In the next selection of interesting science news of the week: You have probably experienced the amazing effect when a certain scent suddenly takes you back in time. The subtle scent of a Christmas tree reminds you of your childhood and New Year’s presents, while the smell of antiseptic makes you shudder at the memory of a visit to the dentist. Scientists at the Center for Systems Neuroscience at Boston University became interested in the ability of smell to evoke memories. They decided to investigate whether it was possible to use smell as a means of treating depression associated with traumatic memories. “If it is possible to use scent to evoke vivid memories, even of negative events, it can always be used for therapeutic purposes,” argues Steve Ramirez, lead researcher of the neurological department.
Until recently, the relationship between smell and memory, as well as the mechanism of memory formation, remained a mystery. The established theory of system consolidation states that memories begin to form in a small part of the brain called the hippocampus, where they become saturated with details. Over time, especially during sleep, the cluster of brain cells containing a particular memory is reactivated and reorganized. After this process, the prefrontal region of the brain takes over the function of processing the memory from the hippocampus, but during the transfer of information, some details are lost. This theory explains well why memories fade and become blurred over time, as well as the fact that when the hippocampus is damaged, people lose the ability to acquire new memories, but still vividly remember events from many years ago. Conversely, people with trauma to the prefrontal cortex show signs of amnesia. But this theory does not explain why some people, especially those suffering from post-traumatic stress disorder, still have vivid memories of past events, and how smells processed by the hippocampus can suddenly evoke memories that have been dormant for a long time.
We explain quickly, simply, and clearly what happened, why it matters, and what happens next. The number of episodes should remain the same. End of story Advertising Podcasts In search of answers to these questions, Ramirez and his colleagues conducted an experiment. They decided to create a memory of fear in mice by exposing them to a weak but sensitive electric shock. Half of the mice received an electric shock accompanied by the scent of almond extract, while the other half were shocked without any aromatic accompaniment. The next day the same thing happened, only without electricity, but according to the theory of system consolidation, the mice showed activity in the hippocampus region, i.e. the memory of fear returned. However, when the researchers repeated the experiment 20 days later, the real shock came. As expected, in the group of mice that did not experience the odor, the memory of fear shifted to the prefrontal cortex, but in the second group that experienced the odor, the active processing of memories continued in the hippocampus. “This suggests that the hippocampus was involved at a time when, according to established theory, it should not have been, because the memory was clearly outdated,” Ramirez explains. “But the smell served as a signal to enrich that memory with details.” Many psychotherapeutic and pharmacological treatments for post-traumatic stress are based on attempting to suppress traumatic memories, but treatment is only possible if people can vividly recall these events in their memories. “Knowing how odors affect memory, we can potentially activate and deactivate the hippocampus at will to completely suppress the memory of fear,” Ramirez explains. In other words, smells that evoke different memories can be a much stronger lever than previously thought, and if today they serve as a trigger for nostalgia, sadness or joy, tomorrow they can become a real remedy for depression.
Battle in the Martian sandbox: Who hit the probe on the head with a small shovel?
Stuck “mole The “Insight” lander currently operating on the surface of Mars has encountered unforeseen difficulties. It was carrying out a planned drilling with a probe called “Mole”, and this mole got hopelessly stuck. The point is that NASA scientists did not expect the soil on Mars to be so lumpy. They hoped that the mole would easily dig into the sand (or something similar), but in reality the ground turned out to be quite solid.
And this is the same little shovel… In the end, to free the mole, “Insight” literally had to hit it on the head with its telescopic arm, armed with a small shovel. There was certainly a considerable risk in doing so, as the Insight probe is heavy and the mole is delicate, so the power supply and communications system could have been damaged. Fortunately, NASA engineers on Earth have been practicing similar situations for several months, so the impact was precise and painless. Now, Insight will try again to deploy the mole below the surface of the Red Planet, where it will measure temperature variations.
The mention of transparent skin made Associate Professor Benjamin T. (in the background) think of jellyfish. Inspired by the jellyfish, Singaporean scientists have created an electronic skin that is transparent, waterproof, and capable of self-healing. A group of researchers led by Associate Professor Benjamin Tee of the National University of Singapore, in collaboration with colleagues from Tsinghua University and the University of California, Riverside, has succeeded in developing an entirely new material in just one year. In fact, Ti already had experience in this area. “One of the characteristics of self-healing materials is that they are not transparent and perform poorly in high humidity,” explains the scientist. “This limits their use in electronics. And that’s when we had the idea of getting to know jellyfish better, because they are transparent and love moisture.” The result is a conductive electrical gel based on a fluorocarbon polymer and a high fluoride ionic liquid with a high self-healing ability. “Most polymer gels, such as hydrogels, swell in water or dry out over time,” says Benjamin Tee. “Our material differs from them in that it retains its shape in both wet and dry environments. It performs excellently in seawater and even in acidic and alkaline conditions. As for the electronic skin itself, it is created by printing a new gel directly onto electronic circuits using a 3D printer. The result is a soft and flexible material that changes its electrical properties when stretched, compressed, or simply touched. “All these changes can be measured and converted into readable electrical signals for further broad application in sensor technologies,” the scientist explains. “And the ability to print our transparent electronic skin on a 3D printer means that it can be used for a new generation of soft robots.” It is important to clarify that soft robotics – and soft electronics in general – aim to mimic biological tissues as closely as possible to enable full and more comfortable communication between humans and electronic systems. By the way, the new material has another very useful property. “Discarded cell phones and tablets turn into millions of tons of waste every year,” says Tee. “We hope that in the future, electronics made of smart materials will be able to repair themselves, thereby reducing e-waste worldwide.”
Asteriornis occupies a middle position between land birds like a turkey (left) and water birds like a duck (right). In the days when huge and ferocious dinosaurs ruled the planet, there was literally a duck or a chicken scurrying at their feet that few paid attention to. But tens of millions of years have passed, and… “When I saw this fossil, it was the most exhilarating moment of my entire scientific career,” said paleontologist Daniel Field of the University of Cambridge. The scan revealed that the skull and leg bone remains are over 66 million years old, making them the oldest fossilized bird remains in the modern sense of the word discovered to date. The bird was immediately named Asteriornis maastrichtensis – in honor of the ancient Greek goddess Asteria, who transformed herself into a quail to escape the lustful Zeus (or was transformed into a bird by Zeus himself). After analyzing the remains, Field and his colleagues concluded that the bird combined features of modern waterfowl, such as ducks, with features of land birds, such as chickens and quail. This suggests that Asteriornis may have been their common ancestor. We already know for certain that birds evolved from predatory dinosaurs, thanks to the discovery of the missing link – Archaeopteryx, which is 150 million years old and had teeth similar to dinosaurs, but at the same time had feathers like a bird. However, scientists can only speculate as to how real birds appeared.
Daniel Field is hoping for new loud discoveries. When the abrupt and brutal asteroid impact ended the Cretaceous period about 66 million years ago, the super chicken and its relatives successfully survived the catastrophe and gave rise to the diversity of birds we enjoy today. However, their distant toothed relatives were less fortunate and shared the fate of the dinosaurs. “This specimen has given us a lot of valuable information,” says paleontologist Amy Balanoff of Johns Hopkins University. “It tells us about some key traits that were necessary to survive such a catastrophe.” Fossilized remains of early birds discovered in the southern hemisphere led some scientists to believe that modern birds originated on the continent of Gondwana. However, the superchicken found in a Belgian quarry (i.e., in the northern hemisphere) casts doubt on this theory. “Asteriornis will give us an idea of future discoveries,” Field hopes. “And it will help us understand where and when the first birds appeared.”