title: Locomotion, Theta Oscillations, and the Speed-Correlated Firing of Hippocampal Neurons Are Controlled by a Medial Septal Glutamatergic Circuit.
abstract: Before the onset of locomotion, the hippocampus undergoes a transition into an activity-state specialized for the processing of spatially related input. This brain-state transition is associated with increased firing rates of CA1 pyramidal neurons and the occurrence of theta oscillations, which both correlate with locomotion velocity. However, the neural circuit by which locomotor activity is linked to hippocampal oscillations and neuronal firing rates is unresolved. Here we reveal a septo-hippocampal circuit mediated by glutamatergic (VGluT2(+)) neurons that is activated before locomotion onset and that controls the initiation and velocity of locomotion as well as the entrainment of theta oscillations. Moreover, via septo-hippocampal projections onto alveus/oriens interneurons, this circuit regulates feedforward inhibition of Schaffer collateral and perforant path input to CA1 pyramidal neurons in a locomotion-dependent manner. With higher locomotion speed, the increased activity of medial septal VGluT2 neurons is translated into increased axo-somatic depolarization and higher firing rates of CA1 pyramidal neurons. VIDEO ABSTRACT.
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Falko
authors.initials: F
authors.lastname: Fuhrmann
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Justus
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Liudmila
authors.initials: L
authors.lastname: Sosulina
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Beutel
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Friedrichs
authors.affiliation: Department of Epileptology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany; Section of Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schoch
authors.affiliation: Functional Neuroconnectomics Group, Department of Epileptology, Life & Brain Center, University of Bonn, Medical School, Sigmund-Freud Strasse 25, D-53105 Bonn, Germany.
authors.forename: Martin Karl
authors.initials: MK
authors.lastname: Schwarz
authors.affiliation: Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Fuhrmann
authors.affiliation: Neuronal Networks Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany; Department of Epileptology, University of Bonn Medical Center, Sigmund-Freud Strasse 25, 53127 Bonn, Germany. Electronic address: stefan.remy@dzne.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Remy
mesh_terms: D000818:Animals; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D020665:Septum of Brain / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*