title: Distinct neuronal interactions in anterior inferotemporal areas of macaque monkeys during retrieval of object association memory.
abstract: In macaque monkeys, the anterior inferotemporal cortex, a region crucial for object memory processing, is composed of two adjacent, hierarchically distinct areas, TE and 36, for which different functional roles and neuronal responses in object memory tasks have been characterized. However, it remains unknown how the neuronal interactions differ between these areas during memory retrieval. Here, we conducted simultaneous recordings from multiple single-units in each of these areas while monkeys performed an object association memory task and examined the inter-area differences in neuronal interactions during the delay period. Although memory neurons showing sustained activity for the presented cue stimulus, cue-holding (CH) neurons, interacted with each other in both areas, only those neurons in area 36 interacted with another type of memory neurons coding for the to-be-recalled paired associate (pair-recall neurons) during memory retrieval. Furthermore, pairs of CH neurons in area TE showed functional coupling in response to each individual object during memory retention, whereas the same class of neuron pairs in area 36 exhibited a comparable strength of coupling in response to both associated objects. These results suggest predominant neuronal interactions in area 36 during the mnemonic processing, which may underlie the pivotal role of this brain area in both storage and retrieval of object association memory.
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan thirabay@m.u-tokyo.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hirabayashi
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Tamura
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Takeuchi
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takeda
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Kenji W
authors.initials: KW
authors.lastname: Koyano
authors.affiliation: Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyashita
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology*; D003463:Cues; D008253:Macaca mulatta; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000145:classification / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*
keywords: associative object memory; cell assembly; coherence; inferior temporal cortex; macaque monkey; multiple single-unit recordings