N-甲基-D-天门冬氨酸-R1不同mRNA构型在斜视性弱视猫视皮层的表达  

Expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic amblyopic cats

作　　者：阴正勤[1] 邓泽明 陈莉 Grewther SG 

机构地区：[1]第三军医大学西南医院眼科 [2]SchoolofOpometry,UniversityofNewSorthWales20015,Australia

出　　处：《中华眼底病杂志》2000年第2期118-120,共3页Chinese Journal of Ocular Fundus Diseases

基　　金：国家自然科学基金!资助项目 (39770 2 58);国家教委留学回国人员科研启动基金!项目 (97436)

摘　　要：目的　了解在视觉发育可塑期 ,NMDA- R1受体基因的 m RNA构型与斜视性弱视猫视皮层神经元细胞水平表达减少有关的。　方法　同胞正常猫和斜视性弱视猫各两对 (共 4只 )。采用一系列地高辛核酸分子探针做猫脑片原位杂交 ,检测 NMDA- R1不同 m RNA构型在视皮层的表达情况。　结果　与正常猫相比 ,NMDA- R1m RNA“Pan”探针和 R1- a,R1- b,R1- 1构型探针在斜视性弱视猫视皮层的表达显著减少 ,主要在第 层。 R1- 3构型的表达在斜视性弱视猫视皮层比正常猫增加 ,主要在第 - 层。 R1- 2和 R1- 4构型的表达在正常猫和斜视猫视皮层的差异不显著。　结论　斜视性弱视猫视皮层 NMDA- R1m RNA特异构型的转录抑制导致受体蛋白水平表达的改变。Purpose To identify the expression of alternatively spliced mRNA isoforms of the NMDA R1 in the visual cortex of strabismic cats. Methods Two pairs of normal and strabismic cats were used.The amblyopic cats had been made monocularly esotropic (by tenotomy) at the age of weeks,resulting in behavioral amblyopia.Animals were sacrificed about 6 months by intraperitoneal administration of Nembutal.Cryostat sections of fresh,frozen central visual cortex of the ats were cut to 20 micron thickness.A series of digoxygenin labelled oligonucleotide probes basing on the human gene sequence were used for ISH.Control probes included sense oligonucleotides and short segment probes which were adjacent to,but did not,span the splice junctions.A computer assisted systematic morphometric ounting procedure was used to enumerate hybridising cells. Results The number of positive cells expressing NMDA R1 mRNA in the strabismic amblyopic cats was decreased,notably in layer IV of visual cortex (P<0.0001).The pattern of isoform expression varied between normal and strabismic amblyopic cats with decreased numbers of 1 a,1 b and 1 1 is oforms and apparently increased expression of 1 3 (P<0.0001),whereas no significant difference was found for the 1 2 and 1 4 isoforms (P>0.05). Conclusion Transcriptional inhibition of NMDA R1 mRNA and of specifie isoforms may underlie the change in receptor expression.Alternatively,preferential loss of neurones bearing particular NMDA R1 isoforms and compensation with a proportional increase in cells expressing other isoforms may occurr during the critical period of visual plasticity.

关 键 词：斜视 弱视 神经递质 受体 NMDA-R1 MRNA 

分 类 号：R777[医药卫生—眼科]