Animal bites, rainforest hallucinogens, and “dancing” rats

Which animals are biting us? And what to do if you get bitten

To avoid an infection that’s worse than the bite, experts say you’d better make it snappy when seeking medical care after an animal bite.

Snake, dog, and cat bites were responsible for the majority of hospitalizations in tropical Queensland, Australia, according to a new study which examined more than 1700 patients admitted to Cairns Hospital after an animal bite, sting, or other related injury.

The study, one of the largest of its kind, found that patients that presented to hospital more than 24 hours after their animal bite encounter were more likely to develop a wound infection, and had a higher chance of death, ICU admission, amputation, and other complications. The research was published in the International Journal of Infectious Diseases.

“Our data suggests that antibiotics probably only have a limited role in preventing serious complications from animal bites,” explains first author Dr John Vardanega, an Infectious Diseases Registrar at the Princess Alexandra Hospital, Queensland. “The key to good outcomes is for patients to present early for medical review.”

So don’t dally when getting that animal bite checked out.

Hoverfly brains used to detect the sound of distant drones

In some nifty new Australian research, scientists have reverse engineered the visual systems of hoverflies to detect the acoustic signatures of drones from almost four kilometers away. They found that using bio-inspired processing techniques had up to a 50% better detection rate than existing methods. This is the first time that bio-vision has been applied to acoustic data.

The findings, which could help combat the growing global threat posed by IED-carrying drones, including in Ukraine, have been published in The Journal of the Acoustical Society of America.

To pick up drone acoustics at short and medium distances researchers look for specific patterns (narrowband) and/or general signals (broadband). But at greater distances the signal is weaker and both techniques struggle to achieve reliable results.

To convert acoustic signals into two-dimensional ‘images’ (called spectrograms), researchers used a mathematical model of the neural pathway of the hoverfly brain to improve and suppress unrelated signals and noise, increasing the detection range for the sounds they wanted to find.

Ancient jaws evolved to be strong and snappy

The earliest jaws in the fossil record were caught in a trade-off between maximizing their strength and speed, according to new research.

Almost all vertebrates (animals with a backbone) are jawed vertebrates that are distinguished by jaws that have teeth. They first evolved more than 400 million years ago from gill arches, a series of structures in fish that support their gills.

Researchers collected data on the shapes of fossil jaws during their early evolution and used mathematical models to characterize them. From these models they were able to extrapolate a wide range of theoretical jaw shapes, and these were tested for their strength (how likely they were to break during a bite) and their speed – how efficiently they could open and close.

There’s usually a trade-off between the two; increasing the strength usually means decreasing the speed and vice versa. By comparing the real and theoretical jaw shapes they found that real-world jaw evolution has been constrained to shapes that optimize this trade-off, forming jaw structures with the highest possible speed and strength.

The study was published in Science Advances.

Dunkleosteus – one of the animals involved in the research. Credit: Nobu Tamura

“Dancing” lab rats show how the brain learns skillful movement

Learning a complex skill like tying your shoes or playing an instrument takes practice. Although we perform repetitive tasks every day, we don’t know a lot about how the brain learns, perfects, then unconsciously performs these skilled movements.

Now, researchers have shown in a study on rats how several brain regions work together to train and carry out a practiced skill. The research was published in Science Advances. In the experiments, the rats learned to press a lever in a specific way to get a drink of water, and developed additional little movements that they performed while doing so.

“During the learning process, they develop a little dance, and each rat comes up with their own choreography,” says Dr Steffen Wolff, assistant professor of Pharmacology at the University of Maryland School of Medicine, US

“After they have perfected their technique, they continue to do whatever worked for them when learning: one animal will scratch the wall, another will tap their foot, and another sticks out their tongue, while simultaneously pressing the lever.”

Building on their prior research, the researchers wanted to see if a region of the brain – the basal ganglia – worked together with other brain regions to execute the learned skill. By disrupting its connection to the thalamus, they found the rats could still press the lever but completely lost their idiosyncratic learned “dances”.

“This work helps to reveal the logic of how individual brain regions work together to control skill learning and execution, a first step in our quest to help treat patients with motor movement disorders like Parkinson’s disease, and injuries from trauma or stroke to the motor- controlling parts of the brain,” says Dean E Albert Reece, professor at the University of Maryland School of Medicine, US

Synthesizing new neuroactive compounds found in a rainforest tree

Potions made from the bark of the rainforest tree Galbulimima belgraveana and its close cousin Galbulimima baccata – which are native to Papua New Guinea, tropical northern Australia, and Malaysia – have long been known to have hallucinogenic and other neuroactive effects.

But the precise compounds involved and their biological targets have largely remained a mystery, due to the dense structural complexity of these compounds, their variable mix within the bark, and the difficulty of obtaining bark from these species in quantity.

Now, a new and improved approach to synthesising one of these compounds, himgaline, has been developed by synthetic chemists. The previous best method took 19 steps – too many for routine use – while the new method takes only seven steps, enabling easy synthesis at the scale needed to study the compound in detail.

This new method starts with a broad approach that allows the specific compound, or other related compounds, to be made relatively easily from there. Using this method, researchers aim to make and study other Galbulimima compounds to hopefully yield clues to the design of future psychiatric and neurological drugs.

The study was published in Science.

Galbulimima baccata.  Credit csiro
Scripps Research chemists discovered a quick way to synthesize novel neuroactive compounds found in the bark of the Galbulimima belgraveana tree, which could be the basis for new psychiatric and neurological drugs. Credit: CSIRO



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