Abstract

Accumulating evidence suggests that the olfactory bulbs (OBs) function as an independent circadian system regulating daily rhythms in olfactory performance. However, the cells and signals in the olfactory system that generate and coordinate these circadian rhythms are unknown. Using real-time imaging of gene expression, we found that the isolated olfactory epithelium and OB, but not the piriform cortex, express similar, sustained circadian rhythms in PERIOD2 (PER2). In vivo, PER2 expression in the OB of mice is circadian, approximately doubling with a peak around subjective dusk. Furthermore, mice exhibit circadian rhythms in odor detection performance with a peak at approximately subjective dusk. We also found that circadian rhythms in gene expression and odor detection performance require vasoactive intestinal polypeptide (VIP) or its receptor VPAC2R. VIP is expressed, in a circadian manner, in interneurons in the external plexiform and periglomerular layers, whereas VPAC2R is expressed in mitral and external tufted cells in the OB. Together, these results indicate that VIP signaling modulates the output from the OB to maintain circadian rhythms in the mammalian olfactory system.

Original languageEnglish
Pages (from-to)6040-6046
Number of pages7
JournalJournal of Neuroscience
Volume34
Issue number17
DOIs
StatePublished - 2014

Keywords

  • Circadian
  • Clock
  • Olfaction
  • Olfactory discrimination
  • Rhythms
  • VIP

Fingerprint

Dive into the research topics of 'Vasoactive intestinal polypeptide mediates circadian rhythms in mammalian olfactory bulb and olfaction'. Together they form a unique fingerprint.

Cite this