title: Reversal of interlaminar signal between sensory and memory processing in monkey temporal cortex.
abstract: The primate temporal cortex implements visual long-term memory. However, how its interlaminar circuitry executes cognitive computations is poorly understood. Using linear-array multicontact electrodes, we simultaneously recorded unit activities across cortical layers in the perirhinal cortex of macaques performing a pair-association memory task. Cortical layers were estimated on the basis of current source density profiles with histological verifications, and the interlaminar signal flow was determined with cross-correlation analysis between spike trains. During the cue period, canonical "feed-forward" signals flowed from granular to supragranular layers and from supragranular to infragranular layers. During the delay period, however, the signal flow reversed to the "feed-back" direction: from infragranular to supragranular layers. This reversal of signal flow highlights how the temporal cortex differentially recruits its laminar circuits for sensory and mnemonic processing.
authors.affiliation: Department of Physiology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Takeuchi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hirabayashi
authors.forename: Keita
authors.initials: K
authors.lastname: Tamura
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyashita
mesh_terms: D000818:Animals; D001245:Association Learning; D003463:Cues; D004567:Electrodes, Implanted; D008251:Macaca; D008253:Macaca mulatta; D008568:Memory / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D014796:Visual Perception