This figure shows a decrease in the Ecstacy user's ability to remove this important neurotransmitter from the intracellular space, thereby amplifying its effects within the brain. This decrease lasts at least three weeks after the individual has stopped using Ecstacy. Given serotonin's critical role in many behavioral characteristics, one can speculate that this abnormality of the serotonin system might be responsible for some of Ecstasy's long-lasting behavioral effects. Figure 2 also demonstrates the long-lasting effects that drugs can have on the brain. Here you can see dopamine transporter binding in four different adults.
Brighter colors reflect greater dopamine binding capacity.
The scan on the left is that of a non-drug user, the next is of a chronic methamphetamine user who was drug free for about three years when this image was taken, followed by a chronic methcathinone abuser who was also drug free for about three years. The last image is of the brain of an individual newly diagnosed with Parkinson's Disease. When compared with the control on the left, one can see the significant loss in the brain's ability to transport dopamine back into brain cells. Dopamine function is critical to emotional regulation, is involved in the normal experience of pleasure and is involved in controlling an individual's motor function. The application of these technologies is not only illuminating long-standing issues in our field but actually redirecting our overall approaches.