919
The present study investigated the dose - dependent effects of D - serine ( 10 mg / kg , 30 mg / kg and 100 mg / kg ) on extinction training and drug - primed reinstatement in cocaine - conditioned rats .
 D - serine, cocaine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 D - serine, cocaine