Extended Data Fig. 1: Optogenetic stimulation of SPNs with simultaneous Ca2+ recording from Chx10 Gi neurons.
From: Basal ganglia–spinal cord pathway that commands locomotor gait asymmetries in mice
a, D1Cre and D2Cre, and Chx10Cre alleles exhibit non-overlapping Cre expression within the striatum (Str) and nucleus gigantocellularis (Gi), respectively, in sagittal sections. Top, D1Cre (Gensat EY217);R26RLSL-tdTom mice exhibit tdTom expression in Str, with tdTom+ axons projecting to SNr. tdTom expression is largely absent from Gi. Middle, D2Cre (Gensat ER44);R26RLSL-tdTom mice exhibit tdTom expression in Str, whereas tdTom expression is largely absent from Gi. Bottom, Chx10Cre;R26RLSL-tdTom mice exhibit tdTom expression in Gi, whereas tdTom expression is largely absent in Str. Sagittal images are representative of expression patterns observed in n = 3 mice from one experiment for each genotype. b, In coronal sections including the striatum, D1Cre;R26RLSL-tdTom and D2Cre;R26RLSL-tdTom mice exhibit strong tdTom expression in Str, whereas Chx10Cre;R26RLSL-tdTom mice exhibit scant tdTom expression in Str. c, In coronal sections including Gi, D1Cre; R26RLSL-tdTom and D2Cre;R26RLSL-tdTom mice exhibit scant tdTom expression in Gi. D2Cre;R26RLSL-tdTom mice exhibit some tdTom expression in the neighboring IRt and PCRt. Chx10Cre;R26RLSL-tdTom mice exhibit strong tdTom expression in Gi. Coronal images are representative of expression patterns observed in n = 3–6 mice from one experiment for each genotype. Scale bar (a-c) for overview sagittal and coronal images = 1.0 mm. Scale bar (b, c) for insets = 200 µm. d, Schematic of Chx10 Gileft GCaMP recording with optogenetic stimulation of left or right, D1 or D2 SPNs. e, Examples of bilateral ChR2-2A-mCherry expression and fiber implantation in the dorsomedial Str, and GCaMP7s expression and fiber implantation in Gileft in D1Cre;Chx10Cre dual-allelic mice. ChR2-2A-mCherry and GCaMP7s expression patterns are representative of n = 7 D1Cre;Chx10Cre mice from two independent experiments. D2Cre; Chx10Cre mice exhibited similar ChR2-2A-mCherry and GCaMP7s expression patterns, with notable absence of mCherry+ axons in SNr (n = 7 mice from two independent experiments).
