354
The number of stained microglia cells was significantly higher in the PDN treated groups in the prefrontal cortex than in controls ( moderate - dose , 29 . 1 ; high - dose , 28 . 4 ; control , 17 . 7 cells per field ; p < 0 . 01 ) .
 Chemical: PDN
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: PDN