Background Previous study on critical period plasticity in local cortical circuits primarily was only to test the role of some proteins in visual cortex on visual development based on the existed neural signals expression system,but whole containing proteins analysis in cortical circuits is lack.To perform a whole containing proteins analysis has an important significance for critical period plasticity study.Objective This study was to investigate the influence of dark rearing on visual sense and proteomics in visual cortex for growing rat.Methods Two SD female rats were fed in two cages together with 12 newborn rats on the same day respectively,and half number of newborn rats were exchanged each other from first day after delivering and marked by eartipping.The newborn rats in a cage were bred in the dark environment for 40 days,and newborn rats in other cage were bred in the nature environment as controls.The blink response of rats to nearby object was examined and compared between the two groups of rats.Then three rats from two cages were sacrificed respectively and bilateral primary visual cortex tissue was isolated.Proteomics in rat primary visual cortex was detected by two-dimensional electrophoresis and mass spectrometry and the result was checked from database.Then the survival rats in the dark environment returned to the nature environment for 10 days,and the blink response of rats to nearby object were compared with that of agematched rats in the natural environment.The use and care of experimental rats followed the instruction of Ethic Committee of Nankai University.Results The blink response of rats was (0.33 ± 0.35) times in the dark environment for 40-day group,and that in the natural environment for 40-day group was (6.42±0.68) times,with a significant difference between them (t =24.38,P＜0.01).After returned to natural environment for 10 days,the blink response times of rats were less than those of the natural environment group ([5.00±1.22] times vs.[6.11±0.59]times),but this change was not statistically significant (t =2.09,P＞0.05).Two-dimensional electrophoresis and mass spectrometry assay revealed that 36 different proteins in visual cortex were found in the dark-feed rats compared with the natural environment rats,including 26 loss proteins and 10 extra proteins.Among the different proteins,Eps 15 homology domain-containing protein-3 (EHD3),tubulin alpha-1A chain and 2 ',3 '-cyclic-nucleotide 3 ' phosphordiesterase were the known proteins.Conclusions Dark rearing cause reversible visual loss in critical period plasticity newborn rat,and the change of proteomics in visual cortex is probably an affecting factor.%背景 以往对视皮层发育关键期的研究仅根据已有的神经信号表达系统,就某一种可能是视皮层发育的关键蛋白质进行实验验证,进行视皮层全蛋白质分析对于了解动物进而研究人类视觉发育的可塑性具有重要意义. 目的 了解避光环境对生长发育期大鼠视觉及视皮层蛋白质组学的影响. 方法 将2只同日分娩12只仔鼠的SD母鼠分别饲养在2个鼠笼中,分娩日将2个母鼠的仔鼠一半进行对换,对换的仔鼠剪耳进行区分,即时起一个鼠笼的大鼠在避光处饲养,一个鼠笼的大鼠在自然光照下饲养作为对照.避光饲养的大鼠在完全避光环境下更换食物、水和垫料,至仔鼠40日龄时测定两组仔鼠对近眼物体瞬目的次数.各组分别处死3只大鼠,分离双侧初级视皮层(枕叶),利用二维电泳和质谱分析的方法,检测仔鼠避光环境与自然光照环境下发育和生长的初级视皮层蛋白质组学的差异,经Swissprot与NCBI数据库比对,鉴定差异蛋白.然后将避光饲养的剩余9只大鼠恢复自然光照l0d至大鼠50日龄,作为避光40 d恢复光照10d组比较与同日龄自然光照组9只大鼠对近眼物体瞬目次数的差异. 结果 大鼠40日龄时,避光饲养组大鼠对近眼物体的瞬目次数为(0.33±0.35)次,明显少于自然光照组大鼠的(6.42±0.68)次,差异有统计学意义(t=24.38,P＜0.01);大鼠50日龄时,自然光照组大鼠对近眼物体的瞬目次数为(6.11±0.59)次,避光饲养组大鼠多于避光40 d后恢复至(5.00±1.22)次,但差异无统计学意义(t=2.09,P＞0.05).二维电泳和质谱分析显示,自然光照组仔鼠与避光40 d组大鼠初级视皮层的差异蛋白共36种,避光40 d组大鼠缺失26种,增加10种,其中经质谱分析和数据库比对3种为已知蛋白,分别是Eps 15同源结构域蛋白3(EHD3)、α-微管蛋白1A链和2’,3’-3’-环核苷酸磷酸二酯酶. 结论 生长发育期避光环境中饲养可造成大鼠可逆的视觉障碍,并使其初级视皮层蛋白质组学发生变化.
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