Galanin-like peptide is target for regulation by orexin in the rat hypothalamus.
Galanin-like peptide (GALP) is a newly discovered 60 amino acid peptide from the porcine hypothalamus. GALP has been shown to be expressed predominantly in the arcuate nucleus (ARC) of the rat hypothalamus, a region considered to be one of the most important feeding-regulating centers in the brain. GALP-containing neurons in the ARC express leptin receptors, but relationships between GALP and other feeding-regulating neurons have not yet been fully elucidated. Given that Orexin (OX)-containing neurons make synaptic inputs to the ARC, we thus examined the relationship between GALP and OX in the ARC by use of a dual immunostaining technique. OX-immunoreactive fibers appeared to be closely apposed to GALP-immunoreactive cell bodies and their processes. We also examined whether the OX receptor, OX(1)-R was expressed in the GALP-containing neurons. Immunoreactivity for both OX(1)-R and GALP was detectable in 9.6 % neurons (range 4.2-14.6%) in the ARC. These findings strongly suggest that GALP may participate in the regulation of feeding behavior under the influence of leptin and OX.
Takenoya
Fumiko
F
Department of Anatomy, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Aihara
Kenji
K
Funahashi
Hisayuki
H
Matsumoto
Hirokazu
H
Ohtaki
Tetsuya
T
Tsurugano
Shinobu
S
Yamada
Shuori
S
Katoh
Sachi
S
Kageyama
Haruaki
H
Takeuchi
Masao
M
Shioda
Seiji
S
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis* / Q000502:physiology; D044089:Galanin-Like Peptide; D007031:Hypothalamus / Q000737:chemistry* / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000502:physiology; D009479:Neuropeptides / Q000032:analysis* / Q000502:physiology; D064446:Orexin Receptors; D000068797:Orexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide / Q000032:analysis* / Q000502:physiology
D002352:Carrier Proteins; D044089:Galanin-Like Peptide; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide