Older news items (pre-2010) brought over from the old website

Factors helping you maintain cognitive function in old age

An 8-year study of over 2,500 seniors in their 70s, has found that 53% showed normal age-related decline, 16% showed major cognitive decline, and an encouraging 30% had no change or improved on the tests over the years. The most important factors in determining whether a person maintained their cognitive health was education and literacy: those with a ninth grade literacy level or higher were nearly five times as likely to stay sharp than those with lower literacy levels; those with at least a high school education were nearly three times as likely to stay sharp as those who have less education. Lifestyle factors were also significant: non-smokers were nearly twice as likely to stay sharp as smokers; those who exercised moderately to vigorously at least once a week were 30% more likely to maintain their cognitive function than those who do not exercise that often; people working or volunteering and people who report living with someone were 24% more likely to maintain cognitive function.

[909] Ayonayon, H. N., Harris T. B., For the Health ABC Study, Yaffe K., Fiocco A. J., Lindquist K., et al.
(2009).  Predictors of maintaining cognitive function in older adults: The Health ABC Study.
Neurology. 72(23), 2029 - 2035.

http://www.eurekalert.org/pub_releases/2009-06/aaon-ssn060209.php

Better cognitive performance from US seniors compared to British

A study involving over 8,000 older Americans and over 5,000 British seniors has found a significant difference in cognitive performance between the two nationalities, with the Americans scoring on average as if they were ten years younger than the British. The U.S. advantage in "brain health" was greatest for the oldest old---those aged 85 and older. Part of the difference can be accounted for by higher levels of education and net worth in the United States, and part by significantly lower levels of depressive symptoms (possibly attributable to the much greater degree of medication in the US for depression). It was also found that dramatically more U.S. seniors reported no alcohol use (over 50%), compared to the British (15.5%). It is also speculated that the earlier retirement in Britain may be a factor, and also the greater prevalence of untreated hypertension.

[773] Langa, K. M., Llewellyn D., Lang I., Weir D., Wallace R., Kabeto M., et al.
(2009).  Cognitive health among older adults in the United States and in England.
BMC Geriatrics. 9(1), 23 - 23.

Full text available at http://www.biomedcentral.com/content/pdf/1471-2318-9-23.pdf
http://www.eurekalert.org/pub_releases/2009-06/bc-aet062309.php
http://www.eurekalert.org/pub_releases/2009-06/uom-us062309.php

Memory gets worse with age if you think about it

Confirming earlier research (and what I’ve been saying for ten years), thinking that memory diminishes with age is sufficient for some elderly people to score lower on cognitive tests. Moreover, and confirming other research relating to gender and race, the study also found that a senior's ability to remember something was heavily influenced by the activation or inactivation of negative stereotypes (for example, by being told before the test that older people perform more poorly on that type of memory test). The effects of negative stereotypes were experienced more by those in their sixties than older (but those in their seventies performed worse when they felt stigmatized), and more by the very well-educated. There was some indication that these effects occur through their effect on motivation.

[1013] Hess, T. M., Hinson J. T., & Hodges E. A.
(2009).  Moderators of and Mechanisms Underlying Stereotype Threat Effects on Older Adults' Memory Performance.
Experimental Aging Research: An International Journal Devoted to the Scientific Study of the Aging Process. 35(2), 153 - 153.

http://news.softpedia.com/news/Memory-Gets-Worse-With-Age-If-you-Think-About-It-109909.shtml
http://www.physorg.com/news159544866.html
http://www.eurekalert.org/pub_releases/2009-04/ncsu-tmw042109.php

Circadian clock may be critical for remembering what you learn

We know circadian rhythm affects learning and memory in that we find it easier to learn at certain times of day than others, but now a study involving Siberian hamsters has revealed that having a functioning circadian system is in itself critical to being able to remember. The finding has implications for disorders such as Down syndrome and Alzheimer's disease. The critical factor appears to be the amount of the neurotransmitter GABA, which acts to inhibit brain activity. The circadian clock controls the daily cycle of sleep and wakefulness by inhibiting different parts of the brain by releasing GABA. It seems that if it’s not working right, if the hippocampus is overly inhibited by too much GABA, then the circuits responsible for memory storage don't function properly. The effect could be fixed by giving a GABA antagonist, which blocks GABA from binding to synapses. Recent mouse studies have also demonstrated that mice with symptoms of Down syndrome and Alzheimer's also show improved learning and memory when given the same GABA antagonist. The findings may also have implications for general age-related cognitive decline, because age brings about a degradation in the circadian system. It’s also worth noting that the hamsters' circadian systems were put out of commission by manipulating the hamsters' exposure to light, in a technique that was compared to "sending them west three time zones." The effect was independent of sleep duration.

[688] Ruby, N. F., Hwang C. E., Wessells C., Fernandez F., Zhang P., Sapolsky R., et al.
(2008).  Hippocampal-dependent learning requires a functional circadian system.
Proceedings of the National Academy of Sciences. 105(40), 15593 - 15598.

http://www.eurekalert.org/pub_releases/2008-10/su-ccm100808.php

Occasional memory loss tied to lower brain volume

A study of 503 seniors (aged 50-85) with no dementia found that 453 of them (90%) reported having occasional memory problems such as having trouble thinking of the right word or forgetting things that happened in the last day or two, or thinking problems such as having trouble concentrating or thinking more slowly than they used to. Such problems have been attributed to white matter lesions, which are very common in older adults, but all of the participants in the study had white matter lesions in their brains, and the amount of lesions was not tied to occasional memory problems. However it was found that those who reported having such problems had a smaller hippocampus than those who had no cognitive problems. This was most noteworthy in subjects with good objective cognitive performance.

