The morphometry of astrocytes in the rostral preoptic area exhibits a diurnal rhythm on proestrus: Relationship to the luteinizing hormone surge and effects of age
The morphometry of astrocytes in the rostral preoptic area exhibits a diurnal rhythm on proestrus: Relationship to the luteinizing hormone surge and effects of age
复制标题
DOI：
10.1210/en.2002-220711
复制
发表时间：
2003-01-01
期刊：
影响因子：
4.8
通讯作者：
Wise, PM
中科院分区：
文献类型：
--
作者：
Cashion, AB;Smith, MJ;Wise, PM
弓形核星形胶质细胞形态在发情周期中呈现周期性变化，导致调节垂体激素分泌的神经递质和神经肽之间的交流发生动态变化。数据表明，对GnRH神经元的直接和/或间接输入的重塑可能会影响幼鼠排卵前LH激增的时间和/或幅度。我们之前已经发现，衰老会改变LH激增的时间和幅度。因此，本研究的目的是关注GnRH细胞体所在的吻侧视前区。我们评估了在吻侧视前区星形胶质细胞的形态测定在发情前显示时间相关和年龄依赖的变化的可能性。我们的研究结果表明，在年轻的大鼠中，星形胶质细胞表面积在黄体生成素激增开始之前的0800 - 1200h之间减少。在整个循环中，表面积的变化是与GnRH神经元密切相关的星形胶质细胞所特有的。相反，中年大鼠的星形胶质细胞表面积明显小于年轻大鼠，并且在白天没有变化。这些发现表明，星形胶质细胞可塑性的丧失可能导致先前在中年大鼠中观察到的LH激增的延迟和减弱。
The morphometry of astrocytes in the arcuate nucleus exhibits cyclic changes during the estrous cycle leading to dynamic changes in the communication between neurotransmitters and neuropeptides that regulate pituitary hormone secretion. Data suggest that remodeling of direct and/or indirect inputs into GnRH neurons may influence the timing and/or amplitude of the preovulatory LH surge in young rats. We have previously found that aging alters the timing and amplitude of the LH surge. Therefore, the purpose of this study was to focus on the rostral preoptic area where GnRH cell bodies reside. We assessed the possibility that the morphometry of astrocytes in the rostral preoptic area displays time-related and age-dependent changes on proestrus.Our results demonstrate that, in young rats, astrocyte cell surface area decreases between 0800 h and 1200 h, before the initiation of the LH surge. Changes in surface area over the cycle were specific to astrocytes in close apposition to GnRH neurons. In contrast, in middle-aged rats astrocyte surface area was significantly less than in young rats and did not change during the day. These findings suggest that a loss of astrocyte plasticity could lead to the delayed and attenuated LH surge that has been previously observed in middle-aged rats.