COMPARTMENTAL DISTRIBUTION OF SULFATED GLYCOSAMINOGLYCANS IN LATERAL AND MEDIAL MIDBRAIN ASTROGLIAL CULTURES

Sulfated glycosaminoglycans (S-GAGs) were isolated from the pericellul ar (P), intracellular (I), and extracellular (E) compartments of astro cytes cultures from lateral (L) and medial (M) sectors of embryonic mo use midbrain; these sectors differ in their ability to support neurite growth (L, permissive, M, non-permissive for growth) and laminin depo sition patterns (L, fibrillar; M, punctate pattern). The total amount of S-GAGs in M cultures was twice that in L cultures and was particula rly high in the P compartment of M glia. Both glial cultures showed he paran sulfate (HS) in the three cellular compartments but chondroitin sulfate (CS) GAGs were vestigial in I and P compartments of L glia. Ou r results suggest that M and L astrocytes are heterogeneous concerning the ability to synthesize GAGs and distribute them among the differen t cellular compartments. Together with other data (Garcia-Abreu et al: J Neurosci Res 40:471, 1995; Garcia-Abreu et al: Neuroreport 6:761, 1 995), the present results suggest that this heterogeneous features mig ht be at least partially responsible for the differential effects of L and M glial cultures on the growth of midbrain neurons and may also b e involved in complex ways in the guidance of axons at the brain midli ne. (C) 1996 Wiley-Liss, Inc.