This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Anaesthesia
Ketamine acts on: 
Select and explain. 
A. NMDA receptor, B. Glycine receptor, C. GABAa receptor, D. Ach receptor
A: NMDA receptor
Answer: A: NMDA receptor 
Explanation: (A) NMDA receptor > Pharmacologically Ketamine is classified as NMDA receptor antagonist. At high, fully anasthetic level doses ketamine ha:; also been found to bind to opioid p receptors type II in cultured human neuroblastoma cells, without agonist activity. Ketamine interacts with receptors, descending monoaminergic pain pathways and voltage gaenerated calcium channels. It induces dissociative anastehsia and is used as recreational drug