‘Sacred objects’ display discredits Golgi and Ramón y Cajal’s rivalry: Q&A with curator Daniel Colón Ramos

NEW HAVEN, CONNECTICUT—The dimly lit room at the Yale Peabody Museum looks almost like the interior of a chapel. The ceiling lights cast a golden glow over dozens of intricate illustrations of neurons, axons and dendrites that adorn the walls—the work of renowned neuroscientists Santiago Ramón y Cajal and Camillo Golgi, displayed side by side for the first time.

The pair shared the 1906 Nobel Prize in Physiology or Medicine for their work documenting the anatomy of the nervous system. They independently used similar tools to observe the same structures in nervous tissue, and their drawings, many of them in unassuming black ink or pencil on white paper, can be mistaken for each other’s. Yet they arrived at opposite conclusions about the cells that the brain comprises: Whereas Golgi proposed that the brain is a continuous network of neurons, Ramón y Cajal insisted that the brain is composed of individual, discrete cells.

As a result, the two scientists have often been portrayed as rivals. But their disagreement makes them partners, not intellectual enemies, says Daniel Colón Ramos, professor of neuroscience and cell biology at Yale University. “In the arc of history, we like to simplify things—it’s simpler to tell a story of antagonism between Golgi and Cajal,” Colón Ramos says. “But in reality, you take Golgi out of history, there’s no Cajal, and you take a Cajal out of history, and there’s no Golgi. They were collaborators.”

Colón Ramos makes his case in “Mind/Matter: The Neuroscience of Perception, Attention and Memory,” an exhibit of drawings from Ramón y Cajal and Golgi he curated at the Yale Peabody Museum in collaboration with the Wu Tsai Institute of Yale University. “Butterflies of the Soul,” a section named after Ramón y Cajal’s metaphor for neurons, also showcases letters between the two researchers, in which they share findings and a drive to find common ground.

The exhibit also examines how the brain’s building blocks first revealed by Ramón y Cajal and Golgi give rise to complex capabilities, including perception, attention and memory—and how those capabilities can shift in the face of optical illusions or neurological conditions, or from one species to another.

To plan the exhibit, which opened 7 December, Colón Ramos harnessed his collaborations with neuroscientists at Yale and museum curators across the world. He even flew to Spain to learn about Ramón y Cajal’s works and how they were exhibited. The near-religious atmosphere in the room is not only to protect the drawings from the light, he says. “They are sacred objects to the field.”

The Transmitter talked with Colón Ramos about the inspiration for the exhibit and what he hopes neuroscientists will take from it.

This interview has been edited for length and clarity.

The Transmitter: Why did you want to pair drawings from Ramón y Cajal and Golgi?

Daniel Colón Ramos: I had the idea when talking to an Italian colleague here at Yale who’s also neuroscientist, Pietro De Camilli, that it would be wonderful to bring work from both Cajal and Golgi side by side. There’s a really interesting topic there—not only in terms of the history of how these discoveries were made, but also how the two researchers perceived the same data. They’re using their brains to interpret data about the brain, but their brains are also vulnerable and limited, as are all of ours. It is very clear that the prevailing view at the time—their biases and priors that shaped how they thought about things—was the notion of the brain as a network that is not separated into individual cells. We wanted to discuss both the process of discovery and also how priors affect our perception.

TT: Throughout the exhibit there are examples of how animals perceive the world. Why did you decide to include that?

DCR: My lab works on the cell biology of the synapses of Caenorhabditis elegans and how the cell biology changes as the animal is navigating the world. It got me thinking about what that perceptive space might look like for other organisms. I felt that I needed to think more deeply about how to translate that perceptual space into a perception that I, as a human, could understand. For example, to show snake vision, we present a red image. But the dragonfly, for example, has 10-fold more photoreceptors than we do, so they can see many other colors that we cannot see. How do you represent that? It’s easy to say, “The human brain is the most fascinating, complex organ in the universe.” And that might lead to anthropocentric views about how unique the human brain is. But a honeybee brain is also unique, and so is a bat brain.

One of the other things that I became interested in thinking about is if for a—relatively speaking—simpler organism such as C. elegans, in which we can kind of map the perceptive space onto the neuronal encoding, could we come up with a useful representation of the umwelt in a way that might help us predict how illusions might look for the animal? We wanted to try to understand that interface between the processes of perception and sensory processing.

TT: What would you like neuroscientists to take away from this exhibit?

DCR: The exhibit builds to a reflection about the limits of perception. While our senses are capturing physical information of the world, the brain is putting that together into a perceptive reality that is an interpretation of that physical information. Most of that time the brain is making assumptions, and sometimes those assumptions are wrong.

And in the story of Cajal and Golgi, it’s only in putting their findings together that science was able to make the massive leap that it needed to make into cellular neuroscience, which is what has really been the foundation of modern neuroscience. There’s a lesson there about how these big discoveries happen that is worth reflecting on—especially at a time in which neuroscience is at a crux of trying to link cognitive, systems and molecular neurosciences. Sometimes those discussions are more about which of these approaches is better, rather than about how these are different fields that we need to start integrating, because in reality they are different abstractions of the same thing.

It was [Charles Scott] Sherrington, who was a physiologist, and that whole school of physiology that led to a huge support of Cajal’s neuron doctrine, because you could not understand the physiological principles of the brain unless you understood that the brain was actually composed of cells. Physiology was abstracting away neuronal signals; it wasn’t thinking about cells. But by linking those two approaches, you could start gleaning the existence of cells and then later quanta and synaptic vesicles. It’s in the merging of those concepts that truths emerge. And if you separate those fields, then you just cannot get to the answer.