Although research has so far been confined to mouse studies, researchers are optimistic about the promise of histone deacetylase inhibitors in reversing age-related memory loss — both normal decline, and the far more dramatic loss produced by Alzheimer’s. The latest study reveals that memory impairment in the aging mouse is associated with altered hippocampal chromatin plasticity, specifically with the failure of histone H4 lysine 12 acetylation, leading to a failure to initiate the gene expression program associated with memory consolidation. Restoring this acetylation leads to the recovery of cognitive abilities.
Promise of drug therapy for age-related memory loss
Reference
Peleg, S., Sananbenesi, F., Zovoilis, A., Burkhardt, S., Bahari-Javan, S., Agis-Balboa, R. C., … Fischer, A. (2010). Altered Histone Acetylation Is Associated with Age-Dependent Memory Impairment in Mice. Science, 328(5979), 753-756. Retrieved from http://www.sciencemag.org/cgi/content/abstract/328/5979/753
Related News
'Cocktail' for improved memory
A study has found that gerbils given a ‘cocktail’ of DHA, uridine and choline performed significantly better on learning and memory tests than untreated gerbils, and their brains had up to 70% more phosphatides (a type of molecule that forms cell membranes) than controls, suggesting that new synapses are forming. Some of the gerbils received all three compounds and some received only two; the improvements were greatest in those given all three. An earlier study had found that the treatment improved function in rats with cognitive impairment.
Tracking preclinical Alzheimer's progression
Submitted by Fiona McPherson
on
New research supports the classification system for preclinical Alzheimer’s proposed two years ago. The classification system divides preclinical Alzheimer's into three stages:
Stage 1: Levels of amyloid beta begin to decrease in the spinal fluid. This indicates that the substance is beginning to form plaques in the brain.
Stage 2: Levels of tau protein start to increase in the spinal fluid, indicating that brain cells are beginning to die. Amyloid beta levels are still abnormal and may continue to fall.
Gene variation associated with brain atrophy in MCI
Submitted by Fiona McPherson
on
Analysis of data from 237 patients with mild cognitive impairment (mean age 79.9) has found that, compared to those carrying the ‘normal’ ApoE3 gene (the most common variant of the ApoE gene), the ApoE4 carriers showed markedly greater rates of shrinkage in 13 of 15 brain regions thought to be key components of the brain networks disrupted in Alzheimer’s.
http://www.eurekalert.org/pub_releases/2014-01/rson-gva010714.php
Greater muscle strength = better cognitive function
A Finnish study involving 338 older adults (average age 66) has found that greater muscle strength is associated with better cognitive function.
Muscle strength was measured utilising handgrip strength, three lower body exercises such as leg extension, leg flexion and leg press and two upper body exercises such as chest press and seated row.
How blood flow is controlled in the brain
Increases in brain activity are matched by increases in blood flow. Neurons require a huge amount of energy, but can’t store it themselves, so must rely on blood to deliver the nutrients they need.
Two new studies help explain how blood flow is controlled.
The first study found blood appears to be stored in the blood vessels in the space between the brain and skull.
Does mental stimulation help fight age-related cognitive decline?
Can computer use, crafts and games slow or prevent age-related memory loss?
A study involving 2,000 healthy older adults (average age 78) found that mentally stimulating activities were linked to a lower risk or delay of MCI, and that the timing and number of these activities may also play a role.
During the study, 532 participants developed MCI.
Age differences in the allocation of study time
Journal Article
Dunlosky, J. & Connor, L.T. (1997). Age differences in the allocation of study time account for age differences in memory performance. Memory and Cognition, 25, 691-700.
- It is well-established that older adults commonly need to practice more than younger adults to achieve the same level of performance.
- It may be that such age deficits in remembering are at least partly due to poorer monitoring of their learning.
It has been well-established that, compared to younger adults, older adults require more practice to achieve the same level of performance1. Sometimes, indeed, they may need twice as much2.
In the present study, two groups of adult subjects were given paired items to learn during multiple study-test trials. During each trial items were presented at the subject's pace. Afterwards the subjects were asked to judge how likely they were to be able to recall each item in a test.
It was found that people were very good at accurately judging the likelihood of their correct recall. Correlations between judgments and the amount of time the subjects studied the items suggested that people were monitoring their learning and using this to allocate study time.
However, older adults (with a mean age of 67) used monitoring to a lesser degree than the younger adults (with a mean age of 22), and the results suggested that part of the reason for the deficit in recall commonly found with older adults is due to this factor.
References
1. For a review, see Kausler, D.H. 1994. Learning and memory in normal aging. New York: Academic Press.
2. Delbecq-Derousné, J. & Beauvois, M. 1989. Memory processes and aging: A defect of automatic rather than controlled processes? Archives of Gerontology & Geriatrics, 1 (Suppl), 121-150.
Salthouse, T.A. & Dunlosky, J. 1995. Analyses of adult age differences in associative learning. Zeitschrift für Psychologie, 203, 351-360
Distinguishing normal cognitive decline from more serious disorders
Submitted by Fiona McPherson
on
Data from two longitudinal studies of older adults (a nationally representative sample of older adults, and the Alzheimer’s Disease Neuroimaging Initiative) has found that a brief cognitive test can distinguish memory decline associated with healthy aging from more serious memory disorders, years before obvious symptoms show up.
Moreover, the data challenge the idea that memory continues to decline through old age: after excluding the cognitively impaired, there was no evidence of further memory declines after the age of 69.
One Alzheimer's risk gene may begin to affect brains from childhood
Submitted by Fiona McPherson
on
A gene linked to Alzheimer's has been linked to brain changes in childhood. This gene, SORL1, has two connections to Alzheimer’s: it carries the code for the sortilin-like receptor, which is involved in recycling some molecules before they develop into amyloid-beta; it is also involved in lipid metabolism, putting it at the heart of the vascular risk pathway.
Daily crosswords linked to sharper brain in later life
Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.
Study participants took part in online cognitive tests, as well as being asked how frequently they did word puzzles such as crosswords. There was a direct relationship between the frequency of word puzzle use and the speed and accuracy of performance on nine cognitive tasks.