Virtual reality maze could predict onset of Alzheimer’s disease

“The risk carriers showed a less stable grid pattern in the entorhinal cortex – many decades before they might develop Alzheimer’s dementia”, says Lukas Kunz, who conducted the experiment at the German Center for Neurodegenerative Diseases in Bonn.

By examining the function of certain brain cells during the task, the scientists reckon they can identify those with a higher genetic risk of developing the condition.

“Our results could provide a new basic framework for preclinical research on Alzheimer’s disease and may provide a neurocognitive explanation of spatial disorientation in Alzheimer’s disease”, the researchers said in the report.

Those with a higher risk of Alzheimer’s went through the task differently because the brain cells responsible for spatial navigation weren’t as strong. As we move around, the grid activates like an internal Global Positioning System, tracking our movements and creating mental maps that allow us to navigate without visual cues.

Kunz and colleagues assessed grid cell function in people using an fMRI-based test developed previously by Döller (see Döller et al., 2010). “If you close your eyes and walk ten feet forward and turn right and walk three feet forward, the grid cells are believed to [track your position]”, says neuroscientist Joshua Jacobs at Columbia University.

Researchers have found an early warning detection system for Alzheimer’s disease even in young people.

Scientists found behavioural differences depending on which part of the brain participants used to navigate.

Although not all study subjects carried the genetic material that can cause early-stage Alzheimer, a few of them did. Participants were then asked to navigate a circular virtual arena. Nikolai Axmacher, senior researcher of the project, said that the results, although unclear, needs to be investigated in further studies in order to draw a conclusion. Axmacher and his team also observed an uptick of activity in the hippocampus (a nearby brain region usually implicated in emotion and memory) during the trial, but only in the at-risk population that wasn’t relying on the grid-cell network. Others just had to navigate a virtual arena. Grid cells facilitate navigation in open spaces, while neurons in the hippocampus may rely on objects or boundaries to generate a sense of place, he told Alzforum. This brain area, the so-called entorhinal cortex, contains cells that fire in a spatial grid pattern, the grid cells. While it’s probably unlikely that the navigational test will be used as an early diagnostic for Alzheimer’s in the near future, the insights into the disease’s progression and mechanism could be a step toward preventative therapies.