The latest study established that dopamine in the brain can be naturally activated through behavioural actions and that these actions enhance memory retention. The study tested 120 mice to establish a link between locus coeruleus (LC) neurons and neuronal circuits of the hippocampus -- the region of the brain responsible for recording memories -- that receive dopamine from the LC. One part of the research involved putting the mice in an arena to search for food hidden in sand that changed location each day.