title: Interlamellar CA1 network in the hippocampus.
abstract: To understand the cellular basis of learning and memory, the neurophysiology of the hippocampus has been largely examined in thin transverse slice preparations. However, the synaptic architecture along the longitudinal septo-temporal axis perpendicular to the transverse projections in CA1 is largely unknown, despite its potential significance for understanding the information processing carried out by the hippocampus. Here, using a battery of powerful techniques, including 3D digital holography and focal glutamate uncaging, voltage-sensitive dye, two-photon imaging, electrophysiology, and immunohistochemistry, we show that CA1 pyramidal neurons are connected to one another in an associational and well-organized fashion along the longitudinal axis of the hippocampus. Such CA1 longitudinal connections mediate reliable signal transfer among the pyramidal cells and express significant synaptic plasticity. These results illustrate a need to reconceptualize hippocampal CA1 network function to include not only processing in the transverse plane, but also operations made possible by the longitudinal network. Our data will thus provide an essential basis for future computational modeling studies on information processing operations carried out in the full 3D hippocampal network that underlies its complex cognitive functions.
authors.affiliation: Departments of Neurology and.
authors.forename: Sunggu
authors.initials: S
authors.lastname: Yang
authors.affiliation: Center for Integrative Neuroscience, Department of Neurology, University of California, San Francisco, CA 94608;
authors.forename: Sungchil
authors.initials: S
authors.lastname: Yang
authors.affiliation: Departments of Neurology and.
authors.forename: Thais
authors.initials: T
authors.lastname: Moreira
authors.affiliation: Department of Biology, Morgan State University, Baltimore, MD 21251;
authors.forename: Gloria
authors.initials: G
authors.lastname: Hoffman
authors.affiliation: Center for Neurobiology and Behavior, University of Pennsylvania, Philadelpia, PA 19104-3403.
authors.forename: Greg C
authors.initials: GC
authors.lastname: Carlson
authors.affiliation: Center for Integrative Neuroscience, Department of Neurology, University of California, San Francisco, CA 94608;
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Bender
authors.affiliation: Physiology, University of Maryland School of Medicine, Baltimore, MD 21201;
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Alger
authors.affiliation: Departments of Neurology and Physiology, University of Maryland School of Medicine, Baltimore, MD 21201; Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201; and ctang@som.umaryland.edu.
authors.forename: Cha-Min
authors.initials: CM
authors.lastname: Tang
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods; D056547:CA1 Region, Hippocampal / Q000166:cytology* / Q000502:physiology; D056654:CA3 Region, Hippocampal / Q000166:cytology* / Q000502:physiology; D003712:Dendrites / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology / Q000502:physiology; D017774:Long-Term Potentiation / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009434:Neural Pathways; D009473:Neuronal Plasticity / Q000502:physiology*; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D055366:Synaptic Potentials / Q000502:physiology
keywords: CA1 association fibers; DHR; longitudinal axons; sequence memory