Latest news

  • Blood flow deficits in the brain, seen early on in Alzheimer's, have now been linked to some capilleries being block by white blood cells.

It’s been known that decreased blood flow in the brain occurs in people with Alzheimer's, and recent studies suggest that brain blood flow deficits are one of the earliest detectable symptoms of dementia.

  • A study shows that blood is stored in the blood vessels in the space between the brain and skull, and its flow  is closely linked to the flow of cerebrospinal fluid in and out of the brain's ventricles.
  • A second study shows that capilleries, the smallest blood vessels in the brain, monitor the flow of blood within the brain and actively direct it to the areas that need it the most.

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.

  • Age-related changes in gene enhancers have been linked to faster cognitive decline in Alzheimer's brains.

New findings identify a mechanism that accelerates aging in the brain and gives rise to Alzheimer's disease.

  • A mouse study has shown that, as cells age, their ability to remove damaged proteins and structures (autophagy) declines, due to a decrease in the cell components (autophagosomes) that collect the damaged proteins.
  • A study found that the process of breaking down defective mitochondria and recycling the components (mitophagy) is impaired in those with Alzheimer's.
  • Microglia clear damage by engulfing the damaged matter then releasing it inside exosomes, which can be absorbed by other cells. Studies have now shown that these exosomes, designed to transmit information, can also spread harmful tau & amyloid-beta protein.
  • A mouse study has shown how amyloid plaques lead to tau tangles, and that weakened microglia facilitate this. It also links weak microglia to the risky variant of the TREM2 gene.
  • However, the common TREM2 variant is linked to faster plaque growth at later stages.
  • TREM2 appears to modify the way immune cells respond to tau tangles.
  • Another mouse study found that overactive microglia (achieved by turning off another gene) were linked to both better removal of amyloid-beta, and loss of synapses. This may help explain why reducing amyloid plaques often fails to improve cognition.

Aging linked to impaired garbage collection in the brain

  • Study indicates APOE4 carriers are only at greater Alzheimer's risk if they have chronic inflammation.
  • Large study finds increasing inflammation linked to more white matter damage.
  • Common causes of chronic inflammation include cardiovascular disease, heart failure, diabetes, high blood pressure and infections.

Link found between chronic inflammation and Alzheimer's gene risk

  • Synapses in Alzheimer's brains found to be clogged with clusterin and amyloid-beta proteins, and APOE4 carriers had more protein clumps than those without the gene variant.
  • APOE4 decreases activity in hippocampus that is critical for memory consolidation.
  • Study of Amazonian hunter-gatherers show APOE4 gene can provide benefits when exposure to parasites is high.

Alzheimer's gene linked to damage to brain connections

A study has found that synapses in people who had died with Alzheimer's contained clumps of clusterin and clumps of amyloid beta. These protein clumps may be damaging the links between neurons.

  • More evidence that Alzheimer's disease is not a single disease with a single cause and single pathway comes from a large study classifying patients into 6 groups, only two of which showed strong genetic association.
  • Another study using post-mortem brain tissue found that different genes were associated with different types of brain damage.

A study involving 4,050 people with late-onset Alzheimer's disease (mean age 80) has classified them into six groups based on their cognitive functioning at the time of diagnosis. A genetic study found two of the groups showed strong genetic associations.

  • Very large study finds 5 new genes linked to increased Alzheimer's risk.
  • A rare gene variant that protects APOE4 gene carriers from getting Alzheimer's has been identified.
  • Two large surveys found that verbal recall score was significantly affected by TOMM40 genotype. TOMM40 is adjacent to APOE on their chromosome.
  • A study found that TOMM40's effect on Alzheimer's depends on parental history.
  • Data from three very large studies has produced a tool for assessing an individual's genetic risk for developing Alzheimer's, based on 31 genetic markers.
  • A small study found that, of the top 9 genes that affect Alzheimer's risk, excluding the APOE gene, only 2 affect brain atrophy.
  • A new gene variant that is associated with greater amyloid plaque than APOE4 has been identified.