[895] van Norden, A. G. W., Fick W. F., de Laat K. F., van Uden I. W. M., van Oudheusden L. J. B., Tendolkar I., et al.
(2008).  Subjective cognitive failures and hippocampal volume in elderly with white matter lesions.
Neurology. 71(15), 1152 - 1159.

http://www.eurekalert.org/pub_releases/2008-10/aaon-oml093008.php

Decline of mental skills in years before death

A long-running study of 288 people with no dementia, who were followed from age 70 to death, has found that there was substantial acceleration in cognitive decline many years prior to death. Time of onset and rate of terminal decline varied considerably across cognitive abilities, with verbal ability beginning its terminal decline 6.6 years prior to death, spatial ability 7.8 years before death, and perceptual speed 14.8 years before death. With verbal ability, it appeared that the decline was not due to age only, but due to health issues.

[212] Thorvaldsson, V., Hofer S. M., Berg S., Skoog I., Sacuiu S., & Johansson B.
(2008).  Onset of terminal decline in cognitive abilities in individuals without dementia.
Neurology. 01.wnl.0000312379.02302.ba - 01.wnl.0000312379.02302.ba.

http://www.eurekalert.org/pub_releases/2008-08/aaon-ewd081908.php

Aging impairs the 'replay' of memories during sleep

During sleep, the hippocampus repeatedly "replays" brain activity from recent experiences, in a process believed to be important for memory consolidation. A new rat study has found reduced replay activity during sleep in old compared to young rats, and rats with the least replay activity performed the worst in tests of spatial memory. The best old rats were also the ones that showed the best sleep replay. Indeed, the animals who more faithfully replayed the sequence of neural activity recorded during their earlier learning experience were the ones who performed better on the spatial memory task, regardless of age. The replay activity occurs during slow-wave sleep.

[1319] Gerrard, J. L., Burke S. N., McNaughton B. L., & Barnes C. A.
(2008).  Sequence Reactivation in the Hippocampus Is Impaired in Aged Rats.
J. Neurosci.. 28(31), 7883 - 7890.

http://www.eurekalert.org/pub_releases/2008-07/sfn-ait072408.php

White-matter changes linked to gait and balance problems

A three-year study involving 639 adults between the ages of 65 and 84 has found that people with severe white matter changes (leukoaraiosis) were twice as likely to score poorly on walking and balance tests as those people with mild white matter changes. The study also found people with severe changes were twice as likely as the mild group to have a history of falls. The moderate group was one-and-a-half times as likely as the mild group to have a history of falls. Further research will explore the effect of exercise.

[1004] Langhorne, P., O'Brien J., Scheltens P., Visser M. C., Wahlund L. O., Waldemar G., et al.
(2008).  Association of gait and balance disorders with age-related white matter changes: The LADIS Study.
Neurology. 70(12), 935 - 942.

http://www.physorg.com/news124990876.html

Lack of imagination in older adults linked to declining memory

In a study in which older and younger adults were asked to think of past and future events, older adults were found to generate fewer details about past events — and this correlated with an impaired ability to imagine future events. The number of details remembered by older adults was also linked to their relational memory abilities. The findings suggest that our ability to imagine future events is based on our ability to remember the details of previously experienced ones, extract relevant details and put them together to create an imaginary event.

[287] Addis, D R., Wong A. T., & Schacter D. L.
(2008).  Age-related changes in the episodic simulation of future events.
Psychological Science: A Journal of the American Psychological Society / APS. 19(1), 33 - 41.

http://www.eurekalert.org/pub_releases/2008-01/afps-loi010708.php

Brain systems become less coordinated with age, even in the absence of disease

An imaging study of the brain function of 93 healthy individuals from 18 to 93 years old has revealed that normal aging disrupts communication between different regions of the brain. The finding is consistent with previous research showing that normal aging slowly degrades white matter. The study focused on the links within two critical networks, one responsible for processing information from the outside world and one, known as the default network, which is more internal and kicks in when we muse to ourselves. “We found that in young adults, the front of the brain was pretty well in sync with the back of the brain [but] in older adults this was not the case. The regions became out of sync and they were less correlated with each other.” However, older adults with normal, high correlations performed better on cognitive tests. Among older individuals whose brain systems did not correlate, all of the systems were not affected in the same way. The default system was most severely disrupted with age. The visual system was very well preserved.

[1052] Andrews-Hanna, J. R., Snyder A. Z., Vincent J. L., Lustig C., Head D., Raichle M E., et al.
(2007).  Disruption of Large-Scale Brain Systems in Advanced Aging.
Neuron. 56(5), 924 - 935.

http://www.eurekalert.org/pub_releases/2007-12/hhmi-tab120307.php
http://www.eurekalert.org/pub_releases/2007-12/hu-bsb120307.php
http://www.eurekalert.org/pub_releases/2007-12/cp-co112907.php

Why neurogenesis is so much less in older brains

A rat study has revealed that the aging brain produces progressively fewer new nerve cells in the hippocampus (neurogenesis) not because there are fewer of the immature cells (neural stem cells) that can give rise to new neurons, but because they divide much less often. In young rats, around a quarter of the neural stem cells were actively dividing, but only 8% of cells in middle-aged rats and 4% in old rats were. This suggests a new approach to improving learning and memory function in the elderly.

[1077] Hattiangady, B., & Shetty A. K.
(2008).  Aging does not alter the number or phenotype of putative stem/progenitor cells in the neurogenic region of the hippocampus.
Neurobiology of Aging. 29(1), 129 - 147.

http://www.eurekalert.org/pub_releases/2006-12/dumc-sca121806.php

Senior’s memory complaints should be taken seriously

A study involving 120 people over 60 found those who complained of significant memory problems who still performed normally on memory tests had a 3% reduction in gray matter density in their brains. This compares to 4% in those diagnosed with mild cognitive impairment. This suggests that significant memory loss complaints may indicate a very early "pre-MCI" stage of dementia for some people.

[979] Saykin, A. J., Wishart H. A., Rabin L. A., Santulli R. B., Flashman L. A., West J. D., et al.
(2006).  Older adults with cognitive complaints show brain atrophy similar to that of amnestic MCI.
Neurology. 67(5), 834 - 842.

http://www.eurekalert.org/pub_releases/2006-09/aaon-fym090506.php

Alzheimer's pathology related to episodic memory loss in those without dementia

A study of 134 participants from the Religious Orders Study or the Memory and Aging Project has found that, although they didn't have cognitive impairment at the time of their death, more than a third of the participants (50) met criteria for a pathologic diagnosis of Alzheimer's disease. This group also scored significantly lower on tests for episodic memory, such as recalling stories and word lists. The results provide further support for the idea that a ‘cognitive reserve’ can allow people to tolerate a significant amount of Alzheimer's pathology without manifesting obvious dementia. It also raises the question whether we should accept any minor episodic memory loss in older adults as 'normal'.

[967] Bennett, D. A., Schneider J. A., Arvanitakis Z., Kelly J. F., Aggarwal N. T., Shah R. C., et al.
(2006).  Neuropathology of older persons without cognitive impairment from two community-based studies.
Neurology. 66(12), 1837 - 1844.

http://www.eurekalert.org/pub_releases/2006-06/aaon-apr062006.php

Does IQ drop with age or does something else impact intelligence?

As people grow older, their IQ scores drop. But is it really that they lose intelligence? A study has found that if college students had to perform under conditions that mimic the perception deficits many older people have, their IQ scores would also take a drop.

[234] Gilmore, G. C., Spinks R. A., & Thomas C. W.
(2006).  Age effects in coding tasks: componential analysis and test of the sensory deficit hypothesis.
Psychology and Aging. 21(1), 7 - 18.

http://www.eurekalert.org/pub_releases/2006-05/cwru-did050106.php

Walking in older people is related to cognitive skills

A study of 186 adults aged 70 and older tested gait speed with and without interference (walking while reciting alternate letters of the alphabet). Walking speed was predictable from performance on cognitive tests of executive control and memory, particularly when the participant was required to recite at the same time. The findings suggest that in old age, walking involves higher-order executive-control processes, suggesting that cognitive tests could help doctors assess risk for falls. Conversely, slow gait could alert them to check for cognitive impairment.

[1812] Holtzer, R., Verghese J., Xue X., & Lipton R. B.
(2006).  Cognitive Processes Related to Gait Velocity: Results From the Einstein Aging Study..
Neuropsychology. 20(2), 215 - 223.

http://www.eurekalert.org/pub_releases/2006-03/apa-opw032306.php

Immune function important for cognition

New research overturns previous beliefs that immune cells play no part in — and may indeed constitute a danger to — the brain. Following on from an earlier study that suggested that T cells — immune cells that recognize brain proteins — have the potential to fight off neurodegenerative conditions such as Alzheimer’s, researchers have found that neurogenesis in adult rats kept in stimulating environments requires these immune cells. A further study found that mice with these T cells performed better at some tasks than mice lacking the cells. The researchers suggest that age-related cognitive decline may be related to this, as aging is associated with a decrease in immune system function, suggesting that boosting the immune system may also benefit cognitive function in older adults.

[435] Ziv, Y., Ron N., Butovsky O., Landa G., Sudai E., Greenberg N., et al.
(2006).  Immune cells contribute to the maintenance of neurogenesis and spatial learning abilities in adulthood.
Nat Neurosci. 9(2), 268 - 275.

http://www.eurekalert.org/pub_releases/2006-01/acft-wis011106.php

Early life stress can lead to memory loss and cognitive decline in middle age

Age-related cognitive decline is probably a result of both genetic and environmental factors. A rat study has demonstrated that some of these environmental factors may occur in early life. Among the rats, emotional stress in infancy showed no ill effects by the time the rats reached adulthood, but as the rats reached middle age, cognitive deficits started to appear in those rats who had had stressful infancies, and progressed much more rapidly with age than among those who had had nurturing infancies. Middle-aged rats who had been exposed to early life emotional stress showed deterioration in brain-cell communication in the hippocampus.

