Fig. 5

Labeling preference of rAAV2-retro and RV-∆G viral tracers in certain brain region and cortical layer. (a-b) Whole-brain quantification analysis of the retrograde labeling of input circuits to the LHA (A) and MPO (B) following injection of rAAV2-retro-Cre-tagBFP and RV-∆G-EGFP. The number of labeled neurons in each nucleus on the side ipsilateral to the injection site was quantified and normalized to the total number of ipsilateral labeled neurons for each mouse (n=3). (c) The percentage of labeled input brain regions to LHA and MPO was represented as pie chart to indicate the labeling preference of rAAV2-retro in cerebral cortex, and RV-∆G in basal ganglia and hypothalamus. (d) Retrograde tracers of rAAV2-retro-YFP, RV-∆G-EGFP, and green retrobeads were separately injected into the dLGN for retrograde labeling of upstream corticothalamic neurons in the primary visual cortex (V1). The corticothalamic neurons in V1 labeled by rAAV2-retro-YFP were predominately localized in the fifth layer (L5). In contrast, both RV-∆G-EGFP and green retrobeads mostly labeled corticothalamic neurons in the sixth layer (L6) of V1. (E) Retrograde tracers of rAAV2-retro-Cre-tagBFP and RV-∆G-EGFP were co-injected into the dLGN of Ai9 mice for simultaneously labeling of upstream corticothalamic neurons in V1. The rAAV2-retro-Cre-tagBFP predominately labeled V1 corticothalamic neurons in the fifth layer (L5), while RV-∆G-EGFP mostly labeled corticothalamic neurons in the sixth layer (L6) of V1. (F) The injection sites of rAAV2-retro-YFP, RV-∆G-EGFP, green retrobeads, and co-injection of rAAV2-retro-Cre-tagBFP with RV-∆G-EGFP. Scale bars = 200 μm in D-E, 1 mm in F