3896
Quantitative analyses of labeled neurons in three regions of the dentate gyrus in the 1 and 2 week groups showed statistically significant decreases in the mean number of GAD mRNA - containing neurons in the hilus of both groups of experimental animals .
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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:
 None