This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
Site of action of ketamine is – 
Select and explain. 
A. Spinal cord, B. Local nerve fibers, C. Primary action on thalamoneocortical projection, D. Posterior column
C: Primary action on thalamoneocortical projection
Answer: C: Primary action on thalamoneocortical projection 
Explanation: The primary site of CNS action of ketamine seems to be the thalamocortical projection system.