title: Olfactory cortical neurons read out a relative time code in the olfactory bulb.
abstract: Odor stimulation evokes complex spatiotemporal activity in the olfactory bulb, suggesting that both the identity of activated neurons and the timing of their activity convey information about odors. However, whether and how downstream neurons decipher these temporal patterns remains unknown. We addressed this question by measuring the spiking activity of downstream neurons while optogenetically stimulating two foci in the olfactory bulb with varying relative timing in mice. We found that the overall spike rates of piriform cortex neurons (PCNs) were sensitive to the relative timing of activation. Posterior PCNs showed higher sensitivity to relative input times than neurons in the anterior piriform cortex. In contrast, olfactory bulb neurons rarely showed such sensitivity. Thus, the brain can transform a relative time code in the periphery into a firing rate-based representation in central brain areas, providing evidence for the relevance of a relative time-based code in the olfactory bulb.
authors.affiliation: Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Rafi
authors.initials: R
authors.lastname: Haddad
authors.forename: Anne
authors.initials: A
authors.lastname: Lanjuin
authors.forename: Linda
authors.initials: L
authors.lastname: Madisen
authors.forename: Hongkui
authors.initials: H
authors.lastname: Zeng
authors.forename: Venkatesh N
authors.initials: VN
authors.lastname: Murthy
authors.forename: Naoshige
authors.initials: N
authors.lastname: Uchida
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001931:Brain Mapping; D000075402:Channelrhodopsins; D004192:Discrimination, Psychological / Q000502:physiology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009812:Odorants; D009830:Olfactory Bulb / Q000502:physiology*; D051842:Olfactory Marker Protein / Q000235:genetics / Q000378:metabolism; D009833:Olfactory Pathways / Q000166:cytology* / Q000502:physiology*; D062308:Optogenetics; D018408:Patch-Clamp Techniques; D012903:Smell / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000235:genetics; D013997:Time Factors; D000098815:T-bet Transcription Factor
chemical_list: D000075402:Channelrhodopsins; D008164:Luminescent Proteins; D051842:Olfactory Marker Protein; C497598:Omp protein, mouse; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor