The Role of Dopamine

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        Dopamine and serotonin are the two neurotransmitters that produce the effects which we can observe in people under the influence of MDMA. Dopamine produces the "pleasure" effects while serotonin produces the psychedelic effects. Although the interaction between these two neurotransmitters is what results in the fun part of the drug, it also opens the door for the inactivation or destruction of the axons which produce serotonin.

        The process by which dopamine destroys serotonin axons begins at the reuptake sites in the terminal button of the axons which produce serotonin. Reuptake sites normally serve as a way for the neurons to clean out a synapse when there is too much of any given neurotransmitter (i.e. serotonin, dopamine). When MDMA is taken, there are large amounts of serotonin released into the synapse. Sometimes there is so much serotonin released that the serotonin backup supply is depleated, leaving less serotonin in the synapse than before the drug was taken. When there are only small amounts of serotonin in the synapse, dopamine is allowed to enter into the serotonin axon because higher than average amounts of dopamine have been released and it needs to be taken out of the syanpse. When dopamine is taken into the serotonin axons it will damage them. The axons are initially damaged by dopamine itself and then damaged by the byproduct that is produced when it is broken down by MAO (monoamine oxidase). Thus, the prevailing theory of the neurotoxic nature of MDMA is that dopamine is allowed to enter into the serotonin axons because of MDMA's inhibition of serotonin reuptake. The dopamine then works as a toxic element, ultimately destroying the serotonin neuron. (Gudelsky 1994).

        This picture is a representation of the neuron (much like the one seen in the seotonin section) which depicts serotonin (red E) and dopamine (blue E). The serotonin is not highly concentrated in the synapse which allows dopamine to enter in throught the reuptake centers (yellow) and go into the serotonin axon. Here, they are broken down by MAO (represented by the hammer) and poison the axon in their original and oxidized (broken down) form.

        The full slide show can be viewed on and one click on the picture will take you to the beginning. The slide show takes the reader through the long process of how serotonin and dopamine work in the body, how MDMA affects these chemicals and how neurotoxicity is believed to occur. It is a very thurough presentation and very easy to understand.




Prevention of Neurotoxicity


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