title: Spatial coding and physiological properties of hippocampal neurons in the Cornu Ammonis subregions.
abstract: It is well-established that the feed-forward connected main hippocampal areas, CA3, CA2, and CA1 work cooperatively during spatial navigation and memory. These areas are similar in terms of the prevalent types of neurons; however, they display different spatial coding and oscillatory dynamics. Understanding the temporal dynamics of these operations requires simultaneous recordings from these regions. However, simultaneous recordings from multiple regions and subregions in behaving animals have become possible only recently. We performed large-scale silicon probe recordings simultaneously spanning across all layers of CA1, CA2, and CA3 regions in rats during spatial navigation and sleep and compared their behavior-dependent spiking, oscillatory dynamics and functional connectivity. The accuracy of place cell spatial coding increased progressively from distal to proximal CA1, suddenly dropped in CA2, and increased again from CA3a toward CA3c. These variations can be attributed in part to the different entorhinal inputs to each subregions, and the differences in theta modulation of CA1, CA2, and CA3 neurons. We also found that neurons in the subregions showed differences in theta modulation, phase precession, state-dependent changes in firing rates and functional connectivity among neurons of these regions. Our results indicate that a combination of intrinsic properties together with distinct intra- and extra-hippocampal inputs may account for the subregion-specific modulation of spiking dynamics and spatial tuning of neurons during behavior. © 2016 Wiley Periodicals, Inc.
authors.affiliation: MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary.
authors.forename: Azahara
authors.initials: A
authors.lastname: Oliva
authors.affiliation: MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary.
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Ruiz
authors.affiliation: New York University Neuroscience Institute, New York, New York.|Center for Neural Science, New York University, New York, New York.
authors.forename: György
authors.initials: G
authors.lastname: Buzsáki
authors.affiliation: MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary.|New York University Neuroscience Institute, New York, New York.
authors.forename: Antal
authors.initials: A
authors.lastname: Berényi
mesh_terms: D000200:Action Potentials; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D056651:CA2 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D056654:CA3 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D004567:Electrodes, Implanted; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D020318:Rats, Long-Evans; D012815:Signal Processing, Computer-Assisted; D013028:Space Perception / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology; D013826:Theta Rhythm / Q000502:physiology
keywords: CA regions; deep vs. superficial; electrophysiology; phase precession; place field