Short-Term Cold Exposure May Cause a Local Decrease of Neuropeptide Y in the Rat Hypothalamus

  • Park, Joong Jean (Department of Physiology, College of Medicine, Korea University) ;
  • Lee, Heung Kyung (Department of Physiology, College of Medicine, Korea University) ;
  • Shin, Min Woo (Department of Physiology, College of Medicine, Korea University) ;
  • Kim, Sung Jin (Department of Physiology, College of Medicine, Korea University) ;
  • Noh, Seung Yeon (Department of Medical Sciences, College of Medicine, Korea University) ;
  • Shin, Jin (Department of Medical Sciences, College of Medicine, Korea University) ;
  • Yu, Woo Sung (Department of Medical Sciences, College of Medicine, Korea University)
  • Received : 2006.11.21
  • Accepted : 2006.11.23
  • Published : 2007.02.28

Abstract

Neuropeptide Y (NPY) is an orexigenic and hypothermic peptide. To understand its role in hypothermic conditions, male rats were placed in a $24^{\circ}C$ or $4^{\circ}C$ air chamber for 1.5 h. The expression of c-Fos protein, and NPY mRNA and protein, was analyzed in the hypothalamus 1 h-2 h later. The cold treatment increased the number of c-Fos-immunoreactive cells in the paraventricular hypothalamic nucleus (PVN) and arcuate nucleus (ARC). At the same time it decreased the density of NPY-immunoreactive components in the PVN, dorsomedial hypothalamic nucleus and ARC, as well as of NPY transcripts in the PVN and ARC. No colocalization of c-Fos with NPY was detected. These results suggest that short-term cold exposure should reduce indirectly NPY production in some hypothalamic nuclei to facilitate thermogenesis without inducing feeding behavior.

Keywords

Arcuate Nucleus;c-Fos;Hypothalamus;Hypothermia;Neuropeptide Y

Acknowledgement

Supported by : Korea Science and Engineering Foundation

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