Cocaine is a strong central nervous system stimulant that increases levels of the neurotransmitter dopamine in brain circuits regulating pleasure and movement.  Normally, dopamine is released by neurons in these circuits in response to potential rewards and then recycled back into the cell that released it, thus shutting off the signal between neurons. Cocaine prevents the dopamine from being recycled, causing excessive amounts to build … Continue reading Researchers begin to map brain regions and circuits changed by cocaine-use.