Scientists have gained new insights into the part of the brain that gives us a sense of direction by tracking neural activity using the latest advances in brain imaging techniques. The findings shed light on how the brain orients itself in changing environments – and even on the processes that can go wrong in degenerative diseases like dementia, leaving people lost and confused.
“Neuroscience research has seen a technological revolution in the last decade that has allowed us to ask and answer questions that were only dreamed of just a few years ago,” said Mark Brandon, associate professor of psychiatry at McGill University and researcher at the Douglas Research Centre. who conducted the research with Zaki Ajabi, a former student at McGill University and now a postdoctoral researcher at Harvard University.
Reading the brain’s internal compass
To understand how visual information affects the brain’s internal compass, the researchers exposed mice to a disorienting virtual world while recording the brain’s neural activity. The team recorded the brain’s internal compass with unprecedented precision using the latest advances in neural recording technology.
This ability to accurately decode the internal direction of an animal’s head allowed the researchers to investigate how Head-Direction cells, which form the brain’s internal compass, support the brain’s ability to reorient itself in a changing environment. Specifically, the research team identified a phenomenon they called “network gain” that allowed the brain’s internal compass to reorient after the mice were disoriented. “It’s as if the brain has a mechanism to implement a ‘reset button’ to quickly reorient its internal compass in confusing situations,” says Ajabi.
Although the animals in this study were exposed to unnatural visual experiences, the authors argue that such scenarios are already relevant to modern human experience, especially with the rapid spread of virtual reality technology. These findings “may ultimately explain how virtual reality systems can easily take control of our sense of direction,” Ajabi added.
The results inspired the research team to develop new models to better understand the underlying mechanisms. “This work is a beautiful example of how experimental and computational approaches can work together to advance our understanding of the brain activity that drives behavior,” said co-author Xue-Xin Wei, a computational neuroscientist and assistant professor at the University of Texas at Austin.
Degenerative disease
The findings also have significant implications for Alzheimer’s disease. “One of the first self-reported cognitive symptoms of Alzheimer’s disease is that people become disoriented and lost, even in familiar environments,” Brandon said.
Scientists expect that a better understanding of how the brain’s internal compass and navigation system works will lead to earlier detection and better treatment of Alzheimer’s disease.
