4 minute read
A Q&A with Moran’s Pioneering Neuroscientists
Surprisingly little is known about the brain and its disorders. John A. Moran Eye Center researchers Alessandra Angelucci, MD, PhD, and Behrad Noudoost, MD, PhD, are studying visual neurons to change that. Here they discuss their pioneering vision research, funded in part by the National Institutes of Health Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative.
What are the main questions your research is trying to answer?
Angelucci: Specialized nerve cells called neurons carry messages in the brain. Neurons work together in teams, creating circuits that help us process certain kinds of information; for example, one circuit allows us to recognize individual faces. My lab studies these circuits, especially in the visual cortex region of the brain responsible for producing vision.
The visual cortex works a bit like building blocks. It builds visual information, bit by bit, starting in the lower centers with the recognition of simple features of objects, such as their contour, color, and shape, and ending in higher centers with the recognition of complex object features and whole objects such as faces. Our goal is to learn not only how individual areas of the brain communicate aspects of vision, such as shape and color, but also how it merges that information into a single scene. We believe this information merge helps us literally distinguish the forest from the trees.
Noudoost: My lab focuses on understanding selective attention and working memory. How does the brain focus attention on one particular aspect of a visual scene?
We record and study communication between individual neurons to better understand communication between different areas of the brain responsible for processing aspects of a visual scene, such as color, motion, and shape. We also work to identify what can affect communication between neurons. For example, we have shown dopamine levels impact the brain’s attentional capacity or how much information it can process at once.
What is most innovative about your research?
Angelucci: I always want to find the most useful technology to answer the questions I want to ask. If that technology doesn’t exist in my lab, we develop it. Over the past 10 years, we’ve developed a new technology that allows us to fill neurons with a fluorescent protein and reveal the shape and roadmap of a brain circuit. This is enabling us to build a diagram of the brain by specific cell types.
Our focus on what scientists call feedback — the exchange of information from higher to lower centers in the brain— also makes our lab unique.
Noudoost: Since the brain has about 10 billion neurons and more than trillions of connections, identifying these communicating neurons can feel a little like trying to find a needle in a haystack. Fortunately, recent technological developments have given us the ability to identify which neurons are active and to study what and when they are communicating.
Our methods allow us to trace connectivity between neurons with a remarkable level of precision and to characterize their response and function to different stimuli. This allows our lab to understand the sequence of events that happen in the brain when someone pays attention to something they see.
How do you hope your research will help patients?
Angelucci: If we know how these circuits process vision, we’ll also find clues about what may be happening when someone can’t see.
In collaboration with Dr. Steve Blair in Electrical and Computer Engineering, we are building on the work of University of Utah Professor Richard A. Normann, PhD, to develop the next generation of a visual prosthesis for people who have gone blind. The prosthesis stimulates neurons using light to create a form of artificial vision.
Noudoost: The brain is constantly selecting which aspect of information to focus on, but in disorders such as ADHD, autism, Parkinson’s disease, and schizophrenia, it is unable to prioritize what is important. Knowing what usually occurs, we can shed light on what may not be happening for these patients. We hope our work is ultimately useful in finding future treatments for disorders related to attention impairment.
