16711
Furthermore , while the higher dose of DA D1 - like receptor antagonist ( SCH23390 , 0 . 5 mu g / mouse ) induced amnesia and anxiogenic - like behaviors , mu receptor antagonist ( naloxone : 0 . 0125 , 0 . 025 and 0 . 05 mu g / mouse ) and DA D2 - like receptor antagonist ( sulpiride : 0 . 0625 , 0 . 125 and 0 . 25 mu g / mouse ) by themselves , could not exert an effect on memory performance in passive avoidance task .
 SCH23390, naloxone, sulpiride
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 SCH23390, naloxone, sulpiride