Mechanisms and functions of respiration-driven gamma oscillations in the primary olfactory cortex
Abstract
Gamma oscillations are believed to underlie cognitive processes by shaping the formation of transient neuronal partnerships on a millisecond scale. These oscillations are coupled to the phase of breathing cycles in several brain areas, possibly reflecting local computations driven by sensory inputs sampled at each breath. Here, we investigated the mechanisms and functions of gamma oscillations in the piriform (olfactory) cortex of awake mice to understand their dependence on breathing and how they relate to local spiking activity. Mechanistically, we find that respiration drives gamma oscillations in the piriform cortex, which correlate with local feedback inhibition and result from recurrent connections between local excitatory and inhibitory neuronal populations. Moreover, respiration-driven gamma oscillations are triggered by the activation of mitral/tufted cells in the olfactory bulb and are abolished during ketamine/xylazine anesthesia. Functionally, we demonstrate that they locally segregate neuronal assemblies through a winner-take-all computation leading to sparse odor coding during each breathing cycle. Our results shed new light on the mechanisms of gamma oscillations, bridging computation, cognition and physiology.
Data availability
All the data employed is freely available at: http://crcns.org, pcx-1 dataset. http://dx.doi.org/10.6080/K00C4SZB
Article and author information
Author details
Funding
Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Adriano BL Tort
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Adriano BL Tort
Comisión Sectorial de Investigación Científica
- Joaquin Gonzalez
- Pablo Torterolo
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: The present study used a third-party dataset and required no ethical permit for the performed computational analyses. The experimental protocols of the original data source (Bolding and Franks, 2018) were approved by Duke University Institutional Animal Care and Use Committee (protocol A220-15-08).
Copyright
© 2023, Gonzalez et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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