Brain
Nucleus Accumbens
The brain's pleasure and reward hub
Overview
The nucleus accumbens (NAcc) is a key component of the basal ganglia's ventral striatum and is the brain's primary reward centre. It receives dense dopaminergic input from the ventral tegmental area (VTA) and integrates motivational signals to drive goal-directed behaviour, reinforcement learning, and the experience of pleasure.
Function
- Mediates reward, pleasure, and reinforcement
- Integrates motivational signals with motor action
- Drives approach behaviour for food, sex, and social reward
- Underlies addiction: repeated drug use hijacks this circuit
- Regulates maternal bonding and pair bonding (via oxytocin + dopamine)
Key Facts
- All drugs of abuse ultimately flood the nucleus accumbens with dopamine
- Deep brain stimulation of NAcc is being tested for treatment-resistant depression
- The NAcc has a "core" (habit formation) and "shell" (reward salience)
- Social rejection activates NAcc-related circuits—the pain of being excluded