News reports of research into memory December 2003
For index of all headlines, go to News & Views main page
To look at research reports sorted by subject go to Research Reports
For news about Alzheimer's research go directly to the Alzheimer's page
You can find links to the journals referred to on this site here: Journal links
December 2003
Grape juice may help memory in older adults
A study of older rats has found that Concord grape juice
significantly improved their short-term memory in a water maze test
as well as their neuro-motor skills in some coordination, balance
and strength tests. The results are similar to those found with
blueberries. Concord grape juice has the highest total antioxidants
of any fruits, vegetables or juices tested (I assume the point of
using “Concord” grape juice is the concentration of grape juice, not
that this effect is specific to Concord grapes – although the fact
that it is a “purple” grape juice is probably significant).
The preliminary report was presented at the 1st International
Conference on Polyphenols and Health recently held in Vichy, France.
http://www.eurekalert.org/pub_releases/2003-12/jai-cgj121803.php
Nicotine patch may alleviate 'senior moments'
A small preliminary clinical trial has found that four weeks of
nicotine skin patches helped decision-making and attention in people
with age-associated memory impairment (the mildest form of cognitive
impairment in seniors). Given the health risks of smoking, and
health risks associated with nicotine patches, it is too early to
recommend the use of nicotine to improve memory, however. Nicotine
mimics the brain chemical acetylcholine, a nerve signal that plays a
role in learning and memory.
The report will appear in a forthcoming issue of
Psychopharmacology.
Reference
http://www.eurekalert.org/pub_releases/2003-12/dumc-npm120303.php
Statins associated with rare cases of temporary amnesia
Two recent studies have documented cases of amnesia and other
nervous-system side effects after taking statins, the
cholesterol-lowering drugs being prescribed to millions of people at
risk of heart disease. It is emphasized that this is a rare problem,
but given the vast numbers of people taking statins, it might still
add up to a significant number of problems.
http://www.eurekalert.org/pub_releases/2003-12/ns-ymw120303.php
http://washingtontimes.com/upi-breaking/20031203-055101-2066r.htm
Estrogen combines with stress to impair memory
A rat study has found that male and female rats performed equally
well on a task involving the prefrontal cortex when under no stress,
and when highly stressed, both made significant memory errors. But
importantly, after exposure to a moderate level of stress, females
were impaired, but males were not. When investigated further, it was
found that female rats only showed this sensitivity when they were
in a high-estrogen phase of their estrus cycle. The estrogen effect
was confirmed in a further study using female rats who had had their
ovaries removed, thus enabling the researchers to compare the
effects of estrogen versus a placebo. These results suggest that
high levels of estrogen can act to enhance the stress response,
causing greater stress-related cognitive impairments, while
providing reassurance that estrogen appears to have no effect on
cognitive performance under non-stressful conditions.
The report appeared in Molecular Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2003-12/mp-epg112603.php
More light shed on how episodic memories are formed
A rat study has revealed more about the workings of the
hippocampus. Previous studies have identified “place cells” in the
hippocampus – neurons which become more active in response to a
particular spatial location. Activity in the hippocampus while rats
searched for food in a maze where the starting and ending point was
varied, has found that, while some cells signaled location alone,
others were also sensitive to recent or impending events – i.e.,
activation depended upon where the rat had just been or where it
intended to go. This finding helps us understand how episodic
memories are formed – how, for example, a spatial location can
trigger a reminder of an intended action at a particular time, but
not others.
The report was published in the December 18th issue of
Neuron.
http://www.eurekalert.org/pub_releases/2003-12/msh-ta121503.php
Sensory processing different in people with dyslexia
An imaging study of dyslexics has found that dyslexic readers
appear to process auditory and visual sensory cues differently than
do normal readers. In the study 30 dyslexic readers and 30 normal
readers performed three matching tasks — an auditory task, a visual
task and a multisensory task — involving consonant-vowel pairs.
During the auditory matching task the dyslexic readers showed
increased activity in the visual pathway of the brain, while that
same region deactivated in the normal readers. The dyslexic readers'
increased activation patterns in the visual pathway corresponded to
poorer performance on the matching task.
The report was presented at the 89th Scientific Assembly and Annual
Meeting of the Radiological Society of North America (RSNA).
Reference
http://www.eurekalert.org/pub_releases/2003-12/rson-fdm112403.php
Reducing the trauma of traumatic memories
For some, stressful memories can reawaken intense fear, with
undesirable consequences. A new study involving mice has found that
such stress induces a change in the expression of the
acetylcholinesterase gene, which normally produces a vital protein
that adheres to neuronal synapses. Following stress, however, the
same gene produces large quantities of a protein with modified
properties that results in heightened electrical signals in the
nerve cells communicating through these synapses. The effect is to
create reactions of extreme fright or immobilizing shock. Later
encounter with a context which triggers those stressful memories can
set off that same neuronal reaction. The researchers have developed
an "antisense" agent that acts to neutralize the process whereby the
modified protein is produced, thereby preventing the extreme
reaction.
The report appeared in the December issue of
Molecular Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2003-12/huoj-hug121103.php
http://www.eurekalert.org/pub_releases/2003-12/mp-abm120803.php
Hippocampal damage seen in those with alcoholic memory disorder and those with Alzheimer's
A comparison between the brains of five men with alcoholic
Korsakoff's syndrome and the brains of men with Alzheimer's disease
as well as the brains of healthy men, found that the brains of all
Korsakoff's patients and Alzheimer's patients were comparable in
significant volume loss in the hippocampus. Greater hippocampal
damage (for Korsakoff's patients) and smaller hippocampal size (for
Alzheimer’s) was correlated with poorer memory performance. It is
suggested that, although there are of course a number of differences
between these disorders, the nature of the memory impairment may be
the same. Awareness of the similarities may help detection of both
disorders.
The study was published in the December 23 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2003-12/aaon-seu121503.php
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