The Science Behind the 2026 Nobel Prize in Medicine
This morning I came across an interesting scientific story that immediately caught my attention.
The 2026 Nobel Prize in Physiology or Medicine has been awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for discoveries that led to optogenetics.
When I first saw the word optogenetics, I had to stop and ask myself: What exactly is optogenetics?
I have spent much of my life around chemistry and pharmaceutical science. I received my PhD in Pharmaceutical Chemistry from the University of Illinois Medical Center and later spent many years in pharmaceutical research and at the U.S. FDA.
But optogenetics is a wonderful example of how modern science can combine several different fields, biology, chemistry, genetics, neuroscience and even light physics to answer one of the oldest mysteries in science:
How does the brain work? A light switch inside the brain
The simplest way I can explain optogenetics is this:
Scientists have found a way to use light as a switch for individual nerve cells.
Our brain contains billions of neurons. These nerve cells communicate with one another through electrical and chemical signals. For many years, scientists could observe brain activity, but it was difficult to determine exactly what a particular group of neurons was doing.
Optogenetics changed that. Scientists can introduce a gene into selected nerve cells that causes those cells to produce a special light-sensitive protein. When light of the appropriate wavelength reaches those cells, the protein acts somewhat like a microscopic switch.
The neuron can be turned on or turned off. That sounds almost like science fiction.
But it is real science.
The surprising beginning: a tiny alga
One of the most fascinating parts of this Nobel Prize story is that it did not begin with the human brain.
It began with a single-celled alga.
Peter Hegemann and Georg Nagel studied light-sensitive proteins known as channelrhodopsins. These proteins are found in microorganisms and can respond to light by allowing ions to pass through a cell membrane.
That discovery eventually provided neuroscientists with something they desperately needed:
a biological light switch.
Karl Deisseroth then helped transform this discovery into a powerful method for controlling nerve cells with light.
The three scientists' work eventually gave birth to optogenetics as we know it today.
How does it work? Here is my simplified explanation.
First, researchers introduce a light-sensitive gene into a particular type of neuron.
That neuron then produces a light-sensitive protein.
Next, researchers deliver light to the selected cells, often using very small optical fibers in experimental animals.
When the light reaches the light-sensitive proteins, the electrical activity of those neurons can be controlled.
The remarkable part is the precision.
Instead of stimulating a large region of the brain and wondering what happened, researchers can manipulate particular populations of neurons and observe what changes.
It is somewhat like having a microscopic electrical control panel inside the brain.
Why is this important?
The human brain remains one of nature's greatest mysteries. How do we form memories?
How do we experience emotions? Why do we become frightened?
How does addiction develop? How does depression affect the brain?
How are movements controlled? How do different parts of the brain communicate?
These are enormously complicated questions.
Optogenetics gives neuroscientists a new way of asking them.
The Nobel Committee explains that the technique makes it possible to investigate how individual nerve cells contribute to memory, feelings and behavior in a living brain.
In other words, scientists are moving from simply observing the brain toward experimentally determining cause and effect.
That is a major scientific advance.
From basic science to possible medicine
Whenever I write about an important scientific discovery, I like to make one distinction.
A scientific breakthrough is not necessarily an immediate medical treatment.
Optogenetics is primarily a research technology today. It has transformed neuroscience laboratories around the world by allowing researchers to investigate neural circuits with extraordinary precision.
But researchers are also exploring possible medical applications.
One particularly interesting area is restoring vision in certain forms of retinal disease. Research groups have been investigating ways to use light-sensitive proteins to make remaining retinal cells responsive to light.
There is still much work to be done before such approaches become routine medical treatments.
That distinction is important. Science moves forward one experiment at a time.
Why this Nobel Prize interests me
At nearly 92, I have lived through an extraordinary period of scientific progress.
When I was studying chemistry at the University of the Philippines in the 1950s, computers were nothing like the machines we use today. The structure and function of the brain were still largely mysterious.
Later, during my pharmaceutical career and my years with the FDA, I saw how basic science could eventually become medicines that help patients.
Today I watch another scientific revolution taking place.
We have artificial intelligence, gene editing, mRNA technology, advanced imaging and optogenetics.
Each field is giving scientists a new way of looking at life.
And sometimes the most important discoveries come from places that initially seem unrelated.
Who would have imagined that studying a tiny light-sensitive protein in an alga could eventually help scientists understand the human brain?
That is one of the beautiful things about science.
A lesson from a Nobel Prize
The story of optogenetics reminds me that we should never underestimate basic research.
A scientist may investigate something simply because it is interesting.
At the time, nobody may know exactly where the discovery will lead.
Years later, another scientist may take that discovery and connect it with an entirely different field.
Then, perhaps decades later, the combination may change medicine.
That is essentially what happened here:
Algae → light-sensitive proteins → nerve cells → neuroscience → possible medical applications.
Three scientists followed different pieces of the puzzle, and eventually those pieces came together.
Science keeps surprising me
I have written many times in my blogs about how rapidly science and technology are changing our world.
Now I can add another word to my growing list: Optogenetics.
It is a complicated word describing a surprisingly simple idea:
Use light to control living nerve cells so that we can better understand the brain.
The 2026 Nobel Prize reminds us that we still have much to learn about ourselves.
At 91, I find that exciting rather than frightening.
I sometimes say that I am no longer afraid of growing older. What I fear is losing my ability to remain curious.
As long as I can still ask: “What is that?” and then search for the answer,
I am still learning. And perhaps that is one of the best ways to grow old.
Keep asking questions. Keep learning. Keep wondering.
FROM The Headlines
The 2026 Nobel Prize in Physiology or Medicine
Karl Deisseroth — United States
Peter Hegemann — Germany
Georg Nagel — Germany
Awarded for: “discoveries concerning light-gated ion channels and optogenetics.”
AI Impressions on this Topic:
I think this topic is very well suited to your “David at nearing 92” science series because you can explain a highly technical Nobel-winning discovery through the eyes of someone who spent his career in chemistry and pharmaceutical science, rather than writing it like a textbook.
