Reduced food anticipatory activity in genetically orexin (hypocretin) neuron-ablated mice

Masashi Akiyama, Tomoyo Yuasa, Naomi Hayasaka, Kazumasa Horikawa, Takeshi Sakurai, Shigenobu Shibata

Research output: Contribution to journalArticle

148 Citations (Scopus)

Abstract

Daily restricted feeding (RF) produces an anticipatory locomotor activity rhythm and entrains the peripheral molecular oscillator independently of the central pacemaker located in the suprachiasmatic nucleus (SCN). As orexins (hypocretins) are neuropeptides that coordinate sleep/wake patterns and motivated behaviours, such as food seeking, we studied the involvement of orexin in the food anticipatory activity (FAA) induced by RF. Daily RF shifted the mRNA rhythm of a clock-controlled gene mDbp in the cerebral cortex and caudate putamen but not in the SCN. Under these experimental conditions, prepro-orexin mRNA and orexin A immunoreactivity in the lateral hypothalamic area (LHA) did not show daily variation. Fasting increased the number of orexin A-ir cells, while RF did not. However, RF shifted the peak of Fos expression of the orexin neurons from night to day. Genetic ablation of orexin neurons in orexin/ataxin-3 transgenic mice severely reduced the formation of FAA under RF conditions. The expression of mNpas2 mRNA, a transcription factor thought to be involved in regulation of the food entrainable oscillator as well as mPer1 and mBmal1 mRNA, was reduced in the forebrain of orexin/ataxin-3 mice. Based on these results, we suggest that activity of the orexin neuron in the LHA contributes to the promotion and maintenance of FAA.

Original languageEnglish
Pages (from-to)3054-3062
Number of pages9
JournalEuropean Journal of Neuroscience
Volume20
Issue number11
DOIs
Publication statusPublished - 2004 Dec 1

Keywords

  • Food anticipatory activity
  • Hypocretin
  • Lateral hypothalamus
  • Orexin
  • Restricted feeding

ASJC Scopus subject areas

  • Neuroscience(all)

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