While Henry Dale and Otto Loewi are credited with discovering the role of acetylcholine in chemical neurotransmission, the initial discovery of acetylcholine is more nuanced.
While neither can be credited as the sole discoverer, the most accurate answer is that Henry Dale and Otto Loewi elucidated the role of acetylcholine as a neurotransmitter.
The Story of Acetylcholine's Discovery:
The discovery of acetylcholine and its role in neurotransmission is a result of the work of several scientists:
- Acetylcholine Identified: Acetylcholine was first identified and characterized chemically by Henry Hallett Dale in 1914. He recognized its presence and physiological effects.
- Role in Nerve Impulse Transmission: Otto Loewi is renowned for providing the first evidence that nerve impulses are transmitted chemically. In 1921, his famous "frog heart experiment" demonstrated that a chemical substance released from the vagus nerve could slow the heart rate of another heart. He initially called this substance "Vagusstoff," which was later identified as acetylcholine.
- Confirmation and Further Elucidation: Dale's further work helped to solidify the understanding of acetylcholine as a key neurotransmitter.
The 1936 Nobel Prize:
In 1936, Henry Dale of London and Otto Loewi of Graz shared the Nobel Prize in Physiology or Medicine "for their discoveries relating to the chemical transmission of nerve impulses." This recognized the significant contribution both scientists made in understanding acetylcholine's function.
Timeline of Key Events:
| Year | Event | Scientist(s) Involved |
|---|---|---|
| 1914 | Acetylcholine is chemically identified and characterized. | Henry Dale |
| 1921 | Loewi's frog heart experiment demonstrates chemical neurotransmission. | Otto Loewi |
| 1936 | Nobel Prize awarded to Dale and Loewi. | Dale and Loewi |
In conclusion, while Dale identified the substance, Loewi proved its role in nerve impulse transmission, leading to their joint Nobel Prize. Both Dale and Loewi are essential to understanding the discovery of acetylcholine as a neurotransmitter.
