Takayama C, Nakagawa S, Watanabe M, Mishina M, Inoue Y
Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan.
Brain Res Dev Brain Res. 1996 Apr 30;92(2):147-55. doi: 10.1016/0165-3806(95)00212-x.
The glutamate receptor (GluR) channel delta 2 subunit is considered to be a functional molecule involved in motor coordination, Purkinje cell synapse formation and cerebellar long-term depression. We examined developmental changes in expression and distribution of the GluR delta 2 in the mouse cerebellum by in situ hybridization and immunohistochemistry. The GluR delta 2 mRNA was detected as early as embryonic day 15 (E15) in a cell mass consisting of Purkinje neuroblasts in the posterior cerebellum. During late embryonic and postnatal periods, the GluR delta 2 mRNA was expressed abundantly and specifically in Purkinje cells. By immunohistochemistry, immunoreactivity of the GluR delta 2 was found in both shafts and spines of Purkinje dendrites at early postnatal period. By P21, however, the intense immunoreactivity became restricted to the dendritic spines, especially along the postsynaptic membrane in contact with parallel fiber terminals. These findings suggested that the transcription of the GluR delta 2 subunit occurs in the Purkinje cells from fetal through adult stage, but the intracellular localization of the protein products undergoes an alteration from non-synaptic to synaptic site when active synaptogenesis takes place.
谷氨酸受体（GluR）通道δ2亚基被认为是参与运动协调、浦肯野细胞突触形成和小脑长时程抑制的功能性分子。我们通过原位杂交和免疫组织化学方法研究了小鼠小脑中GluR δ2表达和分布的发育变化。早在胚胎第15天（E15），在小脑后部由浦肯野神经母细胞组成的细胞团中就检测到了GluR δ2 mRNA。在胚胎后期和出生后时期，GluR δ2 mRNA在浦肯野细胞中大量且特异性地表达。通过免疫组织化学方法，在出生后早期，GluR δ2的免疫反应性在浦肯野树突的轴和棘中均有发现。然而，到出生后第21天，强烈的免疫反应性局限于树突棘，尤其是与平行纤维终末接触的突触后膜沿线。这些发现表明，GluR δ2亚基的转录在胎儿期至成年期的浦肯野细胞中均有发生，但当活跃的突触发生时，蛋白质产物的细胞内定位从非突触部位转变为突触部位。
