Final answer:
Ketamine primarily works on the NMDA glutamate receptor, providing analgesic effects and pain relief.
Step-by-step explanation:
Ketamine primarily works on the NMDA glutamate receptor. Although it is primarily used as an anesthetic, ketamine's mechanism of action involves blocking the NMDA receptor, which plays a key role in pain perception. By blocking this receptor, ketamine can provide analgesic effects and relieve pain.