Differential response of arcuate proopiomelanocortin- and neuropeptide Y-containing neurons to the lesion produced by gold thioglucose administration.
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.
Homma
Akiko
A
Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, 183-8526 Tokyo, Japan.
Li
Hong-Peng
HP
Hayashi
Kaori
K
Kawano
Yukari
Y
Kawano
Hitoshi
H
D000818:Animals; D018501:Antirheumatic Agents / Q000008:administration & dosage*; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000187:drug effects* / Q000293:injuries; D006051:Aurothioglucose / Q000008:administration & dosage*; D002452:Cell Count / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D013997:Time Factors
D018501:Antirheumatic Agents; D005904:Glial Fibrillary Acidic Protein; D009478:Neuropeptide Y; D006051:Aurothioglucose; D011333:Pro-Opiomelanocortin