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A recent study in rats has shown that chronic , daily exposure to 10 mg ATR / kg BW causes hyperactivity , disrupts motor coordination and learning of behavioral tasks , and decreases dopamine levels in the brain .
 ATR, dopamine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ATR, dopamine