Serum and CNTF stimulate oligodendroglia and reduce fiber outgrowth from striatal cultures

Organotypic slice cultures of newborn rat striatal tissue displayed an exce ptionally dense and fasciculated outgrowth of GABAergic fibers when grown i n a chemically defined medium, compared to serum-containing medium, The enh anced fiber growth was not the result of an increased density of GABAergic neurons in the cultures, but coincided with a marked reduction of 2',3'-cyc lic nucleotide 3'-phosphodiesterase (CNPase)-immunoreactive cells within an d around the cultures. An inverse, causal relationship between the number o f CNPase-positive cells, presumably of oligodendroglial lineage, and GABAer gic fiber outgrowth was further evidenced by the observation that addition of ciliary neurotrophic factor (CNTF) to the chemically defined medium resu lted in both an increase in CNPase-positive cells and a decrease in GABAerg ic fiber outgrowth. The observations suggest that CNTF and serum indirectly inhibit axonal growth by stimulating oligodendroglial cells. (C) 1999 Acad emic Press.