Dopaminergic phenotype of hNT cells in vitro

We investigated the catecholaminergic nature of cultured hNT neurons previo usly treated either for 4 or 5 weeks with retinoic acid (RA). There were si gnificantly mon tyrosine hydroxylase (TH)-positive neurons (60%) in culture s treated for 4 weeks with RA compared to 5 week-treated cultures (less tha n or equal to 15%). Furthermore, numerous TH-positive hNT cells were also i mmunoreactive to dopamine transporter (DAT), dopamine receptor (D2) and ald ehyde dehydrogenase (AHD-2), an enzyme exclusively expressed by dopaminergi c (DA) ventral mesencephalic (VM) precursors. Thus this cell line has all t he necessary cellular machinery to produce functional DA neurons and theref ore is a good alternative tissue source to fetal VM. (C) 2000 Elsevier Scie nce B.V. All rights reserved.