Fig. 5. L-DOPA rescues motor but neither olfactory nor gastrointestinal function in ak mice. Four- to six-month-old ak mice were injected with either the dopamine precursor levodopa or with saline control intraperitoneally, then subjected to tests of motor, olfactory and gastrointestinal function. Challenging beam test (A), cylinder test (B) and adhesive removal tests (C) showed that ak mouse motor deficits were efficiently rescued by L-DOPA. In contrast, (D) Y-maze test showed that cognitive function deficits were not corrected by L-DOPA; (E) buried pellet test and (F) odor discrimination tests showed that olfactory functional deficits were not corrected by L-DOPA; and (G-H) charcoal evacuation and bead expulsion tests showed that gastrointestinal functional deficits were also not rescued by L-DOPA. *p < 0.05; ***p < 0.001; Mean ± S.E.M.,  n  = 8–9 for each group.