Tölle T R, Berthele A, Laurie D J, Seeburg P H, Zieglgänsberger W
Max Planck Institute of Psychiatry, Clinical Institute, Munich, Germany.
Eur J Neurosci. 1995 Jun 1;7(6):1235-44. doi: 10.1111/j.1460-9568.1995.tb01114.x.
The regional distribution of alternatively spliced messenger RNA encoding the N-methyl-D-aspartate (NMDA) receptor R1 subunit (NMDAR1) variants was examined by in situ hybridization in the rat lumbar spinal cord. Splice-specific oligonucleotide probes [recognizing full-length mRNA (NMDAR1-1), deletion exon 21 (NMDAR1-2), deletion exon 22 (NMDAR1-3), combined deletion exons 21 and 22 (NMDAR1-4) and mRNA which lacks (NMDAR1-a) or contains exon 5 (NMDAR1-b)] detected marked differences in abundance and distribution of N- and C-terminal spliced variants. The NMDAR1-a, NMDAR1-2 and NMDAR1-4 mRNAs were evenly distributed throughout all laminae of the dorsal and ventral horns. In the superficial dorsal horn NMDAR1-b mRNA was preferentially detected in laminae II inner and III, while NMDAR1-1 mRNA was restricted to laminae I to III. Large neurons in laminae IV and V contained mainly NMDAR1-a, NMDAR1-2 and NMDAR1-4 mRNAs and occasionally NMDAR1-b. The NMDAR1-3 variant was only detected in very low abundance, being restricted to occasional cells in lamina I and II. In the ventral horn, motor neurons showed strong signals for NMDAR1-a, NMDAR1-b, NMDAR1-2 and NMDAR1-4 mRNAs. Serial sectioning through large motor neurons permitted the detection of multiple splice variants in single neurons. Analysis of the subcellular distribution of the mRNAs revealed that the NMDAR1-1 mRNA was almost exclusively found in the cell nucleus, NMDAR1-a mRNA was largely in the cytoplasm, while all other splice variants showed a homogeneous distribution between nucleus and cytoplasm. Comparison of the in situ hybridization images with functional analyses of heteromeric recombinant receptors will be necessary to ascertain whether splice variants of the NMDAR1 receptor subunit can account for some of the known electrophysiological properties of spinal cord neurons under physiological and pathophysiological conditions.
通过原位杂交技术，在大鼠腰段脊髓中检测了编码N-甲基-D-天冬氨酸（NMDA）受体R1亚基（NMDAR1）变体的可变剪接信使核糖核酸（mRNA）的区域分布。剪接特异性寡核苷酸探针[识别全长mRNA（NMDAR1-1）、缺失外显子21（NMDAR1-2）、缺失外显子22（NMDAR1-3）、外显子21和22联合缺失（NMDAR1-4）以及缺失（NMDAR1-a）或包含外显子5（NMDAR1-b）的mRNA]检测到N端和C端剪接变体在丰度和分布上存在显著差异。NMDAR1-a、NMDAR1-2和NMDAR1-4 mRNA在背角和腹角的所有板层中均匀分布。在浅背角，NMDAR1-b mRNA优先在板层II内层和III中检测到，而NMDAR1-1 mRNA局限于板层I至III。板层IV和V中的大神经元主要含有NMDAR1-a、NMDAR1-2和NMDAR1-4 mRNA，偶尔含有NMDAR1-b。NMDAR1-3变体仅以非常低的丰度被检测到，局限于板层I和II中的偶尔细胞。在腹角，运动神经元对NMDAR1-a、NMDAR1-b、NMDAR1-2和NMDAR1-4 mRNA显示出强信号。对大型运动神经元进行连续切片可检测单个神经元中的多种剪接变体。对mRNA亚细胞分布的分析表明，NMDAR1-1 mRNA几乎只存在于细胞核中，NMDAR1-a mRNA主要存在于细胞质中，而所有其他剪接变体在细胞核和细胞质之间呈均匀分布。为了确定NMDAR1受体亚基的剪接变体是否能解释生理和病理生理条件下脊髓神经元的一些已知电生理特性，有必要将原位杂交图像与异源重组受体的功能分析进行比较。
