781
In contrast , the conduction velocity , the number and size of axons in the optic nerve , and the specific localization of Na ( v ) 1 . 6 channels in the nodes of Ranvier were unchanged .
 Chemical: Na
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: Na