A temporal study of axonal degeneration and glial scar formation following a standardized crush injury of the optic nerve in the adult rat.
OBJECTIVE
In this methodological study, we describe a standardized optic nerve injury model in adult rats. The temporal pattern of the glial response is mapped in relation to axonal regeneration and degeneration.


METHODS
A standardized optic nerve crush injury was made in adult rats, using a fine pair of forceps with a preset pressure of 0.6 N during 10 seconds.


RESULTS
This crush injury resulted in a pronounced astroglial and microglial proliferation 2-7 dpi. Degenerative axons distal to the lesion presented a gradual decrease in neurofilament immunoreactivity. In contrast, Fluoro-Jade staining was gradually increased in these degenerative axons from 2-7 dpi. Regeneration was observed proximal to the lesion in sprouts double labeled with the tracer Fluoro-Gold and anti-GAP43.


CONCLUSIONS
The standardized optic nerve crush injury model used in the present study resulted in a reproducible degenerative pattern including a pronounced astroglial and microglial proliferation. The gradual decrease in Neurofilament immunoreactivity in degenerative axons, and a gradual increase in Fluoro-Jade staining was paralleled with a spontaneous regeneration proximal to the lesion, shown with tracing and GAP43-immunoreactivity. The combination of these markers and this experimental setup thus allows analysis of the entire degenerative/regenerative process in a standardized CNS axotomy model.
Ohlsson
Marcus
M
Department of Clinical Neuroscience, Section of Neurosurgery, Karolinska Institutet and Hospital, Stockholm, Sweden. marcus.ohlsson@ks.se
Mattsson
Per
P
Svensson
Mikael
M
D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D001369:Axons / Q000378:metabolism* / Q000502:physiology; D051926:Basigin; D001798:Blood Proteins; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D004195:Disease Models, Animal; D005260:Female; D005452:Fluoresceins; D005456:Fluorescent Dyes / Q000378:metabolism; D019922:GAP-43 Protein / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008562:Membrane Glycoproteins / Q000378:metabolism; D009409:Nerve Crush / Q000379:methods* / Q000592:standards; D009410:Nerve Degeneration / Q000503:physiopathology*; D016900:Neurofilament Proteins / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism / Q000502:physiology*; D020221:Optic Nerve Injuries / Q000378:metabolism / Q000503:physiopathology*; D009930:Organic Chemicals; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; C497886:BSG protein, human; D001798:Blood Proteins; C102624:Bsg protein, Gallus gallus; C079432:Bsg protein, rat; D005452:Fluoresceins; D005456:Fluorescent Dyes; D019922:GAP-43 Protein; D005904:Glial Fibrillary Acidic Protein; D008562:Membrane Glycoproteins; D016900:Neurofilament Proteins; D009930:Organic Chemicals; C435731:fluoro jade; D051926:Basigin; D001973:Bromodeoxyuridine