Normally dopamine carries signals between neurons, binding to cell receptors until a transporter removes it. But cocaine keeps the neurotransmitter latched in place. Dopamine then floods the brain, causing an addictive euphoria. Continued use alters this decision-making center, making it even harder to resist using the stimulant.
AMYGDALA+ NUCLEUS ACCUMBENS
THC binds to cannabinoid receptors on nerve cells, altering communications all over the brain. It can cause contentment in the nucleus accumbens, a reward center, and paranoia via the amygdala, which regulates fear and emotion. THC curbs pain and nausea by hindering signals from sensory nerves.
Sometimes we alter our brain chemistry with sweet stuff. Eating sugar activates a reward pathway that includes the striatum, which tells you to eat that tasty treat again. The cortex then decides whether to act on the urge. Certain types and high amounts of sugar can disrupt this pathway, triggering addiction in some people.
Usually the areas controlling introspection and sensing the outside world light up at the same time only if your eyes are open. But people on acid show simultaneous activity even with thei