Intra-VTA PTX treatment alters forebrain DA receptor mRNA expression. Adult, virgin female rats were infused bilaterally into the VTA with PTX (0.3 μg/hemisphere) or its inactive control. Animals were euthanized on post-treatment day 7, a timeframe corresponding with the emergence of stimulated maternal responding. Data are mRNA expression relative to control (± SEM) for groups of 5–6 animals. Left panel (nucleus accumbens): Student’s t-tests, D1 mRNA - [T(9)=2.511, *P<0.033 vs. control], D2 mRNA - [T(9)=1.79, P<0.106]. Right panel (medial prefrontal cortex): Student’s t-tests, D1 mRNA - [T(9)=1.463, P<0.178], D2 mRNA - [T(9)=1.69, P<0.124].