下丘脑腹内侧核与中脑水管周灰白质间神经网络调节大鼠褐色脂肪组织产热的研究

Study of Neuronal Network from Ventromedial Hypothalamic Nucleus to Caudal Periaqueductal Gray on Regulating Thermogenesis of Brown Adipose Tissue in Rats

目的研究下丘脑腹内侧核(VMH)与中脑水管周灰白质尾侧部(cPAG)间是否存在控制大鼠褐色脂肪组织非寒颤产热效应的下行投射网络。方法制作cPAG刺激诱发大鼠褐色脂肪组织产热局部温度上升的动物模型,再将霍乱毒素B(CTb)0.3μl注射入另一组大鼠的cPAG内。结果发现CTb感染的神经细胞以同侧下丘脑腹内侧核吻侧部最多,其次是前乳头核后侧部,而视前区正中部、下丘脑前部、不定带以及对侧下丘脑腹内侧核则较稀疏。结论实验提示从下丘脑腹内侧核到中脑水管周灰白质尾侧部的下行辐射是兴奋大鼠褐色脂肪组织非寒颤产热效应的传出神经回路。

Objective To investigate the exist of efferent projection from the ventromedial hypothalamic nucleus（VMH） to the caudal periaqueductal gray （cPAG）, and whether the network controls nonshivering thermogenesis of brown adipose tissue in rats. Methods The models whose temperature of the interscapular brown adipose tissue was induced to rise by stimulating cPAG regions were made in rats. Beside, the cholera toxin B subunit （CTb, 0.3μl） was injected into cPAG of another rats, where is the D, L-homocysteic acid （DLH） effective region decided in above test. Results The CTb-labelled ceils were most observed in the rostral part of the ipsilateral VMH, also secondly in the dorsal premammillary nucleus, and less in the median preoptic nucleus, anterior hypothalamic nucleus, zona incerta, and the contralateral VMH. Conclusion The results suggest that the efferent projection from VMH to cPAG is neuronal network to excite nonshivering thermogenesis of brown adipose tissue in rats.