Tolar M, Scott S A, Crutcher K A
Department of Neurosurgery, University of Cincinnati College of Medicine, 231 Bethesda Avenue, Cincinnati, OH 45267, USA.
Brain Res. 1998 Mar 16;787(1):49-58. doi: 10.1016/s0006-8993(97)01455-8.
Senile plaques are a characteristic histopathological feature of Alzheimer's disease (AD) and are associated with altered neuritic morphology. Numerous individual plaque components, most notably beta-amyloid, have been studied for their possible effects on neurite outgrowth in culture. However, the effect of senile plaques on neuronal morphology and function is difficult to assess. In the present study, the effect of senile plaques on neurite outgrowth was studied by culturing embryonic chick sympathetic neuronal explants on Alzheimer's tissue sections. Explants were cultured for 3 days on amygdala tissue sections from AD as well as non-AD patients in serum-free medium. Neurite outgrowth on plaque-rich regions was compared with outgrowth on plaque-poor regions of the same tissue section, and with outgrowth on non-AD tissue, through colocalization of the living explants and the underlying plaques. Explants growing on plaque-rich regions showed significantly less neurite outgrowth compared with those on plaque-poor regions in the same section or on control brain tissue. These results suggest that plaques are poor substrates for neurite outgrowth as compared with non-plaque areas of the same tissue sections, and support the hypothesis that components of the senile plaques may inhibit neurite outgrowth.
老年斑是阿尔茨海默病（AD）的特征性组织病理学特征，且与神经突形态改变有关。许多单个的斑块成分，最显著的是β-淀粉样蛋白，已被研究其对培养中神经突生长的可能影响。然而，老年斑对神经元形态和功能的影响很难评估。在本研究中，通过将胚胎鸡交感神经元外植体培养在AD患者的脑组织切片上来研究老年斑对神经突生长的影响。外植体在无血清培养基中于AD患者以及非AD患者的杏仁核组织切片上培养3天。通过活体外植体与下层斑块的共定位，将富含斑块区域的神经突生长与同一组织切片上斑块较少区域的神经突生长以及非AD组织上的神经突生长进行比较。与同一切片上斑块较少区域或对照脑组织上的外植体相比，在富含斑块区域生长的外植体显示出明显更少的神经突生长。这些结果表明，与同一组织切片的非斑块区域相比，斑块是神经突生长的不良底物，并支持老年斑成分可能抑制神经突生长的假说。
