title: Independent control of gamma and theta activity by distinct interneuron networks in the olfactory bulb.
abstract: Circuits in the brain possess the ability to orchestrate activities on different timescales, but the manner in which distinct circuits interact to sculpt diverse rhythms remains unresolved. The olfactory bulb is a classic example of a place in which slow theta and fast gamma rhythms coexist. Furthermore, inhibitory interneurons that are generally implicated in rhythm generation are segregated into distinct layers, neatly separating local and global motifs. We combined intracellular recordings in vivo with circuit-specific optogenetic interference to examine the contribution of inhibition to rhythmic activity in the mouse olfactory bulb. We found that the two inhibitory circuits controlled rhythms on distinct timescales: local, glomerular networks coordinated theta activity, regulating baseline and odor-evoked inhibition, whereas granule cells orchestrated gamma synchrony and spike timing. Notably, granule cells did not contribute to baseline rhythms or sniff-coupled odor-evoked inhibition. Thus, activities on theta and gamma timescales are controlled by separate, dissociable inhibitory networks in the olfactory bulb.
authors.affiliation: 1] Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany. [2] Division of Neurophysiology, MRC National Institute for Medical Research, London, UK.
authors.forename: Izumi
authors.initials: I
authors.lastname: Fukunaga
authors.affiliation: 1] Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany. [2] Division of Neurophysiology, MRC National Institute for Medical Research, London, UK. [3] Department Anatomy and Cell Biology, Faculty of Medicine, University of Heidelberg, Heidelberg, Germany.
authors.forename: Jan T
authors.initials: JT
authors.lastname: Herb
authors.affiliation: 1] Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany. [2] Division of Neurophysiology, MRC National Institute for Medical Research, London, UK.
authors.forename: Mihaly
authors.initials: M
authors.lastname: Kollo
authors.affiliation: Media Lab, Synthetic Neurobiology Group, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Edward S
authors.initials: ES
authors.lastname: Boyden
authors.affiliation: 1] Behavioural Neurophysiology, Max Planck Institute for Medical Research, Heidelberg, Germany. [2] Division of Neurophysiology, MRC National Institute for Medical Research, London, UK. [3] Department Anatomy and Cell Biology, Faculty of Medicine, University of Heidelberg, Heidelberg, Germany. [4] Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
authors.forename: Andreas T
authors.initials: AT
authors.lastname: Schaefer
mesh_terms: D000818:Animals; D005071:Evoked Potentials / Q000502:physiology; D065818:Gamma Rhythm / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009433:Neural Inhibition / Q000502:physiology; D009812:Odorants; D009830:Olfactory Bulb / Q000166:cytology* / Q000502:physiology*; D062308:Optogenetics; D018408:Patch-Clamp Techniques; D012903:Smell / Q000502:physiology; D013826:Theta Rhythm / Q000502:physiology*; D014851:Wakefulness