Yu Yong, Ugawa Shinya, Ueda Takashi, Ishida Yusuke, Inoue Kiyoshi, Kyaw Nyunt Aung, Umemura Atsushi, Mase Mitsuhito, Yamada Kazuo, Shimada Shoichi
Department of Neurobiology and Anatomy, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan.
Brain Res. 2008 Feb 15;1194:45-55. doi: 10.1016/j.brainres.2007.11.064. Epub 2007 Dec 8.
P2X7 receptor is a member of the P2X family of ATP-gated ion channels. The cellular localization of P2X7 receptors in the central nervous system remains controversial because immunohistochemical staining patterns are inconsistent among antibodies. Here we examined the precise distribution of P2X7 mRNAs in the rat brain using isotopic in situ hybridization. P2X7-positive glial-like small cells were sporadically scattered in almost all areas of the brain. P2X7-positive glial-like small cells were also observed in nerve fiber tracts such as the anterior commissure, corpus callosum (CC), optic tract, and internal capsule. P2X7-positive neurons were found in the anterior olfactory nucleus, cerebral cortex, piriform cortex (Pir), lateral septal nucleus (LS), hippocampal pyramidal cell layers of CA1, CA3, CA4, pontine nuclei, external cuneate nucleus, and medial vestibular nucleus. P2X7 hybridization signals were also observed in the motor neurons of the trigeminal motor nucleus, facial nucleus, hypoglossal nucleus, and the anterior horn of the spinal cord. P2X7 mRNA was expressed in the ependymal cells around the olfactory ventricle, lateral ventricles (LV), third ventricle (3V), cerebral aqueduct (Aq), fourth ventricle (4V), and central canal. The P2X7 hybridization signal was also very strong in the area postrema (AP). The double staining experiments demonstrate that neurons, oligodendrocytes, and microglia expressed P2X7 receptor mRNAs. These findings suggest that P2X7 receptors may play a variety of roles in a wide range of cell types in the brain.
P2X7受体是ATP门控离子通道P2X家族的成员。P2X7受体在中枢神经系统中的细胞定位仍存在争议，因为不同抗体的免疫组织化学染色模式不一致。在此，我们使用同位素原位杂交技术研究了P2X7 mRNA在大鼠脑中的精确分布。P2X7阳性的胶质样小细胞散在分布于脑的几乎所有区域。在诸如前连合、胼胝体、视束和内囊等神经纤维束中也观察到P2X7阳性的胶质样小细胞。在前嗅核、大脑皮质、梨状皮质、外侧隔核、CA1、CA3、CA4区的海马锥体细胞层、脑桥核、楔外核和内侧前庭核中发现了P2X7阳性神经元。在三叉神经运动核、面神经核、舌下神经核和脊髓前角的运动神经元中也观察到P2X7杂交信号。P2X7 mRNA在嗅脑室、侧脑室、第三脑室、中脑导水管、第四脑室和中央管周围的室管膜细胞中表达。在最后区，P2X7杂交信号也非常强。双重染色实验表明，神经元、少突胶质细胞和小胶质细胞表达P2X7受体mRNA。这些发现表明，P2X7受体可能在脑中多种细胞类型中发挥多种作用。
