SphK1 (Ab Bb, Cb, Db) expression in 5-d-old rats receiving saline, DMS, LPS or DMS + LPS injection, and sacrificed 1 h later. Immunofluorescence analysis reveals colocalization of OX-42 (Aa, Ba, Ca, Da) and SphK1 (Ab, Bb, Cb, Db) in AMC of corpus callosum as shown in the merged images (Ac, Bc, Cc, Dc). The intensity of SphK1 expression in AMC is clearly enhanced after LPS injection (Cb) when compared with that of the control (Ab) and DMS (Bb) groups (arrows). In rats treated with either DMS alone or DMS + LPS, SphK1 immunofluorescence intensity in AMC appears to be unchanged (Bb, Db). Nuclei are stained with DAPI. Scale bar = 50 μm.