When a mother gives birth to twins, the offspring are not always identical or even the same gender. Known as fraternal twins, they represent a longstanding evolutionary puzzle. Identical twins arise from a single fertilised egg that accidentally splits in two, but fraternal twins arise when two eggs are released and fertilised. Why this would happen was the puzzle. In research published in Nature Ecology & Evolution we used computer simulations and modelling to try to explain why natural selection favours releasing two eggs, despite the low survival of twins and the risks of twin births for mothers.
The endogenous compound anandamide — often referred to as the body’s own marijuana — plays a role in erasing memories of a traumatic event, reports an international team led by Leiden University. The results may provide a starting point for the treatment of anxiety disorders such as PTSD. When you smoke a joint, the active ingredient THC makes you feel relaxed. But there are also side effects, such as an increased appetite and loss of memory.
From absorbing new languages to mastering musical instruments, young children are wired to learn in ways that adults are not (Johnson and Newport, 1989). This ability coincides with periods of intense brain plasticity during which neurons can easily remodel their connections (Hubel and Wiesel, 1970). Many children are also scandalously good sleepers, typically getting several more hours of sleep per night than their parents (Jenni and Carskadon, 2007). As sleep deprivation has negative effects on learning and memory, learning like a child likely requires sleeping like one (Diekelmann and Born, 2010).
Slow-wave brain activity, a characteristic of sleep and resting states, is controlled by the claustrum, new research from the RIKEN Center for Brain Science (CBS) shows. The synchronization of silent and active states across large parts of the brain by these slow waves could contribute to consciousness. For scientists searching for the brain’s ‘control room’, an area called the claustrum has emerged as a compelling candidate. This little-studied deep brain structure is thought to be the place where multiple senses are brought together, attention is controlled, and consciousness arises.
Raised blood levels of toxic chemicals found in pesticides, nonstick cookware, and fire retardants have been tied to an increased risk for celiac disease in young people, new research shows. According to New York University Grossman School of Medicine researchers who led the study, people with the immune disorder have severe gut reactions, including diarrhea and bloating, to foods containing gluten, a protein found in wheat, rye and barley. The only treatment is a gluten-free diet, with no bread, pasta, or cake, says lead investigator and doctoral student Abigail Gaylord, MPH.
It has long been the ambition of many scientists to find ways to help repair damage to the brain and spinal cord. By studying how the nervous system is able to heal, scientists hope to get clues about exactly how to reverse damage, which in turn may help develop medicines or therapies to treat those with nervous system injuries. One of the ways we can repair damage to the nervous system is by using a type of stem cell that can readily become a brain cell.
People with the mental health condition known as body integrity dysphoria (BID) often feel as though one of their healthy limbs isn’t meant to be a part of their bodies. They may act as though the limb is missing or even seek its amputation “to feel complete.” Now, researchers have found that these feelings that a limb doesn’t belong are mirrored in the brains of people with this condition. “The feeling that a limb belongs to us relies on the extent to which the sensorimotor limb area is functionally connected to all the other brain regions.
New research has found an association between low average levels of vitamin D and high numbers of COVID-19 cases and mortality rates across 20 European countries. Previous observational studies have reported an association between low levels of vitamin D and susceptibility to acute respiratory tract infections. Vitamin D modulates the response of white blood cells, preventing them from releasing too many inflammatory cytokines. The COVID-19 virus is known to cause an excess of pro-inflammatory cytokines.