Fig. 4

Assessment of microglial proliferation and activation in the corpus callosum (CC). a (A–F) Representative images of Iba-1 stained corpus callosum (CC) in each group. a(A) Sham-std; a(B) Sham-3 h; a(C) Sham-full; a(D) BCAS-std; a(E) BCAS-3 h; a(F) BCAS-full. Scale bar represents 50 μm. a(A) Inset showing a normal microglial cell. a(D) Inset showing activated microglial cells. b, c Histograms showing degree of microglial proliferation in each subgroup. EE, especially by limited exposure to EE (BCAS-3 h) suppressed microglial proliferation in the CC induced by BCAS (**P < 0.01). d–f Histograms showing degree of microglial activation in each subgroup. Limited exposure to EE suppressed degree of microglial activation in both moderate (microglial cell body >7 μm) (**P < 0.01) (d) and highly (microglial cell body >10 μm) activated (*P < 0.05) (e) levels, as well as suppressed the number of non-activated microglial cells (**P < 0.01) (f). However, BCAS-full did not show suppressed highly activated microglia in the CC (e). Sham-std, n = 11; Sham-3 h, n = 11; Sham-full, n = 11; BCAS-std, n = 13, BCAS-3 h, n = 10; BCAS-full, n = 12