The science news of the week: Communicating in two or more languages is not a problem for Barcelona residents. Knowing two or more languages not only enriches us, but also allows us to learn about another culture, share our thoughts and gain a deeper understanding of the world. Scientists from two Spanish research centers, the Open University of Catalonia (UOC) and Pompeu Fabra University (UPF), have found that the active use of two languages can protect against cognitive disorders associated with aging.
It has long been known that the use of two languages protects people to some extent against senile dementia. “The prevalence of dementia in countries where two languages are spoken is 50% lower than in regions where the population uses only one language,” said the leader of the recent study (whose results were published in the journal Neuropsychologia), Professor Marco Calabria of the UOC. “We wanted to uncover the mechanism of resistance to mild cognitive impairment and Alzheimer’s disease that exists in bilingual individuals, and learn about the dependence of this mechanism on the degree of proficiency in two languages.”
The researchers chose Barcelona residents as volunteers because almost everyone there speaks Spanish and Catalan equally, including completely healthy people and those suffering from dementia or memory loss. “We found that when people with higher levels of bilingualism were diagnosed with mild cognitive impairment, it occurred at a significantly later age than in those who passively used one of the two languages,” Calabria explains. The professor himself believes that constantly using two languages and switching between them is an excellent workout for the brain.
According to the researcher, this linguistic gymnastics is also linked to other cognitive functions, such as the brain’s executive system, which is activated when we perform multiple actions simultaneously. It also makes it easier to switch between languages without confusing them in speech. Thus, when the executive system is impaired in cognitive disorders, the bilingual brain has an efficient alternative system for problem solving. Moreover, the more both languages are used and the better the speaker masters them, the more neurologically protected they are. In essence, active bilingualism serves as an important factor in delaying the symptoms of mild cognitive impairment – the preclinical phase of Alzheimer’s disease. Now, scientists hope to find out if bilingualism can help prevent the onset of Parkinson’s and Huntington’s diseases.
We explain quickly, simply, and clearly what happened, why it matters, and what happens next. Episodes The end of history: Podcast Advertising Thirst is a familiar feeling to everyone, and everyone knows how to quench it, how many sips of water, preferably cold, it takes to get rid of it. However, no one has been able to decipher exactly how thirst is quenched. As a group of scientists led by Chris Zimmerman of the Princeton University Institute of Neurology has found, during the process of drinking, the brain continuously receives signals about the concentration of water in the blood, mouth, throat, and intestines, and the neurons responsible for thirst instantly evaluate the degree of hydration of the body and, accordingly, the level of thirst. “Thirst is not just a response to dehydration, as classical models assumed, but a dynamic regulation that predicts in real time when the desired level of water will be reached,” Zimmerman explains.
In fact, as early as the 1950s, all textbooks presented a rather simple theory that there is a certain osmosensor in the brain that regulates the level of water in the blood and signals when and how much you need to drink to maintain that level. According to Zimmerman, this model could not answer the simplest question: How does water quench thirst instantly, even though it has not yet entered the bloodstream? Once again, mice came to the rescue, as they are virtually indistinguishable from humans when it comes to thirst. Using fiber-optic technology, scientists led by Cimmerman were able to measure calcium levels in the brains of mice and see how a specific group of neurons responsible for thirst responded. It turns out that these neurons not only have information about the amount of water in the blood, but also receive additional signals from other parts of the body, including the mouth, esophagus, and stomach, instantly creating a big picture so that the mouse (or human) knows when to stop drinking before it gets drunk.
Eat or be eaten – that’s the harsh law of nature at work in every corner of the biosphere. Only viruses have not yet fit into this picture. This is despite the fact that the viral biomass in the soil, atmosphere, and water amounts to tens of millions of tons. Has no one really coveted this wealth? Scientists seem to have found an answer in the waters of the Gulf of Maine on the east coast of North America. There are two types of single-celled organisms that live there, and they are apparently not averse to snacking on such a questionable delicacy as viruses. After studying the insides of these first virophages (i.e., virus eaters), researchers isolated all the DNA discovered there and compiled a real file based on it. As expected, most of the DNA belonged to the plankton itself, with 19% attributed to bacteria that were ingested by the plankton. However, half of the gene database consisted of fragments of genes from 50 or more different viruses. Most of these were sequences of bacteriophage genes – viruses that infect and multiply in bacterial cells, allowing plankton to encounter them as “food additives” to their main diet. But in the case of haptophyte and picoplanktonic protists, the researchers sometimes found no traces of bacterial DNA at all. And if there was no lunch, how could bacteriophage genes get into plankton cells? And while all of these signs of viral snacking may seem indirect, agree that if you found your child covered in chocolate with a wrapper next to it, you would have every reason to be suspicious.