title: Diversity of LFPs Activated in Different Target Regions by a Common CA3 Input.
abstract: Identifying the pathways contributing to local field potential (LFP) events and oscillations is essential to determine whether synchronous interregional patterns indicate functional connectivity. Here, we studied experimentally and numerically how different target structures receiving input from a common population shape their LFPs. We focused on the bilateral CA3 that sends gamma-paced excitatory packages to the bilateral CA1, the lateral septum, and itself (recurrent input). The CA3-specific contribution was isolated from multisite LFPs in target regions using spatial discrimination techniques. We found strong modulation of LFPs by target-specific features, including the morphology and population arrangement of cells, the timing of CA3 inputs, volume conduction from nearby targets, and co-activated inhibition. Jointly they greatly affect the LFP amplitude, profile, and frequency characteristics. For instance, ipsilateral (Schaffer) LFPs occluded contralateral ones, and septal LFPs arise mostly from remote sources while local contribution from CA3 input was minor. In the CA3 itself, gamma waves have dual origin from local networks: in-phase excitatory and nearly antiphase inhibitory. Also, waves may have different duration and varying phase in different targets. These results indicate that to explore the cellular basis of LFPs and the functional connectivity between structures, besides identifying the origin population/s, target modifiers should be considered.
authors.affiliation: Department of Systems Neuroscience, Cajal Institute-CSIC, Madrid 28002, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Martín-Vázquez
authors.affiliation: Department of Systems Neuroscience, Cajal Institute-CSIC, Madrid 28002, Spain.|Current address: Institute for Cellular and Integrative Neuroscience, CNRS UPR 3212 - 5 rue Blaise Pascal, Strasbourg 67084, France.
authors.forename: Nuria
authors.initials: N
authors.lastname: Benito
authors.affiliation: Department of Applied Mathematics, Faculty of Mathematics, Instituto de Matemática Interdisciplinar, Universidad Complutense de Madrid, Madrid 28040, Spain.|N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia.
authors.forename: Valeri A
authors.initials: VA
authors.lastname: Makarov
authors.affiliation: Department of Systems Neuroscience, Cajal Institute-CSIC, Madrid 28002, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Herreras
authors.affiliation: Department of Systems Neuroscience, Cajal Institute-CSIC, Madrid 28002, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Makarova
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology; D056654:CA3 Region, Hippocampal / Q000187:drug effects / Q000502:physiology*; D002408:Catheters, Indwelling; D003198:Computer Simulation; D004567:Electrodes, Implanted; D005260:Female; D007839:Functional Laterality; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D065818:Gamma Rhythm / Q000502:physiology; D008012:Lidocaine / Q000494:pharmacology; D008564:Membrane Potentials; D008959:Models, Neurological; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D017207:Rats, Sprague-Dawley; D012686:Septal Nuclei / Q000187:drug effects / Q000502:physiology; D061567:Voltage-Gated Sodium Channel Blockers / Q000494:pharmacology
chemical_list: D058787:GABA-A Receptor Antagonists; D061567:Voltage-Gated Sodium Channel Blockers; D008012:Lidocaine; D001640:Bicuculline
keywords: CA3; LFP biophysics; gamma oscillations; local field potentials; neuron models