When we enter a place, we usually know whether we have been there before or not. But how does our brain remember a new location? It has to store what we see from this place or perceive with other senses in the nerve cells of our brain. This is the only way we can recognize the surroundings later. In order for this to succeed, not only the neurons in our brain are active: They are supported in this task by a second type of brain cell, the so-called astroglial cells, as scientists led by Kirsten Bohmbach from the University of Bonn have discovered.
The astroglial cells or astrocytes are marked in yellow in the image. Shown in blue is a branched place cell, a neuron specialized in spatial memory. The information that our senses convey to us from a new place arrives at the place cells. If a lot of such information arrives at the same time, the place cell forms what is known as a dendritic spike – an electrical impulse in one of its cell extensions. It migrates towards the cell body, where it triggers further impulses.
These electrical impulses cause the place cell to emit special messenger substances, which then reach the astrocytes and dock to suitable receptors there. As a result, the astrocytes themselves also release a messenger substance, which in turn docks with the place cells and makes it easier for them to form spikes. Through this positive feedback loop, our brain ultimately memorizes the perceived information and thus ensures that we can remember a new place and recognize it the next time we visit.