The molarless condition in aged SAMP8 mice attenuates hippocampal Fos induction linked to water maze performance

doi:10.1016/S0166-4328(01)00268-6

Behavioural Brain Research

Volume 128, Issue 1, 7 January 2002, Pages 19-25

https://doi.org/10.1016/S0166-4328(01)00268-6 Get rights and content

Abstract

The involvement of dysfunctional teeth in senile hippocampal activity was evaluated by examining, in aged SAMP8 mice, the effect of cutting off the upper molars (molarless condition) on hippocampal induction of the protein product, Fos, of the immediate early gene, c-fos, and on spatial performance in a water maze. The molarless condition caused a reduction in the number of Fos-positive cells in the hippocampal CA1 region, in which Fos immunoreactivity was localized in the cell nuclei. This effect was more pronounced the longer the molarless condition persisted. The suppression of both learning ability and Fos induction in the CA1 induced by the molarless condition was considerably reduced by restoring the lost molars with artificial crowns. Taken together with the plethora of research showing a relationship between stress, aging and hippocampal function and our past findings [Brain Res. 1999; 826: 148–53; Behav. Brain Res. 2000;108: 145–55; Exp. Gerontol. 2001; 36:283–95], the present results suggest the detrimental effects of a reduction in chewing on hippocampal processing in aged SAMP8 mice that would be linked with stress induced by the molarless condition.

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Acknowledgements

This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (11671960; 12557173), and an Esso Research Grant for Women (to K.W.). We also express our deep gratitude to K. Hasegawa for his encouragement and co-operation during the course of this work.

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Research reportThe molarless condition in aged SAMP8 mice attenuates hippocampal Fos induction linked to water maze performance

Abstract

Section snippets

Acknowledgements

Neuroscience

Mech. Ageing Dev.

Brain Res.

Brain Res. Rev.

Neurobiol. Aging

J. Neurosci. Methods

Pain

Neurobiol. Aging

Prog. Neurobiol.

Exp. Gerontol.

Behav. Brain Res.

Int. J. Dev. Neurosci.

Brain Res.

J. Neurosci. Methods

Brain Res.

Behav. Brain Res.

Exp. Gerontol.

Behav. Brain Res.

Exp. Gerontol.

c-Fos expression as a tool to search for the neurobiological base of the sexual behaviour of males

Acta Neurobiol. Exp.

Research report
The molarless condition in aged SAMP8 mice attenuates hippocampal Fos induction linked to water maze performance