Which receptor is antagonized by ethanol and is implicated in learning and memory?

The N-methyl-D-aspartate receptor (NMDAR) is a type of glutamate receptor that plays a critical role in synaptic plasticity and is essential for learning and memory processes. Ethanol, or alcohol, antagonizes this receptor, meaning it inhibits its function. This interference can lead to cognitive impairments and memory deficits commonly seen in individuals with alcohol use disorders.

The NMDAR is particularly important in mediating excitatory neurotransmission and is involved in long-term potentiation and long-term depression, which are key mechanisms underlying learning and memory. By antagonizing NMDAR, ethanol disrupts these processes, potentially leading to difficulties in forming new memories and retrieving existing ones.

In contrast, while the GABA-A receptor is important in the context of alcohol's overall effects on the central nervous system, it primarily mediates inhibitory neurotransmission rather than directly influencing learning and memory pathways in the same manner as NMDAR. The mu opioid receptor and dopamine D2 receptor are associated with pain modulation and reward pathways, respectively, but they are not specifically implicated in the learning and memory processes influenced by ethanol.