Discovery of Place Cells in Fish 

Our brain orients itself in space by creating a cognitive model of its environment. Place cells in the hippocampus play an important role in this process. While behavioural studies suggest that spatial cognition may also be present in fish, previous studies have found no clear evidence for place cells outside of birds and mammals.  Using a tracking microscope, we analysed the brain activity of free-swimming zebrafish larvae at cellular resolution and were able to demonstrate the presence of place cells in fish for the first time.