Figure 4.

3D reconstructions of the cerebellar nuclei, showing differences in second-order cerebellar nuclear inputs to the MIP versus the LIPv at 2.5 days (disynaptic inputs via cerebellothalamocortical projections). The 3D reconstructions were made using Neurolucida by stacking together serial 50-μm sections (200-μm spacing). Ventral views (−90° rotation from the plane of the cross sections in Fig. 3, viewed using Solid Model) are shown here in solid mode, without perspective, for the ensemble of the cerebellar nuclei (top left) and for individual contralateral nuclei (boxed images). In this figure and Figure 8, ventral views have been flipped on the y-axis to show the contralateral (right) cerebellum on the right side. In boxed images, horizontal lines indicate the levels of the cross sections shown in Figure 3 (same letter index). Cerebellar nuclei are color coded as in Figure 3 (blue: D; green: IP; orange-brown: IA; magenta: F). Note the predominantly contralateral distribution of transneuronally labeled neurons (dots), with major input to both MIP and LIPv from IP and D and minor contributions from IA and F, and the prominent topographical differences of the cerebellar populations targeting MIP versus LIPv.