Similarly, immunolabeling also revealed a highly significant increase in the GABAA‐α1 signal in GPi neurons at 18 months ( p = .00057), consistent with our SP immunolabeling data showing an abnormality in SP+ terminals in GPi at 18 months (Figure 12 ), and ISHH showed a trend in the same direction for GABAA‐α1 signal in GPi neurons ( p = .12720).
The Q175 mice at 6 months also showed a trend toward reduction in maximum speed (10.6% decrease, p = .07150) that was not evident at 2 months ( p = .42666) or 12 months ( p = .97959) in Q175 mice, but was significant in 18‐month‐old Q175 mice (10.9% decrease, p = .02611; Figure 1d ).
As shown in Figure 10 , we observed no significant difference between WT and Q175 mice in GPe neuron labeling intensity or in the spatial density of neurons labeled for GABAA‐α1 at 2, 6, 12, or 18 months of age by ISHH, although a slight trend toward increased signal intensity was seen at 12 months.