title: Neuronal interactions between galanin-like-peptide- and orexin- or melanin-concentrating hormone-containing neurons.
abstract: Galanin-like peptide (GALP) is a novel orexigenic neuropeptide that is recently isolated from the porcine hypothalamus. GALP-containing neurons predominantly locate in the hypothalamic arcuate nucleus (ARC). The expression of GALP mRNA within the ARC is increased after the administration of leptin. GALP-containing neurons express leptin receptor and contain alpha-melanocyte-stimulating hormone. We have recently reported that neuropeptide Y (NPY)- and orexin-containing axon terminals are in close apposition with GALP-containing neurons in the ARC. In addition, GALP-containing neurons express orexin-1 receptor (OX1-R). Thus, GALP may function under the influence of leptin and orexin. However, the target neurons of GALP have not yet been clarified. To clarify the neuronal interaction between GALP-containing and other feeding regulating neurons, double-immunostaining method using antibodies against GALP- and orexin- or melanin-concentrating hormone (MCH) was performed in the rat lateral hypothalamus (LH). GALP-immunoreactive fibers appeared to project to the LH around the fornix. They were also found from the rostral to the caudal part of the ARC, paraventricular nucleus (PVH), stria terminalis (BST), medial preoptic area (MPA), and lateral septal nucleus (LSV). Moreover, GALP-like immunoreactive nerve fibers were directly contacted with orexin- and melanin-concentrating hormone (MCH)-like immunoreactive neurons in the LH. Our findings strongly suggest that GALP-containing neurons interact with orexin- and/or MCH-containing neurons in the lateral hypothalamus and that it participates in the regulation of feeding behavior in harmony with other feeding-regulating neurons in the hypothalamus.
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Takenoya
authors.forename: Masami
authors.initials: M
authors.lastname: Hirayama
authors.forename: Haruaki
authors.initials: H
authors.lastname: Kageyama
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Funahashi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kita
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ohtaki
authors.forename: Sachi
authors.initials: S
authors.lastname: Katoh
authors.forename: Masao
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Seiji
authors.initials: S
authors.lastname: Shioda
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000502:physiology*; D001369:Axons / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D004435:Eating / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D044089:Galanin-Like Peptide / Q000096:biosynthesis*; D007028:Hypothalamic Hormones / Q000096:biosynthesis*; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008543:Melanins / Q000096:biosynthesis*; D009479:Neuropeptides / Q000096:biosynthesis*; D000068797:Orexins; D010907:Pituitary Hormones / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D044089:Galanin-Like Peptide; D007028:Hypothalamic Hormones; D047908:Intracellular Signaling Peptides and Proteins; D008543:Melanins; D009479:Neuropeptides; D000068797:Orexins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone