4323
Biochemical analyses revealed that the concentration of norepinephrine was reduced significantly in cortex - hippocampus and olfactory bulb but not in other regions , while dopamine and serotonin levels were not altered in any brain region examined .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 None