22688
OBJECTIVES : We investigated the effects of the most selective serotonin reuptake inhibitor escitalopram on sleep rebound following REMS deprivation and , in parallel , on the activation of MCH - containing neurons .
 serotonin, escitalopram
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 serotonin, escitalopram