title: Competing Mechanisms of Gamma and Beta Oscillations in the Olfactory Bulb Based on Multimodal Inhibition of Mitral Cells Over a Respiratory Cycle.
abstract: Gamma (∼40-90 Hz) and beta (∼15-40 Hz) oscillations and their associated neuronal assemblies are key features of neuronal sensory processing. However, the mechanisms involved in either their interaction and/or the switch between these different regimes in most sensory systems remain misunderstood. Based on in vivo recordings and biophysical modeling of the mammalian olfactory bulb (OB), we propose a general scheme where OB internal dynamics can sustain two distinct dynamic states, each dominated by either a gamma or a beta regime. The occurrence of each regime depends on the excitability level of granule cells, the main OB interneurons. Using this model framework, we demonstrate how the balance between sensory and centrifugal input can control the switch between the two oscillatory dynamic states. In parallel, we experimentally observed that sensory and centrifugal inputs to the rat OB could both be modulated by the respiration of the animal (2-12 Hz) and each one phase shifted with the other. Implementing this phase shift in our model resulted in the appearance of the alternation between gamma and beta rhythms within a single respiratory cycle, as in our experimental results under urethane anesthesia. Our theoretical framework can also account for the oscillatory frequency response, depending on the odor intensity, the odor valence, and the animal sniffing strategy observed under various conditions including animal freely-moving. Importantly, the results of the present model can form a basis to understand how fast rhythms could be controlled by the slower sensory and centrifugal modulations linked to the respiration. Visual Abstract: See Abstract.
authors.affiliation: Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard , F-69372 Lyon, France.
authors.forename: François
authors.identifier: 0000-0003-1993-8931
authors.initials: F
authors.lastname: David
authors.affiliation: Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard , F-69372 Lyon, France ; Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research and the Department of Child and Adolescent Psychiatry, New York University Langone Medical Center , New York, New York 10022.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Courtiol
authors.affiliation: Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard , F-69372 Lyon, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Buonviso
authors.affiliation: Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, Université Claude Bernard , F-69372 Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fourcaud-Trocmé
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001611:Beta Rhythm / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D009474:Neurons / Q000502:physiology*; D009812:Odorants; D009830:Olfactory Bulb / Q000166:cytology*; D011652:Pulmonary Circulation / Q000502:physiology; D017208:Rats, Wistar
keywords: Beta oscillations; computational model; gamma oscillations; sensory processing; short-term plasticity; top-down processing