30451
NSDA neurons displayed significant axon terminal degeneration ( as indexed by decreases in DA , tyrosine hydroxylase ( TH ) and DA transporter concentrations in the striatum ) as well as loss of TH - immunoreactive ( IR ) neurons in the substantia nigra ( SN ) following MPTP , whereas TIDA neurons revealed no overt axon terminal pathology or loss of TH - IR cell bodies .
 tyrosine, MPTP
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 tyrosine, MPTP