2397
Nerve fibers immunoreactive for not only sensory neuromarkers , such as calcitonin gene - related peptide ( CGRP ) , but also sympathetic neuromarkers , such as tyrosine hydroxylase ( TH ) and neuropeptide Y ( NPY ) were increased in the periodontal ligament during ETM .
 Chemical: tyrosine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: tyrosine 
Answer:
 Chemical: tyrosine