title: V3 interneuron subpopulations in the mouse spinal cord undergo distinctive postnatal maturation processes.
abstract: Mice develop weight-bearing locomotion within the first 2-3 weeks of birth, a period during which motoneurons (MNs) and interneurons (INs) that control locomotor activities undergo rapid maturation. In this study, we investigate the maturation of two subpopulations of V3 INs in the mouse spinal cord during this period. To do this, we conducted whole-cell patch-clamp recordings of tdTomato fluorescent protein-expressing spinal V3 INs from Sim1(Cre/+);tdTom mice at post-natal day (P) 0, P4, P9 and P14 and compared their properties to those at P21. Combining electrophysiology with computational analyses, we show that dorsal and ventral V3 subpopulations are physiologically distinct at birth, but the electrophysiological properties of V3 INs change significantly during the first three post-natal weeks. We further reveal that there are multiple developmental phases of both V3 subpopulations during the maturation process. The different developmental trajectories of physiological properties also coincide with changes in an animal's locomotor behavior. These properties likely reflect the differential functions of V3 subpopulations in maturing spinal locomotor circuits.
authors: Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
authors: J
authors: J
authors: Borowska
authors: Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
authors: C T
authors: CT
authors: Jones
authors: Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
authors: D
authors: D
authors: Deska-Gauthier
authors: Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada. Electronic address: ying.zhang@dal.ca.
authors: Y
authors: Y
authors: Zhang
mesh_terms: D000200:Action Potentials / Q000235:genetics; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001703:Biophysics; D004558:Electric Stimulation; D007395:Interneurons / Q000145:classification / Q000502:physiology*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018408:Patch-Clamp Techniques; D025341:Principal Component Analysis; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology* / Q000254:growth & development*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D008164:Luminescent Proteins; D012097:Repressor Proteins; C101750:Sim1 protein, mouse
keywords: computational analysis; electrophysiological properties; interneuron subpopulations; neuronal maturation; patch-clamp recordings; spinal cord