High Quality Content by WIKIPEDIA articles! Described by James Papez in 1937, the Papez circuit of the brain is one of the major pathways of the limbic system and is chiefly involved in the cortical control of emotion. The Papez circuit plays a role in storing memory. Papez discovered the circuit after injecting rabies virus into a cat`s hippocampus and monitoring its progression through the brain. The initial pathway was described as follows: