α-Synuclein, a presynaptic protein, is markedly included in Lewy bodies (LB) in Parkinson's and LB diseases. In this study, neuronal loss and the activation of glial cells such as microglia and astrocytes were induced by neurodegenerative insults such as the injection of kainic acid and occlusion of the middle cerebral artery. In contrast, immunoreactivity for α-synuclein did not change even at 7 days after these insults. These results suggest that α-synuclein protein may be so scarcely scavenged by glial cells that it readily condenses in neurodegenerative regions.