RESTRICTED APPEARANCE OF TENASCIN AND CHONDROITIN SULFATE PROTEOGLYCANS AFTER TRANSECTION AND SPROUTING OF ADULT-RAT POSTCOMMISSURAL FORNIX

Citation
K. Lips et al., RESTRICTED APPEARANCE OF TENASCIN AND CHONDROITIN SULFATE PROTEOGLYCANS AFTER TRANSECTION AND SPROUTING OF ADULT-RAT POSTCOMMISSURAL FORNIX, Journal of neurocytology, 24(6), 1995, pp. 449-464
Citations number
76
Categorie Soggetti
Neurosciences,"Cell Biology
Journal title
ISSN journal
03004864
Volume
24
Issue
6
Year of publication
1995
Pages
449 - 464
Database
ISI
SICI code
0300-4864(1995)24:6<449:RAOTAC>2.0.ZU;2-3
Abstract
Transected fibres of the adult rat postcommissural fornix sprout over short distances but fail to traverse the lesion site and terminate in close vicinity to the wound. As a step in defining the molecular envir onment responsible for regeneration failure at the lesion site, we hav e used immunocytochemistry to analyse the spatio-temporal expression p attern of two putative growth-inhibitory extracellular matrix componen ts, tenascin and chondroitin sulphate proteoglycans and their topograp hical relationship to the sprouting axons. Both tenascin and chondroit in sulphate proteoglycan labelling appeared after fornix transection a nd were confined to the immediate vicinity of the lesion site. While t enascin-labelling was associated with astrocytes and microglia/macroph ages, which accumulate around the wound. Tenascin-like immunoreactivit y disappeared between 17 days and 4 weeks, but chondroitin sulphate pr oteoglycan staining persisted at least up to 14 months after transecti on. Regrowing fornix fibres invaded and elongated within the chondroit in sulphate proteoglycan-immunopositive region up to the lesion site, where they terminated. This zone of axonal. growth inhibition was neit her characterized by an increase of chondroitin sulphate proteoglycan immunoreactivity nor by the presence of tenascin-immunopositive struct ures. The spatio-temporal distribution patterns of tenascin and chondr oitin sulphate proteoglycan and the permeability of the chondroitin su lphate proteoglycan-immunopositive region for sprouting axons do not s upport the hypothesis that chondroitin sulphate proteoglycan alone and /or tenascin inhibit the advance of sprouting fornix fibres.