Papa Michele, Boscia Francesca, Canitano Adriana, Castaldo Pasqualina, Sellitti Stefania, Annunziato Lucio, Taglialatela Maurizio
Department of Neuroscience, School of Medicine, University of Naples Federico II, Via Pansini 5-Naples, Italy.
J Comp Neurol. 2003 Nov 3;466(1):119-35. doi: 10.1002/cne.10886.
Voltage-dependent K(+) channels play a pivotal role in controlling cellular excitability within the nervous system. The aim of the present study was to investigate the expression in the adult rat brain of the three ether-a-gogo-related gene (ERG) family members ERG1, ERG2, and ERG3, encoding for K(+) channel subunits. To this aim, the distribution of ERG transcripts was studied by means of reverse-transcription polymerase chain reaction (RT-PCR) and nonradioactive in situ hybridization histochemistry (NR-ISH). Furthermore, ERG1 subunit distribution was studied by immunohistochemical analysis. RT-PCR analysis revealed ERG1, ERG2, and ERG3 expression in the olfactory bulb, cerebral cortex, hippocampus, hypothalamus, and cerebellum. NR-ISH experiments detected transcripts encoded by all three ERG genes in the cerebral cortex and in all CA subfields and in the granular cell layer of the dentate gyrus of the hippocampus; strong ERG1 signals were also detected in scattered large elements throughout the oriens, pyramidal, and radiatum layers, and in the hilus of the dentate gyrus. In the thalamus, positively labeled neurons were detected in the reticular nucleus with ERG1 and ERG3 and in the anterodorsal nucleus with ERG2 riboprobes. Transcripts for ERG1 and, to a lesser degree, also for ERG3, were detected in the basal ganglia and in several brainstem nuclei. All three ERG genes appeared to be expressed in cerebellar Purkinje cells. Finally, ERG1 expression was also revealed in non-neuronal elements such as ependymal and subependymal cells along the ventricular walls and hippocampal astrocytes. These results suggest that the K(+) channel isoforms of the ERG family appear to be expressed in different central nervous system regions where they might differentially control the firing of neurons engaged in several networks.
电压依赖性钾通道在控制神经系统内的细胞兴奋性方面起着关键作用。本研究的目的是调查成年大鼠脑中编码钾通道亚基的三个醚 - 去极化相关基因（ERG）家族成员ERG1、ERG2和ERG3的表达情况。为此，通过逆转录聚合酶链反应（RT-PCR）和非放射性原位杂交组织化学（NR-ISH）研究了ERG转录本的分布。此外，通过免疫组织化学分析研究了ERG1亚基的分布。RT-PCR分析显示ERG1、ERG2和ERG3在嗅球、大脑皮层、海马体、下丘脑和小脑中表达。NR-ISH实验在大脑皮层、海马体的所有CA亚区和齿状回颗粒细胞层中检测到了所有三个ERG基因编码的转录本；在整个海马体的始层、锥体层和辐射层以及齿状回的门区中，还在散在的大细胞中检测到了强烈的ERG1信号。在丘脑中，用ERG1和ERG3核糖探针在网状核中检测到阳性标记神经元，用ERG2核糖探针在前背核中检测到阳性标记神经元。在基底神经节和几个脑干核中检测到了ERG1的转录本，ERG3的转录本含量较少。所有三个ERG基因似乎都在小脑浦肯野细胞中表达。最后，在非神经元成分如脑室壁的室管膜和室管膜下细胞以及海马体星形胶质细胞中也发现了ERG1的表达。这些结果表明，ERG家族的钾通道亚型似乎在不同的中枢神经系统区域表达，在这些区域它们可能以不同方式控制参与多个神经网络的神经元的放电。
