30242
Electrophysiology studies show that this shift in palatability corresponds to an alteration in nucleus accumbens ( NAc ) cell firing ; neurons that previously responded with inhibition during infusion of the palatable sweet shifted to excitatory activity during infusion of the cocaine - devalued tastant .
 Chemical: cocaine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: cocaine 
Answer:
 Chemical: cocaine