SYNAPSE FORMATION OF HYPOTHALAMIC ARCUATE NUCLEUS DURING POSTNATAL-DEVELOPMENT IN FEMALE RAT AND ITS MODIFICATION BY NEONATAL ESTROGEN-TREATMENT
SYNAPSE FORMATION OF HYPOTHALAMIC ARCUATE NUCLEUS DURING POSTNATAL-DEVELOPMENT IN FEMALE RAT AND ITS MODIFICATION BY NEONATAL ESTROGEN-TREATMENT
复制标题
DOI：
10.1016/0306-4530(78)90039-2
复制
发表时间：
1978-01-01
影响因子：
3.7
通讯作者：
MATSUMOTO, A
中科院分区：
文献类型：
--
作者：
ARAI, Y;MATSUMOTO, A
对雌性大鼠的弓状核（ARCN）中的突触结构进行半定量研究，方法是对每个脑中的ARCN中部的18，000 μ m2区域中的突触进行计数。在5日龄大鼠中，神经元处于极其不成熟的状态，其特征在于存在广泛的细胞外间隙。轴树和轴体突触在这个年龄是非常少的。在20日龄大鼠，细胞外空间完全被轴突，其终端，树突和胶质细胞的过程。轴-树和轴-体突触的数目分别增加到5日龄大鼠的4倍和5倍以上。在31日龄时，观察到突触数量进一步增加。虽然在这个年龄段的神经元仍然包含一个混合人口的形态不成熟和成熟的突触，超微结构特征的ARCN接近成年人。150日龄大鼠的轴-树和轴-体突触数分别是5日龄大鼠的16和17倍。在6日龄大鼠中，从1-5天开始用苯甲酸雌二醇（EB）处理，与对照组相比，神经元基质中的细胞外间隙显著减少。这种趋势在从第1-10天注射EB的11日龄大鼠中非常明显。在31日龄的大鼠接受EB注射的前30天的生活中，在同一领域的ARCN的轴树突触的平均数是2.7倍以上的控制。而轴体突触在雌激素组和对照组之间无显著差异。形态学上成熟的突触在雌激素处理的大鼠中更常见。在150日龄时，轴树突触的数量没有进一步增加，平均数量与31日龄雌激素组和150日龄对照组大鼠没有显著差异。轴体突触的平均数量也与对照组无显著差异。出生后早期给予雌激素可能对ARCN中突触结构的发育有促进作用。
Semi-quantitative studies on synaptic structures in the arcuate nucleus (ARCN) of female rats were performed by counting synapses in 18,000 .mu.m2 area in the middle part of the ARCN in each brain. In 5 day old rats, the neuropil was in an extremely immature state, which was characterized by the presence of extensive extracellular space. Axodendritic and axosomatic synapses at this age were very few in number. In 20 day old rats, the extracellular space was fully occupied by axons, their terminals, dendrites and glial processes. The numbers of axodendritic and axosomatic synapses were increased to more than 4 and 5 times those of 5 day old rats, respectively. At 31 days of age, a further increase in the number of synapses was observed. Although the neuropil still contained a mixed population of morphologically immature and mature synapses at this age, the ultrastructural features of the ARCN approached closely those of the adult. The mean numbers of axodendritic and axosomatic synapses at 150 days of age were more than 16 and 17 times those of 5 day old rats. In 6 day old rats which had been treated with estradiol benzoate (EB) from days 1-5, the extracellular space in the neuropil matrix was considerably reduced, compared with that of the control. This tendency was much pronounced in 11 day old rats injected with EB from days 1-10. In 31 day old rats receiving EB injections for the first 30 days of life, the mean number of axodendritic synapses in the same field area of the ARCN was 2.7-fold greater than that of the controls. As for the axosomatic synapses, there was no significant difference between the estrogenized and controls. The morphologically mature synapses were much more frequently encountered in the estrogenized rats. At 150 days of age, axodendritic synapses did not show a further increase in number and the mean number was not significantly different from those of 31 day old estrogenized and 150 day old control rats. The mean number of axosomatic synapses was also not significantly different from that of the controls. Estrogen may have a facilitatory influence on the development of synaptic structures in the ARCN when it is given early postnatally.