[1274] Brunson, K. L., Kramar E., Lin B., Chen Y., Colgin L L., Yanagihara T. K., et al.
(2005).  Mechanisms of Late-Onset Cognitive Decline after Early-Life Stress.
J. Neurosci.. 25(41), 9328 - 9338.

http://www.eurekalert.org/pub_releases/2005-10/uoc--els100605.php

Older people with the 'Alzheimer's gene' find it harder to remember intentions

It has been established that those with a certain allele of a gene called ApoE have a much greater risk of developing Alzheimer’s (those with this allele on both genes have 8 times the risk; those with the allele on one gene have 3 times the risk). Recent studies also suggest that such carriers are also more likely to show signs of deficits in episodic memory – but that these deficits are quite subtle. In the first study to look at prospective memory in seniors with the “Alzheimer’s gene”, involving 32 healthy, dementia-free adults between ages of 60 and 87, researchers found a marked difference in performance between those who had the allele and those who did not. The results suggest an exception to the thinking that ApoE status has only a subtle effect on cognition.

[1276] Driscoll, I., McDaniel M. A., & Guynn M. J.
(2005).  Apolipoprotein E and prospective memory in normally aging adults.
Neuropsychology. 19(1), 28 - 34.

http://www.eurekalert.org/pub_releases/2005-01/apa-opw011805.php

Some brains age more rapidly than others

Investigation of the patterns of gene expression in post-mortem brain tissue has revealed two groups of genes with significantly altered expression levels in the brains of older individuals. The most significantly affected are mostly those related to learning and memory. One of the most interesting, and potentially useful, findings, is that patterns of gene expression are quite similar in the brains of younger adults. Very old adults also show similar patterns, although the similarity is less. But the greatest degree of individual variation occurs in those aged between 40 and 70. Some of these adults show gene patterns that look more like the young group, whereas others show gene patterns that look more like the old group. It appears that gene changes start around 40 in some people, but not in others. It also appears that those genes that are affected by age are unusually vulnerable to damage from agents such as free radicals and toxins in the environment, suggesting that lifestyle in young adults may play a part in deciding rate and degree of cognitive decline in later years.

[1335] Lu, T., Pan Y., Kao S-Y., Li C., Kohane I., Chan J., et al.
(2004).  Gene regulation and DNA damage in the ageing human brain.
Nature. 429(6994), 883 - 891.

http://www.eurekalert.org/pub_releases/2004-06/chb-dgi060204.php

Drugs to improve memory may worsen memory in some

Drugs that increase the activity of an enzyme called protein kinase A improve long-term memory in aged mice and have been proposed as memory-enhancing drugs for elderly humans. However, the type of memory improved by this activity occurs principally in the hippocampus. A new study suggests that increased activity of this enzyme has a deleterious effect on working memory (which principally involves the prefrontal cortex). In other words, a drug that helps you remember a recent event may worsen your ability to remember what you’re about to do (to take an example).

[1404] Ramos, B. P., Birnbaum S. G., Lindenmayer I., Newton S. S., Duman R. S., & Arnsten A. F. T.
(2003).  Dysregulation of protein kinase a signaling in the aged prefrontal cortex: new strategy for treating age-related cognitive decline.
Neuron. 40(4), 835 - 845.

http://www.eurekalert.org/pub_releases/2003-11/naos-mdf110303.php

Memory-enhancing drugs for elderly may impair working memory and other executive functions

A number of pharmaceutical companies are working on developing memory-enhancing drugs not only for patients with clinical memory impairment, but also for perfectly healthy people. Although some drugs have been found that can improve cognitive function in those suffering from impairment, the side effects preclude their use among healthy people. However, a recent study has found evidence that a well-established drug used for narcolepsy (excessive daytime sleepiness) may improve cognition in normal people, without side effects. The drug seems to particularly affect some tasks requiring planning and working memory (and in a further, as yet unpublished study, appears helpful for adults with ADHD). Whether the drug (modafinil) has anything over caffeine in terms of the cognitive benefits it brings is still debated. More interestingly, and in line with the sometimes conflicting results of these kinds of drugs on different people, the researchers suggest that the effect of drugs on cognitive function depends on the level at which the individual cognitive system is operating: if your system is mildly below par, the right brain chemical could improve performance; if it’s well below par, the same dose will have a much smaller effect; if (and this is the interesting one) it’s already operating at peak, the chemical could in fact degrade performance.

[1360] Turner, D. C., Robbins T. W., Clark L., Aron A. R., Dowson J., & Sahakian B. J.
(2003).  Cognitive enhancing effects of modafinil in healthy volunteers.
Psychopharmacology. 165(3), 260 - 269.

Magnetic resonance imaging may help predict future memory decline

A six-year imaging study of 45 healthy seniors assessed changes in brain scans against cognitive decline. They found that progressive atrophy in the medial temporal lobe was the most significant predictor of cognitive decline, which occurred in 29% of the subjects.

[490] Rusinek, H., de Santi S., Frid D., Tsui W-H., Tarshish C. Y., Convit A., et al.
(2003).  Regional brain atrophy rate predicts future cognitive decline: 6-year longitudinal MR imaging study of normal aging.
Radiology. 229(3), 691 - 696.

http://www.eurekalert.org/pub_releases/2003-11/rson-mhr111703.php

Mouse study suggests new approach to reducing age-related cognitive decline

Young and old mice learned that a particular tone was associated with a mild electric footshock. When the tone was immediately followed by a shock, both young and aged mice easily remembered the association on the following day. When the tone was separated from the shock by several seconds, the old mice were strongly impaired in comparison to the young mice. The researchers found highly elevated levels of a calcium-activated potassium channel, the so-called SK3 channel, in the hippocampus of old, but not of young mice. When the researchers selectively downregulated SK3 channels in the hippocampus of aged mice, the impairment in learning and memory was prevented. This suggests a new approach to treating age-related memory decline.

