Figure 7.

LM22A-4 prevents dendritic spine loss on R6/2 striatal MSNs. A, Reconstructed drawings from Neurolucida tracings of one dendritic tree of Golgi-stained MSNs in striatum. Scale bar, 10 μm. B, Spines on the fourth dendritic branch of MSNs from each of the four experimental groups are shown. Scale bar, 2.5 μm. C, Spine density on dendrites of MSNs was reduced in vehicle (Veh)-treated R6/2 mice (n = 7–9 mice/group; **p ≤ 0.01 vs WT Veh). This decrease was prevented by LM22A-4 (LM-4) on each branch order examined (*p ≤ 0.05 vs WT Veh and ⁺p ≤ 0.05 vs R6/2 Veh; two-tailed Student's t tests; left graph) and this protective effect was particularly evident when data from branch orders 2–5 were combined (⁺⁺⁺p < 0.001 vs R6/2 Veh; right graph). Results are expressed as mean ± SEM. Statistical significance was determined by ANOVA with Newman–Keuls post hoc testing.