Cell proliferation and total granule cell number in dentate gyrus of transgenic Tg2576 mouse.

This report provides in vivo evidence of adult neurogenesis and the total granule cell count in the dentate gyrus of the Tg2576 mouse model of Alzheimer's disease. Mice were deeply anaesthetized and perfused with 4 percent buffered paraformaldehyde. Brains were removed and post-fixed in the same fixative overnight. Following equilibration in 30 percent sucrose, 30 micrometer sections were cut in sagittal plane in freezing microtome for immunohistochemistry and 20 micrometer from plastic embedded brains. Thioflavin-S confirmed the presence of amyloid plaques in the Tg2576 mice. Cell proliferation in the subventricular zone and dentate gyrus of hippocampus were observed with Ki-67 and doublecortin markers. Using optical fractionator, total granule number was estimated to be 445,280 per hemisphere in the 18-month-old Tg2576 mouse. Cell proliferation tends to end in the dentate gyrus but continues in the SVZ and the total granule cell number was less compared to normal laboratory and wild rodents.