This petri dish contains an artificial brain consisting of about 60 rat neurons. It's not much, but that doesn't stop the brain from having about 12 seconds worth of working memory, which is probably just long enough for it to start wondering what the heck it's doing in a petri dish anyway.
To grow their own little microbrain, researchers at the University of Pittsburgh took a silicon disk with a layer of proteins on it and cultured some embryonic rat hippocampus cells on top. After a little while, the cells grew together, creating their own ring-shaped neural network that was capable of transmitting and receiving electrical signals.
The researchers found that they could stimulate the neurons with an electrical pulse, and that pulse would travel around the microbrain for up to 12 seconds, which is about 11.75 seconds longer than they figured that it would, meaning that the neurons were storing and transmitting the signal in sequence, forming a sort of short-term memory:
"Persistent activity in the brain is involved in working memory and motor planning. The ability of the brain to hold information 'online' long after an initiating stimulus is a hallmark of brain areas such as the prefrontal cortex."
Now that they've got this brain in a dish remembering things, the researchers plan to use it to try to figure out just exactly how our brains go about transmitting electrical signals, and how our neural networks are able to process and store data as efficiently as we do.