Figure 11. Analysis of vM1 and M2 long-range projections. A–F, Coinjection of AAV-EGFP and retrograde tracer in vM1 or M2 in adult mice. After >2 weeks of expression, animals were sectioned in 100 μm coronal sections and imaged with a fluorescence microscope (AxioImager). Prefixes “i”, “m”, and “c” designate ipsilateral, medial, and contralateral, respectively. A–C, vM1 injection shows reciprocal connections with M2, OC (A), contralateral vM1 (B), and thalamus (C). D–F, M2 injection also reveals reciprocal connections with vM1 (E), OC, contralateral M2 (E), and thalamus with a medial shift relative to vM1 projections (F). G, Quantification of the total fluorescence of from vM1 injections (sum of pixels) across targets in the cortex, basal ganglia, and thalamus for N = 2 animals. Thalamic nuclei are grouped into ipsilateral (iTha), contralateral (cTha), and midline (mTha; for unpaired nuclei) thalamic nuclei. Prefixes “i”, “m”, and “c” designate ipsilateral, medial, and contralateral, respectively. Ect, Ectorhinal cortex; Str, striatum; ZI, zona incerta. H, Output density for vM1 injections, where fluorescence is divided by area and divided by output density to vS1 for normalization. I, J, Quantification of total fluorescence and output density for M2 injections (N = 2 animals) in a similar fashion. vM1 is used for normalization in J.