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Nicotine ( NIC ) , the main psychostimulant compound of smoked tobacco , exerts its effects through activation of central nicotinic acetylcholine receptors ( nAChR ) , which become up - regulated after chronic administration .
 Chemical: Nicotine; Chemical: NIC; Chemical: acetylcholine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Nicotine; Chemical: NIC; Chemical: acetylcholine