Alcohol primarily affects which neurotransmitter systems?

Alcohol primarily modulates the functioning of neurotransmitter systems by stimulating GABA (gamma-aminobutyric acid) receptors and increasing the activity of 5-HT (serotonin) receptors. GABA is the main inhibitory neurotransmitter in the central nervous system, and when alcohol enhances GABAergic neurotransmission, it produces sedative and anxiolytic effects characteristic of alcohol consumption. This stimulation leads to increased inhibitory signaling, which can contribute to the feelings of relaxation and reduction of anxiety that many individuals experience when drinking.

Additionally, alcohol has effects on the serotonin system, promoting the release and activity of serotonin, which can influence mood and contribute to feelings of euphoria or dysphoria depending on various factors such as dosage and individual differences.

The other options describe interactions that are not primary effects of alcohol. Dopamine and norepinephrine are involved in the reinforcement and reward pathways, which can be influenced by alcohol but are not the primary systems affected. Inhibitory effects on serotonin and acetylcholine receptors are less relevant in describing alcohol's main action. Furthermore, while glutamate and endorphins interact with alcohol, they do not directly characterize the fundamental neurotransmitter systems primarily affected by the acute actions of alcohol use.