Diurnal variation in orexin A immunoreactivity and prepro-orexin mRNA in the rat central nervous system

Shahrad Taheri, David Sunter, Catherine Dakin, Sasha Moyes, Leighton Seal, James Gardiner, Michela Rossi, Mohammad Ghatei, Stephen Bloom

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Abstract

Orexins are a family of neuropeptides originally believed to be important mediators of food intake. The wide distribution of orexins and their receptors, however, has suggested other regulatory functions for these peptides including involvement in sleep and arousal mechanisms. In this study, we have demonstrated diurnal variation in orexin A immunoreactivity in the pons, from where locus coeruleus noradrenergic neurones innervate other brain areas to stimulate arousal, and in the preoptic/anterior hypothalamic region, an area implicated in the regulation of sleep and circadian rhythms. Orexin A immunoreactivity decreased by 50% in the preoptic/anterior hypothalamus from 09:00 to 21:00 h (P<0.0001), whilst in the pons, it increased by over 30% from 09:00 to 01:00 h (P=0.02). Prepro-orexin mRNA also displayed diurnal variation. This further suggests that orexins are involved in the regulation of the sleep/wake cycle.

Original languageEnglish
Pages (from-to)109-112
Number of pages4
JournalNeuroscience Letters
Volume279
Issue number2
DOIs
Publication statusPublished - 28 Jan 2000
Externally publishedYes

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Keywords

  • Arousal
  • Diurnal variation
  • Northern blot analysis
  • Orexin A
  • Prepro-orexin mRNA
  • Radioimmunoassay
  • Sleep

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Taheri, S., Sunter, D., Dakin, C., Moyes, S., Seal, L., Gardiner, J., Rossi, M., Ghatei, M., & Bloom, S. (2000). Diurnal variation in orexin A immunoreactivity and prepro-orexin mRNA in the rat central nervous system. Neuroscience Letters, 279(2), 109-112. https://doi.org/10.1016/S0304-3940(99)00955-6