J1-TENASCIN IS A REPULSIVE SUBSTRATE FOR CENTRAL-NERVOUS-SYSTEM NEURONS

J1/tenascin mediates neuron-astrocyte interactions in vitro and is transiently expressed during CNS development in vivo. It is detectable in discrete zones, for example on astrocytes delineating "barrels" in the rodent somatosensory cortex. To investigate the effects of J1/tenascin on neural cell behavior in vitro, we have generated two monoclonal antibodies specific for protein epitopes on J1/tenascin and used them for immunoaffinity isolation of the molecule from postnatal mouse brain. The purified ECM molecule alone did not support attachment and growth of cerebral astrocytes or E14 mesencephalic, E18 hippocampal, and P6 cerebellar neurons. When various ECM constituents were adsorbed to polyornithine-conditioned glass, a favorable substrate for neural cells, the neurons avoided J1/tenascin; but not laminin- or fibronectin-coated surfaces, while they grew on J1/tenascin-free, polyornithine-containing areas of the coverslip. In contrast, astrocytes formed uniform monolayers on all of these substrates. We conclude that J1/tenascin could serve to define repulsive territories for CNS neurons from different stages of neural development. © 1990.