Fig. 7. CK1 inhibitors block the effects of Wnt-5a on dopaminergic differentiation. (A) Wnt-5a (100 ng/ml) increased the number of tyrosine-hydroxylase-positive (TH⁺) neurons in rat E14.5 ventral midbrain precursor cultures. However, addition of increasing doses of the chemical inhibitor of CK1 (D4476) reduced the numbers of TH⁺ neurons. (B) Double TH-Hoechst33258 immunostaining shows an increase in the number of TH immunoreactive neurons after treatment with Wnt-5a (100 ng/ml). Addition of 25 µM D4476 to Wnt-5a-treated cultures decreases the number of TH⁺ neurons after 3 days. Bar, 25 µm.