18780
The action of BoNT to block the release of acetylcholine botulinum toxin at the neuromuscular junction is best understood , however , most experts acknowledge that this effect alone appears inadequate to explain the entirety of the neurotoxin ' s apparent analgesic activity .
 acetylcholine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 acetylcholine