1076
The anti - fatigue effect of modafinil may reflect the activation of the noradrenergic locus coeruleus ( LC ) , since there is evidence that this wakefulness - promoting nucleus is damaged in MS , and that modafinil , probably via the dopaminergic system , can stimulate the LC .
 modafinil, modafinil
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 modafinil, modafinil