In the summer of 1939, fresh Cambridge graduate Andrew
Huxley teamed up with Alan Hodgkin at the Laboratory of the Marine
Biological Association in Plymouth, England. Their goal? To understand how
nerves transmit electrical signals. They chose to study the giant axon of
the Atlantic squid, which contains some of the largest nerve cells in
the animal kingdom, making it ideal for precise experimentation.
Using delicate electrodes, they achieved what no one had
before—measuring electrical activity inside a living nerve cell. This
breakthrough allowed them to record the nerve’s internal signals for the first
time. But just as their research was gaining momentum, history intervened. In
September 1939, World War II broke out. Their scientific journey was put
on hold for nearly seven years as both men contributed to the war effort by
working on defense-related projects.
A Legacy Built on Foundations of
Discovery
Though Hodgkin and Huxley made revolutionary contributions,
they built upon decades of earlier discoveries. Back in 1848, German
physiologist Emil du Bois-Reymond discovered the action potential,
the brief spike in electrical charge that occurs when a nerve sends a signal.
Later, in 1912, Julius Bernstein suggested that these signals
were due to shifts in potassium ions moving across the nerve cell
membrane.
Modern science confirms that potassium (K⁺)
and sodium (Na⁺)
ions are concentrated differently inside and outside of nerve cells. This imbalance
creates a voltage difference, known as the membrane potential. When
these ions rapidly move in and out through the nerve membrane, they generate an
action potential—a brief electrical impulse that allows nerves to
transmit information throughout the body.
Post-War Breakthroughs and a
Mathematical Revolution
When peace returned in 1947, Hodgkin and Huxley
resumed their research with a new tool: the voltage clamp technique.
This allowed them to control and measure voltage changes across the nerve
membrane with unprecedented accuracy.
By 1952, they had developed a sophisticated mathematical
model of how the action potential worked. Their equations accurately
predicted how ion channels—tiny protein-based gateways—allowed sodium
and potassium ions to flow in and out of nerve cells. This quantitative
approach went far beyond earlier qualitative explanations and marked a
turning point in how scientists studied the nervous system.
In the 1970s and 1980s, their predictions were
experimentally verified, proving their model to be both visionary and accurate.
For their contributions, Hodgkin and Huxley were awarded the Nobel Prize in
Physiology or Medicine in 1963. They shared the honor with John Eccles,
who explored how signals jump between nerve cells at synapses—the tiny
gaps where electrical messages are passed from one neuron to the next.
Key Takeaways to Remember
- Giant
squid axons provided a practical model for
early nerve conduction research.
- Hodgkin
and Huxley were the first to directly
measure electrical signals inside a nerve.
- Their
work explained how action potentials result from the flow of sodium
and potassium ions.
- The
voltage clamp technique and their mathematical model set a
new gold standard for neuroscience.
- Their
findings laid the groundwork for our modern understanding of nerve
communication.
- Their
legacy lives on, influencing everything from
brain research to medical treatments for neurological disorders.
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| This oscilloscope (CRO) recording allows researchers to clearly monitor real-time changes in a nerve’s electrical activity, including shifts in voltage and signal frequency over time. |
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