1370
First , we observed that the marked hyperactivity displayed by DAT KO mice was reduced by administration of nicotine .
 Chemical: nicotine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: nicotine 
Answer:
 Chemical: nicotine