a, Left: Cluster of retrogradely labeled cells was observed in the PVT 5 days after injection of RV-mCherry into the medial shell of the NAc (n = 7). Scale bar, 500 μm; Inset shows the RV-mCherry injection site. Right: magnified image shows the morphology of labeled neurons in the boxed area. Scale bar, 50 μm. D, dorsal; L, lateral; 3V, third ventricle; DG, dentate gyrus. b, Schematics of in vivo manipulation of the PVT→NAc circuit in behaving animals. c, Representative RTPP tracks illustrate light-evoked behavioral aversion in ChR2-expressing mice (bottom, n = 10) but not in eGFP-expressing control mice (top, n = 8). d, Quantification of light-evoked aversion and its effect by intra-NAc pharmacological manipulations. Intra-NAc infusions of NBQX (AMPAR antagonist, 1.0 μg in 200 nl, n = 8) but not saline (n = 10), SCH23390 (D1R antagonist, 0.2 μg in 200 nl, n = 8) or Raclopride (D2R antagonist, 0.3 μg in 200 nl, n = 8) abolished behavioral aversion evoked by optical stimulation of the PVT→NAc fibers. One-way ANOVA (F(4, 37) = 29.61, p < 0.0001) followed by Post-hoc Tukey's test. *** p < 0.001. Mean ± s.e.m.