Fig. 2.
Conditioned media from glial cells potentiates the actions of FGF2 on the number of tyrosine hydroxylase-immunoreactive cells in cultures of striatal neuronal precursors. Dissociated striatal cells (5 × 105) were grown on poly-l-ornithine-coated glass coverslips under the indicated conditions (CM, 75%; FGF2, 20 ng/ml). Cells were fixed after a 24 hr culture period and processed for indirect immunocytochemistry for TH, as described in Materials and Methods. Because control culture contained between 0 and 8 TH-IR cells and to allow for multiple comparison, the number of TH-IR neurons present in FGF2-treated cultures was taken as 100% (1.1 ± 0.2 TH-IR of the total number of neurons). Results are the mean ± SEM of three independent experiments, each performed in duplicate. Because of the represented scale of the x-axes, the error bars do not appear in some of the histograms. The asterisk indicates the level of significance with respect to CM-treated cultures;p < 0.01.