Eaj. Joosten et al., Collagen IV deposits do not prevent regrowing axons from penetrating the lesion site in spinal cord injury, J NEUROSC R, 62(5), 2000, pp. 686-691
Scarring is suggested to impede axon regrowth across the lesion site in the
injured adult mammalian central nervous system. Collagen Type IV, as a maj
or component of the scar formed after injury, is an impediment for successf
ul axonal regeneration and a decrease in its amount is a prerequisite for r
egrowing axons to cross the lesion in the postcommissural fornix in the inj
ured adult rat (Stichel et al. [1999] Neurosci. 93:321-333). The aim of the
present study was to analyze the relationship between collagen IV deposits
and regrowing axons at various times after dorsal hemi-section of the adul
t rat spinal cord. Immunohistochemical double staining revealed that penetr
ating neurofilament-positive axons and collagen IV deposits were co-localiz
ed in the lesion site in the initial stages of axonal sprouting (between 7
and 14 days post-operatively) and were still present 1 and 2 months post-op
eratively. Interestingly, collagen IV-immunoreactive areas located around c
ystic cavities formed at the site of injury 1 month post-operatively, were
devoid of axons. In conclusion, our observations indicate that collagen IV
deposits after spinal cord injury do not prevent neurofilament-positive reg
rowing axons from penetrating the lesion site. J. Neurosci. Res. 62: 686-69
1, 2000. (C)2000 Wiley-Liss, Inc.