Q&A with Xin Duan, Professor, Department of Ophthalmology, UCSF
Dr. Xin Duan’s lab is mapping one of biology’s most complex and least understood systems: how the eye communicates with the brain. Through pioneering tools and cross-disciplinary collaboration, his team is revealing how visual information travels and how those pathways might one day be repaired to restore sight. He recently received grant funding from Research to Prevent Blindness to support some of this work
Q: What questions are your lab focused on right now?
We have two major research directions.
The first is understanding how neurons in the eye respond to injury, including glaucoma, diabetic retinopathy or ischemia. We study how those retinal neurons react at the molecular and circuit levels, and we develop tools that other scientists can use to explore those processes in both mice and humans.
The second direction looks at how eye neurons communicate with brain neurons over long distances. This is still early, basic science, but it’s laying the foundation for understanding how visual information is encoded and transmitted to the brain.
Q: What kinds of tools are you developing to make this work possible?
Our lab builds and integrates four main categories of tools:
1. Genetic and viral tools to label and manipulate specific neurons in the eye or brain.
2. Electrophysiology, using sharp electrodes to record neural activity.
3. Imaging technologies that allow us to visualize many neurons simultaneously.
4. Connectivity mapping tools, which trace the precise neural links between the retina and the brain.
Recently, a former MD-PhD student in my lab created a genetically tractable tracer that lights up connected neurons in different colors, letting us see, for the first time, exactly which retinal neurons talk to which brain neurons. We’ve since combined that work with machine learning, so we can now map thousands of these connections at once. It’s giving us a panoramic wiring diagram from the eye to the brain.
Q: What could this mean for the future of vision restoration?
If we know precisely how each retinal neuron connects to its partner in the brain, we can start to think about repairing or even recreating those connections.
That could open the door to next-generation prosthetics or brain-machine interfaces that bypass damaged parts of the eye and deliver visual information directly to the brain. For example, if someone loses the ability to detect motion, we could stimulate the exact brain regions responsible for motion perception.
It’s still early. We’re working primarily in mice, but the goal is to bring back the first electrical signals between the eye and brain. Achieving that would be a major milestone for restoring vision.
Q: You collaborate widely across UCSF and beyond. Why is that integration so important?
For a long time, ophthalmology and neuroscience were somewhat separate. But advances in imaging, materials science, and AI have made it possible to bridge those worlds.
Here at UCSF, we’re surrounded by experts in neurology, physiology, and anatomy who understand the brain from different angles. We’re also close to engineering and biotech innovators at Berkeley, Stanford, and in the Bay Area. That environment, in addition to support from agencies like the NEI and Glaucoma Research Foundation, make it possible to pursue truly cross-disciplinary science.
Ultimately, repairing vision isn’t just an eye problem or a brain problem. It’s both.
Q: What do you hope this research will achieve in 10 years?
I’m hoping we can repair electrical pathways from the eye to the brain, using a combination of molecular, cellular, and imaging tools.
That’s the dream: to reestablish communication between the eye and brain in a living system, whether in non-human primates or human patients. We have the tools and the collaborations to make it possible. Now it’s a matter of time and persistence.
Image caption: “Neurons discovered in the Duan lab with unique neuroprotective functions in the eyes and regenerative abilities back to the brain (Image Credit: Matthew Lum)”