Aberrant dendritic spine morphology in mutant neurons is regulated by TrkB and is rescued by enhancement of PARP1 activity. (A–C) Fluorescence microscopic images of dendritic spines. (A) From the indicated genotypes. Pharmacological treatments and transfections were performed as indicated; scale bar, 2 µm. Quantification of the average length of the spine (B) and the spine density (C) along a 720 µm-long dendrite. Mus., mushroom; Stu., stubby. D, DHIQ; D/N, both DHIQ and NAD. Data are presented as mean ± SEM (n = 18 neurons, three independent experiments, total 540 spines). ns, P > 0.05, ***P < 0.001, ****P < 0.0001 (two-way ANOVA).