Scientists have gained new insights into the part of the brain that gives us a sense of direction, by tracking neural activity with the latest advances in brain imaging technologies. The findings shed light on how the brain orients itself in changing environments — and even processes that can go wrong with degenerative diseases such as dementia, that leave people feeling lost and disoriented.
“Neuroscience research has undergone a technological revolution in the past decade allowing us to ask and answer questions that we could only have dreamed of just a few years ago,” says Mark Brandon, associate professor of psychiatry at McGill University and researcher at the Douglas Research Center. who co-led the research with Zaki Ajabi, a former student at McGill University and now a postdoctoral research fellow at Harvard University.
Read the brain’s inner compass
To understand how visual information affects the brain’s internal compass, the researchers exposed mice to a disruptive virtual world while recording the brain’s neural activity. The team recorded the brain’s internal compass with unprecedented accuracy using the latest advances in neuronal recording technology.
This ability to decipher the animal’s internal head orientation allowed the researchers to explore how head orientation cells, which make up the brain’s internal compass, support the brain’s ability to reorient itself in changing surroundings. Specifically, the research team identified a phenomenon they called “network acquisition” that allowed the brain’s internal compass to reorient after the mice had been disoriented. “It’s as if the brain has a mechanism to implement a ‘reset button’ that allows the internal compass to be quickly reorientated in confusing situations,” Ajabi says.
Although the animals in this study were subjected to unnatural visual experiences, the authors argue that such scenarios are indeed associated with the modern human experience, especially with the rapid spread of virtual reality technology. Ajebi adds that these findings “may eventually explain how virtual reality systems can so easily control our sense of orientation.”
The findings 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 together can advance our understanding of the brain activity that drives behavior,” says co-author Xue-Xin Wei, a computational neuroscientist and assistant professor at the University of Texas at Austin.
The findings also have major implications for Alzheimer’s disease. “One of the first self-cognitive symptoms of Alzheimer’s disease is that people become disoriented and lost, even in familiar settings,” says Brandon. The researchers expect that a better understanding of how the brain’s internal compass and navigation system works will lead to earlier detection and better evaluation of treatments for Alzheimer’s disease.