The neuroscientist who transformed our understanding of the brain while fighting for diversity in science
A few years after Ben Barres became a tenured professor at Stanford, he overheard a colleague praising his work in a telling comparison: "Ben Barres gave a great seminar today, but then his work is much better than his sister's."1 The irony was profound—Barres had no sister in neuroscience. The previous work his colleague referenced had been produced by Barres himself, back when he was living as Barbara before his transition. This unintentional side-by-side comparison of the same scientist's work, evaluated differently based on perceived gender, provided Barres with unique insight into the biases that permeate academic science—and fueled his determination to correct them1 .
Revolutionized our understanding of glial cells, transforming them from "brain glue" to active participants in brain function.
Became a powerful voice for gender equality in science, using evidence and personal experience to fight discrimination.
"I can even complete a whole sentence without being interrupted by a man," he often remarked after transitioning1 .
For more than a century, neurons received nearly all the scientific attention in neuroscience research. These electrically active cells were considered the stars of the brain—the processors, communicators, and information-storers. Meanwhile, glial cells (from the Greek word for "glue") were dismissed as mere packing material, passive support cells that did little more than hold neurons together and provide them with nutrients2 .
When Barres first began studying them in the 1980s, this prevailing view marginalized glia as "not much more than packing peanuts"2 . They outnumber neurons in the human brain by nearly four to one, making up about 90 percent of our brain cells, yet were largely ignored in favor of their more famous counterparts2 .
"What are these cells doing normally and what is their role in disease?" Barres once asked in an interview. "At the time, there were no answers."
of human brain cells are glial cells, yet they were largely ignored before Barres's work2 .
Barres made many discoveries about glial cells, but perhaps his most groundbreaking revelation came from a deceptively simple question: what happens when neurons grow completely alone?
Barres and his team developed innovative methods to separate and purify specific brain cell types, allowing them to study each type in isolation. This was a crucial technical breakthrough—previous studies that mixed cell types made it impossible to determine which cells were responsible for which functions2 .
Researchers isolated retinal ganglion neurons (a type of nerve cell) and provided them with everything scientists thought they needed to survive and thrive. The neurons grew and appeared healthy in every way—except for one critical deficiency.
The team then added astrocytes (the most common type of glial cell) to the mix. The results were astonishing2 .
Barres's ability to purify and study individual brain cell types was key to his discoveries about glial function.
The neurons grown alone, despite their healthy appearance, failed to form synapses—the essential connections that allow nerve cells to communicate with each other. When astrocytes were introduced, however, the neurons suddenly began forming synapses normally.
This demonstrated that synapse formation isn't an intrinsic property of neurons alone, as had been believed for decades. Instead, astrocytes actively instruct neurons where and when to form synapses, playing an indispensable role in building the brain's communication network2 .
| Experimental Condition | Neuron Survival | Synapse Formation | Key Insight |
|---|---|---|---|
| Neurons alone | Good | Poor | Neurons cannot form synapses alone |
| Neurons + astrocytes | Good | Excellent | Astrocytes provide critical signals for synapse formation |
"If we can find a way to rebuild the connections between neurons that are falling apart in these diseases, we might be able to halt the progression of the disease, or even reverse it."
Barres's groundbreaking discoveries were made possible by his development of novel research methods that allowed unprecedented precision in studying brain cells.
| Tool/Method | Function/Application | Significance |
|---|---|---|
| Immunopanning | Used antibodies to purify specific brain cell types | Enabled study of pure cell populations without cross-contamination |
| Patch clamping | Measured ion channel activity in glial cells | Revealed glial cells have diverse ion channels, challenging their passive reputation |
| Cell culture systems | Grew specific brain cells in isolation | Allowed determination of each cell type's specific contributions to brain function |
| Transcriptome analysis | Identified all RNA molecules in specific brain cells | Created "molecular fingerprint" databases for different cell types, shared freely with other researchers |
In 1997, at age 42, Barres transitioned from female to male1 8 . The differences in how he was treated before and after his transition were both striking and revealing. "I can even complete a whole sentence without being interrupted by a man," he often remarked after transitioning1 .
These personal experiences gave him unique insight into the subtle and not-so-subtle forms of discrimination that women face in science. He recalled instances from his time as Barbara: a math professor suggesting his boyfriend must have solved a difficult problem that stumped male classmates; being told he was the most qualified applicant for a fellowship that ultimately went to a man; having difficulty finding a research lab at MIT that would accept a female student1 5 .
Barres's experience provided direct evidence of gender bias in science evaluation.
Barres's advocacy work crystallized in response to two events: Harvard President Larry Summers' 2005 suggestion that "innate differences" might explain why fewer women succeed in science, and the announcement of NIH award winners—all nine were men1 .
Barres responded with a powerful, evidence-based rebuttal in the prestigious journal Nature, titled "Does gender matter?"5 In it, he combined his personal experiences with scientific studies to systematically dismantle arguments about innate gender differences in scientific ability4 6 .
"There are no innate gender differences that would have any meaningful effect on women's ability to do science," Barres stated firmly. "There is, however, a wealth of scientific evidence demonstrating that gender discrimination exists in science and negatively affects women."
Unlike many scientists who shy away from controversy, Barres repeatedly brought discussions of diversity into his scientific lectures, often stopping midway through research presentations to dedicate 5-10 minutes to issues of gender equality and bias in science6 . This was "so outside the norm that it sticks with me to this day," recalled Andrew Giessel, then a biologist at Moderna Therapeutics1 .
Ben Barres was diagnosed with pancreatic cancer in 2016 and died on December 27, 2017, at age 632 . Yet his impact continues to reverberate through both neuroscience and efforts to make science more inclusive.
"I lived life on my terms: I wanted to switch genders and I did. I wanted to be a scientist and I was. I wanted to study glia and I did that too. I stood up for what I believed in and I like to think I made an impact, or at least opened the door for the impact to occur. I have zero regrets and I'm ready to die. I've truly had a great life."4
| Year | Achievement | Significance |
|---|---|---|
| 1993 | Joined Stanford Faculty | Began pioneering research on glial cells |
| 1997 | Transitioned from female to male | Became openly transgender scientist |
| 2005 | Published key paper on astrocytes and synapse formation | Revolutionized understanding of brain development |
| 2006 | Wrote "Does gender matter?" in Nature | Became leading voice against gender discrimination in science |
| 2013 | Elected to National Academy of Sciences | First openly transgender member in NAS history |
| 2017 | Published final paper on reactive astrocytes | Identified potential mechanism for neurodegenerative diseases |
The Barres Lab became a pipeline for future leaders in neuroscience, training generations of scientists who now run their own labs across the world2 6 . These former trainees describe Barres as an exceptionally supportive mentor who treated them as equals and championed their careers1 6 .
"His impact on our understanding of glia was rivaled by his impact on diversity in science... you leave a towering legacy of goodness."1
Through his scientific courage and personal integrity, Ben Barres fundamentally transformed our understanding of the brain while simultaneously making the scientific world more welcoming for all who seek to understand it.