title: Long-Distance Descending Spinal Neurons Ensure Quadrupedal Locomotor Stability.
abstract: Locomotion is an essential animal behavior used for translocation. The spinal cord acts as key executing center, but how it coordinates many body parts located across distance remains poorly understood. Here we employed mouse genetic and viral approaches to reveal organizational principles of long-projecting spinal circuits and their role in quadrupedal locomotion. Using neurotransmitter identity, developmental origin, and projection patterns as criteria, we uncover that spinal segments controlling forelimbs and hindlimbs are bidirectionally connected by symmetrically organized direct synaptic pathways that encompass multiple genetically tractable neuronal subpopulations. We demonstrate that selective ablation of descending spinal neurons linking cervical to lumbar segments impairs coherent locomotion, by reducing postural stability and speed during exploratory locomotion, as well as perturbing interlimb coordination during reinforced high-speed stepping. Together, our results implicate a highly organized long-distance projection system of spinal origin in the control of postural body stabilization and reliability during quadrupedal locomotion.
authors.affiliation: Biozentrum, Department of Cell Biology, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Ludwig
authors.initials: L
authors.lastname: Ruder
authors.affiliation: Biozentrum, Department of Cell Biology, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Aya
authors.initials: A
authors.lastname: Takeoka
authors.affiliation: Biozentrum, Department of Cell Biology, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland. Electronic address: silvia.arber@unibas.ch.
authors.forename: Silvia
authors.initials: S
authors.lastname: Arber
mesh_terms: D000818:Animals; D002574:Cervical Vertebrae; D066294:Commissural Interneurons / Q000502:physiology*; D005552:Forelimb; D005684:Gait / Q000502:physiology*; D006614:Hindlimb; D008124:Locomotion / Q000502:physiology*; D008159:Lumbar Vertebrae; D051379:Mice; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D050599:Vesicular Glutamate Transport Protein 2 / Q000378:metabolism; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism
chemical_list: C493477:Slc17a6 protein, mouse; D050599:Vesicular Glutamate Transport Protein 2; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse
keywords: genetic identity; interlimb coordination; locomotion; motor control; posture; spinal cord