Neonatally born granule cells numerically dominate adult mice dentate gyrus
Neonatally born granule cells numerically dominate adult mice dentate gyrus
复制标题
DOI：
10.1016/j.neuroscience.2007.06.040
复制
发表时间：
2007-09-07
期刊：
影响因子：
3.3
通讯作者：
Koyama, R.
中科院分区：
文献类型：
--
作者：
Muramatsu, R.;Ikegaya, Y.;Koyama, R.
海马颗粒细胞(GC)在齿状回(DG)的颗粒下层不断产生，甚至在成年期也具有整合成齿状神经回路的功能。这就提出了一个问题，即新生儿出生的GC在成年DG中的命运。他们是一直存在到成年，还是在很大程度上被成年出生的GC所取代？为了研究这个问题，我们研究了出生后GCs对成年小鼠DG的贡献。将C5713L/6小鼠分为三组(第1组：P0、第2组：P7和第3组：P35)，每天注射溴-羟尿碱(BrdU)，分别为P0/1/2、P7/8/9和P35/36/37。6个月龄时，取大鼠海马区切片，分别用抗BrdU抗体和同源盒蛋白Prox1抗体进行免疫组织化学染色。将BrdU-和Prox1-双阳性细胞定义为新生GCs，分析其在颗粒细胞层(GCL)的密度和分布，发现注射BrdU 6个月后各组新生GCs仍然存在，P0-2出生的GCs密度明显高于其他组。虽然各组生后GCs的密度无性别差异，但GCL内GCs的径向分布有所不同，第1组男性新生儿GCs定位于分子层，而第2组GCs定位于肝门部。这些结果提示，出生早期出生的GCs在数量上支配成年DG，GC定位存在性别差异，这种定位取决于出生时间。(C)2007年IBRO。爱思唯尔有限公司出版。保留所有权利。
Hippocampal granule cells (GCs) are continuously generated in the subgranular zone of the dentate gyrus (DG) and functionally incorporated to dentate neural circuits even in adulthood. This raises a question about the fate of neonatally born GCs in adult DG. Do they exist until adulthood or are they largely superseded by adult-born GCs? To investigate this question, we examined the contributions of postnatally born GCs to the adult mouse DG. C5713L/6 mice were grouped in three different postnatal (P) ages (group 1: PO, group 2: P7, and group 3: P35) and received a daily bromode-oxyuricline (BrdU) injection for three consecutive days (P0/ 1/2, P7/8/9, and P35/36/37, respectively) to label dividing cells. At 6 months old, hippocampal sections were prepared from the animals and immunostained with anti-BrdU antibody and an antibody against the homeobox prospero-like protein Prox1, a marker of GCs. We defined BrdU- and Prox1-double positive cells as newborn GCs and analyzed their density and distribution in the granule cell layer (gcl), revealing that newborn GCs of each group still existed 6 months after BrdU injections and that the density of GCs born during P0-2 (group 1) was significantly higher compared with the other groups. Although the density of newborn GCs in the each group did not differ between male and female, the radial distribution of them in gcl showed some differences, that is, male newborn GCs localized toward the molecular layer compared with female ones in group 1, while to the hilus in group 2. These results suggest that GCs born in early postnatal days numerically dominate adult DG and that there exist sex differences in GC localizations which depend on the time when they were born. (c) 2007 IBRO. Published by Elsevier Ltd. All rights reserved.