Compensatory sprouting of uninjured magnocellular neurosecretory axons in the rat neural lobe following unilateral hypothalamic lesion.
Compensatory sprouting of uninjured magnocellular neurosecretory axons in the rat neural lobe following unilateral hypothalamic lesion.
复制标题
单侧下丘脑损伤后大鼠神经叶中未受伤的大细胞神经分泌轴突的代偿性出芽。
DOI：
10.1016/0014-4886(91)90046-f
复制
发表时间：
1991
影响因子：
5.3
通讯作者：
Paden,CM
中科院分区：
文献类型：
--
作者：
Watt,JA;Paden,CM
使用单侧下丘脑刀切割下丘脑-神经垂体束以部分去神经化大鼠神经叶（NL），研究大细胞神经分泌系统完整神经元的轴突萌芽。利用密度测定、形态测定、超微结构和代谢测量来证明该系统对去神经支配的代偿反应。光密度分析显示，术后 10 天 (PS) NL 中加压素染色强度短暂降低，随后在 PS 20 天恢复。 NL 的横截面积最初有类似的减少，随后在 90 天 PS 时逐渐恢复到正常。超微结构研究显示，PS 10 天时，NL 中的总轴突数量减少，类似于加压素免疫反应性和 NL 大小的下降。随后轴突数量出现部分恢复，与 PS 30 至 90 天之间恢复到正常 NL 大小相当。在此期间，病变对侧下丘脑视上核和室旁核中的大细胞神经元的体细胞和细胞核肥大也很明显。每日测量尿液渗透压显示，最初出现短暂的低渗透压，随后出现慢性高渗透压，并持续整个术后 90 天。手术后立即开始伴随着每日饮水量和尿液排泄量的慢性减少。这些结果表明，在不存在加压素功能缺陷的情况下，由于 NL 部分去神经，完整的对侧大细胞加压素能传出神经会发生代偿性出芽。
Axonal sprouting of intact neurons of the magnocellular neurosecretory system was investigated using a unilateral hypothalamic knife cut of the hypothalamo-neurohypophysial tract to partially denervate the rat neural lobe (NL). Densitometric, morphometric, ultrastructural, and metabolic measures were utilized to demonstrate the compensatory response to denervation in this system. Densitometric analysis revealed a transient reduction in the intensity of vasopressin staining in the NL at 10 days postsurgery (PS) with a subsequent recovery by 20 days PS. There was a comparable initial reduction in the cross-sectional area of the NL followed by a more gradual recovery to normal by 90 days PS. Ultrastructural investigation revealed a reduction in total axon number in the NL at 10 days PS similar to the declines in vasopressin immunoreactivity and size of the NL. A subsequent partial recovery of axon number occurred, paralleing the return to normal NL size between 30 and 90 days PS. Hypertrophy of both somata and cell nuclei of magnocellular neurons in the supraoptic and paraventricular hypothalamic nuclei contralateral to the lesion was also apparent during this period. Daily measurements of urine osmolality revealed an initial transient hypoosmolality followed by a chronic hyperosmolality which persisted throughout the 90 day postsurgical period. There was a concomitant chronic decrease in both daily drinking and urine excretion volumes which began immediately following surgery. These results suggest that intact, contralateral magnocellular vasopressinergic efferents undergo compensatory sprouting as a result of partial denervation of the NL in the absence of a functional deficit in vasopressin.