Paxillin LIM domains are required for Aβ-induced neuronal dystrophy. A, Cortical neurons were transfected with GFP or GFP-paxillin expression vectors containing full-length paxillin (FL-pax) or deletions of the LIM domains (N-pax) or the LIM domains (LIM-pax), respectively. B, Cortical neurons were transfected at day 5 and treated with fibrillar Aβ. The number of dystrophic neurons was quantified 24 hr later and expressed as a percentage of the number of Aβ-induced dystrophic neurons expressing GFP (100%). Note the significant inhibition of neuronal dystrophy in neurons expressingN-pax (28.6 ± 15.1%). FL-pax and LIM-pax were not significantly different from GFP (FL-pax, 108 ± 12%; LIM-pax, 90.4 ± 21.9%). Values are the mean ± SEM; n = 4 independent experiments; 250 neurons were scored per experiment; *p < 0.05 relative to GFP-transfected cells by ANOVA. C–E, Neurons expressing the indicated GFP-tagged paxillin proteins were immunostained with anti-Aβ antibody (blue) and phalloidin-Texas Red. Note the formation of FA-like structures in neurons expressing FL-pax, N-pax, and LIM-pax (arrows).