Per Andersen was a Norwegian neuroscientist who made fundamental contributions to the study of the hippocampus, the part of the brain associated with memory and spatial navigation. Per pioneered methods and tools that have advanced brain science, and his discoveries shaped our understanding of neural circuitry.

As a medical student in the fledgling Oslo School of Neuroanatomy, Per’s career in neuroscience was inspired by influential mentors. Later, in collaboration with neurophysiologist John Eccles, Per discovered that ‘basket cells’ make inhibitory synapses in the hippocampus and cerebellum. This was the first inhibitory synapse ever identified.

Having discovered the main course of nerve fibres in the hippocampus, Per pioneered the use of transverse slices for study. This prevented severing of the nerve connections, enabling ‘live’ synapses to be studied in the brain slices. Per’s team also discovered long-term potentiation, a neural phenomenon now considered to underlie learning and memory.

Professor Per Andersen ForMemRS died on 17 February 2020.