Cohen B R, Sladek C D
Department of Physiology and Biophysics, Finch University of Health Sciences/The Chicago Medical School, North Chicago, Illinois 60064, USA.
Exp Neurol. 1997 Oct;147(2):525-31. doi: 10.1006/exnr.1997.6621.
The availability of sufficient numbers of dopaminergic neurons for transplantation has been an important issue. Recently, it has been shown that the ventral floor plate (FP4-positive) cells and the transcription factor HNF-3beta are important in the signals that terminate proliferation and produce differentiation of the dopaminergic phenotype. In this study, dispersed mesencephalon from embryonic rats at Day 11 postcoitus (E-11), 1 day prior to the birth of TH cells, were cultured for 48 h and 1 week to evaluate TH neuronal differentiation and/or proliferation in vitro. The number of TH cells increased 14x between 48 h and 1 week in culture. In dispersed E-14 cultures, the presence of FP4 and HNF-3beta markers was demonstrated using immunohistochemistry. The majority of FP4-positive cell clusters were associated with TH neurons, suggesting that floor plate cells may have participated in TH neuron differentiation in culture. Antisense oligonucleotide probe for HNF-3beta mRNA added daily to cultured E-14 cells blocked the HNF-3beta expression, but had no effect on the FP4 or TH expression. These studies suggest a potentially important role for floor plate cells in the differentiation of TH cells, and differentiation and/or proliferation of TH cells in dispersed cultures of E-11 is demonstrated.
