Relationships Between Odor-elicited Oscillations in the Salamander Olfactory Epithelium and Olfactory Bulb. Kathleen M. Dorries and John S. Kauer. Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
APStracts 6:0501N, 1999.
Oscillations in neuronal population activity, or the synchronous neuronal spiking that underlies them, are thought to play a functional role in sensory processing in the CNS. In the olfactory system, stimulus-induced oscillations are observed both in central processing areas and in the peripheral receptor epithelium. To examine the relationship between these peripheral and central oscillations, we recorded local field potentials simultaneously from the olfactory epithelium and olfactory bulb in tiger salamanders (Ambystoma tigrinum). Stimulus-induced oscillations recorded at these two sites were matched in frequency and slowed concurrently over the time-course of the response, suggesting that the oscillations share a common source or are modulated together. Both the power and duration of oscillations increased over a range of amyl acetate concentrations from 2.5 x 10-2 to 1 x 10-1 dilution of saturated vapor, but peak frequency was not affected. The frequency of the oscillation did vary with different odorant compounds in both OE and OB: amyl acetate, ethyl fenchol and d-carvone elicited oscillations of significantly different frequencies, and there was no difference in OE and OB oscillation frequencies. No change in the power or frequency of OE oscillations was observed after sectioning the olfactory nerve, indicating that the OE oscillations have a peripheral source. Finally, application of 1.0 and 10 (M tetrodotoxin to the epithelium blocked OE oscillations in a dose dependent and reversible manner, suggesting that peripheral olfactory oscillations are related to receptor neuron spiking.
Received 22 February 1999; accepted in final form 5 October 1999.
APS Manuscript Number J151-9.
Article publication pending Journal of Neurophysiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 21 December 1999