Anatomical organization of temporally correlated neural calcium activity in the hippocampal CA1 region
Lujia Chen,
Xiaoxiao Lin,
Qiao Ye,
Zoran Nenadic,
Todd C. Holmes,
Douglas A. Nitz,
Xiangmin Xu
Affiliations
Lujia Chen
Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA 92697-1275, USA; Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697-2715, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
Xiaoxiao Lin
Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA 92697-1275, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
Qiao Ye
Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA 92697-1275, USA; Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697-2715, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
Zoran Nenadic
Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697-2715, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
Todd C. Holmes
Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697- 4560, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA
Douglas A. Nitz
Department of Cognitive Science, University of California, La Jolla, La Jolla, CA 92093, San Diego; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA; Corresponding author
Xiangmin Xu
Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA 92697-1275, USA; Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697-2715, USA; Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Department of Computer Science, University of California, Irvine, Irvine, CA 92697-3435, USA; The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA 92697, USA; Corresponding author
Summary: Hippocampal CA1 neuronal ensembles generate sequential patterns of firing activity that contribute to episodic memory formation and spatial cognition. Here we used in vivo calcium imaging to record neural ensemble activities in mouse hippocampal CA1 and identified CA1 excitatory neuron sub-populations whose members are active across the same second-long period of time. We identified groups of hippocampal neurons sharing temporally correlated neural calcium activity during behavioral exploration and found that they also organized as clusters in anatomical space. Such clusters vary in membership and activity dynamics with respect to movement in different environments, but also appear during immobility in the dark suggesting an internal dynamic. The strong covariance between dynamics and anatomical location within the CA1 sub-region reveals a previously unrecognized form of topographic representation in hippocampus that may guide generation of hippocampal sequences across time and therefore organize the content of episodic memory.
