NG2-glia morphological alteration in L-DOPA-induced dyskinesia.
The number of branches, their length (µm), the number of junctions and the soma area (µm2) of NG2-glia were quantified in each of the four subdivisions of striatum (Fig. 3).
Firstly, the ramification index of the NG2-glia after L-DOPA chronic treatment of parkinsonian rats and doxycycline administrationincreased in the dorsolateral striatum, decreased in the dorsomedial and ventromedial striata, and presented no changes in the ventrolateral division (Figs A, A”, B-E) when compared to rats that received only L-DOPA treatment.
Animals receiving L-DOPA treatment and exhibiting LID presenteda decrease in the number of branches per cell and the average of the branch length in the dorsolateral striatum compared to the 6OHDA lesioned animals. In the dorsomedial and ventromedia l striatum L-DOPA treatment-induced, per cell, an increase in the number of branches, the average branches length, and the number of junctions compared to 6OHDA lesioned animals. The dorsomedial striatumalso showed an increase in the average of the soma area. There was a decrease in NG2-glia cells index activation in the dorsolateral striatum of rats presenting LID (Fig 3).
In the dorsolateral striatum of the animals presenting LID and treated with doxycycline was revealed an increased NG2-glia pattern of activation as evaluated by the number and the average branches length per cell, the number of junctions per cell (entangled with each other) and the average soma area when compared to 6OHDA lesion and6OHDA+Vehicle+L-DOPA groups. There was a decrease in the NG2-glia indicators of activation in the dorsomedial and ventromedial striatum.
Doxycycline treatment decreased dyskinesia and the signals of the NG2-glia activation in the dorsomedial and ventromedial striatum (the number of branches per cell and the average branch length). In the dorsomedial striatum it was also observed a decrease in the NG2-glia average of the soma area compared to 6OHDA+L-DOPAgroup.
There were no changes in the NG2-glia cells measured parameters in the ventrolateral striatum in all experimental groups (Nolesion (control), 6OHDA lesion, 6OHDA+DOXY, 6OHDA+Vehicle+ L-DOPA and 6OHDA+L-DOPA+DOXY ).