What does PCP binding to the glutamate receptor do?

PCP, or phencyclidine, is known to act as an antagonist on the NMDA (N-methyl-D-aspartate) subtype of glutamate receptors, which are critical for synaptic plasticity and memory function. When PCP binds to these receptors, it effectively prevents the normal physiological function of the receptor, which includes allowing the entry of positively charged ions such as calcium, sodium, and potassium into the cell.

By blocking the ion channel associated with the NMDA receptor, PCP inhibits the flow of cations, thereby preventing the excitatory action typically mediated by the binding of glutamate. This action can lead to a range of effects, including dissociation and hallucinations, which are characteristic of PCP's psychoactive properties.

In this context, the correct understanding of PCP's action emphasizes its role in obstructing cation entry, validating the choice that outlines its mechanism in relation to glutamate receptor binding.