Fig. 1: Specific transfection of the VTA-hippocampus dopamine pathway.

a Transfected coronal sections by unilateral injection for electrophysiology recording stained for Tyrosine Hydroxylase (TH) and YFP. b quantification for unilaterally injected mice. Transfection and specificity (transfection, specificity) were (91.5 ± 2%, 83.4 ± 4%, n = 6 mice) for YFP and (70 ± 2%, 91.5 ± 2%, n = 57 mice) for ChETA injected mice. c Transfected coronal sections by bilateral injection for behavioral experiments stained for TH and YFP. d. Quantification for transfection and specificity (transfection, specificity) were (83.9 ± 2%, 94.7 ± 1%, n = 27 mice) for YFP, (65.9 ± 2%, 93.3 ± 2%, n = 34 mice) for ChETA and (70.8 ± 5%, 99.4%, n = 11 mice) for eNpHR3.0 bilaterally injected mice. For panels a & c, Dashed line represents midline; rectangle represents sampled area captured at x20 magnification. fr, fasciculus retroflexus; SNc, Substantia Nigra pars compacta; VTA, Ventral Tegmental Area. Scale bars, 100 µm. For panels b and d Quantification of Transfection (green) and Specificity (red) are represented as the number of double-stained cells divided by TH+ cells and YFP+ cells, respectively. In the box plots representations, whiskers show the minimum and maximum values, bounds of the box the 1^st and 3^rd quartile and center line indicate the median. e Representative image of confocal microscopy examination of coronal sections of the dorsal hippocampus of mice injected bilaterally with the YFP virus (n = 27) which revealed a sparse labeling in the CA1 region that was not restricted to a specific layer. Dopaminergic fibers originating from the VTA and expressing YFP are shown in green. TH containing fibers are in red, while cell nuclei labeled with Hoechst are in blue. SO, stratum oriens; SP, stratum pyramidale; SR, stratum radiatum. Scale bar, 20 µm. Source data are provided as a Source Data file.