Anxiety Undermines Good Decision Making, Study Finds

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iStock

For people living with anxiety, decision making can be overwhelming. Now, a recent study published in The Journal of Neuroscience has uncovered exactly what’s happening in your brain when you struggle to make a decision in a state of anxiety. 

According to the study, which tested the decision-making skills of anxious rats, anxiety disengages the prefrontal cortex (PFC), a region of the brain that plays an important role in flexible decision making. Researchers injected a mild dose of an anxiety-inducing drug into one group of rats, and a placebo into another, and tested their ability to make decisions in order to reach a reward. At the same time, they monitored the activity of the rats’ PFC to determine exactly how neurons were affected by anxiety. 

Researchers found that both groups of rats performed relatively well in tests. However, any time decision making involved distractions, or the need to ignore unnecessary information, anxious rats began making more wrong choices. Researchers observed numbing of PFC neurons in anxious rats, and believe that this impairment of the PFC is what made it more difficult for the anxious rats to make decisions on the fly. 

A brain locus of vulnerability for these anxiety-induced mistakes was a group of cells in the PFC that specifically coded for choice,” explains researcher Bita Moghaddam. “Anxiety weakened the coding power of these neurons.”

While most of us experience anxiety at some point, chronic anxiety can have a major impact on many aspects of daily life, says Moghaddam. Earlier this month, a study found that people with generalized anxiety disorder were more likely to interpret harmless things as threats. Moghaddam’s work adds to those findings, showing yet another of the subtle, but potentially harmful, effects of anxiety. 

“We have had a simplistic approach to studying and treating anxiety. We have equated it with fear and have mostly assumed that it over-engages entire brain circuits,” explains Moghaddam. “But this study shows that anxiety disengages brain cells in a highly specialized manner.” 

Bizarre New Giant Salamander Species Discovered in Florida

There’s something in the water in Florida, but it’s not the swamp monster locals may have feared. According to National Geographic, scientists have discovered a new species of giant salamander called a reticulated siren, and you can find the 2-foot-long amphibian in the swamps of southern Alabama and the Florida panhandle.

Locals have long reported seeing a creature with leopard-like spots, the body of an humongous eel, and axolotl-like frills sprouting out of the sides of its head, but its existence wasn’t described in scientific literature until now. Researchers from Texas and Georgia recently published their findings in the journalPLOS ONE.

“It was basically this mythical beast,” David Steen, a wildlife ecologist and one of the paper’s co-authors, tells National Geographic. He had been trapping turtles at the Eglin Air Force Base in Okaloosa County, Florida, in 2009 when he caught one of the creatures by chance. After that encounter, the researchers set out to find more specimens.

Colloquially, locals have long been calling the creature a leopard eel. Because the reticulated siren only has two tiny front limbs, it's easy to mistake it for an eel. Its hind limbs disappeared throughout the course of millions of years of evolution, and it also lacks eyelids and has a beak instead of the teeth that are typical of other salamander species.

They belong to a genus of salamanders called sirens, which are one of the largest types of salamander in the world. The second part of the species’ name comes from the reticulated pattern seen on all of the individuals that were examined by researchers. The reticulated siren is also one of the largest vertebrates to be formally described by scientists in the U.S. in the last 100 years, according to the paper.

There are still a lot of unknowns about the reticulated siren. They lead hidden lives below the surface of the water, and they’re thought to subsist on insects and mollusks. Researchers say further study is urgently needed because there's a chance the species could be endangered.

[h/t National Geographic]

A Dracula Ant's Jaws Snap at 200 Mph—Making It the Fastest Animal Appendage on the Planet

Ant Lab, YouTube
Ant Lab, YouTube

As if Florida’s “skull-collecting” ants weren’t terrifying enough, we’re now going to be having nightmares about Dracula ants. A new study in the journal Royal Society Open Science reveals that a species of Dracula ant (Mystrium camillae), which is found in Australia and Southeast Asia, can snap its jaws shut at speeds of 90 meters per second—or the rough equivalent of 200 mph. This makes their jaws the fastest part of any animal on the planet, researchers said in a statement.

These findings come from a team of three researchers that includes Adrian Smith, who has also studied the gruesome ways that the skull-collecting ants (Formica archboldi) dismember trap-jaw ants, which were previously considered to be the fastest ants on record. But with jaw speeds of just over 100 miles per hour, they’re no match for this Dracula ant. (Fun fact: The Dracula ant subfamily is named after their habit of drinking the blood of their young through a process called "nondestructive cannibalism." Yikes.)

Senior author Andrew Suarez, of the University of Illinois, said the anatomy of this Dracula ant’s jaw is unusual. Instead of closing their jaws from an open position, which is what trap-jaw ants do, they use a spring-loading technique. The ants “press the tips of their mandibles together to build potential energy that is released when one mandible slides across the other, similar to a human finger snap,” researchers write.

They use this maneuver to smack other arthropods or push them away. Once they’re stunned, they can be dragged back to the Dracula ant’s nest, where the unlucky victims will be fed to Dracula ant larvae, Suarez said.

Researchers used X-ray imaging to observe the ants’ anatomy in three dimensions. High-speed cameras were also used to record their jaws snapping at remarkable speeds, which measure 5000 times faster than the blink of a human eye. Check out the ants in slow-motion in the video below.

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