Gonadal hormone modulation of dendrites in the mammalian CNS
Gonadal hormone modulation of dendrites in the mammalian CNS
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DOI：
10.1002/neu.20143
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发表时间：
2005-07-01
期刊：
影响因子：
--
通讯作者：
Woolley, CS
中科院分区：
文献类型：
--
作者：
Cooke, BM;Woolley, CS
本文综述了性腺类固醇激素、雄激素和雌激素对成年大鼠中枢神经系统(CNS)树突的影响。四个激素反应核被认为是：球海绵体脊髓核(SNB)、杏仁内侧核(MEA)、下丘脑腹内侧核(VMN)和背侧海马CA1区。特别强调每个核内荷尔蒙的作用方式。在SNB、VMN和海马体中，激素似乎通过那些表现出形态可塑性的细胞以外的细胞间接调节它们的影响。在MEA中，雌激素和/或雄激素似乎主要作用于那些树突受激素调节的细胞。重要的是，性腺激素水平的增加并不只是导致树突状细胞参数的增加。在VMN，与发情前期相关的高水平雌激素增加了一个细胞亚群中树突棘的密度，而降低了另一个细胞亚群中的树突密度。在整个发情周期，CA1背侧的锥体细胞也经历了树突棘和突触密度的阶段性变化。雌激素诱导的兴奋性突触与预先存在的轴突相连，轴突也与其他CA1细胞形成突触，从而增加兴奋性传入向背侧CA1的发散。这些发现表明，性腺类固醇对树突的形态和突触连接模式有深远的影响。因此，激素水平的实验操作是研究哺乳动物大脑结构-功能关系的有力工具。(C)2005年威利期刊公司。
This review focuses on the effect of gonadal steroid hormones, androgen and estrogen, on dendrites in the adult rat central nervous system (CNS). Four hormone-responsive nuclei are considered: The spinal nucleus of the bulbocavernosus (SNB), the medial nucleus of the amygdala (MeA), the ventromedial nucleus of the hypothalamus (VMN), and the CA1 region of the dorsal hippocampus. Particular emphasis is placed on the mode of hormone action in each nucleus. In the SNB, VMN, and hippocampus, hormones appear to mediate their effects indirectly, via cells other than those that display morphological plasticity. In the MeA, estrogen and/or androgen appears to act primarily on those cells whose dendrites are modulated by the hormone. Importantly, increasing levels of gonadal hormones do not simply result in increases in dendritic parameters. In the VMN, high levels of estrogen associated with proestrus increase dendritic spine density in one subset of cells and reduce spine density in another subset. The pyramidal cells of dorsal CA1 also undergo phasic changes in dendritic spine and synapse density across the estrous cycle. The estrogen-induced excitatory synapses connect with preexisting axonal boutons that also form synapses with other CA1 cells, thereby increasing the divergence of excitatory afferents to dorsal CA1. These findings indicate that gonadal steroids have a profound impact on the morphology of dendrites and patterns of synaptic connectivity. Consequently, the experimental manipulation of hormone levels is a powerful tool to study structure-function relationships in the mammalian brain. (c) 2005 Wiley Periodicals, Inc.