Figure 2.

(a) Nissl-stained section of brain showing representative bilateral cannula placements into the VTA. (b–d) Diagrams of series of sections ordered from rostral (top) to caudal (bottom) showing infusion sites. The gray shading in the sections illustrates the approximate boundaries of the VTA (b and c) and RMTg (d). Black dots indicate on-target infusion sites; gray triangles indicate off-target sites and are identified by the corresponding case numbers. (e) Distance traveled following infusions of vehicle, muscimol or bicuculline into the VTA. For all conditions, n=8. Distance traveled was recorded in 2-min bins for a total of 20 min and analyzed with a two-way ANOVA (distance × time) with post hoc Tukey's multiple comparison's test. (f) Graph showing total distances traveled for each condition shown in panel (e), which were tested with a one-way ANOVA and post hoc Tukey's multiple comparisons test. In panel (e): **p<0.01 and ^#p<0.0001 relative to vehicle. In panel (f): ^#p<0.0001. Scale bar—400 μm.