Mapping your brain's circuitry | ECE | Virginia Tech


Mapping your brain's circuitry

Rosalyn Moran in front of whiteboard with equations

Rosalyn Moran

Rosalyn Moran is applying ECE imaging and modeling expertise to map the electrical activity in the brain. She tackles issues from understanding how we learn to how our brains age, and how parts of the brain interact when facing degenerative diseases like Parkinson's or Alzheimer's.

"The brain is the most fascinating electrical device," says Moran, who joined ECE this past fall as an assistant professor posted at the Virginia Tech Carilion Research Institute (VTCRI).

Nerve cells in the brain are not continuous, but pass signals through their network via synapses, which use electrical signals to boost chemicals that jump the gap between nerve endings. The electrical and chemical activity represents thebrain's function, whether it is conscious thought or the basic process of keeping the heart pumping.

Biology meets electrical engineering

Moran has been in on the ground floor of brain imaging and mapping for understanding this electro-chemical activity. She came to Virginia Tech after spending six years as a member of the group in London, U.K. that is the "standard bearer for how to understand brain imaging," she says. She worked with Karl Friston and Ray Dolan at the Wellcome Trust Centre for Neuroimaging, Institute of Neurology, at the University College London. The group produced the seminal work on dynamic causal modeling (DCM), which is the most commonly used methodology for developing models of the functioning brain.

Moran first went to the London group as a visiting graduate student from University College, Dublin. "We had a molecular measure of glutamate in schizophrenic-type rodents," she says. "The schizophrenic rats had lower glutamate levels and different electrical signatures in the brain than normal rodents. We wanted to understand this, so I went to Friston's group at the human neuroimaging institute to see if we could unravel this electrical and chemical overlap." Glutamate is the cortex's most prominent neurotransmitter.

After earning her Ph.D., Moran joined the group at University College London as a postdoctoral fellow then a seniorresearch associate. "My last two years of post-doc work involved the human brain and the chemicals involved in high-level functioning, including dopamine and acetylcholine."

A "mathematical microscope"

She continues to work on neuroimaging methodologies at Virginia Tech, developing what she calls a mathematicalmicroscope to tease the chemical and synapse-level data from macro-level imaging, such as fMRI, EEG, and magnetoencephalography."Our approach holds promise for better understanding the active neurochemistry of brain networks that support cognition and behavior,"she says.

Brain image

Moran was part of the team that developed the modeling methodology for interpreting neuroimaging results.

She is also working with different teams at Virginia Tech to understand the brain changes caused by Parkinson's and Alzheimer's Diseases. "Here at VTCRI, researchers are interested in a range of different behavioural phenotypes as well as disease, so there's a wealth of information to borrow from when building hypotheses on aging brains and developing interesting paradigms to test them" she explains. "DCM will help show us any directionality changes in aging brain connectivity, which is crucial for pinning our empirical observations to more formal ideas on how the brain may operate as an inference machine" She is also looking forward to collaborating with teams conducting a large scale lifespan study of the people of Roanoke, known as the Roanoke Brain Study.

On another project, she is working with ECE's Yue ( Joseph) Wang from the Virginia Tech Research CenterArlington. They plan to investigate the many circuit mechanisms thought to be disrupted by Alzheimer's. Via brain imaging studies using DCM they want to identify which of the disruptions are most critical in supporting cognitive function. "Abnormal signal propagation may depend on whether these processes affect cells that inhibit or excite neurons," Moran says.

Understanding the brain's aging process

Moran hopes that studying Alzheimer's and Parkinson's can lead to a better quality of life for those afflicted. But she's also interested in answering some broader questions about our brains, such as where do experience or wisdom reside in the brain Is the aging brain really moving toward an optimal state

"We use Bayesian inference in our analysis and in understanding how the brain itself actually computes data and perceives its environment," she says. "I'd like to apply this Bayesian inference to look at how the brain ages. If the brain is an inference machine, how does life experience alter your biology We have the tools at our disposal to figure this out."

Neuroscientists have learned that as the brain ages, it loses synapses in certain areas and is less likely to maintain new ones. The pruning model of the brain suggests that the brain has the capacity to become efficient and process what's at the core of our everyday experience, according to Moran. "This concept suggests that as you age, you can generalize well and you are a better contextualizer. You are better adept at coping with abnormalities," she explains. This has yet to be shown using neuroimaging and is just a theory, she acknowledges. "We don't know the extent to which it's adaptive or if there's evidence for the idea yet."

Moran would also like to understand — or even refute — the idea that after a certain age, the brain is in decline. "The mantra of theories on aging neurobiology give the sense that stuff declines; that there is a cliff at 30," She says. "Maybe something gets better, not worse. Maybe we are aging toward our optimum brain."

There are challenges to being in ECE and working in neurobiology, according to Moran. "You learn to appreciate the diversity of knowledge and that there are things that really require appreciation and serious study like the psychology of human cognition," she says. "You have to train your mind to think of cognitive problems instead of wiring problemsIt's a commitment."

If you want to "get into a messy system and help develop the science around it," why not go into neuroscience she asks.

Spotlight on New Faculty Members

Rosalyn Moran earned a BE (electronics) in 2004 and a Ph.D. in 2007 from University College Dublin in Dublin, Ireland. She served as a postdoctoral research fellow, then a senior research fellow at the Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, UK.