Cyclin D1 Immunoreactivity Changes in CA1 Pyramidal Neurons and Dentate Granule Cells in the Gerbil Hippocampus after Transient Forebrain Ischemia

Abstract Objectives: Cyclin D1, a member of the G1 cyclin family, plays a critical role in the progression of the cell cycle. In the present study, we investigated chronological alterations in cyclin D1 immunoreactivity and its protein levels in the gerbil hippocampus after ischemia/reperfusion. Methods: Chronological alterations in cyclin D1 immunoreactivity and its levels were examined in the gerbil hippocampus after ischemia/reperfusion using immunohistochemistry and western blot analysis. Results: Changes in cyclin D1 immunoreactivity in the ischemic hippocampus were distinct in pyramidal neurons of the CA1 region and granule cells of the dentate gyrus. Cyclin D1 immunoreactivity in pyramidal neurons of the CA1 region was increased up to 1 day after ischemia/reperfusion, although a transient decrease of cyclin D1 immunoreactivity was detected at 12 hour after ischemia/reperfusion. Thereafter, cyclin D1 immunoreactivity in the CA1 pyramidal neurons was very weak 2 days and disappeared nearly 4 ...