▁Production ▁voice ▁actors <0x0A> </s> ▁An ▁ac et yl ch oline ▁re ceptor ▁( ab bre vi ated ▁A Ch R ) ▁is ▁an ▁integral ▁memb rane ▁protein ▁that ▁respond s ▁to ▁the ▁binding ▁of ▁ac et yl ch oline , ▁a ▁ne uro trans mit ter . ▁ ▁Classification ▁Like ▁other ▁transm emb rane ▁re cept ors , ▁ac et yl ch oline ▁re cept ors ▁are ▁class ified ▁according ▁to ▁their ▁" ph arm ac ology ," ▁or ▁according ▁to ▁their ▁relative ▁aff in ities ▁and ▁sens it iv ities ▁to ▁different ▁mole cules . ▁ ▁Although ▁all ▁ac et yl ch oline ▁re cept ors , ▁by ▁definition , ▁respond ▁to ▁ac et yl ch oline , ▁they ▁respond ▁to ▁other ▁mole cules ▁as ▁well . ▁ ▁Nic ot in ic ▁ac et yl ch oline ▁re cept ors ▁( n A Ch R , ▁also ▁known ▁ ▁as ▁" ion otrop ic " ▁ac et yl ch oline ▁re cept ors ) ▁are ▁particularly ▁respons ive ▁to ▁nic ot ine . ▁The ▁nic ot ine ▁A Ch ▁re ceptor ▁is ▁also ▁a ▁Na + , ▁K + ▁and ▁Ca 2 + ▁ion ▁channel . ▁Mus car in ic ▁ac et yl ch oline ▁re cept ors ▁( m A Ch R , ▁also ▁known ▁as ▁" met ab otrop ic " ▁ac et yl ch oline ▁re cept ors ) ▁are ▁particularly ▁respons ive ▁to ▁mus car ine . ▁ ▁Nic ot in ic ▁and ▁mus car in ic