This dataset explores the neurotoxic effect of accumulated, phoshorylated alpha-synuclein induced by recombinant preformed fibrils in cultured hippocampal neurons. Recombinant preformed fibrils of alpha-synuclein effectively induce phosphorylation and accumulation of alpha-synuclein into Lewy Body-like inclusions, but exactly how these inclusions lead to neuronal death remains elusive. To examine early stress responses, the phoshorylation of tau and the formation of stress granules were examined in vitro by confocal imaging. The dataset reveals a relationship between phosphorylated, aggregated alpha-synuclein and the formation of stress granules.