Ghrelin enhances olfactory sensitivity and exploratory sniffing in rodents and humans.

Journal Article (Journal Article)

Olfaction is an integral part of feeding providing predictive cues that anticipate ingestion. Although olfactory function is modulated by factors such as prolonged fasting, the underlying neural mechanisms remain poorly understood. We recently identified ghrelin receptors in olfactory circuits in the brain. We therefore investigated the role of the appetite-stimulating hormone ghrelin in olfactory processing in rodents and humans, testing the hypothesis that ghrelin lowers olfactory detection thresholds and enhances exploratory sniffing, both being related to food seeking. In rats, intracerebroventricular ghrelin decreased odor detection thresholds and increased sniffing frequency. In humans, systemic ghrelin infusions significantly enhanced sniff magnitudes in response to both food and nonfood odorants and air in comparison to control saline infusions but did not affect the pleasantness ratings of odors. This is consistent with a specific effect on odor detection and not the hedonic value of odors. Collectively, our findings indicate that ghrelin stimulates exploratory sniffing and increases olfactory sensitivity, presumably enhancing the ability to locate, identify, and select foods. This novel role is consistent with ghrelin's overall function as a signal amplifier at the molecular interface between environmental and nutritional cues and neuroendocrine circuits controlling energy homeostasis.

Full Text

Duke Authors

Cited Authors

  • Tong, J; Mannea, E; Aimé, P; Pfluger, PT; Yi, C-X; Castaneda, TR; Davis, HW; Ren, X; Pixley, S; Benoit, S; Julliard, K; Woods, SC; Horvath, TL; Sleeman, MM; D'Alessio, D; Obici, S; Frank, R; Tschöp, MH

Published Date

  • April 13, 2011

Published In

Volume / Issue

  • 31 / 15

Start / End Page

  • 5841 - 5846

PubMed ID

  • 21490225

Pubmed Central ID

  • PMC3089941

Electronic International Standard Serial Number (EISSN)

  • 1529-2401

Digital Object Identifier (DOI)

  • 10.1523/JNEUROSCI.5680-10.2011


  • eng

Conference Location

  • United States