In the developing CNS nestin expression becomes progressively restricted to proliferative zones. Analysis of nestin expression in the head by whole mount in situ hybridization. (A-C): lateral views, anterior left, dorsal up, eyes were removed for better visualization of the expression pattern in the DC. A mid-saggital focal plane is shown (D-O, except L): dorsal views, anterior left, the dorsoventral level of the focal plane is indicated at left. (L): lateral view. Abbreviations: CCe: Cerebellum; CMZ: ciliary marginal zone; DC: diencephalon; GCL: ganglion cell layer; MHB: midbrain hindbrain boundary; Pr: pretectum; Ret: retina; S: subpallium: TC: telencephalon; TeO: optic tectum. Scale bars: 100 μm.