Document Detail


Electrophysiological effects of neuropeptide S on rat ventromedial hypothalamic neurons in vitro.
MedLine Citation:
PMID:  19925841     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The newly identified neuropeptide S (NPS) is a ligand for a previously orphan G protein-coupled GPR 154 receptor, now named the NPS receptor (NPSR). Previous studies have shown that NPS induces hyperlocomotion, increases arousal and suppresses anxiety-like behaviors via NPSR. Although NPS also inhibits food intake, nothing is known about the neuronal mechanisms underlying this action. Anatomical studies show that NPSRs are expressed abundantly in the dorsomedial part of the ventromedial hypothalamic nucleus (VMH), a satiety center for food intake. Hence, we examined the electrophysiological effects of NPS on rat VMH neurons in vitro. NPS predominantly depolarized the VMH neurons, and the effects were postsynaptic and dose-dependent. Membrane resistance was significantly decreased during the depolarization, suggesting an opening of some ionic channels. The NPS-induced depolarization was significantly attenuated in Ca(2+)-free, NiCl(2)-containing and mibefradil-containing TTX ACSFs, but it did not disappear. The NPS-induced depolarization was also attenuated in low-Na(+) TTX ACSF, and completely abolished in Ca(2+)-free/low-Na(+) TTX ACSF. Pretreatment with 30 microM KB-R7943, an inhibitor of forward-mode Na(+)/Ca(2+) exchanger, did not have any significant effect on the NPS-induced depolarization in Ca(2+)-free TTX ACSF. These results suggest that NPS depolarizes VMH neurons via activations of R- and T-type Ca(2+) channels and nonselective cation channels, and that VMH neurons might be involved in the cellular process through which NPS participates in the regulation of food intake and energy homeostasis.
Authors:
Keitaro Yoshida; Juhyon Kim; Kazuki Nakajima; Yutaka Oomura; Matthew J Wayner; Kazuo Sasaki
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-11-17
Journal Detail:
Title:  Peptides     Volume:  31     ISSN:  1873-5169     ISO Abbreviation:  Peptides     Publication Date:  2010 Apr 
Date Detail:
Created Date:  2010-03-12     Completed Date:  2010-07-01     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8008690     Medline TA:  Peptides     Country:  United States    
Other Details:
Languages:  eng     Pagination:  712-9     Citation Subset:  IM    
Copyright Information:
Copyright (c) 2009 Elsevier Inc. All rights reserved.
Affiliation:
Division of Bio-Information Engineering, Faculty of Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan.
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MeSH Terms
Descriptor/Qualifier:
Animals
Calcium / metabolism
Calcium Channel Blockers / pharmacology
Dose-Response Relationship, Drug
Electrophysiological Phenomena / drug effects*
Male
Mibefradil / pharmacology
Neurons / cytology,  drug effects,  physiology
Neuropeptides / pharmacology*
Nickel / pharmacology
Patch-Clamp Techniques
Rats
Rats, Wistar
Sodium / metabolism
Sodium Channel Blockers / pharmacology
Tetrodotoxin / pharmacology
Ventromedial Hypothalamic Nucleus / cytology*,  drug effects*,  physiology
Chemical
Reg. No./Substance:
0/Calcium Channel Blockers; 0/Neuropeptides; 0/Sodium Channel Blockers; 116644-53-2/Mibefradil; 4368-28-9/Tetrodotoxin; 7440-02-0/Nickel; 7440-23-5/Sodium; 7440-70-2/Calcium; 7718-54-9/nickel chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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