27087
In the cultured hippocampal neurons treatment with NMDA ( 10 mu M ) for 48 hrs reduced surface expression of delta and alpha 4 subunits , but did not increase expression of gamma 2 subunits .
 NMDA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 NMDA