HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 98/1/394    most recent 00124.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Lowry, C. A. Articles by Kay, L. M. Search for Related Content PubMed PubMed Citation Articles by Lowry, C. A. Articles by Kay, L. M.

Chemical Factors Determine Olfactory System Beta Oscillations in Waking Rats

¹Committee on Neurobiology and ²Department of Psychology, Institute for Mind and Biology, The University of Chicago, Chicago, Illinois

Submitted 3 February 2007; accepted in final form 17 April 2007

Recent studies have pointed to olfactory system beta oscillations of the local field potential (15–30 Hz) and their roles both in learning and as specific responses to predator odors. To describe odorant physical properties, resultant behavioral responses and changes in the central olfactory system that may induce these oscillations without associative learning, we tested rats with 26 monomolecular odorants spanning 6 log units of theoretical vapor pressure (estimate of relative vapor phase concentration) and 10 different odor mixtures. We found odorant vapor phase concentration to be inversely correlated with investigation time on the first presentation, after which investigation times were brief and not different across odorants. Analysis of local field potentials from the olfactory bulb and anterior piriform cortex shows that beta oscillations in waking rats occur specifically in response to the class of volatile organic compounds with vapor pressures of 1–120 mmHg. Beta oscillations develop over the first three to four presentations and are weakly present for some odorants in anesthetized rats. Gamma oscillations show a smaller effect that is not restricted to the same range of odorants. Olfactory bulb theta oscillations were also examined as a measure of effective afferent input strength, and the power of these oscillations did not vary systematically with vapor pressure, suggesting that it is not olfactory bulb drive strength that determines the presence of beta oscillations. Theta band coherence analysis shows that coupling strength between the olfactory bulb and piriform cortex increases linearly with vapor phase concentration, which may facilitate beta oscillations above a threshold.

This article has been cited by other articles:

				R. A. Fuentes, M. I. Aguilar, M. L. Aylwin, and P. E. Maldonado Neuronal Activity of Mitral-Tufted Cells in Awake Rats During Passive and Active Odorant Stimulation J Neurophysiol, July 1, 2008; 100(1): 422 - 430. [Abstract] [Full Text] [PDF]

				C. Martin, J. Beshel, and L. M. Kay An Olfacto-Hippocampal Network Is Dynamically Involved in Odor-Discrimination Learning J Neurophysiol, October 1, 2007; 98(4): 2196 - 2205. [Abstract] [Full Text] [PDF]