The PET-scan images to the right show the brain’s response to the avalanche of dopamine in the nucleus accumbens of people with dependencies. To relieve the chronic stimulation of its neurons, the nucleus accumbens simply reduces the number of dopamine receptors that they have.
In these images of the brain, the red areas indicate large numbers of dopamine receptors. These images show that people who are alcoholic, obese, or cocaine-dependent have fewer dopamine receptors than normal people do. |