6569
However , assessment of opioid and dopamine receptor gene expression in the NAcc did not reveal evidence of the involvement of these genes in driving large meals , at least at the investigated time point .
 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: dopamine