Fig. 3. Isoflurane (Iso) inhibits proliferation. Neural progenitor cells were plated in equal numbers and exposed to 3.4% isoflurane for 6 h. Fold increase relative to control cultures was determined 48 h later. All cultures showed growth over 48 h, but isoflurane exposure inhibited proliferation by 42% relative to untreated cultures. Wilcoxon matched pairs  t test *  P < 0.05; IQR = interquartile range; No Tx = no treatment.