Scientists Identify Cells in the Brain That Control Anxiety

iStock
iStock

People plagued with the uncomfortable thoughts and sensations characteristic of anxiety disorders may have a small group of cells in the brain to blame, according to a new study. As NPR reports, a team of researchers has identified a class of brain cells that regulates anxiety levels in mice.

The paper, published in the journal Neuron, is based on experiments conducted on a group of lab mice. As is the case with human brains, the hippocampus in mouse brains is associated with fear and anxiety. But until now, researchers didn't know which neurons in the hippocampus were responsible for feelings of worry and impending danger.

To pinpoint the cells at work, scientists from Columbia University, the University of California, San Francisco, and other institutions placed mice in a maze with routes leading to open areas. Mice tend to feel anxious in spacious environments, so researchers monitored activity in the hippocampus when they entered these parts of the maze. What the researchers saw was a specialized group of cells lighting up when the mice entered spaces meant to provoke anxiety.

To test if anxiety was really the driving factor behind the response, they next used a technique called optogenetics to control these cells. When they lowered the cells' activity, the mice seemed to relax and wanted to explore the maze. But as they powered the cells back up, the mice grew scared and didn't venture too far from where they were.

Anxiety is an evolutionary mechanism everyone experiences from time to time, but for a growing portion of the population, anxiety levels are debilitating. Generalized anxiety disorder, social anxiety disorder, and panic disorder can stem from a combination of factors, but most experts agree that overactive brain chemistry plays a part. Previous studies have connected anxiety disorders to several parts of the brain, including the hippocampus, which governs memory as well as fear and worry.

By uncovering not just how the brain produces symptoms of anxiety but the individual cells behind them, scientists hope to get closer to a better treatment. There's more work to be done before that becomes a possibility. The anxiety cells in mice aren't necessarily a perfect indicator of which cells regulate anxiety in humans, and if a new treatment does eventually come from the discovery, it will be one of many options rather than a cure-all for every patient with the disorder.

[h/t NPR]

Periodic Table Discovered at Scotland's St Andrews University Could Be World's Oldest

Alan Aitken
Alan Aitken

The oldest surviving periodic table of elements in the world may have been found at the University of St Andrews in Scotland, according to the Scottish newspaper The Courier.

University researchers and international experts recently determined that the chart, which was rediscovered in a chemistry department storage area in 2014, dates back to 1885—just 16 years after Russian chemist Dmitri Mendeleev invented the method of sorting the elements into related groups and arranging them by increasing atomic weight.

Mendeleev’s original periodic table had 60 elements, while the modern version we use today contains 118 elements. The chart found at St Andrews is similar to Mendeleev’s second version of the table, created in 1871. It’s thought to be the only surviving table of its kind in Europe.

The periodic table soaks in a washing treatment
Richard Hawkes

The St Andrews table is written in German, and was presumably produced for German universities to use as a teaching aid, according to St Andrews chemistry professor David O’Hagan. The item itself was dated 1885, but St Andrews researcher M. Pilar Gil found a receipt showing that the university purchased the table from a German catalog in 1888. A St Andrews chemistry professor at the time likely ordered it because he wanted to have the latest teaching materials in the scientific field, even if they weren't written in English.

When university staffers first found the table in 2014, it was in “bad condition,” O’Hagan tells The Courier in the video below. The material was fragile and bits of it flaked off when it was handled. Conservators in the university's special collections department have since worked to preserve the document for posterity.

The 19th century table looks quite a bit different from its modern counterparts. Although Mendeleev laid the groundwork for the periodic table we know today, English physicist Henry Moseley improved it in 1913 by rearranging the elements by the number of protons they had rather than their atomic weight. Then, in the 1920s, Horace Deming created the boxy layout we now associate with periodic tables.

Learn more about the St Andrews discovery in the video below.

[h/t The Courier]

Can You Tell an Author’s Identity By Looking at Punctuation Alone? A Study Just Found Out.

iStock.com/RyersonClark
iStock.com/RyersonClark

In 2016, neuroscientist Adam J Calhoun wondered what his favorite books would look like if he removed the words and left nothing but the punctuation. The result was a stunning—and surprisingly beautiful—visual stream of commas, question marks, semicolons, em-dashes, and periods.

Recently, Calhoun’s inquiry piqued the interest of researchers in the United Kingdom, who wondered if it was possible to identify an author from his or her punctuation alone.

For decades, linguists have been able to use the quirks of written texts to pinpoint the author. The process, called stylometric analysis or stylometry, has dozens of legal and academic applications, helping researchers authenticate anonymous works of literature and even nab criminals like the Unabomber. But it usually focuses on an author's word choices and grammar or the length of his or her sentences. Until now, punctuation has been largely ignored.

But according to a recent paper led by Alexandra N. M. Darmon of the Oxford Centre for Industrial and Applied Mathematics, an author’s use of punctuation can be extremely revealing. Darmon’s team assembled nearly 15,000 documents from 651 different authors and “de-worded” each text. “Is it possible to distinguish literary genres based on their punctuation sequences?” the researchers asked. “Do the punctuation styles of authors evolve over time?”

Apparently, yes. The researchers crafted mathematical formulas that could identify individual authors with 72 percent accuracy. Their ability to detect a specific genre—from horror to philosophy to detective fiction—was accurate more than half the time, clocking in at a 65 percent success rate.

The results, published on the preprint server SocArXiv, also revealed how punctuation style has evolved. The researchers found that “the use of quotation marks and periods has increased over time (at least in our [sample]) but that the use of commas has decreased over time. Less noticeably, the use of semicolons has also decreased over time.”

You probably don’t need to develop a powerful algorithm to figure that last bit out—you just have to crack open something by Dickens.

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