Alcohol acts primarily on the nerve cells within the brain. Enhancing an inhibitor would have the effect of making things sluggish, which matches the behavior you see in a drunk person. Glutamine is an excitatory neurotransmitter that alcohol weakens. By making this excitatory neurotransmitter less effective, you also get sluggishness. Alcohol does this by interacting with the receptors on the receiving cells in these pathways.
Alcohol affects various centers in the brain, both higher and lower order.
As the BAC increases, more and more centers of the brain are affected. Summary of alcohol's effects on the brain. Move your cursor over the colored bar in the lower left hand corner to see which areas of the brain are affected by increasing BAC . The cerebral cortex is the highest portion of the brain. Inhibits thought processes - the person does not use good judgement or think clearly.