The mechanism of action of cocaine

Cocaine modifies the action of dopamine in the brain. The dopamine rich areas of the brain are the ventral tegmental area, the nucleus accumbens and the caudate nucleus – these areas are collectively known as the brain’s ‘reward pathway’. Cocaine binds to dopamine re-uptake transporters on the pre-synaptic membranes of dopaminergic neurones. This binding inhibits the removal of dopamine from the synaptic cleft and its subsequent degradation by monoamine oxidase in the nerve terminal. Dopamine remains in the synaptic cleft and is free to bind to its receptors on the post synaptic membrane, producing further nerve impulses. This increased activation of the dopaminergic reward pathway leads to the feelings of euphoria and the ‘high’ associated with cocaine use.