MPTP-intoxication increases T cell migration. CD3+ T cells were obtained and enriched from spleen and lymph nodes of male donor C57BL/6J mice. Isolated T cells were activated with anti-CD3 for 3 days. Syngeneic recipients were treated with 4 doses of MPTP-HCl in PBS (18 mg/kg, based on freebase MPTP) or PBS alone; each dose administered at 2 hour intervals. Activated T cells were labeled with 111In-oxyquinoline (GE Healthcare), and 20 ×106111In-labeled T cells were adoptively transferred to each MPTP- or PBS-treated recipient. CT/SPECT images from each animal were acquired at 24, 48, 72, 96, and 120 hours post-transfer. For each mouse at each sampling time, electronic bit maps were drawn to circumscribe (A) brain, (B) lungs, (C) kidneys, (D) spleen, (E) cervical lymph nodes, (F) all other lymph nodes, and entire body. Counts of radiolabeled T cells were determined by digital image analysis software (VIVID, GE Healthcare) and corrected for decay from the time of labeling. Counts for each organ were normalized as the percentage of total body counts for each time (A-F). Means ± SEMs of radiolabel percentages were determined for 3–5 mice/treatment group and differences between the 2 treatment groups were determined by Student’s t-test where p ≤0.05 was considered significant.