Experimental design
Experiments were performed in accordance with the ARRIVE and BJP guidelines. Experimenters were blinded to treatments. Twelve (12) fully dyskinetic rats were randomized to L-Dopa (6 mg kg-1 + benserazide 15 mg kg-1, s.c.) in combination with AT-403 (0.03 mg kg-1), CCG-203920 (10 mg kg-1), AT-403 + CCG-203920, or saline. Each animal was tested four times, with a 3-day washout allowed between treatments. A separate cohort of 12 rats was subjected to the same treatments as above for the analysis of motor performance on the rotarod, both before (OFF L-Dopa) and after L-Dopa administration (ON L-Dopa). This to evaluate whether the potential antidyskinetic effect was associated with an improvement of global motor activity (Arcuri et al. , 2018; Marti et al. , 2012; Paolone et al. , 2015). In fact, a truly antidyskinetic compound would alleviate LID and consequently improve rotarod performance whereas whether a motor inhibiting or a sedative agent would reduce AIMs along with motor performance. Rotarod performance was assessed at 60 min after L-Dopa administration since the ALO AIMs time course showed a peak 60-80 min after L-Dopa administration (Arcuri et al. , 2018; Marti et al. , 2012; Paolone et al. , 2015).