Complex inter- and intraregional oscillatory dynamics in olfactory processing

Leslie M. Kay, Department of Psychology, The University of Chicago

The rodent olfactory system consists of bidirectionally coupled populations of neurons within and between brain areas. This system produces prominent oscillations in the theta (4-12 Hz), beta (15-30 Hz) and gamma (35-100 Hz) bands, and all of these states represent different types of population cooperativity or synchrony at different time scales and involving unique functional connectivity patterns. Gamma oscillations and neural synchrony within the olfactory bulb (first stage in central olfactory processing) are significantly enhanced when pattern discrimination is difficult. Theta oscillations represent system-wide coupling at the respiratory frequency and help transfer the system between resting and activated states. Beta oscillations indicate olfactory system processes involved in approach/avoid behavioral association learning. Rats modify all of these effects dynamically according to task demands and behavioral state.