Blank, T., Nijholt, I., Kye, M-J., Radulovic, J. & Spiess, J. 2003. Small-conductance, Ca²⁺-activated K⁺ channel SK3 generates age-related memory and LTP deficits. Nature Neuroscience, 6(9),911–912. Published online: 27 July 2003, doi:10.1038/nn1101

http://tinyurl.com/nm3r

Rat study offers more complex model of brain aging

A study of young, middle-aged, and aged rats, trained on two memory tasks, has revealed 146 genes connected with brain aging and cognitive impairment. Importantly, the changes in gene activity had mostly begun in mid-life, suggesting that changes in gene activity in the brain in early adulthood might set off cellular or biological changes that could affect how the brain works later in life. The study provides more information on genes already linked to aging, including some involved in inflammation and oxidative stress, and also describes additional areas in which gene activity might play a role in brain aging, including declines in energy metabolism in cells and changes in the activity of neurons (nerve cells) in the brain and their ability to make new connections with each other, increases in cellular calcium levels which could trigger cell death, cholesterol synthesis, iron metabolism and the breakdown of the insulating myelin sheaths that when intact facilitate efficient communication among neurons.

[852] Blalock, E. M., Chen K-C., Sharrow K., Herman J. P., Porter N. M., Foster T. C., et al.
(2003).  Gene Microarrays in Hippocampal Aging: Statistical Profiling Identifies Novel Processes Correlated with Cognitive Impairment.
J. Neurosci.. 23(9), 3807 - 3819.

http://www.eurekalert.org/pub_releases/2003-05/nioa-nsi050203.php

Is a dwindling brain chemical responsible for age-related cognitive decline?

A study of what are probably the world's oldest monkeys may explain age-related mental decline. The study found that the very old monkeys' nerves in the visual cortex lose their ability to discriminate between one signal and another and that this loss was directly related to the presence of a chemical called gamma-aminobutyric acid (Gaba), a neurotransmitter that appears to dwindle in old age. If a lack of GABA is indeed responsible for the old neurons' indiscriminate firing, this problem may be simple enough to treat. There already exist drugs that increase GABA production, although these drugs have yet to be carefully tested on the elderly.

[660] Leventhal, A. G., Wang Y., Pu M., Zhou Y., & Ma Y.
(2003).  GABA and its agonists improved visual cortical function in senescent monkeys.
Science (New York, N.Y.). 300(5620), 812 - 815.

http://www.eurekalert.org/pub_releases/2003-05/aaft-sow042403.php http://www.newswise.com/articles/2003/5/OLDBRAIN.UUT.html
http://www.utah.edu/unews/releases/03/may/oldbrain.html
http://news.independent.co.uk/world/science_medical/story.jsp?story=402317

Rat studies provide more evidence on why aging can impair memory

Among aging rats, those that have difficulty navigating water mazes have no more signs of neuron damage or cell death in the hippocampus, a brain region important in memory, than do rats that navigate with little difficulty. Nor does the extent of neurogenesis (birth of new cells in an adult brain) seem to predict poorer performance. Although the researchers have found no differences in a variety of markers for postsynaptic signals between elderly rats with cognitive impairment and those without, decreases in a presynaptic signal are correlated with worse cognitive impairment. That suggests that neurons in the impaired rat brains may not be sending signals correctly.

Gallagher, M. 2002. Markers for memory decline. Paper presented at the Society for Neuroscience annual meeting in Orlando, Florida, 5 November.

http://news.bmn.com/conferences/list/view?rp=2002-SFN-3-S4

An enzyme that helps us to forget

A series of experiments on genetically altered laboratory mice showed those with low levels of the enzyme protein phosphatase-1 (PP1), were less likely to forget what they had learned. This enzyme appears to be critical in helping us forget unwanted information, but it may also be partly responsible for an increase in forgetting in older adults. It was found that as the mice aged, the level of PP1 increased. When the action of PP1 was blocked, the mice recovered their full learning and memory abilities.

[1357] Genoux, D., Haditsch U., Knobloch M., Michalon A., Storm D., & Mansuy I. M.
(2002).  Protein phosphatase 1 is a molecular constraint on learning and memory.
Nature. 418(6901), 970 - 975.

http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2002/08/29/MN2052.DTL
http://news.bbc.co.uk/1/hi/health/2222871.stm

Age-related changes in brain dopamine may underpin the normal cognitive problems of aging

A new model suggests why and how many cognitive abilities decline with age, and offers hope for prevention. Research in the past few years has clarified and refined our ideas about the ways in which cognitive abilities decline with age, and one of these ways is in a reduced ability to recall the context of memories. Thus, for example, an older person is less likely to be able to remember where she has heard something. According to this new model, context processing is involved in many cognitive functions — including some once thought to be independent — and therefore a reduction in the ability to remember contextual information can have wide-reaching implications for many aspects of cognition. The model suggests that context processing occurs in the prefrontal cortex and requires a certain level of the brain chemical dopamine. It may be that in normal aging, dopamine levels become low or erratic. Changes in dopamine have also been implicated in Alzheimer’s, as well as other brain-based diseases.

