5709
We have recently reported that selective cannabinoid 2 ( CB ( 2 ) ) receptor agonists upregulate 5 - HT ( 2A ) receptors by enhancing ERK1 / 2 signaling in prefrontal cortex ( PFCx ) .
 Chemical: 5 - HT
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: 5 - HT