21390
These findings indicate that nicotine - induced structural plasticity in mesencephalic dopaminergic neurons involves alpha 4 beta 2 nAChRs together with dopamine D3R - mediated recruitment of ERK / Akt - mTORC1 signaling .
 Chemical: nicotine; Chemical: dopamine
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: dopamine