A 22-year-old man is brought after snorting a substance at a party. He is diaphoretic, tachycardic, hypertensive, and has dilated pupils. He reports intense euphoria followed by severe dysphoria and craving. He uses the substance every weekend. Which neurotransmitter is primarily responsible for the reinforcing and rewarding effects of this substance?
- A Norepinephrine
- B Serotonin
- C Dopamine ✓
- D GABA
Correct answer: C. Dopamine
Explanation
The presentation is consistent with cocaine intoxication (snorting, euphoria, sympathetic activation, subsequent dysphoria and craving). Cocaine blocks dopamine reuptake, causing accumulation of dopamine in the nucleus accumbens, which mediates the reinforcing and rewarding effects of virtually all addictive substances. The mesolimbic dopamine pathway is the common final pathway for reward in substance use disorders.
Reference: Katzung's Basic and Clinical Pharmacology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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