Through high-tech imaging and virtual reality, a University of South Florida medical engineering professor is creating a detailed map of the brain that can be used to better understand developmental disorders such as autism and provide earlier, more effective treatments for brain injuries and diseases.
Funded by a $3.3 million grant from the National Institutes of Health, George Spyrou is expanding his four decades of brain research to focus on the part of the brain that processes sound, called the calyx of Held—the largest nerve terminal in the human brain. . Hearing impairment is often the source of symptoms in disorders such as autism, which usually result in social and cognitive impairment.
Although we are focusing on a specific part of the brain involved in hearing, the information we gather can help us understand serious developmental disorders that occur when the brain does not develop properly early on. Our findings could also pave the way for innovative strategies to repair and rewire damaged neural circuits affected by disease and injury later in life.”
George Spyrou, Professor of Medical Engineering, University of South Florida
Using high-resolution imaging technology combined with image analysis in the Auditory Development and Connectomics Lab at USF, Spyrou is creating the most accurate timeline of development for any neural system in the brain. They are able to chart the journey of neurons in mice from birth to the formation of complex synaptic connections. According to the NIH, mouse and human brains have very similar neuron types and connections.
With software created by Spyrou and his colleagues, he and his doctoral student, Daniel Heller, use virtual reality to intricately examine the neurons recorded in the images and analyze the synapses through an immersive experience. While developing neural systems have been studied, Spyrou said no to this combined level of temporal and spatial resolution.
“Between the fourth and fifth months of gestation, the number of neurons in the nervous system explodes almost exponentially, and synapses are formed at a rate of about one million per second during this time, which is an incredible number when you consider that there are nearly 100 trillions of synapses in an adult human brain,” he said. “I like to think of it as there are about 100 billion stars in our galaxy, and there are about that many neurons in the brain.”
Heller has worked alongside Spyros for several years, even following him from West Virginia University to USF in 2019 to continue learning Spyros’ interdisciplinary and collaborative approach to research. Now nearing graduation, Heller’s dissertation focuses heavily on this project.
“At the cellular level, the physical manifestations of these disorders are caused by developmental defects in brain connectivity,” Heller said. “From a clinical perspective, research to treat these disorders is difficult without a better understanding of how the brain develops under normal conditions and results in treating symptoms rather than aiming for a global cure.”
Over the next five years, their goal is to pinpoint what signals drive the precise formation of this particular nervous system—a missing detail that, once understood, would reveal how formation works in other neuronal circuits. In the event of an injury to a mature brain, this information would be useful to help reorganize and possibly rewire neurons to aid in the patient’s recovery through surgery and other treatment options.
“I’m completely fascinated by what happens at this stage of development in the brain and how the brain directs its own formation – that for me is enough to get me up in the morning and come do our work,” Spyrou said.
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