21327
In contrast to AM251 , there is a distinct lack of activation of the brain reward centres , such as the ventral tegmental area , nucleus accumbens and orbitofrontal cortex , which normally form a functional activity signature for the central action of synthetic CB1 receptor inverse agonists .
 Chemical: AM251
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: AM251