neuroscience

An international team trained 85 people to activate a part of the brain associated with reward and positive expectations, after which they received a hepatitis B vaccine. Overall, those who learned to maintain greater activity in this area showed a greater increase in antibody levels after immunization. According to the authors, the results “suggest that positive thinking could help the brain strengthen the immune system in a non-invasive way.” The work is published in Nature Medicine. 

A research team identified five major phases of brain topology throughout human life—changes in the structure of neural connections—as detailed in an article published in Nature Communications. Using brain images from 3,802 people between the ages of 0 and 90, it defines four turning points around the ages of 9, 32, 66, and 83.

A team from the Miguel Hernández University of Elche and the Alicante Hospital has implanted a microelectrode array in the brains of two blind people. This array is capable of sending electrical stimuli that evoke visual perceptions, something that has been done before, and also of "reading" neuronal responses and adapting to them in real time. The system has allowed them to recognize various complex patterns, movements, shapes, and even some letters. According to the researchers, this new technology "can help make the difference between perceiving a flash and seeing the world." The results are published in the journal Science Advances.  

An international consortium has published the most detailed maps to date of brain development in mammals, including mice and humans. According to the researchers, this work provides a detailed outline of how different types of brain cells arise and mature over time, which “will allow us to begin discovering how alterations in this process can lead to disorders such as autism or schizophrenia.” The results are published simultaneously in a set of 12 articles in the journal Nature. 

In women suffering from post-traumatic stress disorder (PTSD) after experiencing sexual assault, the connectivity between two areas of the brain within the fronto-limbic system is altered, according to a study presented at the European College of Neuropsychopharmacology conference held in Amsterdam (Netherlands). The study, led by a researcher at Hospital Clínic in Barcelona, compared brain images of 40 women with PTSD following a recent sexual assault and 45 control cases. In 22 of these 40 women, communication between the amygdala—which helps process emotions such as fear—and the prefrontal cortex—which helps regulate those emotions—had almost completely disappeared.

A team of neuroscientists from the International Brain Laboratory has described for the first time a virtually complete map of brain activity in mice during the decision-making process. To do so, they recorded the activity of more than half a million neurons across 12 different laboratories, representing 95% of brain volume. The map contradicts a hierarchical view of information processing and shows that decision-making is distributed in a coordinated manner across multiple brain areas. The results are published in two articles simultaneously in the journal Nature.

Various studies claimed that the loss of a limb caused a reorganisation of the “body map” integrated in the brain: neighbouring regions invaded and reused the brain area that previously represented the amputated limb. But a new study refutes this theory. Cortical representation remains stable even when the body suffers the loss of a limb. The team, which published its study in Nature Neuroscience, analysed three people who were about to undergo amputation of one of their hands, studying for the first time the maps of the hand and face before and after amputation, with follow-up for up to five years. Even without the hand, the corresponding brain region was activated in an almost identical way.

Researchers at Harvard Medical School have published new findings in Nature on the role of reduced lithium levels in Alzheimer's disease, based on experiments with mice and analysis of brain tissue and blood samples from humans. The team claims to have achieved improvements in memory in mouse models with lithium orotate. They caution that they have not proven that lithium is safe or effective in protecting against neurodegeneration in patients, and that their findings must be confirmed in humans through clinical trials.

Researchers in the United States have used stem cells created from patients with a very rare type of ALS, more prevalent in Brazil, to target a key gene in the stress response and reverse the damage suffered by motor neurons in the laboratory. They believe it is "a promising proof-of-concept for future therapeutic strategies" and "could help lay the foundation for genetically informed clinical trials".

A team from Sweden has analysed post mortem brain samples from people aged between 0 and 78 using various techniques and found that, although it varies between individuals, new neurons continue to form in the hippocampus with no apparent age limit. Although previous studies had reached similar conclusions, controversy remains about these results. According to the authors, the new work ‘provides an important piece of the puzzle in understanding how the human brain works and changes throughout life.’ The results are published in the journal Science.