| First Author | Holahan MR | Year | 2007 |
| Journal | Learn Mem | Volume | 14 |
| Issue | 6 | Pages | 407-15 |
| PubMed ID | 17554085 | Mgi Jnum | J:136930 |
| Mgi Id | MGI:3797351 | Doi | 10.1101/lm.581907 |
| Citation | Holahan MR, et al. (2007) GAP-43 gene expression regulates information storage. Learn Mem 14(6):407-15 |
| abstractText | Previous reports have shown that overexpression of the growth- and plasticity-associated protein GAP-43 improves memory. However, the relation between the levels of this protein to memory enhancement remains unknown. Here, we studied this issue in transgenic mice (G-Phos) overexpressing native, chick GAP-43. These G-Phos mice could be divided at the behavioral level into 'spatial bright' and 'spatial dull' groups based on their performance on two hidden platform water maze tasks. G-Phos dull mice showed both acquisition and retention deficits on the fixed hidden platform task, but were able to learn a visible platform task. G-Phos bright mice showed memory enhancement relative to wild type on the more difficult movable hidden platform spatial memory task. In the hippocampus, the G-Phos dull group showed a 50% greater transgenic GAP-43 protein level and a twofold elevated transgenic GAP-43 mRNA level than that measured in the G-Phos bright group. Unexpectedly, the dull group also showed an 80% reduction in hippocampal Tau1 staining. The high levels of GAP-43 seen here leading to memory impairment find its histochemical and behavioral parallel in the observation of Rekart et al. (Neuroscience 126: 579-584) who described elevated levels of GAP-43 protein in the hippocampus of Alzheimer's patients. The present data suggest that moderate overexpression of a phosphorylatable plasticity-related protein can enhance memory, while excessive overexpression may produce a 'neuroplasticity burden' leading to degenerative and hypertrophic events culminating in memory dysfunction. |
