WFA immunoreactivity in various brain stem regions following SH exposure and microinjection of ChABC into the 4th ventricle. A: no effect of SH or ChABC on WFA immunoreactivity in nTS, DMNV, AP, or XII. Values are means ± SE; n = 9 NX + S, 9 NX + ChABC, 8 SH + S, and 9 SH + ChABC. B: representative images of brain stem regions. Ctrl (NX), normoxia treated rats. Scale bar = 100 μm.