Homma Akiko, Li Hong-Peng, Hayashi Kaori, Kawano Yukari, Kawano Hitoshi
Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, 183-8526 Tokyo, Japan.
J Comp Neurol. 2006 Nov 1;499(1):120-31. doi: 10.1002/cne.21097.
The effect of gold thioglucose (GTG) administration on neurons containing feeding-related peptides in the hypothalamic arcuate nucleus was examined in mice. Intraperitoneal GTG injection increased the body weight and produced a hypothalamic lesion that extended from the ventral part of the ventromedial nucleus to the dorsal part of the arcuate nucleus. Neurons containing proopiomelanocortin (POMC) and neuropeptide Y (NPY) present in the dorsal part of the arcuate nucleus were destroyed by GTG. In addition, the peptide-containing fibers that extended from the remaining arcuate neurons were degenerated at the lesion site. The number of POMC-containing fibers in the paraventricular nucleus, dorsomedial nucleus, and lateral hypothalamus was found to have decreased significantly when examined at 2 days and 2 weeks after the GTG treatment. In contrast, the number of NPY-containing fibers in the lateral hypothalamus remained unchanged after the GTG treatment, probably because of the presence of an unaffected NPY-containing fiber pathway passing through the tuberal region and projecting onto the lateral hypothalamus. The number of NPY-immunoreactive fibers in the paraventricular and dorsomedial nuclei showed a moderate but significant decrease at 2 days after the GTG treatment, but it recovered to the normal levels 2 weeks later. The NPY-containing fibers were found to have regenerated across the lesion site 2 weeks later, and this might contribute to the recovery of the NPY-immunoreactive fibers in these regions. The present results first demonstrate that POMC- and NPY-containing neurons in the arcuate nucleus respond differently to the lesion produced by the GTG treatment.
在小鼠中研究了注射硫代葡萄糖金（GTG）对下丘脑弓状核中含进食相关肽的神经元的影响。腹腔注射GTG增加了体重，并造成了下丘脑损伤，该损伤从腹内侧核的腹侧部分延伸至弓状核的背侧部分。弓状核背侧部分中含阿黑皮素原（POMC）和神经肽Y（NPY）的神经元被GTG破坏。此外，从剩余弓状神经元延伸出的含肽纤维在损伤部位发生退化。在GTG处理后2天和2周检查时发现，室旁核、背内侧核和下丘脑外侧区中含POMC的纤维数量显著减少。相比之下，GTG处理后下丘脑外侧区中含NPY的纤维数量保持不变，这可能是因为存在一条未受影响的含NPY纤维通路，该通路穿过结节区并投射到下丘脑外侧区。GTG处理后2天，室旁核和背内侧核中NPY免疫反应性纤维的数量出现中度但显著的减少，但在2周后恢复到正常水平。2周后发现含NPY的纤维已穿过损伤部位再生，这可能有助于这些区域中NPY免疫反应性纤维的恢复。目前的结果首次证明，弓状核中含POMC和NPY的神经元对GTG处理产生的损伤反应不同。
