(A) Left: schematic and representative images for injections of CTB-647 into the VP (green) and CTB-488 into the VTA (blue) of D1-tdTomato mice (red) (scale bar, 500 μm). Right: confocal images of retrogradely labeled neurons in the NAcMS (arrows indicate dual-labeled MSNs; scale bar, 100 μm).
(B) Left: quantification of CTB and tdTomato overlap in the NAcMS (total cell count of three slices per mouse, five mice). Right: summary of the number of D1+VTA, D1+VP and dual-projecting MSNs in the NAcMS (average number of labeled cells of three slices per mouse, five mice).
(C) Two-photon images of D1+VTA, D1+VP, and D1− MSNs (left) (scale bar, 20 μm) and quantification of total dendritic length for all reconstructed cells (right), showing no differences.
(D) Examples of physiological responses of D1+VTA, D1+VP, and D1− MSNs to current injections of 250 and −50 pA. Right: summary of current step-evoked firing, showing similar number of action potentials (APs) for D1+VTA and D1+VP MSNs.
Box-and-whisker plots represent median and minimum to maximum. F-I curve is presented as mean ± SEM. *p < 0.05.
See also Figure S1.