In vitro and/or ex vivo binding specificity and brain distribution of [3H]TZ1964B and [11C]TZ1964B in rat brain. Representative images of in vitro autoradiography of [3H]TZ1964B in rat brain showed high radiotracer uptake in striatum, globus pallidus, nucleus accumbens, and substantia nigra, which could be blocked by MP-10 (A, sagittal section; B, sagittal section with MP-10 blocking; C, horizontal section with and without MP-10 blocking; D. Saturation binding curve obtained from striatal uptake of [3H]TZ1964B). Representative images of ex vivo autoradiography of [11C]TZ1964B in rat brain (E, horizontal section; F, Bar graph showing binding intensity.) confirmed the high radiotracer uptake in the striatum, but not in the cerebellum. PSL/mm2, photo-stimulated luminescence signals per square millimeter.