Figure 3.
Validation of VTK vector cell-type specificity
(A) Example of VTKS1-hChR2-tBFP injection in the thalamus and corresponding thalamocortical projections in the cortex. Scale bar: 100 μm (left) and 200 μm (right).
(B) Colocalization of somatostatin (SOM) and Gq-HA tag showing SST-Cre-specific VTKS2-Dreadd-Gq recombination (87.32% ± 1.12%, N = 4). Scale bar: 100 μm.
(C) Colocalization of SOM with mCherry showing the recombination of VTKS3-TeTLC upon SST-FlpO (92.26% ± 4.31%, N = 3). Scale bar: 100 μm.
(D) Left, colocalization of V5 labeling with SOM and parvalbumin (PV). Scale bar: 100 μm. Right, quantification of V5 colocalization with SOM, PV, and vasoactive intestinal peptide (VIP)-expressing interneurons (SOM: 83.17% ± 5.95%; PV: 8.97% ± 2.67%; VIP: 5.5% ± 1.22%, N = 3) showing the recombination of VTKD4-NES-APEX2 in GABAergic interneurons and primarily in SOM+ cells.
(E) Colocalization of EGFP and SOM showing the exclusion of VTKS5-helpers from SOM+ neurons (97.42% ± 0.19%, N = 3). Scale bar: 100 μm.
(F) Left, colocalization of V5 with SOM and PV in the hippocampus. Scale bar, 100 μm. Right, quantification of V5 with SOM, PV, and VIP (PV: 78.27% ± 10.99%; VIP: 11.13% ± 2.55%; SOM: 4.5% ± 2.55%, N = 3) showing the recombination of VTKD6-NES-APEX2 in GABAergic interneurons and a majority of PV+ neurons (full arrows), except for SOM+ cells (empty arrows).