NEUROSC M101C Lecture Notes - Lecture 6: Dopamine Antagonist, Methamphetamine, Analgesic
Document Summary
Emergency of negative emotional state when access to drug is prevented. Drug-taking despite negative consequences or other, healthier options. Addictive substance can potentiate wanting process and not liking process. Stimuli in environment can become potent triggers (maintaining drug use or triggering relapse) - relapse/reinstatement of drug behavior. We didn"t evolve circuits that facilitated drug addiction -- but drugs hijack a preexisting reward circuitry that is important for motivated behavior and decision making. Unlike a pure homeostatic model, setpoint can change - will repeated exposure to drugs, the setpoint can either increase or decline over time. Intense euphoric effect produced by initial use causes mood to exceed homeostatic range. Positive reinforcement => over time with continued drug use, negative emotional states emerge when access is prevented => negative reinforcement, as individual"s drug-seeking behavior is motivated by a desire to alleviate negative emotional state. With continued drug usage, opponent process b compounds and overall mood gradually declines over time.
