I confirmed the action of the dopamine synthesis inhibitor 3-Iodo-L-tyrosine (3IY) in a previous trial, where treated flies showed decreased walking speed and distance when tested in an open field. In this trial I tested the flies “fresh out of the tube” so that they were able to feed on 3IY right to the point where they were tested. For the main experiment however, flies will be transferred from the food 2-5 hours before the experiment. To confirm, that the effect of 3IY treatment will persist also after this time span I moved flies from 3IY supplemented vials to fresh, empty vials at least 4 hours before measuring walking behavior in the open field. The results confirm, that the effect of 3IY is still present after this time.