8987
However , recent molecular approaches using null mutant mice with specific regional lentiviral re - expression , in combination with neuroanatomical and electrophysiological techniques , have allowed the elucidation of the influence of different nAChR types on neuronal circuit activity and behavior .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None