Researchers have successfully carried out a new experiment that has resulted in discovery of a new type of brain cells. The newly-discovered brain cells helps keep track of locations while navigating through unfamiliar surroundings, just like a GPS tracker.
The research was conducted by Prof. Michael Kahana, Department of Psychology at the School of Arts & Sciences at Swansea University, with his former graduate student Joshua Jacobs in collaboration with researchers at UCLA and Thomas Jefferson University for the study.
The participants were intractable epilepsy patients who had intracranial depth electrodes implanted to identify seizure foci for potential surgical treatment. Electrode location was based solely on clinical criteria. The spatial memory researchers, with the patients' consent, "piggybacked" their research.
The researchers at the university were able to triangulate brain activity that helped the participants navigate using the electrodes places in their brains. 14 patients were asked to play a navigation video game which made them walk from one point to another to retrieve objects. The patients then had to recall how to get back to the places where each object came from. The participants used a joystick to ride a virtual bicycle across a wide-open terrain displayed on a laptop by their hospital beds. The flags were hidden, so the players had to use their own cognitive senses to find them.
The new cells have been named "grid cells", after the triangular grid pattern in which they activate during navigation. The cells gave people “spatial memory” and were discovered by examining the brains of neurosurgery patient volunteers. The discovery of grid cell may be able to help scientists working to beat Alzheimer’s disease.
A similar study has earlier done on rats in 2010, which also exhibited similar “grid cells” that helped them navigate. “Without grid cells, it is likely that humans would frequently get lost or have to navigate based only on landmarks,” Jacobs says.
“The present finding of grid cells in the human brain, together with the earlier discovery of human hippocampal ‘place cells,’ which fire at single locations, provide compelling evidence for a common mapping and navigational system preserved across humans and lower animals,” Kahana says.