Task engagement, body weight and striatal DA content as a function of lesion group. (A) The number of licks emitted during the session did not differ between the sham and the lesioned groups. An initial decrease in the measure during the second week normalized by the third week, leading to a significant overall effect of time. (B) Body weight was decreased similarly in the unilateral and bilateral groups during the weeks 2 and 3 post-lesion. At week 4, however, body weights recovered in the bilaterally-lesioned group. (C) Striatal DA content was decreased (compared to the contralateral striatum) by 97% in the unilateral group, and ~90% in the bilateral group (compared to the sham group). *p<0.05.