Effects of chronic doxycycline on the development of LID
L-DOPA induced the appearance of dyskinesia in the parkinsonian rats (6-OHDA+chronic-vehicle+L-DOPA; Fig. 4-A). Co-administration of doxycycline with L-DOPA (6-OHDA+chronic-doxycycline+L-DOPA decreased the AIMs measured at days 1, 7, and 14 of the combined treatment (p<0.0001; Fig. 4-A). Post hoc analyses revealed a significant reduction of the total AIMs (Fig. 4-A) and the different AIMs types (Supplementary Figs. 2-D, -E and -F; p<0.05, 6-OHDA+chronic-vehicle+L-DOPA vs. 6-OHDA+chronic-doxycycline+L-DOPA). AIMs were not observed in the control group or the 6-OHDA-lesioned rats that were treated with vehicle or doxycycline only (data not shown).
The lesioned animals showed a decrease in the distance traveled, as evaluated by the open-field test (6-OHDA+chronic-vehicle+vehicle; Supplementary Table 1), demonstrating compromised motor ability. L-DOPA treatment increased the distance traveled (6-OHDA+chronic-vehicle+L-DOPA Supplementary Table 1), and the co-administration of L-DOPA+doxycycline did not affect the improvement in locomotor activity (6-OHDA+chronic-doxycycline+L-DOPA p<0.05; Supplementary Table 1).