2007 Fiscal Year Final Research Report Summary
The effect of bite-raised condition on dendritic spine number in hippocampus
| Project/Area Number |
18592153
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
補綴理工系歯学
|
|---|
| Research Institution | Asahi University |
|---|
Principal Investigator |
KUBO Kinya Asahi University, School of Dentistry, Assistant Professor (00329492)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUJIWARA Shu Asahi University, School of Dentistry, Professor (50229069)
IINUMA Mitsuo Asahi University, School of Dentistry, Associate Professor (70184364)
ONOZUKA Minoru Kanagawa Dental College, School of Dentistry, Professor (90084780)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Keywords | Occlusal disharmony / Hippocampus / Spine / Learning ability / SAMP8 |
|---|
| Research Abstract |
Occlusal disharmony is induced by the loss of teeth or increases in the vertical dimension of crowns, bridges, or dentures. These findings suggest that, in old age, occlusal disharmony attenuates input activities in the CAl region, leading to deficits in learning and memory. In aged SAMP8 mice, the bite-raised condition (i.e., an increase in the vertical dimension) induces an increase in plasma corticosterone levels and deficits in spatial memory, accompanied by various pathologic changes, such as degeneration of hippocampal CA3 pyramidal cells, decreased Fos induction in the hippocampal CAl region, and increased number of hippocampal CA3 astroglial cells. In the central nervous system, decreased input activity in the central nervous system results in the degeneration and loss of target neurons. Thus, we hypothesized that the bite-raised condition-induced spatial memory impairment in aged mice is associated with a reduction in the number of hippocampal CAl dendritic spines.The results of several recent studies suggest that occlusal disharmony affects the central nervous system. The present study examined the effect of the bite-raised condition on the number of dendritic spines on hippocampal pyramidal cells in SAMP8 mice and related the results with learning ability in a water maze test. Aged mice in the bite-raised condition had reduced learning ability and a lower number of CAl pyramidal cell dendritic spines. The results suggest that the bite-raised condition exacerbates the age-related spatial learning impairment, and that this may be due to the degeneration of hippocampal dendritic spines.
|
Research Products
(14 results)