[1180] Mumenthaler, M. S., Jagust W. J., Reed B. R., Braver T. S., Barch D. M., Keys B. A., et al.
(2001).  Context processing in older adults: evidence for a theory relating cognitive control to neurobiology in healthy aging.
Journal of Experimental Psychology. General. 130(4), 746 - 763.

http://www.eurekalert.org/pub_releases/2001-12/apa-ocf121701.php

Older news items (pre-2010) brought over from the old website

Diabetic episodes affect memory

A study involving 62 children with type 1 diabetes, of whom 33 had experienced diabetic ketoacidosis, has found those with such experience performed significantly worse on a memory test that tested their ability to recall events in association with specific details. The finding points to the importance of avoiding diabetic ketoacidosis, which is avoidable in those known to have diabetes.

[1384] Ghetti, S., Lee J. K., Sims C. E., DeMaster D. M., & Glaser N. S.
(2010).  Diabetic Ketoacidosis and Memory Dysfunction in Children with Type 1 Diabetes.
The Journal of Pediatrics. 156(1), 109 - 114.

http://www.eurekalert.org/pub_releases/2009-10/uoc--dea101909.php

Poor glucose control linked to cognitive impairment in diabetics

The ongoing Memory in Diabetes (MIND) study, involving some 3,000 type 2 diabetics 55 years and older, has found that cognitive functioning abilities drop as average blood sugar levels rise. However, there was no connection between daily blood glucose levels and cognitive performance. The study adds to growing evidence that poorer blood glucose control is strongly associated with poorer memory function, that may eventually lead to mild cognitive impairment, vascular dementia and Alzheimer's disease. It is also possible that people with impaired cognitive ability are less compliant in taking medications and controlling their diabetes. Further research will test the hypothesis that improving glucose control results in improved cognitive function.

[797] Marcovina, S. M., Launer L. J., Cukierman-Yaffe T., Gerstein H. C., Williamson J. D., Lazar R. M., et al.
(2009).  Relationship Between Baseline Glycemic Control and Cognitive Function in Individuals With Type 2 Diabetes and Other Cardiovascular Risk Factors.
Diabetes Care. 32(2), 221 - 226.

http://www.eurekalert.org/pub_releases/2009-02/wfub-hbs021109.php

Adult-onset diabetes slows mental functioning in several ways, with deficits appearing early

A comparison of 41 adults with diabetes and 424 adults in good health, aged between 53 and 90, has revealed that healthy adults performed significantly better than adults with diabetes on two of the five domains tested: executive functioning and speed of processing. There were no significant differences on tests of episodic and semantic memory, verbal fluency, reaction time and perceptual speed. The effect remained even when only the younger group (those below 70) were analyzed, indicating that the diabetes-linked cognitive deficits appear early and remain stable.

[796] Yeung, S. E., Fischer A. L., & Dixon R. A.
(2009).  Exploring effects of type 2 diabetes on cognitive functioning in older adults.
Neuropsychology. 23(1), 1 - 9.

http://www.eurekalert.org/pub_releases/2009-01/apa-ads123008.php

Blood sugar linked to normal cognitive aging

Following research showing that decreasing brain function in the area of the hippocampus called the dentate gyrus is a main contributor of normal age-related cognitive decline, an imaging study has been investigating the cause of this decreasing function by looking at measures that typically change during aging, like rising blood sugar, body mass index, cholesterol and insulin levels. The study of 240 community-based nondemented elders (average age 80 years), of whom 60 had type 2 diabetes, found that decreasing activity in the dentate gyrus only correlated with levels of blood glucose. The same association was also found in aging rhesus monkeys and in mice. The finding suggests that maintaining blood sugar levels, even in the absence of diabetes, could help maintain aspects of cognitive health. It also suggests that one reason why physical exercise benefits memory may be its effect on lowering glucose levels.

[830] Mayeux, R., Vannucci S. J., Small S. A., Wu W., Brickman A. M., Luchsinger J., et al.
(2008).  The brain in the age of old: The hippocampal formation is targeted differentially by diseases of late life.
Annals of Neurology. 64(6), 698 - 706.

http://www.eurekalert.org/pub_releases/2008-12/cumc-rac121508.php

Diabetic seniors may experience memory declines after eating high-fat food

Growing evidence links diabetes to cognitive impairment. Now a small study of 16 adults (aged 50 years and older) with type 2 diabetes compared their cognitive performance on three separate occasions, fifteen minutes after consuming different meals. One meal consisted of high fat products – a danish pastry, cheddar cheese and yogurt with added whipped cream; the second meal was only water; and the third was the high-fat meal plus high doses of vitamins C (1000 mg) and E (800 IU) tablets. Researchers found that vitamin supplementation consistently improved recall scores relative to the meal alone, while those who ate the high fat meal without vitamin supplements showed significantly more forgetfulness of words and paragraph information in immediate and time delay recall tests. Those on water meal and meal with vitamins showed similar levels in cognitive performance. The finding indicates not only that diabetics can temporarily further worsen already underlying memory problems associated with the disease by consuming unhealthy meals, but also that this can be remedied by taking high doses of antioxidant vitamins C and E with the meal, suggesting that the effect of high-fat foods is to cause oxidative stress. However, this is hardly a recommended course of action, and the real importance of this finding is that it emphasizes the need for diabetics to consume healthy foods high in antioxidants, like fruits and vegetables. Of course, this is a very small study, and further replication is needed.

