22119
mu - Opioid receptors in the stimulation of mesolimbic dopamine activity by ethanol and morphine in Long - Evans rats : a delayed effect of ethanol .
 Chemical: dopamine; Chemical: ethanol; Chemical: morphine; Chemical: ethanol
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; Chemical: ethanol; Chemical: morphine; Chemical: ethanol