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: Unknown
[{'content': 'Stimulation of which brain area can modulate the sensation of pain? \nSelect and explain. \nA. Superior olivary complex, B. Locus ceruleus, C. Periaquaductal gray, D. Amygdala', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Endogenous analgesic system\n\xa0\nperiaqueductal gray (PAG)-projects to nucleus raphé magnus and rostral ventromedial medulla\n\xa0\nproject to the dorsal horn of the spinal cord- release serotonin and norepinephrine\n\xa0\nLocus coerulus-Nor epinephrine\n\xa0\nStress induced analgesia:\n\xa0\nrelease of endogenous cannabinoids such as 2-arachidonoylglycerol (2AG) and anandamide acts on CB1(Euphoria) and CB 2 (Pain)receptors', 'role': 'assistant'}]