Affiliations: Department of Clinical Neuroscience, Section of
Neurosurgery, Karolinska Institutet and Hospital, Stockholm, Sweden
Note: [] Corresponding author: Marcus Ohlsson, M.D., Department of
Neurosurgery, Karolinska Hospital, 171 76 Stockholm, Sweden. Tel.: +46 8 5177
0000 operator; Fax: +46 8 5177 1778; E-mail: marcus.ohlsson@ks.se
Abstract: Purpose: 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. Conclusion: 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.
