Beyond Sensory Coding: The Cognitive Context of Olfactory Neurodynamics

Abstract

The local field potential from the mammalian olfactory system displays several oscillatory modes. Gamma oscillations (40–100 Hz) are associated with odor stimulation in the olfactory bulb (OB) and are enhanced with odor discrimination learning in a 2-alternative choice task when odors are very similar. Beta oscillations (15–30 Hz) are associated with learning in a go/no-go task. These two oscillatory modes represent different cognitive states, and different networks appear to support them. Gamma oscillations are produced locally within the OB, while beta oscillations rely on bidirectional connections with the rest of the olfactory and limbic systems. These results help elucidate the context-dependent sensory representation seen at every neurophysiological level in the OB.