title: State-dependent sensory gating in olfactory cortex.
abstract: Sensory systems show behavioral state-dependent gating of information flow that largely depends on the thalamus. Here we examined whether the state-dependent gating occurs in the central olfactory pathway that lacks a thalamic relay. In urethane-anesthetized rats, neocortical EEG showed a periodical alternation between two states: a slow-wave state (SWS) characterized by large and slow waves and a fast-wave state (FWS) characterized by faster waves. Single-unit recordings from olfactory cortex neurons showed robust spike responses to adequate odorants during FWS, whereas they showed only weak responses during SWS. The state-dependent change in odorant-evoked responses was observed in a majority of olfactory cortex neurons, but in only a small percentage of olfactory bulb neurons. These findings demonstrate a powerful state-dependent gating of odor information in the olfactory cortex that works in synchrony with the gating of other sensory systems. They suggest a state-dependent switchover of signal processing modes in the olfactory cortex.
authors.affiliation: Department of Physiology, Graduate School of Medicine, School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Murakami
authors.forename: Hideki
authors.initials: H
authors.lastname: Kashiwadani
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kirino
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
mesh_terms: D000818:Animals; D004569:Electroencephalography; D008297:Male; D019579:Neocortex / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009830:Olfactory Bulb / Q000502:physiology*; D009833:Olfactory Pathways / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*; D012903:Smell / Q000502:physiology*