title: Probing diversity within subpopulations of locomotor-related V0 interneurons.
abstract: The V0 interneuronal population is derived from Dbx1 expressing progenitors. Initial studies on these interneurons in the mouse spinal cord demonstrated that they project commissural axons and are involved in coordinating left-right alternation during locomotion. Subsequent work has indicated that the V0 population can be divided into genetically distinct ventral (V0V) and dorsal (V0D) subpopulations, and experimental evidence suggests that each is responsible for left-right alternation at different locomotor speeds. In this study, we perform a series of experiments to probe the location and connectivity of these subpopulations in neonatal mice and demonstrate that they are more diverse than previously predicted. While the distribution of either subpopulation remains consistent along the extent of the lumbar spinal cord, a cluster of V0D cells lateral to the central canal receive substantial input from primary afferents. Retrograde tracing and activity dependent labeling experiments demonstrate that a group of V0 interneurons located in this same region preferentially project axons towards contralateral motoneurons via an oligosynaptic pathway, and are active during fictive locomotion. Our results suggest that this subset of V0 interneurons may be primarily responsible for coordination of left-right alternation during locomotion. Furthermore these experiments indicate that while genetic identity is one determinant of the function of a neuron during locomotion, the specific position in which the cell is located may also play a key role.
authors: Neuroscience and Mental Health Institute, Women and Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.
authors: Anna
authors: A
authors: Griener
authors: Neuroscience and Mental Health Institute, Women and Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.|Department of Physiology, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.
authors: Wei
authors: W
authors: Zhang
authors: Department of Engineering Physics, University of British Columbia, Hennings Building, Room 333A, 6224 Agricultural Road, Vancouver, BC, Canada, V6T 1Z1.
authors: Henry
authors: H
authors: Kao
authors: Neuroscience and Mental Health Institute, Women and Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.
authors: Christine
authors: C
authors: Wagner
authors: Neuroscience and Mental Health Institute, Women and Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.|Department of Physiology, University of Alberta, 3-020D Katz Building, Edmonton, Alberta, T6G 2E1, Canada.
authors: Simon
authors: S
authors: Gosgnach
mesh_terms: D000344:Afferent Pathways / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D007839:Functional Laterality / Q000502:physiology; D005998:Glycine / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D008159:Lumbar Vertebrae; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology; D058953:Neural Stem Cells / Q000502:physiology; D056347:Neuroanatomical Tract-Tracing Techniques; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology / Q000254:growth & development / Q000502:physiology*
chemical_list: C103403:Dbx1 protein, mouse; D018398:Homeodomain Proteins; D016760:Proto-Oncogene Proteins c-fos; D012701:Serotonin; D005998:Glycine
keywords: CPG; development; interneuron; locomotion; spinal cord