Interaction of orexin/hypocretin-like immunoreactive neurons with melanin-concentrating hormone and α-melanocyte-stimulating hormone neurons in brain of a pleuronectiform fish, barfin flounder
Article first published online: 5 OCT 2008
© 2008 Japanese Society of Fisheries Science
Volume 74, Issue 5, pages 1040–1046, October 2008
How to Cite
AMIYA, N., AMANO, M., IIGO, M., YAMANOME, T., TAKAHASHI, A. and YAMAMORI, K. (2008), Interaction of orexin/hypocretin-like immunoreactive neurons with melanin-concentrating hormone and α-melanocyte-stimulating hormone neurons in brain of a pleuronectiform fish, barfin flounder. Fisheries Science, 74: 1040–1046. doi: 10.1111/j.1444-2906.2008.01622.x
- Issue published online: 5 OCT 2008
- Article first published online: 5 OCT 2008
- Received 27 February 2008. Accepted 30 April 2008.
- barfin flounder;
- melanin-concentrating hormone;
- melanocyte-stimulating hormone;
Immunohistochemical localization of orexin/hypocretin in the brain of a pleuronectiform fish, the barfin flounder Verasper moseri was examined as the first step in unraveling the possible function of the hormone in the brain. Orexin-A-like immunoreactive (ir) cell bodies were found to be located in the nucleus posterioris periventricularis (NPPv) of the hypothalamus, and orexin-A-like-ir fibers were detected not only in the hypothalamus but also extensively throughout the brain. The orexin-A-like-ir cell bodies did not project their fibers to the pituitary gland. Since melanin-concentrating hormone (MCH) and α-melanocyte-stimulating hormone (α-MSH) are suggested to regulate food intake in addition to orexin/hypocretin in the teleost fish, it was examined whether neural connections exist between orexin neurons and the MCH and α-MSH neurons in the barfin flounder brain by using double-staining immunohistochemistry. Some orexin-A-like-ir fibers were in close contact with the MCH-ir and α-MSH-ir cell bodies in the hypothalamus. Moreover, a few MCH-ir and α-MSH-ir fibers were in close contact with the orexin-A-like-ir cell bodies in the hypothalamus. These results suggest that reciprocal connections exist between the orexin and MCH neurons and between the orexin and α-MSH neurons in the brain of the barfin flounder.