SCIENTISTS TEACH BRAIN CELLS IN A PETRI DISH TO PLAY PONG
Next they plan to get the brain cells drunk, in a bid to learn more about the effects of drugs on the brain
Since its release in 1972, the table tennis-themed video game Pong has provided hours of entertainment to players of all genders, ages and walks of life. Now, thanks to an international team of neuroscientists, it can add a Petri dish containing 800,000 living brain cells to that list.
Named DishBrain, the ‘player in a Petri’ provides evidence that brain cells can display signs of intelligent behaviour, even when they’re not part of a fully formed organ.
To create DishBrain, the team used human brain cells derived from stem cells, as well as brain cells harvested from embryonic mice. The cells were then grown in a Petri dish on a special type of silicon chip hooked up to a system that enabled them to learn to play Pong.
A signal indicating the location of the ball on screen was fed to DishBrain through the chip it was sitting on. When the ball was on the left, electrodes on the left of the chip fired, and vice versa. Meanwhile, the ball’s distance from the paddle was indicated by the signal’s frequency.
Electric probes were then used to give DishBrain feedback that got stronger the closer it could move the paddle towards the ball.
“The beautiful and pioneering aspect of this work rests on equipping the neurons with sensations – the feedback – and, crucially, the ability to act on their world,” said Prof Karl Friston, a theoretical neuroscientist at University College London and part of the research team.
“Remarkably, the cultures learned how to make their world more predictable by acting upon it. This is remarkable because you can’t teach this kind of self-organisation, simply because, unlike a pet, these mini brains have no sense of reward or punishment.”
While previous experiments have successfully monitored the activity of neurons mounted on chips, DishBrain is the first example of them being stimulated in a meaningful way, the researchers say.
DishBrain could enable scientists to conduct experiments using real brain cells rather than computer models when researching neurodegenerative diseases and the effects of potential medicines. “The translational potential of this work is truly exciting: it means we don’t have to worry about creating ‘digital twins’ to test therapeutic interventions,” said Friston.
“We now have the ultimate biomimetic ‘sandbox’ in which to test the effects of drugs and genetic variants”
“We now have, in principle, the ultimate biomimetic ‘sandbox’ in which to test the effects of drugs and genetic variants – a sandbox constituted by exactly the same computing, that is, neuronal, elements found in your brain and mine.”
Before they can get started on investigating the effects of medicines, though, the neuroscientists want to see what effect alcohol will have on DishBrain.
“We have shown we can interact with living biological neurons in such a way that compels them to modify their activity, leading to something that resembles intelligence,” said lead researcher Dr Brett Kagan, chief scientific officer of biotech start-up Cortical Labs, in Melbourne, Australia.
“We’re trying to create a dose response curve with ethanol – basically get DishBrain ‘drunk’ and see if it plays the game more poorly, just as when people drink.”