The lab has been working on the underlying mechanics of gamma oscillations in the olfactory bulb for some time.  This pair of publications by theoretician Guoshi Li and slice physiologist Shane Peace has established the core principles of bulbar oscillogenesis:  glomerulus-associated columns oscillate independently via a GABA(A) receptor-independent mechanism (likely based directly on mitral cell subthreshold oscillations) and are coupled by GABA(A) receptors into a broadly synchronized and resonance-enhanced PRING dynamics (for pyramidal resonance interneuron network gamma).

Li G, Cleland TA (2017)  A coupled-oscillator model of olfactory bulb gamma oscillations.  PLoS Computational Biology 13(11): e1005760.

The olfactory bulb transforms not only the information content of the primary sensory representation, but also its underlying coding metric. High-variance, slow-timescale primary odor representations are transformed by bulbar circuitry into secondary representations based on principal neuron spike patterns that are tightly regulated in time. This emergent fast timescale for signaling is reflected in gamma-band local field potentials, presumably serving to efficiently integrate olfactory sensory information into the temporally regulated information networks of the central nervous system. To understand this transformation and its integration with interareal coordination mechanisms requires that we understand its fundamental dynamical principles. Using a biophysically explicit, multiscale model of olfactory bulb circuitry, we here demonstrate that an inhibition-coupled intrinsic oscillator framework, pyramidal resonance interneuron network gamma (PRING), best captures the diversity of physiological properties exhibited by the olfactory bulb. Most importantly, these properties include global zero-phase synchronization in the gamma band, the phase-restriction of informative spikes in principal neurons with respect to this common clock, and the robustness of this synchronous oscillatory regime to multiple challenging conditions observed in the biological system. These conditions include substantial heterogeneities in afferent activation levels and excitatory synaptic weights, high levels of uncorrelated background activity among principal neurons, and spike frequencies in both principal neurons and interneurons that are irregular in time and much lower than the gamma frequency. This coupled cellular oscillator architecture permits stable and replicable ensemble responses to diverse sensory stimuli under various external conditions as well as to changes in network parameters arising from learning-dependent synaptic plasticity.

Peace ST, Johnson BC, Li G, Kaiser ME, Fukunaga I, Schaefer AT, Molnar AC, Cleland TA (2017)  Coherent olfactory bulb gamma oscillations arise from coupling independent columnar oscillators.  BioRxiv doi: 10.1101/213827.

Spike timing-based representations of sensory information depend on embedded dynamical frameworks within neural structures that establish the rules of local computation and interareal communication. Here, we investigated the dynamical properties of mouse olfactory bulb circuitry. Neurochemical activation or optogenetic stimulation of sensory afferents evoked persistent (minutes) gamma oscillations in the local field potential. These oscillations arose from slower, GABA(A) receptor-independent intracolumnar oscillators coupled by GABA(A)-ergic synapses into a faster, broadly coherent network oscillation. Consistent with the theoretical properties of coupled-oscillator networks, the spatial extent of zero-phase coherence was bounded in slices by the reduced density of lateral interactions. The intact in vivo network, however, exhibits long-range lateral interactions theoretically sufficient to enable zero-phase coherence across the complete network. These coupled-oscillator dynamics thereby establish a common clock, robust to biological heterogeneities, that is capable of supporting gamma-band phase coding across the spiking output of olfactory bulb principal neurons.