A reliable sense of place is essential for daily life and memory formation. Removal of sugar-coated proteins around neurons in the inner gps of the brain makes the mental map of space unstable, shows in a study published in the journal Nature communication.
Scientists from the University of Oslo, Norway have shown that the extracellular matrix proteins covered with sugar, called perineuronal nets, which circulate closely around neurons in the brain, are responsible for the long-term stability of the mind maps . This study is the first to link an extracellular matrix to the stability of our sense of place.
Every time you go back to a place, neurons reactivate in the same place telling you where you are.
When we removed the perineuronal nets from neurons in the entorhinal cortex in rats, we found that new grid maps formed more slowly in novel environments compared to grid cells from rats that had incomplete perineuronal nets. . It was all the more surprising when the rats returned to their familiar sites, that the stored grid maps had become unstable. This suggests that the perineuronal networks contribute to maintaining the integrity of stored mind maps and preventing them from being overwritten by new experiences. “
Charlotte Christensen, Lead Author, University of Oslo
They found that not only was the grid map unstable, but also that the exact time between grid cell burns was weakened after the perineuronal nets were removed. This opens up for future studies to clarify whether the disruption with time or space in Alzheimer’s patients is associated with changes in the extracellular matrix of the brain.
Source:
University of Oslo, Faculty of Mathematics and Natural Sciences
Magazine Reference:
Christensen, AC, et al. (2021) Perineuronal networks stabilize the grid cell network. Nature Communication. doi.org/10.1038/s41467-020-20241-w.