17941
An evaluation of the serotonin system and perseverative , compulsive , stereotypical , and hyperactive behaviors in dopamine transporter ( DAT ) knockout mice .
 Chemical: serotonin; 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: serotonin; Chemical: dopamine