Subtitles section Play video Print subtitles Your brain contains billions of cells. They consist of a cell body, dendrites and an axon. The cell body stores DNA and other stuff. Dendrites receive signals from other cells and the axon carries signals from the cell body to the axon terminals. Axon terminals contain neurotransmitters, which serve to communicate with other cells. Some cells contain just one type of neurotransmitter. Serotonin cells only produce and release serotonin. Serotonin cells release their serotonin into the synapse. This is the gap between their axon terminals and the dendrites of another cell. Serotonin is involved with the regulation of your mood, heart rate, sleep and - - appetite. MDMA causes cells to release large amounts of serotonin. These large amounts are responsible for the primary effects of MDMA, such as: euphoria, empathy, the urge to communicate and mild hallucinations. Side effects are increased heart rate, difficulty sleeping and loss of appetite. Serotonin is stored in vesicles that float around inside the axon terminals. When a signal comes down the axon the vesicles merge with the membrane - and releases serotonin into the synapse. Released serotonin can enter a different cell through receptors that are attachted to the membrane of dendrites. When serotonin attaches to such a receptor, the receptor sends information - - to the cell body. Based on the information from all the receptors together the cell body - - will decide whether or not to send a signal down it's own axon. When it does send a signal more serotonin gets released into more synapses.into more synapses After a while the serotonin will detach from the receptor and float back into the synapse. Serotonin can also bind to re-uptake transporters. Re-uptake transporters work as a revolving door. After the serotonin enters, the transporter spins around and - - pushes the serotonin back into the axon terminal. Some serotonin makes it way back into the vesicles, but some of it gets broken - - down by an enzyme called monoamine oxidase. After four to six hours you've used up most of your serotonin and you should start to feel somewhat normal again. However, your low serotonin levels can make you feel depressed, extremely -non-social and tired. Your brain needs time to rebuild your serotonin levels. This could take up to two weeks. MDMA causes the release of serotonin by entering the axon terminal through the re-uptake transporters. Once there, it interacts with the vesicle, causing it to poor serotonin into the synapse.