Transcript (en)

Our brains are composed of networks of billions of tiny nerve cells. Signals race around these networks, crossing the gaps between the nerve cells using chemical messengers. One network is dedicated to making us feel good when we do something that is essential to survival, such as eat, drink or have sex. Normally, when this network is activated, the nerve cells in it release the feel-good chemical messenger, dopamine. Dopamine travels across the gap from one nerve cell to receptors on its neighbor, triggering a chain reaction which makes you feel good. This dopamine then returns to the nerve cell that released it for further use. Cocaine hijacks the feel-good network in the brain. It causes huge increases in the amount of dopamine throughout the network, flooding the brain with feel-good chemicals. And it also stops the dopamine returning to the nerve cells that have released it, meaning more and more builds up. Cocaine blocks something called the dopamine transporter, and what that does is it mops up dopamine that sits in the space between two cells. And if that reuptake is blocked, what you get is an awful lot of dopamine floating around this space. The flood of dopamine sends the feel-good network in the brain into overdrive, producing a sense of euphoria and self-assurance, making the user more animated and talkative.