[1094] Chui, M., & Greenwood C.
(2008).  Antioxidant vitamins reduce acute meal-induced memory deficits in adults with type 2 diabetes.
Nutrition Research. 28(7), 423 - 429.

http://www.eurekalert.org/pub_releases/2008-06/bcfg-swt062408.php

Stress hormone impacts memory, learning in diabetic rodents

A rodent study sheds light on why diabetes can impair cognitive function. The study found that increased levels of a stress hormone (called cortisol in humans) in diabetic rats impaired synaptic plasticity and reduced neurogenesis in the hippocampus. When levels returned to normal, the hippocampus recovered. Cortisol production is controlled by the hypothalamic-pituitary axis (HPA). People with poorly controlled diabetes often have an overactive HPA axis and excessive cortisol.

[1050] Stranahan, A. M., Arumugam T. V., Cutler R. G., Lee K., Egan J. M., & Mattson M. P.
(2008).  Diabetes impairs hippocampal function through glucocorticoid-mediated effects on new and mature neurons.
Nature Neuroscience. 11(3), 309 - 317.

http://www.eurekalert.org/pub_releases/2008-02/nioa-shi021508.php

Tight diabetes control does not impact cognitive ability in type 1 diabetes

A long-running study involving 1,441 type 1 diabetics, aged 13 to 39, has demonstrated that multiple episodes of severe hypoglycaemia, though they can cause confusion, irrational behavior, convulsions and unconsciousness, do not lead to long-term loss of cognitive ability.

[1120] The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications(DCCT/EDIC) Study Research
(2007).  Long-Term Effect of Diabetes and Its Treatment on Cognitive Function.
N Engl J Med. 356(18), 1842 - 1852.

http://www.eurekalert.org/pub_releases/2007-05/jdc-sst050107.php

Brain function not impaired by tight diabetes control and hypoglycemia

Previous research had indicated that tight blood glucose control -- achieved by taking three or more insulin injections daily – meant type 1 diabetics were three times as likely to suffer episodes of severe hypoglycemia, raising the fear that it might lead to a long-term loss of cognitive ability. Now a follow-up study provides the reassuring news that there was no link between multiple severe hypoglycemic reactions and impaired cognitive function in people with type 1 diabetes.

Jacobson, A.M. et al. 2006. Effects of Intensive and Conventional Treatment on Cognitive Function Twelve Years after the Completion of the Diabetes Control and Complications Trial (DCCT). Abstract Number 750232, presented at the American Diabetes Association's 66th Annual Scientific Sessions held in Washington, D.C, June 9—13.

http://www.eurekalert.org/pub_releases/2006-06/jdc-lss060806.php

Fat hormone linked to learning and memory

A new study reveals why obese patients who have diabetes also may have problems with their long-term memory. Leptin — the so-called ‘fat’ hormone — doesn't cross into the brain to help regulate appetite in obese people. Leptin also acts in the hippocampus, suggesting that leptin plays a role in learning and memory. The new study supports this by demonstrating that mice navigated a maze better after they received leptin. Moreover, mice with elevated levels of amyloid-beta plaques (characteristic of Alzheimer's) were particularly sensitive to leptin.

[2400] Farr, S. A., Banks W. A., & Morley J. E.
(2006).  Effects of leptin on memory processing.
Peptides. 27(6), 1420 - 1425.

http://www.sciencedaily.com/releases/2006/06/060614090511.htm
http://www.eurekalert.org/pub_releases/2006-06/slu-alb061306.php

Age-related vision problems may be associated with cognitive impairment

Age-related macular degeneration (AMD) develops when the macula, the portion of the eye that allows people to see in detail, deteriorates. An investigation into the relationship between vision problems and cognitive impairment in 2,946 patients has been carried out by The Age-Related Eye Disease Study (AREDS) Research Group. Tests were carried out every year for four years. Those who had more severe AMD had poorer average scores on cognitive tests, an association that remained even after researchers considered other factors, including age, sex, race, education, smoking, diabetes, use of cholesterol-lowering medications and high blood pressure. Average scores also decreased as vision decreased. It’s possible that there is a biological reason for the association; it is also possible that visual impairment reduces a person’s capacity to develop and maintain relationships and to participate in stimulating activities.

Chaves, P.H.M. et al. 2006. Association Between Mild Age-Related Eye Disease Study Research Group. 2006. Cognitive Impairment in the Age-Related Eye Disease Study: AREDS Report No. 16. Archives of Ophthalmology,124, 537-543.

http://www.eurekalert.org/pub_releases/2006-04/jaaj-avp040606.php

Review supports link between lifestyle factors and cognitive function in older adults

A review of 96 papers involving 36 very large, ongoing epidemiological studies in North America and Europe looking at factors involved in maintaining cognitive and emotional health in adults as they age has concluded that controlling cardiovascular risk factors, such as reducing blood pressure, reducing weight, reducing cholesterol, treating (or preferably avoiding) diabetes, and not smoking, is important for maintaining brain health as we age. The link between hypertension and cognitive decline was the most robust across studies. They also found a consistent close correlation between physical activity and brain health. However, they caution that more research is needed before specific recommendations can be made about which types of exercise and how much exercise are beneficial. They also found protective factors most consistently reported for cognitive health included higher education level, higher socio-economic status, emotional support, better initial performance on cognitive tests, better lung capacity, more physical exercise, moderate alcohol use, and use of vitamin supplements. Psychosocial factors, such as social disengagement and depressed mood, are associated with both poorer cognitive and emotional health in late life. Increased mental activity throughout life, such as learning new things, may also benefit brain health.

