Format

Send to

Choose Destination
See comment in PubMed Commons below
Eur J Neurosci. 2009 Mar;29(5):1027-34. doi: 10.1111/j.1460-9568.2009.06644.x.

Perceptual stability during dramatic changes in olfactory bulb activation maps and dramatic declines in activation amplitudes.

Author information

  • 1Department of Physiology, Yale University School of Medicine, New Haven, CT 06510, USA. ryota.homma@yale.edu

Abstract

We compared the concentration dependence of the ability of rats to identify odorants with the calcium signals in the nerve terminals of the olfactory receptor neurons. Although identification performance decreased with concentrations both above and below the training stimuli it remained well above random at all concentrations tested (between 0.0006% and 35% of saturated vapor). In contrast, the calcium signals in the same awake animals were much smaller than their maximum values at odorant concentrations <1% of saturated vapor. In addition, maps of activated glomeruli changed dramatically as odorant concentration was reduced. Thus perceptual stability exists in the face of dramatic changes in both the amplitude and the maps of the input to the olfactory bulb. The data for the concentration dependence of the response of the most sensitive glomeruli for each of five odorants was fitted with a Michaelis-Menten (Hill) equation. The fitted curves were extrapolated to odorant concentrations several orders of magnitude lower the smallest observed signals and suggest that the calcium response at low odorant concentrations is > 1000 times smaller than the response at saturating odorant concentrations. We speculate that only a few spikes in olfactory sensory neurons may be sufficient for correct odorant identification.

PMID:
19291227
PMCID:
PMC2762425
DOI:
10.1111/j.1460-9568.2009.06644.x
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Support Center