500
Most drugs of abuse directly or indirectly target the brain's reward system by flooding the circuit with _________.
What is dopamine.
Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, motivation, and feelings of pleasure. When activated at normal levels, this system rewards our natural behaviors. Overstimulating the system with drugs, however, produces euphoric effects, which strongly reinforce the behavior of drug use, which teaches the user to repeat it.