How the brain's 'internal compass' works
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 techniques. The findings shed light on how the brain orients itself in changing environments 鈥� and even the processes that can go wrong with degenerative diseases like dementia, that leave people feeling lost and confused.
鈥淣euroscience research has witnessed a technology revolution in the last decade allowing us to ask and answer questions that could only be dreamed of just years ago,鈥� says Mark Brandon, an Associate Professor of psychiatry at 平特五不中 and researcher at the Douglas Research Centre, who co-led the research with Zaki Ajabi, a former student at 平特五不中 and now a postdoctoral research fellow at Harvard University.
Reading the brain's internal compass
To understand how visual information impacts the brain鈥檚 internal compass, the researchers exposed mice to a disorienting virtual world while recording the brain's neural activity. The team recorded the brain鈥檚 internal compass with unprecedented precision using the latest advances in neuronal recording technology.
This ability to accurately decode the animal's internal head direction allowed the researchers to explore how the Head-Direction cells, which make up the brain鈥檚 internal compass, support the brain鈥檚 ability to re-orient itself in changing surroundings. Specifically, the research team identified a phenomenon they term 鈥榥etwork gain鈥� that allowed the brain鈥檚 internal compass to reorient after the mice were disoriented. 鈥淚t鈥檚 as if the brain has a mechanism to implement a 鈥榬eset button鈥� allowing for rapid reorientation of its internal compass in confusing situations,鈥� says Ajabi.
Although the animals in this study were exposed to unnatural visual experiences, the authors argue that such scenarios are already relevant to the modern human experience, especially with the rapid spread of virtual reality technology. These findings 鈥渕ay eventually explain how virtual reality systems can easily take control over our sense of orientation,鈥� adds Ajabi.
The results inspired the research team to develop new models to better understand the underlying mechanisms. 鈥淭his work is a beautiful example of how experimental and computational approaches together can advance our understanding of brain activity that drives behaviour,鈥� says co-author Xue-Xin Wei, a computational neuroscientist and an Assistant Professor at The University of Texas at Austin.
Degenerative diseases
The findings also have significant implications for Alzheimer's disease. 鈥淥ne of the first self-reported cognitive symptoms of Alzheimer鈥檚 is that people become disoriented and lost, even in familiar settings,鈥� 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 assessment of treatments for Alzheimer鈥檚 disease.
About the study
"" by Zaki Ajabi, Alexandra Keinath, Xue-Xin Wei, and Mark Brandon was published in Nature. The research was supported by the Natural Sciences and Engineering Research Council of Canada and the Canadian Institutes of Health Research.
About 平特五不中
Founded in Montreal, Quebec, in 1821, 平特五不中 is Canada鈥檚 top ranked medical doctoral university. 平特五不中 is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning three campuses, 11 faculties, 13 professional schools, 300 programs of study and over 39,000 students, including more than 10,400 graduate students. 平特五不中 attracts students from over 150 countries around the world, its 12,000 international students making up 30% of the student body. Over half of 平特五不中 students claim a first language other than English, including approximately 20% of our students who say French is their mother tongue.