title: Two distinct olfactory bulb sublaminar networks involved in gamma and beta oscillation generation: a CSD study in the anesthetized rat.
abstract: A prominent feature of olfactory bulb (OB) dynamics is the expression of characteristic local field potential (LFP) rhythms, including a slow respiration-related rhythm and two fast alternating oscillatory rhythms, beta (15-30 Hz) and gamma (40-90 Hz). All of these rhythms are implicated in olfactory coding. Fast oscillatory rhythms are known to involve the mitral-granule cell loop. Although the underlying mechanisms of gamma oscillation have been studied, the origin of beta oscillation remains poorly understood. Whether these two different rhythms share the same underlying mechanism is unknown. This study uses a quantitative and detailed current-source density (CSD) analysis combined with multi-unit activity (MUA) recordings to shed light on this question in freely breathing anesthetized rats. In particular, we show that gamma oscillation generation involves mainly the upper half of the external plexiform layer (EPL) and superficial areas of granule cell layer (GRL). In contrast, the generation of beta oscillation involves the lower part of the EPL and deep granule cells. This differential involvement of sublaminar networks is neither dependent on odor quality nor on the precise frequency of the fast oscillation under study. Overall, this study demonstrates a functional sublaminar organization of the rat OB, which is supported by previous anatomical findings.
authors.affiliation: Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, CNRS UMR5292 - INSERM U1028 Lyon, France ; Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, Université Claude Bernard Lyon 1 Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fourcaud-Trocmé
authors.affiliation: Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, CNRS UMR5292 - INSERM U1028 Lyon, France ; Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, Université Claude Bernard Lyon 1 Lyon, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Courtiol
authors.affiliation: Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, CNRS UMR5292 - INSERM U1028 Lyon, France ; Team Olfaction from Coding to Memory, Center for Research in Neuroscience of Lyon, Université Claude Bernard Lyon 1 Lyon, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Buonviso
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000777:Anesthetics; D000818:Animals; D001611:Beta Rhythm / Q000187:drug effects / Q000502:physiology*; D065818:Gamma Rhythm / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009415:Nerve Net / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009812:Odorants; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D009833:Olfactory Pathways / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000777:Anesthetics
keywords: beta; current-source density; gamma; olfactory bulb; oscillation; rat