5707
Pre - training peripheral injections of methyllycaconitine ( MLA ) or dihydro - beta - erythroidine ( DH beta E ) , which are specific alpha 7 and alpha 4 beta 2 nicotinic receptor antagonists , respectively , dose - dependently impaired retention latencies in an inhibitory avoidance task when tested 7 - days but not 1 h after training .
 Chemical: methyllycaconitine; Chemical: MLA; Chemical: dihydro - beta - erythroidine; Chemical: DH beta E
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: methyllycaconitine; Chemical: MLA; Chemical: dihydro - beta - erythroidine; Chemical: DH beta E