What type of receptor does PCP act as an antagonist on?

PCP, or phencyclidine, primarily acts as an antagonist at the NMDA glutamate receptor channels. These receptors play a crucial role in excitatory neurotransmission in the brain and are involved in processes such as learning and memory. By blocking these receptors, PCP alters the normal functioning of glutamate signaling, leading to various psychoactive effects, including dissociation and hallucinations.

Understanding the mechanism of action of PCP is important in addiction medicine, as it helps clarify the drug's effects on the central nervous system and can guide treatment approaches for individuals who may misuse or become addicted to substances that similarly affect glutamate neurotransmission. The other types of receptors mentioned in the options are not the primary targets for PCP's action, hence why they do not apply in this context.