'Jekyll and Hyde' dementia clue
10 December 2005
In the study, the researchers "switched on" p25 at will in the brain's learning and memory centre, the hippocampus.
In these mice, they found that switching on p25 for only two weeks boosted learning and memory compared to normal mice.
But if the p25 was switched on for six weeks, mice displayed impaired learning and memory in tests.
Physiological studies showed that these mice showed significant brain damage and lost nerve cells in the hippocampus.
But those who had elevated p25 levels for just two weeks had no such effects.
The researchers concluded that short-term production of p25 boosts learning - but long term exposure affects the ability to form new memories.
The researchers, led by Dr Li-Huei Tsai, say the study suggested that the protein was normally beneficial, helping form memories and enable learning.
But if there was too much p25, perhaps because of other changes in the brain linked to dementias, nerve cells can die.
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Anthony H. Risser | neuroscience | neuropsychology | brain