Fig. 4: Actinification is triggered during cell swelling.
From: INF2-mediated actin filament reorganization confers intrinsic resilience to neuronal ischemic injury
a Simultaneous quantification of dendrite diameter (red triangles) and F-actin intensity (black squares) in an individual neuron following addition of NMDA at the indicated time. b Removal of either extracellular sodium or calcium prevents NMDA-induced actinification. n = 2 independent experiments; unpaired t test, two tailed (p = 0.0039, NMDA vs NMDA w/ zero Na+; p = 0.0032, NMDA vs NMDA w/ zero Ca2+). c Effect of various chloride flux inhibitors on NMDA-induced actinification. n = 5 (veh; DIDS; bum); 3 (GlyH); 2 (NPPB) independent experiments. Two-way ANOVA [(−) NMDA vs (+) NMDA, F (1, 36) = 230.8; p < 0.0001; all drugs, F (4, 36) = 0.1954, p < 0.0001]. d Mannitol inhibits NMDA-induced actinification. n = 2 independent experiments; two-way ANOVA [(−)NMDA vs (+) NMDA, F (1, 4) = 11.85; p = 0.0262; (−) mannitol vs (+) mannitol, F (1, 4) = 11.41, p = 0.0279], with Tukey’s post hoc multiple comparison analysis (p = 0.0285 NMDA w/ mannitol vs NMDA w/o mannitol). e Ionomycin induced actinification in the absence (−) or presence (+) of either extracellular sodium depletion or a cocktail of the NMDAR antagonists APV and MK-801. n = 2 independent experiments; Kruskal–Wallis one-way ANOVA (p = 0.0286); unpaired t-test (p = 0.0074, iono vs iono w/ zero Na+; n.s. p = 0.4645, iono vs iono w/APV &MK801). f Thapsigargin (Tpg) neither induces or prevents NMDA-induced actinification. n = 3 independent experiments; two-way ANOVA [(−)NMDA vs (+) NMDA, F (1, 16) = 805.1; p = 0.0001; Tpg (2 min), vs (30 min), vs (2 h), F (3, 16) = 0.8284, n.s. p = 0.4974]. g Veratridine (VTD) induces actinification by activating NMDARs and voltage gated calcium channels (VGCCs), but not AMPARs. Three cocktails of inhibitors were used against either NMDARs (APV, MK-801, CGP), AMPARs (NBQX), or VGCCs (nifedipine, ω-conotoxin, mibefradil); respective vehicles were tested in combination. n = 3 independent experiments; Kruskal–Wallis one-way ANOVA (p = 0.0071); unpaired t test, two-tailed (p = 0.0019, VTD vs VTD + NMDAR antagonists (ANT); n.s. p = 0.1491, VTD vs VTD + AMPAR ANT; p = 0.002, VTD vs VTD + VGCCs inhibitors (INH); p = 0.0003 VTD vs VTD + All drugs). All graphs: data presented as mean ± SEM, and source data are provided as source data file.
