Which of the following statements best refects the efect of alcohol on neurotransmitters in the brain?
ExplanationAlcohol has efects on many neurotransmitters in the brain. The predominant efect of alcohol lies in its ability to cause release of γ-aminobutyric acid (GABA), and it acts primarily at the GABAA receptors. GABA is the primary inhibitory neurotransmitter in the brain and is associated with the sedative efects of alcohol. Many other drugs afect the GABA system including benzodiazepines, nonbenzodiazepine sleep aids such as zolpidem, anticonvulsants, and muscle relaxants. The euphoric efects of alcohol consumption are related to increases in dopamine, which is common to all pleasurable activities. The efects on dopamine are thought to be important in alcohol craving and relapse. In addition, alcohol alters opioid receptors and can lead to a release of β-endorphins during acute ingestion. In addition to these efects, alcohol also inhibits postsynaptic NMDA excitatory glutamate receptors. Glutamate is the primary excitatory neurotransmitter of the brain, and its inhibition further contributes to the sedative efects of alcohol. Additional important efects on neurotransmitters include increased serotonin activity and decreased nicotinic acetylcholine receptors.
