Leslie Kay

Institute for Mind and Biology

University of Chicago

Task-dependent Functional Reconfiguration of the Olfactory Network

The mammalian olfactory system displays several oscillatory modes at the level of the local field potential (LFP). Gamma oscillations (40-100 Hz) have been linked to processing of odorant stimuli in the olfactory bulb (OB), beta oscillations (15-30 Hz) have been linked to associative learning and systemwide coupling. We find differential expression of these two oscillatory states dependent on the task that a rat performs in odor discrimination. In a 2-alternative choice (2AC) task, gamma oscillations predominate when rats learn to discriminate highly overlapping input patterns. In a go/no-go (GNG) task, beta oscillations predominate with the same odorants. We also show that the beta oscillation network, while weaker in the 2AC task, appears to mediate information transfer in the same manner as in the GNG task, with the OB driving beta oscillations in other olfactory and limbic areas. The beta oscillatory mode is presented as an underlying default network that may be weakened in the 2AC task. Thus, the olfactory system modifies its dynamic structure as needed for the task at hand.

References

Kay LM, Beshel J, Brea J, Martin C, Rojas-Libano D, Kopell N (2009) Olfactory oscillations: the what, how and what for. Trends Neurosci 32:207-14

 

Kay LM (2005) Theta oscillations and sensorimotor performance. Proc Natl Acad Sci USA 102:3863-8