1964
In experiments using specific adrenergic antagonists , we found that pretreatment with the beta - adrenergic receptor antagonist propranolol blocked cocaine - induced anxiety - like behavior in Dbh + / - and wild - type C57BL6 / J mice , while the alpha ( 1 ) antagonist prazosin and the alpha ( 2 ) antagonist yohimbine had no effect .
 propranolol, cocaine, anxiety, prazosin, yohimbine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 propranolol, cocaine, anxiety, prazosin, yohimbine