Researchers at the Flanders Institute for Biotechnology have identified a new region of the brain responsible for navigation and spatial memory.
Patients with Alzheimer’s disease or other neurological conditions have a failure in the specialized neural networks in the brain that are responsible for navigation — leading to memory deficits and disorientation.
Scientists at Neuro-Electronics Research Flanders have discovered significant neural activity patterns in a region of the brain, known as the retrosplenial cortex, that could assist with spatial memory and navigation.
“Previous studies could only record from a few retrosplenial neurons simultaneously. With our cellular imaging technique, we could monitor the activity of hundreds to thousands of neurons simultaneously, which gave us a rich view into the neurons’ activity patterns,” professor Vincent Bonin, of the neuro-electronics group, said in a news release.
Spatial information coding is the firing of place cells in the hippocampus, a region of the brain responsible for navigation and memory. These place cells are active when an animal enters a certain place in its environment, however, only a small number of the place cells are active, leaving the rest dormant.
This pattern maximizes information storage but minimizes energy demands.
Researchers found that the hippocampus is not the only area of the brain responsible for spatial orientation, but that the retrosplenial cortex also is highly active in navigation and memory retrieval and connects the hippocampus to the visual cortex and other brain regions.
The study, published in the August edition of Nature Communications, found that damage to the retrosplenial cortex results in disorientation and memory deficits. People with Alzheimer’s disease have reduced activity in the retrosplenial cortex.
Researchers measured and compared the activity of neurons in the retrosplenial cortex in the brains of mice that moved on a treadmill with tactile stimuli, with the activity of neurons in the hippocampus.
They discovered a new group of cells that fire in sequences resembling the activity of the hippocampus place cells in their intermittent firing properties. However, the retrosplenial neurons responded differently to sensory input.
“The next step is to investigate directly the relationship between retrosplenial activity and hippocampus as well as its link to visual inputs,” Bonin said. “It will also be interesting to know how activity in the retrosplenial cortex relates to the development of different neuronal diseases in mouse models.”
By Amy Wallace