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


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.


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


Supported by : Korea Science and Engineering Foundation


  1. Bernardis, L. L. and Bellinger, L. L. (1998) The dorsomedial hypothalamic nucleus revisited: 1998 update. Proc. Soc. Exp. Biol. Med. 218, 284−306
  2. Bing, C., Pickavance, L., Wang, Q., Frankish, H., Trayhurn, P., et al. (1997) Role of hypothalamic neuropeptide Y neurons in the defective thermogenic response to acute cold exposure in fatty Zucker rats. Neuroscience 80, 277−284
  3. Egawa, M., Yoshimatsu, H., and Bray, G. A. (1991) Neuropeptide Y suppresses sympathetic activity to interscapular brown adipose tissue in rats. Am. J. Physiol. 260, R328−334
  4. Elias, C. F., Aschkenasi, C., Lee, C., Kelly, J., Ahima, R. S., et al. (1999) Leptin differentially regulates NPY and POMC neurons projecting to the lateral hypothalamic area. Neuron 23, 775−786
  5. Grove, K. L. and Smith, M. S. (2003) Ontogeny of the hypothalamic neuropeptide Y system. Physiol. Behav. 79, 47−63
  6. Wouterlood, F. G., Gaykema, R. P., Steinbusch, H. W., Watanabe, T., and Wada, H. (1988) The connections between the septum- diagonal band complex and histaminergic neurons in the posterior hypothalamus of the rat. Anterograde tracing with Phaseolus vulgaris-leucoagglutinin combined with immunocytochemistry of histidine decarboxylase. Neuroscience 26, 827−845
  7. Nagashima, K., Nakai, S., Tanaka, M., and Kanosue, K. (2000) Neuronal circuitries involved in thermoregulation. Auton. Neurosci. 85, 18−25
  8. Kollack-Walker, S., Don, C., Watson, S. J., and Akil, H. (1999) Differential expression of c-fos mRNA within neurocircuits of male hamsters exposed to acute or chronic defeat. J. Neuroendocrinol. 11, 547−559
  9. Nakamura, K., Matsumura, K., Hubschle, T., Nakamura, Y., Hioki, H., et al. (2004) Identification of sympathetic premotor neurons in medullary raphe regions mediating fever and other thermoregulatory functions. J. Neurosci. 24, 5370− 5380
  10. Bing, C., Frankish, H. M., Pickavance, L., Wang, Q., Hopkins, D. F., et al. (1998) Hyperphagia in cold-exposed rats is accompanied by decreased plasma leptin but unchanged hypothalamic NPY. Am. J. Physiol. 274, R62−68
  11. Skofitsch, G. and Jacobowitz, D. M. (1985) Immunohistochemical mapping of galanin-like neurons in the rat central nervous system. Peptides 6, 509−546
  12. Lowell, B. B. and Flier, J. S. (1997) Brown adipose tissue, beta 3-adrenergic receptors, and obesity. Annu. Rev. Med. 48, 307−316
  13. Merchenthaler, I., Lopez, F. J., and Negro-Vilar, A. (1993) Anatomy and physiology of central galanin-containing pathways. Prog. Neurobiol. 40, 711−769
  14. Park, J. J., Baum, M. J., and Tobet, S. A. (1997) Sex difference and steroidal stimulation of galanin immunoreactivity in the ferret's dorsal preoptic area/anterior hypothalamus. J. Comp. Neurol. 389, 277−288
  15. Szekely, M., Petervari, E., Pakai, E., Hummel, Z., and Szelenyi, Z. (2005) Acute, subacute and chronic effects of central neuropeptide Y on energy balance in rats. Neuropeptides 39, 103−115
  16. Cao, W. H., Fan, W., and Morrison, S. F. (2004) Medullary pathways mediating specific sympathetic responses to activation of dorsomedial hypothalamus. Neuroscience 126, 229− 240
  17. Petervari, E., Balasko, M., Uzsoki, B., and Szekely, M. (2006) Effects of neuropeptide Y antagonists on food intake in rats: differences with cold-adaptation. Peptides 27, 150−156
  18. Baulmann, J., Spitznagel, H., Herdegen, T., Unger, T., and Culman, J. (2000) Tachykinin receptor inhibition and c-Fos expression in the rat brain following formalin-induced pain. Neuroscience 95, 813−820
  19. Najimi, M., Bennis, M., Chigr, F., Kopp, N., Moyse, E., et al. (1999) Benzodiazepine binding sites in the human hypothalamus. Autoradiographic study. J. fur Hirnforschung. 39, 493−502
  20. Li, S. P., Park, M. S., Yoon, H., Rhee, K.-H., Bahk, J. Y., et al. (2003) Differential distribution of GABAB1 and GABAB2 receptor mRNAs in the rat brain. Mol. Cells 16, 40−47
  21. McCarthy, H. D., Kilpatrick, A. P., Trayhurn, P., and Williams, G. (1993) Widespread increases in regional hypothalamic neuropeptide Y levels in acute cold-exposed rats. Neuroscience 54, 127−132
  22. Kotz, C. M., Briggs, J. E., Grace, M. K., Levine, A. S., and Billington, C. J. (1998) Divergence of the feeding and thermogenic pathways influenced by NPY in the hypothalamic PVN of the rat. Am. J. Physiol. 275, R471−477