16634
N - methyl - D - aspartate receptors ( NMDARs ) and nicotinic acetylcholine receptors ( nACHRs ) are thought to be effective in the learning and memory - generating process .
 Chemical: N - methyl - D - aspartate; Chemical: acetylcholine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: N - methyl - D - aspartate; Chemical: acetylcholine