Approximately three hours into your ecstasy experience your serotonin transporters have removed much of the serotonin from the synapse, but there is still plenty around to activate the receptors, so you still feel the desired effects of the drug. Pretty soon, however, the reuptake transporters will remove most of the serotonin from the synapse, and you will start coming down.

We said in the last slide that some of the serotonin finds its way back into the receptor where the MDMA causes it to be released again. This is true, but notice the hammers inside the axon. This is "monoamine oxidase" (MAO), an enzyme that breaks down serotonin (serotonin is a monoamine, remember). After your reuptake pumps remove the serotonin, MAO breaks most of it down. MAO doesn't really look like a hammer, but thinking of it as a hammer that smashes up serotonin molecules is a good way to remember what it does. (For more information on MAO and the dangers of taking Ecstasy with MAO inhibitors, click here.) Notice too that the dopamine receptors are also still activated as well.