2129
Pre - treatment with an antibody raised against the 5 - HT ( 2A ) - receptor ( an irreversible antagonist ) greatly attenuated neuronal death promoted by 48 h exposure to DOI or MDMA .
 5 - HT, DOI, MDMA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 5 - HT, DOI, MDMA