Eric R. Kandel, Howard Hughes Medical
Institute investigator, probes into the mind to demonstrate how it is much more complex
than just a series of processes carried out by the brain. The brain produces our every
emotional, intellectual and athletic act. It allows us to acquire new facts and skills,
and to remember them for as long as a lifetime. Memory exists in two major forms, each
located in different brain regions. Explicit memory is for people, places, and objects. In
contrast, implicit memory serves perceptual and motor skills. In concert, these two memory
systems help make us who we are.
Low-carb diets can affect dieters'
A new study from the psychology department at Tufts University shows that when dieters
eliminate carbohydrates from their meals, they performed more poorly on memory-based tasks
than when they reduce calories, but maintain carbohydrates. When carbohydrates were
reintroduced, cognition skills returned to normal."This study demonstrates that the
food you eat can have an immediate impact on cognitive behavior," explains Holly A.
Taylor, professor of psychology at Tufts and corresponding author of the study. "The
popular low-carb, no-carb diets have the strongest potential for negative impact on
thinking and cognition."
Decreased levels of binding gene
affect memory and behavior
Reducing the activity of a gene called FKBP12 in the brains of mice affected
neuron-to-neuron communication (synapse) and increased both fearful memory and obsessive
behavior, indicating the gene could provide a target for drugs to treat diseases such as
autism spectrum disorder, obsessive-compulsive disease and others, said researchers from
Baylor College of Medicine in Houston in a report in the current issue of the journal
Neuron. The protein FKBP12 regulates several important cell signaling pathways, and
decreasing its activity enhances long-term potentiation in the hippocampus, said Dr. Susan
Hamilton, chair of molecular physiology and biophysics at BCM and a senior author of the
report. (Long-term potentiation means the enhancement of the synapse or communication
between neurons.) It accomplishes this by fine-tuning a particular pathway called mTOR
signaling (mammalian target of rapamycin). The mice in whose brains the activity of the
gene was reduced had longer memories and were more likely to exhibit repetitive behaviors
than normal mice.
Mitochondria defects linked to
social behavior and spatial memory
Respiration deficiencies in mitochondria, the cells powerhouses, are associated with
changed social behavior and spatial memory in laboratory mice, report scientists at the
American Society for Cell Biology 47th Annual Meeting.
Improved estrogen reception may
sharpen fuzzy memory
Finding ways to boost the brain's estrogen receptors may be an alternative to adding
estrogen to the body in efforts to improve cognition in postmenopausal women and younger
women with low estrogen levels, according to neuroscientists at the University of
Florida's McKnight Brain Institute.
In the journal Diabetes a research team from Umeå University and Stockholm University in
Sweden presents findings that indicate that elevated levels of blood sugar may have a
negative impact on the memory function. It was previously known that patients with
diabetes run a higher risk of developing various forms of dementia, including
Alzheimers disease. This increased risk may be caused by a combination of the risk
factors for cardiovascular disorders that this patient group has, including high blood
pressure, high blood fats, heightened inflammatory activity, and high blood sugar.
Previously it was not know whether blood sugar alone could have a negative effect in
people without diabetes, and it has also been unclear what part of the brain might be the
most sensitive to high blood sugar levels. By analyzing 411 healthy people who took part
in both Västerbotten Health Examinations and the Betula Project, the research team has
been able to established that elevated blood sugar levels probably affect a specific part
of the brain, the hippocampus, and especially in women. The hippocampus is a part of the
brain that stores memories, and it is often the first part of the brain to be impacted
with the onset of Alzheimers disease. The study provides key information that can
serve as a basis for further studies designed to examine how elevated blood sugar can
affect the memory.
Researchers led by Prof. Itzhak Fried, a neurosurgeon at Tel Aviv Universitys
Sackler Faculty of Medicine, are proving scientifically what scientists have always
suspected -- that the neurons excited during an experience are the same as those excited
when we remember that experience. This finding, reported in the prestigious journal
Science in October, gives researchers a clearer picture of how memory recall works and has
important implications for understanding dementias such as Alzheimer's, in which fragments
of the memory puzzle seem to disintegrate over time.
Stress-related disorders affect
brain's processing of memory
Researchers using functional MRI (fMRI) have determined that the circuitry in the area of
the brain responsible for suppressing memory is dysfunctional in patients suffering from
stress-related psychiatric disorders. Results of the study will be presented today at the
annual meeting of the Radiological Society of North America (RSNA). "For patients
with major depression and other stress-related disorders, traumatic memories are a source
of anxiety," said Nivedita Agarwal, M.D., radiology resident at the University of
Udine in Italy, where the study is being conducted, and research fellow at the Brain
Imaging Center of McLean Hospital, Department of Psychiatry at Harvard Medical School in
Boston. "Because traumatic memories are not adequately suppressed by the brain, they
continue to interfere with the patient's life." Dr. Agarwal and colleagues used brain
fMRI to explore alterations in the neural circuitry that links the prefrontal cortex to
the hippocampus, while study participants performed a memory task. Participants included
11 patients with major depression, 13 with generalized anxiety disorder, nine with panic
attack disorders, five with borderline personality disorder and 21 healthy individuals.
All patients reported suffering varying degrees of stressful traumatic events, such as
sexual or physical abuse, difficult relationships or "mobbing" a type of
bullying or harassment at some point in their lives.