Example histology showing overlap between mPFC terminals anterogradely labeled with td Tomato and retrogradely labeled eyeblink-associated cerebellar neurons. Example histology showing overlap between mPFC terminals anterogradely labeled with td Tomato and retrogradely labeled eyeblink-associated cerebellar neurons. A, Mice that received cerebellar cortex infusions showed retrogradely labeled neurons that extended throughout the anterior–posterior basilar pons (green cells, top 2 images) and into and throughout the RTN (2nd and 3rd images). Substantial overlap between mPFC terminals (magenta) and putative eyeblink-associated cells (green) was observed in the anterior basilar pons (top image, inset 1) and extensively in the RTN (2nd and 3rd images, inset 2). B, Mice that received deep nuclei infusions showed retrogradely labeled neurons (green cells) restricted to the caudal basilar pons (2nd image) and less dense labeling in the more anterior RTN (3rd image). Few if any mPFC terminals were observed in the caudal basilar pons and did not appear to overlap substantially with the labeled pontocerebellar neurons observed there (2nd image, notice the general absence of magenta terminal labeling in inset 3). Overlap was observed the RTN (3rd image, inset 4). Br, Bregma; mcp, middle cerebellar peduncle; ml, medial lemniscus; py, pyramidal tract; scp, superior cerebellar peduncle; MR, median raphe nucleus; RPN, reticular nucleus of the pons. Jennifer J. Siegel et al. eneuro 2015;2:ENEURO.0051-14.2015 ©2015 by Society for Neuroscience