Electron-microscopic examination of effects of yokukansan, a traditional Japanese medicine, on degeneration of cerebral cells in thiamine-deficient rats
Version of Record online: 10 MAR 2010
© 2010 Japanese Society of Neuropathology
Volume 30, Issue 5, pages 524–536, October 2010
How to Cite
Iizuka, S., Kawakami, Z., Imamura, S., Yamaguchi, T., Sekiguchi, K., Kanno, H., Ueki, T., Kase, Y. and Ikarashi, Y. (2010), Electron-microscopic examination of effects of yokukansan, a traditional Japanese medicine, on degeneration of cerebral cells in thiamine-deficient rats. Neuropathology, 30: 524–536. doi: 10.1111/j.1440-1789.2010.01101.x
- Issue online: 10 MAR 2010
- Version of Record online: 10 MAR 2010
- Received 28 April 2009; revised 10 December 2009 and accepted 13 December 2009; published online 10 March 2010.
- neurological symptoms;
- thiamine deficiency;
We previously demonstrated that yokukansan ameliorated not only learning disturbance but also behavioral and psychological symptoms of dementia-like behaviors (anxiety, aggressiveness) and neurological symptoms (opisthotonus) induced in rats by dietary thiamine deficiency (TD). In the present study, the effects of yokukansan on degeneration of cerebral cells were further examined electron-microscopically during pre-symptomatic and symptomatic stages in TD rats. In the pre-symptomatic TD stage, which appeared as increase in aggressive behaviors on the 21st and 28th days of TD diet-feeding, severe edematous degeneration of astrocytes was detected by electron microscopy, although the changes were not observed by light microscopy. In the symptomatic TD stage (the 34th day) characterized by development of neurological symptoms, severe sponge-like degeneration and multiple hemorrhages in the parenchyma were obvious by light microscopy. The electron-microscopic examination showed degeneration in neurons, oligodendroglias, and myelin sheaths in addition to astrocytes. TD rats, which exhibited multiple hemorrhages light microscopically, showed severe edematous changes and hypertrophy of the foot processes of astrocytes surrounding blood vessels. Administration of yokukansan ameliorated not only the TD-induced aggressive behavior and neurological symptoms but also degeneration of the cerebral cells. These results suggest that the inhibitory effect of yokukansan on degeneration in various brain cells might be closely related to the amelioration of aggression and neurological symptoms in TD rats.