INDUCTION OF TYROSINE-HYDROXYLASE GENE-EXPRESSION IN HUMAN FETAL CEREBRAL-CORTEX

Human foetal cerebral cortex (9-14 weeks gestational age) was dissecte d out and cultured in microwell plates. It was then treated with brain -derived neurotrophic factor (BDNF, 50 ng/ml), dopamine (10 mM) or the ir combination. After 5 weeks of this treatment tyrosine hydroxylase ( TH)-immunopositive neurones were detected at a level of 0.73% of total neurones present. This represented 300-500 TH + neurones per microwel l. None were seen in untreated cultures. This correlates with inductio n of the entire dopaminergic phenotype in foetal rat cerebral cortex ( E1214) by the same co-treatment applied for a much shorter time period (7 days), which implies that the complete dopaminergic phenotype is a lso induced in cultured human foetal tissue over a longer period, refl ecting the 5-fold longer neuronal gestational period. (C) 1998 Elsevie r Science Ireland Ltd. All rights reserved.