Fig. 5.  TAT-Pep5 decreases isoflurane-mediated reduction in phalloidin immunofluorescence. Primary neurons (4–7 days in vitro , DIV4–7) were exposed to 1.4% isoflurane (ISO) for 3 h with or without pretreatment with TATctrl (10 μm, 15 min) and TAT-Pep5 (10 μm, 15 min) and stained with the actin binding toxin phalloidin (conjugated to Alexa-594) and the nuclear marker DAPI (4′,6-diamidino-2-phenylindole). Phalloidin (red pixels) is normalized to DAPI (blue pixels). (A ) basal, (B ) TATctrl basal, (C ) TAT-Pep5 basal, (D ) isoflurane, (E ) TATctrl isoflurane, and (F ) TAT-Pep5 isoflurane. Exposure of DIV4–7 neurons to isoflurane significantly (n = 4; # P = 0.0107 vs.  basal, P = 0.0094 vs.  TATctrl basal, P = 0.0237 vs.  TAT-Pep5 basal) decreased phalloidin immunofluorescence (D ). Isoflurane-mediated effects were significantly attenuated by TAT-Pep5 (**P = 0.0165 vs.  isoflurane, P = 0.019 vs.  TATctrl isoflurane). Pretreatment with TATctrl did not attenuate the neurotoxic effects from isoflurane (## P = 0.0099 vs.  basal, P = 0.0209 vs.  TATctrl basal, P = 0.0213 vs.  TAT-Pep5 basal). Scale bar, 50 μm. (G ) Quantitation of the data. Error bars, SEM.