7795
The greater effects in MRL / MpJ mice on 5 - HT levels were not maintained after local perfusion of citalopram , suggesting that mechanisms outside of the hippocampus were responsible for the greater effect of citalopram after systemic injection .
 5 - HT, citalopram, citalopram
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 5 - HT, citalopram, citalopram