Task: Text Categorization
Input (English): 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.
Output (English): Science