UWM researchers develop mathematical model to reveal brain’s neural activity

Groundbreaking research at the University of Wisconsin-Milwaukee has implications for understanding and predicting the progression of degenerative disorders of the brain, including Alzheimer’s disease, and for lessening the impact of traumatic brain injuries. The research also suggests the possibility of creating a higher-resolution brain imaging technology to replace functional magnetic resonance imaging (fMRI) for improved diagnostics of such disorders.

Research led by Ramin Pashaie, an associate professor of electrical engineering at UWM, concluded in a better understanding of the brain’s vascular network’s response to the metabolic demands — including oxygen and energy — of nearby neurons as they process sensory information.

“These two networks are tightly coupled,” Pashaie said. “In many disease conditions, including Alzheimer’s, the blood flow regulation mechanisms of the brain are dysfunctional, which leads to the progression of the disease.”

To that end, Pashaie’s team developed mathematical models that formulate how the brain’s vascular network responds to nearby neural activity. Using data from blood vessels alone — including blood flow velocity and vessel dilation — the model pulls back the curtain to reveal the distribution of activity in neurons.

The model even captures the activity within capillaries, providing a clear and detailed image of changes in these narrowest of blood vessels.

The Journal of Neural Engineering has accepted the paper detailing Pashaie’s findings. It is available on the journal’s website.

The project was supported by a 2018 Army Research Office award of $265,000. This was Pashaie’s second grant from the ARO for research on imaging the activity of neurons by monitoring blood vessels within the brain.

Pashaie’s research could shed light on lessening the impacts of traumatic brain injuries, which is of interest to the U.S. Army.

“This knowledge is very relevant to Army modernization priorities for the soldier and could ultimately guide soldier performance initiatives to optimize brain health, in addition to offering new insights that might help to combat the impacts of traumatic brain injuries,” said Frederick Gregory, manager of ARO’s Neurobiology Cognition Program, an element of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. “These mathematical models could allow for a greater understanding of non-neuronal influences on the biophysics of computation in the brain.”

In the first phase of this project, the UWM research team developed a complex brain interface system that can communicate with brain cells and monitor their activity by using light and micro-fabricated transparent electrodes that are implanted on the brain tissue. By using such technologically advanced tools, the team collected a large amount of data from the brains of small rodents.

The team then used the data to develop the mathematical models used to estimate the level and spatial distribution of neural activity. These models are poised to be the springboard of new brain functional imaging technology that offers microscopic resolution of vascular activity, deformities and changes, Pashaie said.

The team now hopes to test these models as diagnostic tools to predict the stage and progression of degenerative diseases like Alzheimer’s when the connection between neural activity and the vascular network is disrupted.