Fig. 8. Forebrain neuronal patterning differences observed in cavefish are Shh-dependent. Cavefish embryos were treated between 15 and 24 hpf with 0.1% ethanol (control), 20 µmol/l or 200 µmol/l cyclopamine and compared to surface fish embryos. In toto lateral views (A-U) and ventral views (insets in V-X) of 48 hpf brains hybridised with the indicated probes. Note the dose-dependence and regionspecificity of the effects. For example, the pituitary Lhx7 or the dorsal hypothalamic Lhx6 signals are not affected by cyclopamine. Scale bar: 50 µm. hyp, hypothalamus; mes, mesencephalon; p3, prosomere 3 (ventral thalamus); pit, pituitary; po, preoptic region; SP, subpallium; zli, zona limitans.