24403
Here , we first highlight basic characteristics of the serotonergic system including the biosynthesis of 5 - HT as well as the anatomy and firing activity of serotonergic neurons .
 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