In 1921, its functional significance was determined.  Otto Loewi took fluid from a frog's heart, whose contractions had been slowed, and let it perfuse a second, unstimulated heart, slowing its beating as well.  Mimicked by nicotine, this neurotransmitter plays a major role 
In 1921, its functional significance was determined.  Otto Loewi took fluid from a frog's heart, whose contractions had been slowed, and let it perfuse a second, unstimulated heart, slowing its beating as well.  Mimicked by nicotine, this neurotransmitter plays a major role in memory as well as muscle control.  FTP, name this primary neurotransmitter between neurons and muscles.
In 1921, its functional significance was determined.  Otto Loewi took fluid from a frog's heart, whose contractions had been slowed, and let it perfuse a second, unstimulated heart, slowing its beating as well.  
acetylcholine