BDNF and glioma: After exposure to 2.5% sevoflurane for 4 h, the mRNA levels of Arc (50.34 ± 5.635 vs. 100.00 ± 12.14, P < 0.0001), Bdnf (62.83 ± 12.92 vs. 100.00 ± 15.76, P = 0.0012), and Reln (73.77 ± 16.75 vs. 100.00 ± 20.99, P = 0.0378) in C6 glioma cells also decreased significantly (Figures 1F–H).