Mice learn fastest and most reliably when they experience an increase in dopamine paired with an inhibition of serotonin in their nucleus accumbens, a new study shows, helping to resolve long-standing questions about the neuromodulators’ relationship.

The co-author of the classic textbook “The Biochemical Basis of Neuropharmacology” and pioneer in studying the roles of neurotransmitters in the brain died on 8 January at 88 years old.