6830
To this end , single - unit extracellular recordings of the noradrenergic nucleus , locus coeruleus ( LC ) , and the serotonergic nucleus , dorsal raphe ( DRN ) combined with behavioural approaches were performed .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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