Analysis of transient expression of estrogen receptor in the newborn rat brain

新生大鼠脑内雌激素受体瞬时表达分析

基本信息

批准号：
13640667
负责人：
HAYASHI Shinji
金额：
$ 2.3万
依托单位：
YOKOHAMA CITY UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

We have found that estrogen receptor (ER) alpha is expressed transiently in the facial nucleus and in the primary auditory cortex of new born rats. However, biological meaning of this expression is still left unexplained. Using TUNEL method, we failed to detect any apoptotic signals in the facial nucleus of fetal to newborn rats between 16 days after conception (FE16) and 11days after birth (PN11). Thus, it is suggested that the cells expressing ER alpha are not those die early in the life. On the other hand, the birth date of the ER alpha positive cells was estimated by giving BrdU to pregnant mothers followed by immunohistochemical detection of ER signals. Colocalization of the BrdU and ER alpha signals was only detected in those samples given BrdU at 11 and 12 days after conception (FE11-12). Thus, motoneurons in the facial nucleus is suspected to attain final cell division around FE11-12 and only a part of them express ER alpha. Since ER signals disappear after PN14, our hypothesis that only immature motoneurons contain ER signals is supported. On the other hand, we examined in the primary auditory cortex of the newborn rats if ER signals were co-expressed with any neuropeptides, such as neuropeptides Y (NPY), gleaning, substance P, cholecystokinine 8 (CCK8), and vasoactive intestinal peptide (VIP) by using double immunohistochemistry method. So far we failed to detect any distinct Colocalization of ER alpha signals with any of these peptides. However, since we detected ER alpha signals in extranuclear loci by electron microscopy in the hippocampal pyramidal neurons, there is a possibility of extra-nuclear action of estradiol through estrogen receptor.

我们发现雌激素受体（ER）α在新生大鼠的面核和初级听觉皮层中短暂表达。然而，这种表达的生物学意义仍然无法解释。使用TUNEL方法，我们未能在受孕后16天（FE16）至出生后11天（PN11）的胎儿至新生大鼠的面神经核中检测到任何凋亡信号。因此，表明表达ERα的细胞并不是在生命早期死亡的细胞。另一方面，通过向怀孕母亲给予BrdU，然后通过免疫组织化学检测ER信号来估计ERα阳性细胞的出生日期。仅在受孕后 11 天和 12 天给予 BrdU 的样本 (FE11-12) 中检测到 BrdU 和 ER α 信号的共定位。因此，面部核中的运动神经元被怀疑在 FE11-12 周围实现最终细胞分裂，并且其中只有一部分表达 ER α。由于 ER 信号在 PN14 后消失，因此支持我们的假设，即只有未成熟的运动神经元含有 ER 信号。另一方面，我们在新生大鼠的初级听觉皮层中检查了 ER 信号是否与任何神经肽共表达，例如神经肽 Y (NPY)、拾穗、P 物质、胆囊收缩素 8 (CCK8) 和血管活性肠肽(VIP)采用双重免疫组织化学方法。到目前为止，我们未能检测到 ER α 信号与任何这些肽的任何明显共定位。然而，由于我们通过电子显微镜在海马锥体神经元的核外位点检测到ERα信号，因此雌二醇有可能通过雌激素受体发挥核外作用。