Immunohistochemical analyses of the rat hippocampus after hypoxia/ischemia followed by reperfusion.

<p>(<b>A</b>) Coronal sections of the rat hippocampus immunostained for a neuronal marker (NeuN) and the astrocytic marker glial fibrillary acidic protein (GFAP) in sham-operated rats (CTRL) and those 7 days (7D) after hypoxia/ischemia (H/I). Enlargements of the tissue section shown on the right demonstrate pyramidal cell loss and the formation of reactive gliosis in the hippocampal CA1 region 7D after H/I when compared to controls. (<b>B</b>) TRPV4 immunostaining in the CA1 region of the hippocampus. Coronal slices from controls and ischemic rats were labeled for TRPV4 (green) and GFAP (red). Note that in controls the TRPV4 immunoreactivity was detected in pyramidal cells and more rarely in astrocytes. With developing astrogliosis TRPV4 immunoreactivity was increased in astrocytes. Seven days after H/I no TRPV4 expression was detected in pyramidal cells, whereas it was markedly increased in astrocytes. The following abbreviations are used: H/I (hypoxia/ischemia), CTRL (sham-operated rats), 1H (1 hour), 7D (7 days) after hypoxia/ischemia, s.p. (stratum pyramidale), s.r. (stratum radiatum).