903310305
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发表时间：
1993-05-15
影响因子：
2.5
通讯作者：
HOUSER, CR
中科院分区：
文献类型：
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作者：
ESCLAPEZ, M;TILLAKARATNE, NJK;HOUSER, CR
用地高辛标记的cRNA探针进行非放射性原位杂交，对大鼠脑内两种谷氨酸脱羧酶（GAD）mRNA进行定位。这些mRNA编码两种形式的GAD，它们都合成GABA，但在许多特征上不同，包括它们的分子大小（65和67 kDa）。对于每个GAD mRNA，离散的神经元标记与高细胞分辨率和低背景染色，在大多数已知的GABA神经元群体。此外，目前的方法揭示了神经元之间对每种GAD mRNA的标记强度存在差异，这表明某些GABA神经元组中每种GAD mRNA的相对浓度可能高于其他神经元组。大多数主要类别的GABA神经元都被标记为每种GAD mRNA。在某些GABA神经元组中，这两种mRNA的标记几乎是相同的，就像在丘脑网状核中一样。在其他组的神经元中，虽然每个GAD mRNA都有大量的标记，但其中一种mRNA的标记明显强于另一种。在大多数脑区，如小脑皮质，GAD 67 mRNA的标记强于GAD 65 mRNA，但也有一些脑区，其中GAD 65 mRNA的标记更明显，这些包括下丘脑的一些区域。最后，一些GABA神经元组主要标记的GAD mRNA之一，并表现出很少或没有检测到的标记的其他GAD mRNA，例如，在下丘脑的结节乳头核的神经元中，GAD 67 mRNA的标记非常强，但没有标记的GAD 65 mRNA是明显的。这些发现表明，中枢神经系统（CNS）中的大多数GABA神经元含有至少两种形式的GAD的mRNA，因此具有合成GABA的双酶系统。在某些GABA神经元组中，一种或另一种GAD mRNA的较高水平可能与这些神经元的功能特性及其调节GABA合成的手段的差异有关。
Nonradioactive in situ hybridization methods with digoxigenin-labeled cRNA probes were used to localize two glutamic acid decarboxylase (GAD) mRNAs in rat brain. These mRNAs encode two forms of GAD that both synthesize GABA but differ in a number of characteristics including their molecular size (65 and 67 kDa). For each GAD mRNA, discrete neuronal labeling with high cellular resolution and low background staining was obtained in most populations of known GABA neurons. In addition, the current methods revealed differences in the intensity of labeling among neurons for each GAD mRNA, suggesting that the relative concentrations of each GAD mRNA may be higher in some groups of GABA neurons than in others.Most major classes of GABA neurons were labeled for each GAD mRNA. In some groups of GABA neurons, the labeling for the two mRNAs was virtually identical, as in the reticular nucleus of the thalamus. In other groups of neurons, although there was substantial labeling for each GAD mRNA, labeling for one of the mRNAs was noticeably stronger than for the other. In most brain regions, such as the cerebellar cortex, labeling for GAD67 mRNA was stronger than for GAD65 mRNA, but there were a few brain regions in which labeling for GAD65 mRNA was more pronounced, and these included some regions of the hypothalamus. Finally, some groups of GABA neurons were predominantly labeled for one of the GAD mRNAs and showed little or no detectable labeling for the other GAD mRNA, as, for example, in neurons of the tuberomammillary nucleus of the hypothalamus where labeling for GAD67 mRNA was very strong but no labeling for GAD65 mRNA was evident. The findings suggest that most classes of GABA neurons in the central nervous system (CNS) contain mRNAs for at least two forms of GAD, and thus, have dual enzyme systems for the synthesis of GABA. Higher levels of one or the other GAD mRNA in certain groups of GABA neurons may be related to differences in the functional properties of these neurons and their means of regulating GABA synthesis.