Fig. 3.

Cerebello-striatal connectivity to MSNs and ChAT interneurons. a Stereotaxic injection and analysis scheme for multisynaptic tracing. Injections in D1R-cre (N = 3), A2A-cre mice (N = 9) and ChAT-cre mice (N = 7) are initiated at P11-P12. First, AAV2-DiO-G-TVA is injected into the dorsal striatum (ST). This results in cre-dependent expression of viral Glycoprotein (G) and the surface receptor TVA in D2R-positive or ChAT-positive striatal cells. At the same time, AAV2-DiO-G and AAV2-cre-GFP are injected into the intralaminar thalamic nuclei (ILN) to express glycoprotein in ILN neurons (see Supplementary Figs. 3 and 4 for additional information on relay cells and RV-G expression). Seven days after the first injection, EnvA-pseudotyped, glycoprotein-deficient rabies viruses are injected into the dorsal striatum. Five dorsal–ventral (DV) planes (plane 1, 2, 3, 4, 5) used for analysis illustrated. b Retrogradely labeled DCN neurons are registered at four dorsal–ventral planes. Cells obtained by back-labeling in D1R-cre, A2A-cre, and ChAT-cre mice are color-coded blue, magenta, and black, respectively. Data derived from tracings performed in N = 3 D1R-cre mice, N = 7 A2A-cre mice, and N = 7 ChAT-cre mice. Scale bar: 1 mm. c–e Morphology of DCN neurons retrogradely labeled in D1R-cre, A2A-cre, and ChAT-cre (arrows). Camera lucida drawings of example cells (arrows) reveal columnar and multipolar neuron morphologies. Scale bars: 500 µm and 100 µm, respectively. f Subnuclei distribution of retrogradely labeled DCN neurons. Note the overall preference for interposed nuclei (IntA, IntP) and lateral dentate nucleus in D1R-cre, A2A-cre and ChAT-cre mice. Back-labeled DCN neurons in A2A-cre mice have preferential labeling in medial dentate nucleus when compared to ChAT-cre mice (p < 0.05, chi-square test). N = 3 mice and n = 51 DCN cells for D1R-cre, N = 9 mice and n = 350 DCN cells for A2A-cre, and N = 7 mice and n = 226 DCN cells for ChAT-cre. Mean ± SEM