Astrocytes detect when the mouse is spatially oriented and then increase the probability of dendritic spikes by signaling molecules. Credit: Dr. Kirsten Bohmbach/University Hospital BonnThere are two fundamentally different cell types in the brain, neurons, and glial cells. One purpose of the latter is to insulate the “wiring” of nerve cells or guarantee optimal working conditions for them.
Place cells have long extensions, the dendrites. These are branched like the crown of a tree and dotted with numerous contact points. Information that our senses convey to us about a location arrives here. These contacts are called synapses. “When signals arrive at many neighboring synapses at the same time, a strong voltage pulse occurs in the dendrite — a so-called dendritic spike,” explains Dr. Kirsten Bohmbach, who performed most of the experiments in the study.
“If we inhibit the assistance provided by astrocytes in mice, they are less likely to recognize familiar places,” Henneberger says. However, this does not apply to locations that are particularly relevant — for example, because they pose a potential danger: These continue to be avoided by the animals. “The mechanism we discovered therefore controls the threshold at which location information is stored or recognized.” The results provide a new insight into how memory works and is controlled.