Figure 4.

Induced dyskinesia in Prrt2-deficient mice. (A) Prrt2^Stop mice manifested profound paroxysmal dyskinesia after kindling-induced generalized seizures. Left panel, incidence of generalized seizure-induced dyskinesia; the number of mice in each group is shown in the columns. Middle panel, box-and-whisker plot shows the range of stimulations required to evoke the seizure-induced dyskinesia in mutant mice. Right panel, dyskinesia scores of mutant mice after kindling-induced seizure activity; individual symbols indicate all the cases in each group. ^*P< 0.05 and ^***P < 0.001 vs WT; Fisher's exact test. (B) Representative images of dyskinesia attack in a Prrt2^Stop mouse in kindling model. Arrow indicates a rigor and hunched posture. (C) Paroxysmal dyskinesia triggered by PTZ-induced generalized seizures in Prrt2^Stop mice. Cases are indicated in the column of each group. ^*P < 0.05 vs WT; Fisher's exact test. (D) Representative EEG recordings of Prrt2^Stop mice during kindled seizures (top), PTZ-evoked seizures (middle) and induced dyskinesia (bottom). Filled arrow, application of electrical stimulation in kindling; open arrow, post-stimulation refractory period; arrowheads, termination point of electrographic seizures. Note there were no obvious abnormalities in EEG recordings during occurrence of induced dyskinesia. (E) 5-min exposure to 50 °C ambient temperature induced paroxysmal dyskinesia in Prrt2^Stop mice. ^**P < 0.01 and ^***P < 0.001 vs WT; middle panel, Fisher's exact test; right panel, one-way ANOVA with post hoc Dunnett's test. (F, G) Exposure to 50 °C for 5 min induced dyskinesia in Nestin-Cre;Prrt2^−/− mice. Individual symbols indicate all the cases in each group. Nestin-Cre and Prrt2^loxP/loxP littermates expressing PRRT2 normally were pooled as controls. ^*P < 0.05, ^**P < 0.01 and ^***P < 0.001 vs control littermates; Fisher's exact test or Student's t-test. (H) Schematic diagram (left and middle) and representative image of ChR2-mCherry expression (right) for optogenetic manipulation in Prrt2^Stop mice. Distribution of the actually implanted sites was indicated using red bulb individually. (I) Optical stimulation in cerebellar vermis sufficiently induced intensive paroxysmal dyskinesia in Prrt2^Stop mice, but not in WT mice. Individual symbols indicate all the cases in each group. ^*P < 0.05 and ^***P < 0.001 vs WT; Student's t-test. (J) Representative images of optogenetic stimulation-induced dyskinesia in Prrt2^Stop mice. Het, heterozygote.