19905
Further research suggested the antidepressant and cognition - enhancing effects of post - serotonin metabolite , N - acetylserotonin ( NAS ) , an agonist to tyrosine kinase B ( TrkB ) receptor ; and link between depression and chronic inflammation - associated disorders ( e . g . , insulin resistance , hepatitis C virus ) via inflammation - induced activation of indoleamine 2 , 3 - dioxygenase , brain located rate - limiting enzyme of TRY - KYN metabolism .
 Chemical: serotonin; Chemical: N - acetylserotonin; Chemical: NAS; Chemical: tyrosine; Chemical: indoleamine; Chemical: TRY; Chemical: KYN
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: serotonin; Chemical: N - acetylserotonin; Chemical: NAS; Chemical: tyrosine; Chemical: indoleamine; Chemical: TRY; Chemical: KYN