Stimulant
drugs such as the amphetamines and methamphetamines alter the
release and/or re-uptake of neurotransmitters. They affect the "Pleasure Reward Pathway"(PRP)
by altering the level of dopamine present in the synapse. Methamphetamine is
chemically
similar to dopamine and norepinephrine and readily crosses the
blood/brain barrier. It produces its effects by causing dopamine
and norepinephrine to be released into the synapse in several
areas of the brain. Methamphetamine enters nerve terminals by
passing directly through nerve cell membranes. It is also carried
into the nerve terminals by transporter molecules that normally
carry dopamine or norepinephrine from the synapse back into the
nerve terminal. Once in the nerve terminal, meth enters dopamine
and norepinephrine containing vesicles and causes the release of
these neurotransmitters.
Additionally, meth blocks the breakdown of
excess dopamine and norepinephrine. It does so by blunting the
effects of Monoamine oxidase (MAO), which is an enzyme capable of
cleaving monoamines such as dopamine and norepinephrine. The
result is an excess of neurotransmitters.
The high concentration of dopamine within the
PRP elicits feelings of pleasure and euphoria. Excess
norepinephrine may be responsible for the alertness and
anti-fatigue effects of meth.
Interactive Synapse
(Explore the numbered components
in the diagram with your cursor)
Stimulant
drugs such as the amphetamines and methamphetamines alter the
release and/or re-uptake of neurotransmitters. They affect the "Pleasure Reward Pathway"(PRP)
by altering the level of dopamine present in the synapse. Methamphetamine is
chemically
similar to dopamine and norepinephrine and readily crosses the
blood/brain barrier. It produces its effects by causing dopamine
and norepinephrine to be released into the synapse in several
areas of the brain. Methamphetamine enters nerve terminals by
passing directly through nerve cell membranes. It is also carried
into the nerve terminals by transporter molecules that normally
carry dopamine or norepinephrine from the synapse back into the
nerve terminal. Once in the nerve terminal, meth enters dopamine
and norepinephrine containing vesicles and causes the release of
these neurotransmitters.