PC Gamer reports we are clearly heading to a cyberpunk dystopia... I mean... what could possibly go the fuck wrong with a 'living' computer? 
Why are scientists experimenting with this sort of computing? So-called reservoir computing matches neurons made from living cells with conventional computer chips used to read the data they produce. The idea is that the division of labor between meat and silicon cuts down the time and energy needed to train more traditional neural networks.
Eventually it's hoped that reservoir computing could be used to create more efficient devices, that could also maintain continued functionality if parts are damaged or break down. The New Scientist report states that at the moment this mouse brain-bot can't yet match conventional neural networks in terms of raw performance, but the team is aiming to make a larger living computer.
Peak Storage
Somewhat worryingly, they're also hoping this larger mouse brain-bot will start to exhibit behavior they didn't input or train the neural network for. I've read enough science fiction to know how that goes.