Dietary vitamin E deficiency increases anxiety-related behavior in rats under stress of social isolation

It has been demonstrated that vitamin E deficiency from birth increases anxiety-related behavior using knockout animals with no vitamin E transfer proteins. The current study was undertaken to elucidate the effect of dietary vitamin E deficiency on anxiety-related behavior of rats in different housing conditions. Mate Wistar strain rats were divided into two groups during the weaning period and fed a control or vitamin E-deficient diet. Alt rats were housed in groups (three rats per cage) for 3 weeks. In the fourth week, half of the rats in each dietary treatment were kept in social housing and the other half were kept in individual housing. Before sacrifice, rota-rod and elevated plus-maze (EPM) tests were performed to measure motor coordination and anxiety, respectively. The EPM test revealed that vitamin E-deficient rats spent less time in the open arms and showed more stretch-out posture than the control rats, showing that anxiety increased with dietary vitamin E deficiency. Furthermore, vitamin E deficiency-induced anxiety behavior was observed more prominent in individual housed rats than in social housed rats. On the basis of these results, we conclude that dietary vitamin E deficiency induces anxiety in rats especially under stress of social isolation. (C) 2009 International Union of Biochemistry and Molecular Biology, Inc. Volume 35, Number 3, May/June 2009, Pages 273-278. E-mail: takenaka@isc.meiji.ac.jp