Extended Data Figure 6. Purkinje cell axons contact NE processes in the LC.

a, Coronal sections counterstained with DAPI (blue) showing representative GFP+ Purkinje cells (green) from Dbh-Cre trans-synaptic tracing experiments described in Fig. 2. Labeled Purkinje cells span the anterior-posterior axis, but are enriched in the medial portion of the ipsilateral cerebellum. b, Sagittal section through the LC of mice heterozygous for the transgenes Pcp2-Cre and Ai14, in which tdTomato (tdT) expression was restricted to cerebellar Purkinje cells and their processes (red). Sections were labeled with DAPI (blue) and anti-TH antibody (green) to label LC-NE neurons. The right panel is a maximum-projection confocal stack taken with a 40X objective of the boxed region in the left panel. Purkinje cell axons are intermingled with TH+ LC neurons and their processes. c, Left, Representative image of a horizontal section collected through the LC of a mouse heterozygous for the transgenes Pcp2-Cre and Ai14. Sections were stained with anti-TH antibody (green) to label LC-NE neurons and their processes, and anti-gephyrin (geph) antibody (white) to label inhibitory post-synaptic densities. Middle, maximum-projection confocal stack taken with a 40X objective of the dashed box of the left panel showing the overlap between tdTomato+ Purkinje cell axons and TH+ LC processes. Right, high magnification of the dashed box of the middle panel, showing that several of these contact points also contained gephyrin+ puncta (arrowheads) within green processes apposing the red processes, consistent with GABAergic Purkinje cell axons forming synapses onto dendrites of TH+ LC-NE neurons. Images in (a) were derived from larger composite images generated by a Leica Ariol Slide Scanner. D, dorsal; V, ventral; A, anterior; P, posterior; L, lateral; M, medial.