2978
The Met - enkephalin versus Leu - enkephalin concentration ratio was around five in each area of the brain assayed .
 Anatomy: area; Anatomy: brain
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
 Anatomy: area; Anatomy: brain