Women with Alzheimer’s live longer than men with the disease, scientists at UC San Francisco now have evidence from research in both humans and mice that this is because they have genetic protection from the ravages of the disease. By virtue of having a second X chromosome, women get two doses of a protective protein from a gene that only exists on this female sex chromosome. Some people, both male and female, have an especially potent varient of this gene , which is called KDM6A, that gives them even more protection. Because of the way sex chromosomes work, women have two X’s but men only have one. The new study offers a first look at how sex chromosomes affect vulnerability to Alzheimer’s. This helps explain why women survive longer and with less severe symptoms than men during early stages of the disease, even when they have comparable levels of toxic Alzheimer’s proteins in their brains.
Sports and Memory Go Hand in Hand
Right after a sporting exercise, such as running or cycling, one feels physical and psychological well-being. This feeling is due to endocannabinoids, small molecules produced by the body during physical exertion. They circulate in the blood and easily cross the blood-brain barrier. They then bind to specialise cellular receptors and trigger this feeling of euphoria. In addition, these same molecules bind to receptors in the hippocampus, the main brain structure for memory processing. By evaluating memory performance following a sport session, neuroscientists from the University of Geneva demonstrate that an intensive physical exercise session as short as 15 minutes on a bicycle improves memory, including the acquisition of new motor skills. This is done through the action of endocanabinoids, molecules known to increase synaptic plasticity. This study, highlights the virtues of sport for both health and education. School programmes and strategies aimed at reducing the effects of neurodegeneration on memory could indeed benefit from it.
New Risk factors for Alzheimer’s Disease
A new study led by researchers at UC San Francisco has found that among older Americans with cognitive impairment, the greater the air pollution in their neighborhood, the higher the likelihood of amyloid plaques. The study adds to a body of evidence indicating that pollution from cars, factories, power plants, and forest fires joins established dementia risk factors like smoking and diabetes. In the study, the researchers looked at the PET scans of more than 18,000 seniors whose average age was 75. The participants had dementia or mild cognitive impairment and lived in zip codes throughtout the nation. The researchers found that those in the most polluted areas had a 10 percent increased probability of a PET scan showing amyloid plaques, compared to those in the least polluted areas. This study provides additional evidence to a growing and convergent literature, ranging from animal models to epidemiological studies, that suggests air pollution is a significant risk factor for Alzheimer’s disease and dementia. “I think it’s very appropriate that air pollution has been added to the modifiable risk factors highlighted by the Lancet Commision on dementia,” Gil Rabinovici, senior author of the UCSF Memory and Aging Center, said referring to the journal’s decision this year to include air pollution, together with excessive alcohol intake and traumatic brain injury.