The accumulation of ?7nAChR and the relationship between ?7nAChR and A?_(1-42) in Alzheimer's disease brains / 中华神经科杂志

ABSTRACT

Objective To investigate the role of ?7nAChR in the pathogenesis of Alzheimer's disease(AD)through exploring the relationship between ?7nAChR and A?_(1-42) in AD brains.Methods The accumulation of ?7nAChR and the possible relationship between ?7nAChR and A?_(1-42) were observed in 3 clinically and pathologically confirmed AD brains by immunohistochemistry. 3 normal brains were set as controls.Results Respective staining of anti-?7nAChR and anti-A?_(1-42) showed that the abnormal accumulation of ?7nAChR existed in AD brains. The main location was at hippocampus and temporal cortex which was just in accordance with senile plaque consisted mainly of A?_(1-42). The major part of ?7nAChR was located extra-cellular and within senile plaque from the view of morphology. No accumulation of ?7nAChR existed in normal brains. Co-staining of anti-?7nAChR and anti-A?_(1-42) further showed that ?7nAChR and A?_(1-42) could accumulate together in senile plaque of AD brain. The average rate of positive co-staining in hippocampus, temporal lobe and frontal lobe is 57.8%, 51.0% and 21.8% respectively. The accumulation of ?7nAChR in hippocampus and temporal lobe seems much than that in the frontal lobe. Conclusion ?7nAChR may combine with A?_(1-42) in AD brains. It is suggested that the combination should destroy the ?7nAChR receptor, block the receptor or mediate the injury of cholinergic neurons with the result of recognition and memory impairment and that ?7nAChR might play an important role in the pathogenesis of Alzheimer's disease.