Ischemia-induced changes in PIP2 levels of gerbil hippocampus.

We carried out an immunohistochemical study to detect changes in phosphatidylinositol 4,5-bisphosphate (PIP2) in gerbil hippocampus at various times after transient ischemia, using an anti-PIP2 antibody. About 24 h after transient ischemia for 5 min, an increase in the immunoreactivity was observed which was restricted to the area of CA1 pyramidal neurons. On the other hand, after less severe ischemia lasting 2 min, which did not lead to neuronal death, a decrease in PIP2 immunoreactivity was observed at about 48 h. The results indicate that levels of PIP2 following ischemia reflect dynamic changes in phosphatidylinositol (PI) turnover which may be related to neuronal degeneration.