Serotonin neurons project widely in the brain. Acute stress is associated with increased serotonin turnover in several brain regions, including the amygdala, the nucleus accumbens and the PFC. Serotonin modulates neural responses to stress, with both anxiogenic and anxiolytic effects (depending on the brain region and receptor subtype involved)3. Serotonin function is also closely linked to mood regulation. Dopamine neurons are activated in response to reward or the expectation of reward and generally are inhibited by aversive stimuli, as detailed below. Dopamine signalling facilitates fear extinction, but its role in resilience per se is unclear.
