Figure 1 : Selective viral-mediated ChR2 expression in striatal direct- or indirect-pathway MSNs.

From: Regulation of parkinsonian motor behaviours by optogenetic control of basal ganglia circuitry

Figure 1

a, Schematic of the double-floxed Cre-dependent AAV vector expressing ChR2–YFP under control of the EF-1α promoter. DIO, double-floxed inverted open reading frame; eYFP, enhanced YFP; ITR, inverted terminal repeat; WPRE, woodchuck hepatitis virus post-transcriptional regulatory element. b, Sagittal mouse brain schematic. Ctx, cortex; Str, striatum; GP, globus pallidus; SNr, substantia nigra pars reticulata; Th, thalamus; Hipp, hippocampus. The box indicates the region shown in panels c and d. c, Sagittal section showing striatal direct-pathway MSNs expressing ChR2–YFP following injection of Cre-dependent AAV1 into D1-Cre BAC transgenic mice. Direct-pathway MSN axons target the SNr. d, Expression of ChR2–YFP in striatal indirect-pathway MSNs of D2-Cre BAC transgenic mice. Indirect-pathway MSN axons target the GP. Scale bars in c and d, 1 mm. e, f, Examples of ChR2–YFP-expressing neurons that do not co-express the interneuronal markers parvalbumin (PV) and choline acetyltransferase (ChAT). Scale bars in e and f, 15 μm. g, Percent of ChAT, PV or neuropeptide Y neurons that co-express ChR2–YFP. Error bars, s.e.m.