Wagster M, Hendrie H, Albert M, Butters M, Gao S, Knopman DS, Launer L, Yaffe K, Cuthbert B, Edwards E. The NIH Cognitive and Emotional Health ProjectReport of the Critical Evaluation Study Committee. Alzheimer's and Dementia [Internet]. 2006 ;2(1):12 - 32. Available from: http://www.alzheimersanddementia.com/article/S1552-5260(05)00503-0/abstract?articleId=&articleTitle=&citedBy=false&medlinePmidWithoutMDLNPrefix=&overridingDateRestriction=&related=false&restrictdesc_author=&restrictDescription=&restrictName.jalz=jalz&rest

http://www.eurekalert.org/pub_releases/2006-02/aa-nss021606.php

Risk for lowered cognitive performance greater in people at high risk for stroke

A new large-scale study supports earlier suggestions that those with a high risk for stroke within 10 years are also at risk for lowered cognitive function and show a pattern of deficits similar to that seen in mild vascular cognitive impairment. It is speculated that the reason may lie in structural and functional changes in the brain that do not rise to the level of clinical detection, and this is supported by a recent brain imaging study showing that abnormal brain atrophy is related both to higher risk of stroke and poorer cognitive ability. The probability of experiencing stroke within 10 years was calculated using weighted combinations of age, systolic blood-pressure, presence of diabetes, cigarette smoking, history of cardiovascular disease, treatment for hypertension and atrial fibrillation.

[1422] Elias, M. F., Sullivan L. M., D'Agostino R. B., Elias P. K., Beiser A., Au R., et al.
(2004).  Framingham stroke risk profile and lowered cognitive performance.
Stroke; a Journal of Cerebral Circulation. 35(2), 404 - 409.

http://www.eurekalert.org/pub_releases/2004-01/ama-rfl010804.php

Age-related changes in the brain's white matter affect cognitive function

From around age 60, "white-matter lesions" appear in the brain, significantly affecting cognitive function. But without cognitive data from childhood, it is hard to know how much of the difference in cognitive abilities between elderly individuals is due to aging. A longitudinal study has been made possible by the Scottish Mental Survey of 1932, which gave 11-year-olds a validated cognitive test. Scottish researchers have tracked down healthy living men and women who took part in this Survey and retested 83 participants. Testing took place in 1999, when most participants were 78 years old.
It was found that the amount of white-matter lesions made a significant contribution to general cognitive ability differences in old age, independent of prior ability. The amount of white-matter lesions contributed 14.4% of the variance in cognitive scores; early IQ scores contributed 13.7%. The two factors were independent.
Although white-matter lesions are viewed as a normal part of aging, they are linked with other health problems, in particular to circulatory problems (including hypertension, diabetes, heart disease and cardiovascular risk factors).

[442] Deary, I. J., Leaper S. A., Murray A. D., Staff R. T., & Whalley L. J.
(2003).  Cerebral white matter abnormalities and lifetime cognitive change: a 67-year follow-up of the Scottish Mental Survey of 1932.
Psychology and Aging. 18(1), 140 - 148.

http://www.eurekalert.org/pub_releases/2003-03/apa-aci031703.php

High sugar blood levels linked to poor memory

A new study takes an important step in explaining cognitive impairment in diabetics, and suggests a possible cause for some age-related memory impairment. The study assessed non-diabetic middle-aged and elderly people. Those with impaired glucose tolerance (a pre-diabetic condition) had a smaller hippocampus and scored worse on tests for recent memory. These results were independent of age or overall cognitive performance. The brain uses glucose almost exclusively as a fuel source. The ability to get glucose from the blood is reduced in diabetes. The study raises the possibility that exercise and weight loss, which help control blood sugar levels, may be able to reverse some of the memory loss that accompanies aging.

[543] Convit, A., Wolf O. T., Tarshish C., & de Leon M. J.
(2003).  Reduced glucose tolerance is associated with poor memory performance and hippocampal atrophy among normal elderly.
Proceedings of the National Academy of Sciences of the United States of America. 100(4), 2019 - 2022.

http://www.eurekalert.org/pub_releases/2003-02/nyum-hsb013003.php

Diabetes and high blood pressure linked to decline in mental ability

A large-scale six-year study of people aged 40 to 70 years old found that people with diabetes and high blood pressure are more likely to experience cognitive decline. Diabetes was associated with greater cognitive decline for those younger than 58 as well as those older than 58, but high blood pressure was a risk factor only for the 58 and older group.

[2534] Knopman, D. S., Boland L. L., Mosley T., Howard G., Liao D., Szklo M., et al.
(2001).  Cardiovascular risk factors and cognitive decline in middle-aged adults.
Neurology. 56(1), 42 - 48.

http://www.eurekalert.org/pub_releases/2001-01/MC-Nsld-0701101.php
http://www.eurekalert.org/pub_releases/2001-01/AAoN-Dahb-0801101.php