Characterization of Neurophysiological and Behavioral Changes, MRI Brain Volumetry and 1H MRS in zQ175 Knock-In Mouse Model of Huntington's Disease (original) (raw)
Figure 4
Electrophysiological deficits in zQ175 mice.
Box and whisker plots of (A) resting membrane potential (B) membrane resistance (C) rheobase current and (D) action potential amplitude from MSNs in zQ175 wild-type, heterozygous and homozygous mice at 3–4 and 6–9 months of age. Box and whisker plots: + = mean, box = interquartile range, whiskers = 10–90 percentile, outliers = closed circles. (E–F) Measurement of evoked EPSCs in MSNs following cortical stimulation in zQ175 wild-type, heterozygous and homozygous mice at (E) 3–4 and (F) 6–9 months of age. (E–F inset) Paired-pulse ratio (inter-stimulus interval = 20–500 ms) at (E, inset) 3–4 months and (F, inset) 6–9 months for all genotypes. (G) Representative traces of mEPSCs from zQ175 wild-type, heterozygous and homozygous mice at 2 and 7–9 months of age. (H–K) Average cumulative plots of mEPSC inter-event interval (0.25 s bins; H, J) or amplitude (2 pA bins; i, k) in all 3 genotypes at (H–I) 2 months and (J–K) 7–9 months of age. zQ175 mice show a minor reduced frequency at 2 months of age, and a strongly depressed mEPSC frequency at 7–9 months of age (note difference in y axis in J compared to K). Mean mEPSC amplitude showed a slight increase in the frequency distribution towards higher amplitude events in the zQ175 mice, which appeared more pronounced in the 7–9 month age group (see also Table 1). Statistical analysis was performed as described in methods (one-way ANOVA values shown in H–K). ns = not significant, *p<0.05, **p<0.01, ***p<0.001.