title: Remodelling of spared proprioceptive circuit involving a small number of neurons supports functional recovery.
abstract: Studies show that limited functional recovery can be achieved by plasticity and adaptation of the remaining circuitry in partial injuries in the central nervous system, although the new circuits that arise in these contexts have not been clearly identified or characterized. We show here that synaptic contacts from dorsal root ganglions to a small number of dorsal column neurons, a caudal extension of nucleus gracilis, whose connections to the thalamus are spared in a precise cervical level 1 lesion, underwent remodeling over time. These connections support proprioceptive functional recovery in a conditioning lesion paradigm, as silencing or eliminating the remodelled circuit completely abolishes the recovered proprioceptive function of the hindlimb. Furthermore, we show that blocking repulsive Wnt signalling increases axon plasticity and synaptic connections that drive greater functional recovery.
authors.affiliation: Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Edmund R
authors.initials: ER
authors.lastname: Hollis
authors.affiliation: Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Nao
authors.initials: N
authors.lastname: Ishiko
authors.affiliation: Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Maysam
authors.initials: M
authors.lastname: Pessian
authors.affiliation: Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Kristine
authors.initials: K
authors.lastname: Tolentino
authors.affiliation: Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Corinne A
authors.initials: CA
authors.lastname: Lee-Kubli
authors.affiliation: Department of Pathology, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Nigel A
authors.initials: NA
authors.lastname: Calcutt
authors.affiliation: Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Zou
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D005260:Female; D005727:Ganglia, Spinal / Q000502:physiology; D006614:Hindlimb / Q000294:innervation; D009416:Nerve Regeneration / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D020127:Recovery of Function / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology; D013569:Synapses / Q000502:physiology