Recently, I sat down with Dr. Duygu Kuzum at Joe's coffee near the Penn campus to chat research, computers, and the brain. Duygu is a post-doc working in Dr. Brian Litt's lab developing new technology to understand the circuitry of the brain. This summer, she was named one of the 35 Innovators Under 35 by MIT Technology Review (see the full list of innovators here). Her latest work was published in Nature Communications just yesterday! (Check it out here.)
Duygu grew up and attended college in Ankara, Turkey and moved to the United States to pursue her PhD at Stanford. Although she now lives far from home, she tells me that her father has always been one of her biggest supporters.
“In our family, my father was a policeman. He had a college degree, but this was after he became a policeman. He didn't have chances when he was much younger. But he always encouraged me a lot, especially to get my PhD. And he has a cousin who also went to Stanford for a PhD. He was so impressed by her. They were good friends too and always kept in touch. So that was another inspiration and [my father] encouraged me to be like her.”
“Some people, they don't want their children to go out of Turkey. It kind of feels dangerous [to them].” Duygu's father always encouraged her to take advantage of every opportunity, whether it was going to the Intel Science Fair while in high school, college internships in California and Germany, or doing her PhD at Stanford.
The first time Duygu came to the US was for the Intel International Science & Engineering Fair while she was in high school. “I came to Detroit in 2000 for the science fair, and it was amazing. In Turkey, science fairs are very small-scale. There aren't many high schools that are interested. And here it was huge— lots of interesting projects from all over the world, not just the US. I was amazed. It was at that time that I first thought, 'Maybe I should come to the US after college.'”
Intel, electronics, and nanofab
At first, she was impressed by companies like Intel and IBM and thus focused her research on semiconductor electronics and nanofabrication. “During my PhD I developed some nanoscale devices that would basically enhance the performance of computer processors. So that's the type of thing Intel does. [In research] we were targeting two generations ahead [of the commercially available model].”
Towards the end of her PhD, Duygu had the opportunity to do an internship at Intel. “It was great— it was very focused research. But too focused. It was very product-development oriented.” As a PhD student, Duygu had grown accustomed to being very creative and having flexibility in her projects. At Intel, the development specifications were quite stringent. For example, she could only use silicon in her designs, even when she knew more experimental materials might be a better solution.
Although she enjoyed her experience at Intel, it helped her realize that she felt most at home in the research world. “I really enjoy learning new things beyond what I already know. And trying to enhance the same product 5% or 10% felt a little boring after that summer,” she says, laughing.
“It helped me make the right decision.”
Building a brain-inspired computer
At that time, a large DARPA project was beginning at Stanford, in collaboration with other universities and IBM, called Synapse (more info here and here). The goal of the project was to build a 'brain-like' computer. “So we needed to first build neurons and synapses. And instead of using conventional circuits to make these, maybe we can make single devices like a neuron or synapse: a single resistor or capacitor-like device that works like a synapse.”
“I found it very interesting because it combined my interests with my background. So I jumped into it.” After finishing her PhD, Duygu worked on the Synapse project for a year as a post-doc at Stanford with H.S. Philip Wong. Her focus was the development of synapse-like nanodevices. One of the most challenging aspects was making the device energy-efficient. The goal was to consume only as much energy as a naturally occurring synapse. (Learn more about these concepts here.)
In addition to these challenging requirements, the team also wanted the synapse-like devices to be plastic. Currently available hardware (i.e. the board in your computer) is static, meaning that it does not change based on the system requirements. “You want it to learn. It shouldn't just be pre-programmed like your [current] computer. It should basically acquire data, process it, and learn. [The computer] should change its connectivity over time— that's what the brain does.”
The project is ongoing, particularly at IBM. (Check out the latest paper in Science here.) At this point, the system is being utilized for very specific applications, including pattern recognition in real time using complex scenes.
New technology to understand the brain
“There isn't a single technique, at this point, for studying the brain that [captures] microscale features and can be expanded to macroscale. Beyond not knowing how the brain works, we don't really have a tool to study it [properly].” Duygu decided that she wanted to develop a technique that allows scientists to do both. Currently, her goal is to combine high resolution imaging techniques with high resolution measurements of neuronal activity.
Duygu joined the Litt Lab in 2011 to develop a new type of electrode that is made out of graphene. These graphene electrodes are special because they can be used while using various imaging modalities. Currently, neuroscientists use many different modalities to learn about brain structure and function, “But all of them have different limitations.” For example, inserting currently available electrodes in the brain are not stable over time— leaving an electrode in the brain to perform recordings over several time points can leave the brain permanently injured. Additionally, there is a spatial limitation— from where, specifically, is the electrode recording?
She was inspired to use the graphene material when she ran across it in journal articles as a potential material for circuitry. In addition to being conductive (pretty essential for an electrode!) the material is also a monolayer and transparent. This means that thin, low-noise electrodes can be placed on the brain and will not block images from being acquired in parallel. “You can image a population of neurons and at the same time record [neural activity] from them.”
Currently, the project is in the in vivo phase. Duygu has collaborated with other labs on campus to examine how well recordings can be achieved in a rat. Next, she hopes to explore use of the electrode paired with several imaging modalities. Eventually, the goal is to use the technology for clinical and human research applications. One of the greatest strengths of the graphene is that it does not interact with brain tissue in the same way that current electrodes do. “[Brain tissue] reacts with the metal electrode...the neurons migrate away from the electrode and the astrocytes migrate in.” In addition, metal electrodes tend to corrode due to interactions with the extracellular fluids. Graphene, on the other hand, acts like a seal and blocks diffusion. It is extremely biocompatible. Yesterday, the first full-length paper on the electrodes was published in Nature Communications and covered by Penn Medicine news!
In the long term, Duygu says she wants to, “Find problems to solve using this technology. The primary problem [to solve] would be small scale circuits, such as the hippocampus. To understand all of the temporal dynamics. What are the mechanisms for [burst generation in the hippocampus]? How are these generated? Is there a biomarker for the generation of epileptic seizures? Can we detect it?”
“It's good to keep your boundaries very broad so that you learn about different things. If you only look at a specific field, there is not much you can do.”
“I think talking to people is great if they have time for you. A lot of the time people don't have time...” she says laughing. “Senior people, post-docs, different labs, lunch discussions are really helpful. You can find new collaborations and come up with new things. It's mostly interactions with people and reading. When you first come up with an idea, you must figure out if its been done. [And] does it make sense?
She also says that Gyorgy Buzsaki's book Rhythms of the Brain is a book she turns to for inspiration. “It's not a standard neuroscience textbook. It's very easy to understand and it's very broad. I enjoy it a lot, so it's a big inspiration.”
Overall, it seems like Duygu's main inspiration for innovation is the people whom her work would benefit. “As I became older, I decided that maybe I should focus on a big problem that affects humanity, lots of people. [Through this], I will feel as though I am helping others. This is my main motivation.”