Watanabe M, Mishina M, Inoue Y
Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan.
J Comp Neurol. 1994 May 22;343(4):513-9. doi: 10.1002/cne.903430402.
The distribution of five NMDA receptor channel subunit mRNAs was examined in the mouse cerebellum from embryonic day 13 through postnatal day 56, by in situ hybridization with subunit-specific oligonucleotide probes. At postnatal days 21 and 56, each cerebellar neuron displayed differential expressions of the epsilon subunit mRNAs. The granule cells showed hybridizing signals for the epsilon 1 and epsilon 3 subunit mRNAs, the molecular layer neurons for the epsilon 4 subunit mRNA, and the cerebellar nucleus neurons for the epsilon 1 and epsilon 4 subunit mRNAs, whereas the Purkinje cells did not express any epsilon subunit mRNAs. At early postmitotic stages of development, the epsilon 2 subunit mRNA appeared in each cerebellar neuron, including the Purkinje cells, and the epsilon 4 subunit mRNA appeared in neurons of the molecular layer and the cerebellar nuclei. The expression patterns in the cerebellum altered drastically during the first 2 postnatal weeks; the epsilon 1 and epsilon 3 subunit mRNAs appeared in the granule cells and the cerebellar nucleus neurons, whereas the epsilon 2 subunit mRNA disappeared from each neuron and the signal levels of the epsilon 4 subunit mRNA decreased remarkably. In contrast to the differential expressions of the four epsilon subunit mRNAs, intense signals for the zeta 1 subunit mRNA were observed in each cerebellar neuron from early postmitotic stages through the mature stage. These findings suggest that anatomical organization of the epsilon subunits is heterogeneous in the cerebellum both spatially and temporally, which would give rise to functional diversity of the NMDA receptor channel.
通过与亚基特异性寡核苷酸探针进行原位杂交，研究了从胚胎第13天到出生后第56天小鼠小脑中五种NMDA受体通道亚基mRNA的分布。在出生后第21天和第56天，每个小脑神经元均表现出ε亚基mRNA的差异表达。颗粒细胞显示出ε1和ε3亚基mRNA的杂交信号，分子层神经元显示出ε4亚基mRNA的杂交信号，小脑核神经元显示出ε1和ε4亚基mRNA的杂交信号，而浦肯野细胞不表达任何ε亚基mRNA。在发育的有丝分裂后早期阶段，ε2亚基mRNA出现在每个小脑神经元中，包括浦肯野细胞，ε4亚基mRNA出现在分子层和小脑核的神经元中。出生后前两周内，小脑中的表达模式发生了剧烈变化；ε1和ε3亚基mRNA出现在颗粒细胞和小脑核神经元中，而ε2亚基mRNA在每个神经元中消失，ε4亚基mRNA的信号水平显著下降。与四种ε亚基mRNA的差异表达相反，从有丝分裂后早期到成熟阶段，在每个小脑神经元中均观察到ζ1亚基mRNA的强烈信号。这些发现表明，ε亚基的解剖学组织在小脑的空间和时间上都是异质的，这将导致NMDA受体通道的功能多样性。
