PCR genotyping results and immunohistochemistry confirmation. (A) Typical example of PCR genotyping results indicate the presence (or absence) of the wild type & CART knockout alleles, as well as, the actin internal control bands (880, 658, & 353 bps, respectively). Periodically, the PCR genotyping results were verified with immunohistochemistry in brain tissues using a CART antibody (B). The nucleus accumbens region of the brain expresses CART in the wild type sample, but not in the CART knockout sample. NAc – nucleus accumbens, ac – anterior commissure.