Scientists have taught 800,000 living brain cells in a dish how to play the iconic arcade game “Pong.” This is the work of a team of neuroscientists and programmers from Cortical Labs, Monash University, RMIT University, University College London and the Canadian Institute for Advanced Research.
In this system, called DishBrain, the nerve cells are overlaid on a multi-electrode array, which is like a sort of CMOS chip that’s able read very small changes in the electrical activity in the neuron. Nerve cells have well-known action potentials-they will fire in response to a certain sequence of voltage changes across the cell membrane.
The cells connect to each other, integrate into the chip, and can survive for many months. The electrode array allows researchers to send and read out signals from the nerve cells at specific locations on the grid, at a given rate.
Electrodes on the array could fire on one side or the other to tell DishBrain where the ball was on, and the frequency of signals could indicate how far away the ball was from the paddle.
“We can kind of decode information going out and encode information going in just through these very small electrical signals and use that to represent what’s happening to the cells,” says Brett Kagan, chief scientific officer of biotech start-up Cortical Labs and the lead author of the Neuron paper.
“Video games help people understand what’s going on. If we simply did it as a function of random numbers, people wouldn’t appreciate or understand the significance of the results.” But why did they choose “Pong?” “From a science perspective, we needed a task that was real-time, continuous, and had a really discrete lose condition that was pretty easy to conceptualize and to encode into the cells,” says Kagan.
“We want to show that there’s a dose response curve on their ability to play the game as a way of validating that these neurons can be used in actual drug assays and discoveries and also for personalized medicine,” says Chong.
Brain cells, Kagan notes, are an interesting biomaterial system that can efficiently process information in real-time without the need for mountains of input samples.
“That’s kind of the commercialization point of view we’re trying to observe at the company.” Since the nerve cells used in DishBrain can be derived from pluripotent human stem cells, this opens possibilities for personalized medicine.
“You can take samples from donors, grow genotypically similar neurons, which we can then use to test drugs, which will then hopefully have the same parameters as donor cells,” Chong says.