Neuroanatomy of melanocortin-4 receptor pathway in the lateral hypothalamic area

Huxing Cui, Jong Woo Sohn, Laurent Gautron, Hisayuki Funahashi, Kevin W. Williams, Joel K. Elmquist, Michael Lutter

Research output: Contribution to journalArticle

50 Scopus citations

Abstract

The central melanocortin system regulates body energy homeostasis including the melanocortin-4 receptor (MC4R). The lateral hypothalamic area (LHA) receives dense melanocortinergic inputs from the arcuate nucleus of the hypothalamus and regulates multiple processes including food intake, reward behaviors, and autonomic function. By using a mouse line in which green fluorescent protein (GFP) is expressed under control of the MC4R gene promoter, we systemically investigated MC4R signaling in the LHA by combining double immunohistochemistry, electrophysiology, and retrograde tracing techniques. We found that LHA MC4R-GFP neurons coexpress neurotensin as well as the leptin receptor but do not coexpress other peptide neurotransmitters found in the LHA including orexin, melanin-concentrating hormone, and nesfatin-1. Furthermore, electrophysiological recording demonstrated that leptin, but not the MC4R agonist melanotan II, hyperpolarizes the majority of LHA MC4R-GFP neurons in an ATP- sensitive potassium channel-dependent manner. Retrograde tracing revealed that LHA MC4R-GFP neurons do not project to the ventral tegmental area, dorsal raphe nucleus, nucleus accumbens, and spinal cord, and only limited number of neurons project to the nucleus of the solitary tract and parabrachial nucleus. Our findings provide new insights into MC4R signaling in the LHA and its potential implications in homeostatic regulation of body energy balance.

Original languageEnglish (US)
Pages (from-to)4168-4183
Number of pages16
JournalJournal of Comparative Neurology
Volume520
Issue number18
DOIs
StatePublished - Dec 15 2012

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Keywords

  • Electrophyiosology
  • Leptin receptor
  • Melanin-concentrating hormone
  • Nesfatin
  • Neurotensin
  • Orexin

ASJC Scopus subject areas

  • Neuroscience(all)

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