Size-controllable networked neurospheres as a 3D neuronal tissue model for Alzheimer's disease studies.

Intensive in vitro studies on the neurotoxicity of amyloid beta have been conducted for decades; however, a three-dimensional neuronal tissue model for Alzheimer's disease has not yet been achieved. In this study, we developed size-controllable networked neurospheres comprised of cerebral cortical neuronal cells that mimics the cytoarchitecture of the cortical region of the brain. The toxicity of amyloid beta on the neurosphere model was assessed quantitatively and qualitatively. Decreased cell viability after amyloid beta exposure was demonstrated using MTT and live/dead assays. Neurite degeneration after amyloid beta exposure was evident in both SEM and fluorescence images. Ultrastructural features of apoptotic neurons were analyzed and quantitative analysis of synapsin II concentration and an acetylcholine assay were also performed. The three-dimensional neurospheres, produced using a concave microwell array, are a potential in vitro model for Alzheimer's disease studies.