Neuronal interaction between melanin-concentrating hormone- and alpha-melanocyte-stimulating hormone-containing neurons in the goldfish hypothalamus |
| |
Authors: | Shimakura Sei-Ichi Kojima Kenji Nakamachi Tomoya Kageyama Haruaki Uchiyama Minoru Shioda Seiji Takahashi Akiyoshi Matsuda Kouhei |
| |
Institution: | Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan. |
| |
Abstract: | Intracerebroventricular (ICV) administration of melanin-concentrating hormone (MCH) inhibits food intake in goldfish, unlike in rodents, suggesting that its anorexigenic action is mediated by alpha-melanocyte-stimulating hormone (alpha-MSH) but not corticotropin-releasing hormone. This led us to investigate whether MCH-containing neurons in the goldfish brain have direct inputs to alpha-MSH-containing neurons, using a confocal laser scanning microscope, and to examine whether the anorexigenic action of MCH is also mediated by other anorexigenic neuropeptides, such as cholecystokinin (CCK) and pituitary adenylate cyclase-activating polypeptide (PACAP), using their receptor antagonists. MCH- and alpha-MSH-like immunoreactivities were distributed throughout the brain, especially in the diencephalon. MCH-containing nerve fibers or endings lay in close apposition to alpha-MSH-containing neurons in the hypothalamus in the posterior part of the nucleus lateralis tuberis (NLTp). The inhibitory effect of ICV-injected MCH on food intake was not affected by treatment with a CCK A/CCK B receptor antagonist, proglumide, or a PACAP receptor (PAC(1) receptor) antagonist, PACAP((6-38)). ICV administration of MCH at a dose sufficient to inhibit food consumption also did not influence expression of the mRNAs encoding CCK and PACAP. These results strongly suggest that MCH-containing neurons provide direct input to alpha-MSH-containing neurons in the NLTp of goldfish, and that MCH plays a crucial role in the regulation of feeding behavior as an anorexigenic neuropeptide via the alpha-MSH (melanocortin 4 receptor)-signaling pathway. |
| |
Keywords: | Goldfish MCH α -MSH Anorexigenic action Neuronal interaction |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|