Fig. 8. TAG-1-immunoreactive cells form a continuous band from the thalamic eminence to the neocortical MZ. This coronal section is taken from an E12 mouse telencephalon. TAG-1-immunoreactive cells are densely packed in the thalamic eminence (eminentia thalami, EMT) where it approaches the MGE (1), and these cells extend into the mantle layers of both the MGE and the LGE, forming a pioneer migratory stream (arrows). This hitherto unobserved anatomical distribution of TAG-1 immunoreactivity suggests that the MZ pioneer neurons may originate caudal to MGE and may explain the lack of effects of the Nkx2.1 deletion on the distribution and migration of these neurons. V3, third ventricle; LV, lateral ventricle. (Scale bar = 100 ?m.)

1. Kim, A. S., Anderson, S. A., Rubenstein, J. L., Lowenstein, D. H. & Pleasure, S. J. (2001) J. Neurosci. 21, RC132.