MIGRATING FETAL ASTROCYTES DO NOT INTRAVASATE SINCE THEY ARE EXCLUDEDFROM BLOOD-VESSELS BY VITAL BASEMENT-MEMBRANE

Astrocytes appear to be excluded from blood vessels. In order to test this observation, pial blood vessels were seeded upon cultures of puri fied E14 fetal astrocytes. One to seven days later cocultures were imm unohistochemically stained for laminin and fibronectin. Confocal micro scopy revealed that laminin-positive cultured astrocytes migrated from the coverslip to and on to the surface of the blood vessels. The feta l astrocytes migrated along the basement membrane but did not enter th e blood vessel. Viable (live) basement membrane is a barrier to astroc yte intravasation and is a pathway for astrocyte migration. Published by Elsevier Science Ltd.