Five new risk genes for Alzheimer's disease

Genetic data from more than 94,000 individuals has revealed five new risk genes for Alzheimer's disease, and confirmed 20 known others. The new genes are: IQCK, ACE, ADAM10, ADAMTS1 and WWOX.

  • Brain scans suggest that tau proteins may spread more rapidly through women’s brains, increasing Alzheimer's risk and speeding its progression.

Accumulating evidence suggests that tau spreads through brain tissue like an infection, traveling from

  • Review found APOE4 carriers scored lower on IQ tests during childhood and adolescence.
  • A large internet-based study found that adults with a first-degree relative with Alzheimer's performed worse on a paired-learning task.

Alzheimer's gene affects IQ from childhood

Analysis of some old longitudinal studies has found that those carrying the APOE4 gene scored lower on IQ tests during childhood and adolescence. The effect was much stronger in girls than in boys, and affected reasoning most strongly.

  • A gene present in 75% of the human population may be a key reason why a class of drugs for Alzheimer’s disease seem promising in animal studies but fail in human studies.
  • Cell study finds APOE4 protein is slightly misshapen, causing it to break down into disease-causing fragments. But APOE4 doesn't affect amyloid-beta in mice.

Data from a ten-year study involving 345 Alzheimer's patients has found that

  • A large study has found that smoking, high blood pressure, diabetes, and obesity are each linked to more brain atrophy, and damage to white matter.
  • The more of these you have, the greater the shrinkage and damage.

Brain scans of 9,772 people aged 44 to 79, who were enrolled in the UK Biobank study, have revealed that smoking, high blood pressure, high pulse pressure, diabetes, and high BMI — but not high cholesterol — were all linked to greater brain shrinkage, less

  • A very large study shows that greater exposure to air pollution was linked to poorer cognitive performance in older adults, especially men and the less educated.

A large Chinese study involving 20,000 people has found that the longer people were exposed to air pollution, the worse their cognitive performance in verbal and math tests. The effect of air pollution on verbal tests became more pronounced with age, especially for men and the less educated.

  • A review of 34 studies confirms depression is linked to faster cognitive decline in older adults.

A review of 34 longitudinal studies, involving 71,244 older adults, has concluded that depression is associated with greater cognitive decline.

  • A small study of young adults found that 10 minutes of light exercise improved memory for details and increased relevant brain activity.
  • Another study found that 15 minutes of more intense exercise after learning a new motor skill resulted in better skill performance a day later.

Ten minutes of light exercise boosts memory

  • New research shows memory consolidation requires simultaneous replay with hippocampal 'ripples'. These may depend on deeper processing.

A study involving epilepsy patients who had electrodes implanted into their brain has revealed that memory

  • The connection between sleep apnea and depression may lie in a problem with autobiographical memory.

Obstructive sleep apnea (OSA) occurs when a person's breathing is interrupted during sleep.

People with OSA are known to suffer memory problems and also have higher rates of depression.

  • A new study adds to recent research challenging the idea that bilingualism benefits children's executive function.

The idea that bilingual children have superior executive function compared to monolingual children has been challenged in recent research.

  • A carefully managed aerobic exercise program might help those suffering sports-related concussions recover faster.

A randomized clinical trial involving 103 teenage athletes who sustained concussions while playing sports found that those who underwent a supervised, aerobic exercise program took significantly less time to recover compared to those who instead engaged in mild stretching.

  • A large, long-running study has found an association between consumption of fruit & vegetables and subjectively assessed memory skills in older men.

A study following nearly 28,000 older men for 20 years has found that regular consumption of leafy greens, dark orange and red vegetables and berry fruits, and orange juice, was associated with a lower risk of memory loss.

Pages

Research topics

Error | About memory

Error

The website encountered an unexpected error. Please try again later.