Schematic of experimental design to deplete mice of 25(OH)D levels and challenge with MPTP.

<p>On day 1, mice were weighed and randomly assigned to either a group receiving vitamin D depleted chow or a group receiving control chow supplemented with vitamin D. Mice were weighed weekly to check for changes in body mass. After 36 days, 25(OH)D depletion was confirmed by ELISA assay. Then, mice were trained daily to learn the forepaw stride length task from days 44–48. On day 49, baseline behavior was measured. On day 50, MPTP injections began. Mice received a daily injection of either PBS or 15 mg/kg MPTP for 4 days. The mice were allowed to recover for 7 days. On day 60, post-MPTP behavior was measured prior to sacrificing the mice.