Proliferation of Neurons Caused by Intrahippocampal Injection of Aggregated β-amyloid in Rat

Objective To investigate the effect ofβ-amyloid(Aβ)deposits on neuron proliferation.Methods Aggregated Aβ_(1-42)was stereotaxicaly injected into the hippocampus of rats and reverse peptide Aβ(1-42)or phosphate buffer saline(PBS)were injected as controls.Proliferating ceils were labeled with intraperitoneal injection of Bromodeoxyuridine (BrdU).Brain sections were analyzed with immunohistochemistry and immunofluorescence to determine Brdu labelled newborn cells and doublecortin(DCX)labelled immature neurons.Results Aβ_(1-42)significantly increased the number of BrdU labelled cells and the expression of DCX in two neuroproliferative regions-the subgranular zone of the dentate gyrus and the rostral subventricular zone(P0.01).Most cells labelled with BrdU expressed the immature neuronal markers DCX, suggesting that they were nascent neurons.Conclusion Proliferation cells in Aβdeposited models suggest that neurogenesis may be a compensatory response and the method could have therapeutic potential for Alzheimer's disease(AD).