Effects of Aβ25-35 on neurogenesis in the adult mouse subventricular zone and dentate gyrus

It has been demonstrated that neuorgenesis driven by neural precursor cells persists well into theadult period. This study was to observe the effects of Amyloid-beta (25-35) peptide (A beta(25-35)) on neurogenesis in the subventricular zone and dentate gyrus of adult mouse grain. Aggregated A beta(25-35) (1 mg/ml, 3 mu l) was injected into the lateral ventricle of adult mouse. Animals were transcardially perfused with 4% paraformaldehyde in PBS, respectively at 5, 10, 20, 30 days after the A beta(25-35) injection. All the animals were injected with BrdU (50 m i.p) to label the neural precursor cells 24 h before the each perfusion. NeuN immunofluorescence and BrdU immunohistology were performed. It was found that A beta(25-35) could injure the mature neurons and decrease the number of NeuN positive neurons. It also showed that A beta 25-35 inhibited neurogenesis and significantly decreased the number of BrdU positive cells in the dentate gyrus of hippocampus, but it had no obvious effects on neurogenesis in the subventricular zone. The present results indicated that A beta(25-35) could impair neurogenesis in the hippocampus of adult mouse brain.