2-Minute Neuroscience: MDMA
MDMA, better known as ecstasy, molly, or
one of a number of other street names, is a stimulant drug that is
chemically related to amphetamine. Like other stimulants, MDMA causes
increased alertness and a positive mood. But MDMA’s effects are also distinct from the
effects of other stimulants, as the drug causes unique prosocial effects such as strong feelings
of trust, openness, and closeness with others. Although we don’t have a full understanding
of the effects of MDMA on the brain, MDMA’s mechanism is similar in many ways to the
mechanism of other amphetamines. MDMA inhibits the function of proteins called transporter proteins,
which typically remove neurotransmitters like serotonin, dopamine, and norepinephrine from the
space between neurons known as the synaptic cleft. By inhibiting transporter proteins,
MDMA causes serotonin, dopamine, and norepinephrine to accumulate in the synaptic
cleft, increasing neurotransmitter activity there. In contrast to other amphetamines, MDMA inhibits
the serotonin transporter more potently than the dopamine or norepinephrine transporter.
MDMA
also uses transporter proteins to enter neurons; once inside, MDMA disrupts the storage of
neurotransmitters in synaptic vesicles, causing the buildup of serotonin, dopamine,
and norepinephrine inside neurons; then, MDMA facilitates the release of these
neurotransmitters into the synaptic cleft, leading to increased neurotransmitter levels
and activity. In addition to these mechanisms, MDMA also binds to a number of receptors
directly, including specific subtypes of the serotonin receptor; these interactions
may contribute to the effects of MDMA. It’s not clear what mechanism accounts
for the unique prosocial effects of MDMA. A number of studies have found that MDMA
promotes the release of the hormone oxytocin, which itself has been linked to prosocial effects. At the same time, most studies have failed
to find a link between increasing oxytocin levels and the prosocial effects of MDMA,
leaving these effects still unexplained..
