You may have missed… octopus brain waves, 3D printing with bacteria ink, “forbidden” planet, regular physical activity linked to better brain function

First-ever brain waves recorded from freely moving octopuses

A new study in Current Biology is a critical step forward in figuring out how octopus’ brains control their behaviour.

Measuring octopus brainwaves has been a technical challenge until now because they are soft bodied animals and don’t have a skull to anchor recording equipment  to prevent it from being removed by their eight flexible arms.

To get around this problem, scientists anaesthetised three octopuses (Octopus cyanea) before implanting small, lightweight data loggers into a cavity in the muscle wall of the mantle. The scientists then implanted electrodes into an easily accessible area of the octopus’ brain.

They were returned to their home tank and monitored by video for the following 12 hours as their brain activity was recorded, before the technology was removed again. The researchers identified several distinct patterns of brain activity, some of which were similar in size and shape to those seen in mammals, whilst others were very long lasting, slow oscillations that have not been described before. 

“This is a really pivotal study, but it’s just the first step,” says Professor Michael Kuba, who led the project at the Okinawa Institute of Science and Technology (OIST) in Japan.

“Octopus are so clever, but right now, we know so little about how their brains work. This technique means we now have the ability to peer into their brain while they are doing specific tasks. That’s really exciting and powerful.”   

The researchers recorded the brain activity of an octopus for 12 hours. Here, the octopus is in active sleep, a stage in which there are rapid changes in color and texture, as well as fast sucker motion. Credit: Current Biology

3D printing with bacteria loaded ink to make bone-like materials

For nature, it’s a walk in the park to produce composite materials – like shells or bone – that are simultaneously light and strong, porous, and rigid.

But doing the same thing in a lab or factory is extremely challenging, so researchers turned to nature for a solution to the problem.

Materials scientists have pioneered a 3D printable ink (BactoInk) that contains Sporosarcina pasteurii – abacterium which, when exposed to a urea-containing solution, triggers a process that produces calcium carbonate (CaCO3) – the main component of limestone. 

Existing 3D printing inks containing small mineral particles tend to produce structures that are soft or shrink upon drying, but the new method doesn’t suffer from this.

“We came up with a simple trick: instead of printing minerals, we printed a polymeric scaffold using our BactoInk, which is then mineralised in a second, separate step,” says senior author Esther Amstad, an associate professor from the Soft Materials Laboratory at the Swiss Federal Institute of Technology Lausanne.

“After about four days, the mineralisation process triggered by the bacteria in the scaffold leads to a final product with a mineral content of over 90%.”

The material could be used to restore artworks by being directly injected into a mould or target site like a crack. It’s a promising candidate for building artificial corals, and its properties (which mimic bone) could potentially make it interesting for biomedical applications.

The research is in the journal Materials Today.

A small statue of a man in a petri dish with a syringe injecting a fluid into a crack in its face
The method could be used to restore damaged artworks. Credit: Eva Baur

“Forbidden” planet challenges gas giant formation theories

A team of astronomers has discovered an unusual planetary system in which a large gas giant orbits a small red dwarf star, challenging long-held ideas about planet formation.

“The host star, TOI-5205, is about four times the size of Jupiter, yet it has somehow managed to form a Jupiter-sized planet, which is quite surprising!” says Shubham Kanodia, a postdoctoral fellow at Carnegie Institution for Science in the US, and first author of the new study in The Astronomical Journal.

M dwarf stars (the littlest of the red dwarfs) are smaller and cooler than our sun,but this makes them unlikely candidates to host gas giants. The most commonly used theory of gas planet formation requires about 10 Earth masses of rocky material to accumulate and form a massive rocky core, after which it rapidly sweeps up large amounts of gas from the neighbouring regions of the disk.

A small number of gas giants have been discovered orbiting older M dwarf stars but, until now, no gas giant has been found in a planetary system around a low-mass M dwarf like TOI-5205.

“In the beginning, if there isn’t enough rocky material in the disk to form the initial core, then one cannot form a gas giant planet.  And at the end, if the disk evaporates away before the massive core is formed, then one cannot form a gas giant planet,” explains Kanodia.

“And yet TOI-5205b formed despite these guardrails. Based on our nominal current understanding of planet formation, TOI-5205b should not exist; it is a “forbidden” planet.”

On the left is a small red dwarf and on the right a larger, yellow sun-like star. Below both is the gas giant toi-5205b for scale.
A Jupiter-like planet orbiting a Sun-like star could be compared to a pea going around a grapefruit; for TOI-5205b, because the host star is so much smaller, it is more like a pea going around a lemon, says lead author Shubham Kanodia. Credit: Katherine Cain/Carnegie Institution for Science

Regular physical activity at any age linked to better brain function in later life

Staying active throughout your whole adult life is linked to better brain function as you age, according to international researchers. A long term study in the Journal of Neurology Neurosurgery & Psychiatry suggests that maintaining an exercise routine throughout adulthood seems to be best for preserving mental acuity and memory.

In a study of 1417 people, they compared reported leisure time physical activity at the ages of 36, 43, 53, 60-64, and 69, with the outcomes of a range of cognitive tests at age 69.

Analysis of the results showed that being physically active at all 5 time points was associated with higher cognitive performance, verbal memory, and processing speed at 69 years old.

Limitations of the study are that it included only white participants and had a disproportionately high attrition rate among those who were socially disadvantaged.

This is also an observational study, so it can only discover a link and not establish cause.

Nevertheless, the researchers say that their findings “support guidelines to recommend participation in any physical activity across adulthood and provide evidence that encouraging inactive adults to be more active at any time, and encouraging already active adults to maintain activity, could confer benefits on later life cognition.”

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