Neuronal plasticity in the deafferented hypothalamic arcuate nucleus of adult female rats and its enhancement by treatment with estrogen
Neuronal plasticity in the deafferented hypothalamic arcuate nucleus of adult female rats and its enhancement by treatment with estrogen
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成年雌性大鼠下丘脑弓形核神经元可塑性及其雌激素治疗的增强
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
Y. Arai
中科院分区：
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作者：
A. Matsumoto;Y. Arai
在去卵巢的成年雌性大鼠下丘脑内侧基底核（MBH）完全脱神经后3、21天对下丘脑弓状核（ARCN）进行超微结构观察。在每脑ARCN中部1.8万μm2的范围内计数轴突轴（axoddendritic shaft， SHS）和脊柱突触（spine synapses， SPS）。在脱牙后3天或21天，SHS和SPS的平均数量减少到正常对照动物的一半左右。在给予雌二醇（2 μg/d）治疗后3 d检测去卵巢MBH岛大鼠的arcn， SHS和SPS的数量与未给予EB治疗的去卵巢MBH岛大鼠无显著差异。然而，在切除卵巢的MBH岛雌性中，EB治疗21天显著增加了SHS和SPS的数量，这些雌性的SHS数量几乎恢复到完整水平的75%；SPS的发病率也显著高于完整对照动物。在这些经EB治疗、去卵巢的MBH岛大鼠中，经常观察到双突触（脊柱-脊柱和脊柱-轴双突触）。然而，在没有MBH分化的去卵巢雌性小鼠中，雌激素并没有增加SHS、SPS和双突触的数量，这与未受卵巢切除和未受卵巢切除的对照组几乎相当。
The hypothalamic arcuate nucleus (ARCN) was examined ultrastructurally 3 or 21 days after complete deafferentation of the medial basal hypothalamus (MBH) in ovariectomized adult female rats. Axodendritic shaft (SHS) and spine synapses (SPS) were counted in a field of 18,000 μm2 in the middle part of the ARCN in each brain. The mean numbers of SHS and SPS at 3 or 21 days after deafferentation were reduced to about half of those in intact control animals. When the ARCNs of the ovariectomized MBH‐island rats were examined 3 days after treatment with estradiol benzoate (EB, 2 μg/day), the numbers of SHS and SPS did not differ from those in ovariectomized MBH‐island rats without EB treatment. However, EB treatment for 21 days produced a marked increase in the number of both SHS and SPS in the ovariectomized MBH‐island females, with the number of SHS in these females being restored to almost 75% of the intact level; the incidence of SPS was also significantly greater than that in the intact control animals. In these EB‐treated, ovariectomized MBH‐island rats, double synapses (spine‐spine and spine‐shaft double synapses) were frequently observed. In ovariectomized females without MBH deafferentation, however, estrogen failed to increase the numbers of SHS, SPS, and double synapses, which were almost comparable to those in intact and ovariectomized controls.