title: Intraganglionic interactions between satellite cells and adult sensory neurons.
abstract: Perineuronal satellite cells have an intimate anatomical relationship with sensory neurons that suggests close functional collaboration and mutual support. We examined several facets of this relationship in adult sensory dorsal root ganglia (DRG). Collaboration included the support of process outgrowth by clustering of satellite cells, induction of distal branching behavior by soma signaling, the capacity of satellite cells to respond to distal axon injury of its neighboring neurons, and evidence of direct neuron-satellite cell exchange. In vitro, closely adherent coharvested satellite cells routinely clustered around new outgrowing processes and groups of satellite cells attracted neurite processes. Similar clustering was encountered in the pseudounipolar processes of intact sensory neurons within intact DRG in vivo. While short term exposure of distal growth cones of unselected adult sensory neurons to transient gradients of a PTEN inhibitor had negligible impacts on their behavior, exposure of the soma induced early and substantial growth of their distant neurites and branches, an example of local soma signaling. In turn, satellite cells sensed when distal neuronal axons were injured by enlarging and proliferating. We also observed that satellite cells were capable of internalizing and expressing a neuron fluorochrome label, diamidino yellow, applied remotely to distal injured axons of the neuron and retrogradely transported to dorsal root ganglia sensory neurons. The findings illustrate a robust interaction between intranganglionic neurons and glial cells that involve two way signals, features that may be critical for both regenerative responses and ongoing maintenance.
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Christie
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: Dilip
authors.initials: D
authors.lastname: Koshy
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: Chu
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: GuiFang
authors.initials: G
authors.lastname: Guo
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Martinez
authors.affiliation: Division of Neurology, University of Alberta.
authors.forename: Arul
authors.initials: A
authors.lastname: Duraikannu
authors.affiliation: Division of Neurology, University of Alberta. Electronic address: zochodne@ualberta.ca.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Zochodne
mesh_terms: D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000378:metabolism / Q000502:physiology; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D020439:Growth Cones / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D027161:Satellite Cells, Perineuronal / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000502:physiology*
keywords: Dorsal root ganglia; Nerve injury; Neuron-glia communication; Perineuronal satellite cells; Peripheral nerve