Survival and neurite outgrowth of rat cortical neurons in three-dimensional agarose and collagen gel matrices

To better understand interactions between neurons and extracellular matrix equivalents, embryonic day-18 rat cortical neurons were immobilized and mai ntained in culture for up to 24 days in agarose and type I collagen gels. U sing live/ dead staining, neuronal cultures in low density collagen gel las ted at least 3 weeks. At 14 days, over 50% of immobilized cells in collagen gel were found viable while in low density agarose gel no cells survived. In situ cell death detection showed that most, if not all, dead cells in ei ther of the gels underwent apoptosis. The collagen-trapped neurons exhibite d normal neuronal polarity and developed long neurites, estimated at over 5 00 mum. The results suggest that collagen, because it is a major extracellu lar matrix constituent, suppresses apoptosis and provides a suitable substr ate for neuronal survival and differentiation. (C) 2001 Elsevier Science Ir eland Ltd. All rights reserved.