Generation of new neurons in dorsal root Ganglia in adult rats after peripheral nerve crush injury.
The evidence of neurons generated ex novo in sensory ganglia of adult animals is still debated. In the present study, we investigated, using high resolution light microscopy and stereological analysis, the changes in the number of neurons in dorsal root ganglia after 30 days from a crush lesion of the rat brachial plexus terminal branches. Results showed, as expected, a relevant hypertrophy of dorsal root ganglion neurons. In addition, we reported, for the first time in the literature, that neuronal hypertrophy was accompanied by massive neuronal hyperplasia leading to a 42% increase of the number of primary sensory neurons. Moreover, ultrastructural analyses on sensory neurons showed that there was not a relevant neuronal loss as a consequence of the nerve injury. The evidence of BrdU-immunopositive neurons and neural progenitors labeled with Ki67, nanog, nestin, and sox-2 confirmed the stereological evidence of posttraumatic neurogenesis in dorsal root ganglia. Analysis of morphological changes following axonal damage in addition to immunofluorescence characterization of cell phenotype suggested that the neuronal precursors which give rise to the newly generated neurons could be represented by satellite glial cells that actively proliferate after the lesion and are able to differentiate toward the neuronal lineage.
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy ; Neuroscience Institute "Cavalieri Ottolenghi" (NICO), 10043 Orbassano, Italy.
Luisa
0000-0002-4881-3313
L
Muratori
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy ; Neuroscience Institute "Cavalieri Ottolenghi" (NICO), 10043 Orbassano, Italy.
Giulia
0000-0002-4795-7024
G
Ronchi
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy ; Neuroscience Institute "Cavalieri Ottolenghi" (NICO), 10043 Orbassano, Italy.
Stefania
0000-0002-8907-473X
S
Raimondo
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy ; Neuroscience Institute "Cavalieri Ottolenghi" (NICO), 10043 Orbassano, Italy.
Stefano
0000-0002-6962-831X
S
Geuna
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy.
Maria Giuseppina
0000-0003-4811-3250
MG
Giacobini-Robecchi
Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy ; Neuroscience Institute "Cavalieri Ottolenghi" (NICO), 10043 Orbassano, Italy ; Department of Anatomy, Chicago College of Osteopathic Medicine, Midwestern University, 555 31st Street, Downers Grove, IL 60515, USA.
Michele
0000-0003-1852-9167
M
Fornaro
D000818:Animals; D002452:Cell Count; D005260:Female; D005727:Ganglia, Spinal / Q000503:physiopathology* / Q000648:ultrastructure; D055495:Neurogenesis; D059348:Peripheral Nerve Injuries / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D011984:Sensory Receptor Cells / Q000502:physiology* / Q000648:ultrastructure