Last Week in Science (3rd Dec 2023)

10,000 naps

Have you experienced a power nap? Can you remember the shortest nap you had? It might have lasted at least a few minutes. The naps of chinstrap penguins lasts from 4 to 32 seconds. What is interesting is they survive on thousands of such naps that they take during a day, including night times. The naps that they take amounts to some 11 hours of sleep in a day and this is all they need to survive. Think of taking 600 naps in an hour.

Scientists from Neuroscience Research Center of Lyon in Bron, France implanted electrodes in chinstrap penguins housed in King George Island, Antarctica to record sleep pattern of the penguins over a duration of 10 days. The scientists were intrigued by this finding and are now hoping to understand how and whether other organisms use such microsleep or naps to stay alert. Would you exchange your 6-8 hours of sleep for 10,000 micro naps?

Reference: https://www.nature.com/articles/d41586-023-03777-x

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Robots made of human cells

Kids often wonder whether there are humanoid robots inside our bodies that perform the functions that help us survive. While that is not the reality but what may be a reality soon is scientists sending robots (not humanoid but made of human cells) inside the human body. 

In this cool experiment, scientists at  University of Pennsylvania in Philadelphia created tiny robots made of human cells- called as 'anthrobots', each one made of 100s of cells. These robots were created in a dish and were found to be moving in circles, straight line or haphazardly. Next they created a layer of neurons and then made a scratch on it. When the tiny robots were added to this layer, they could repair the layer by causing formation of more neurons. The scientists are hoping that if we can make anthrobots from a person's body cells then they can be used in repair processes, like clearing of an artery (that may have caused a heart attack if not cleared) or deliver medicines inside the body. 

Reference: https://www.nature.com/articles/d41586-023-03777-x

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Attack on the brain due to stress

As the cases of depression increase a need to understand what causes depression becomes imperative. While many individuals with depression respond to medication, one thirds of the patients do not respond. So, there is also a need to develop new treatment options. 

It has been seen in individuals with major depressive disorder (MDD) - who have a chronic form of depression - that incidence of autoimmune diseases are high. Immune system that helps in defense of the body when starts attacking itself that is when autoimmune diseases happen. It is known that after facing chronic stressful conditions, immune cells of the body (like neutrophils and monocytes) can start to attack the brain in individuals who have MDD. It is not known whether it is a cause of depression and whether it can affect the severity of the disease.

A recent study was performed to study the effect on immune system using mice that were made depressed by creating social stress; these mice were kept together with an aggressive mice for 1 hour/ day for a total of 10 days. The aggressive mice fight and defeat the non-aggressive mice. Such social defeat stress causes depression in mice. It was found that the depressed mice had antibodies against brain tissue. Antibodies are created by B cells of the body to fight invading pathogens and cause their destruction. What was interesting was that the mice who had low B cell counts did not get affected by the social defeat stress. So, can we use targeting of antibody producing cells to treat depression? It will take a while to find that answer so till then keep yourselves away from stress as much as possible. 

Reference: https://www.pnas.org/doi/10.1073/pnas.2305778120