Genetic knockout of CS4 sulfation of perineuronal nets as a source of juvenile like plasticity in processes of memory and learning

Extracellular matrix affects the functioning of the brain. Among others, learning and memory can be affected by the changes in the composition and properties of the extracellular matrix. Different sulfation patterns on the chondroitin sulfate proteoglycans, one of the extracellular matrix components, can either enhance or reduce synaptic plasticity and neuronal growth. This leads to the changes in the formation of memory. In my thesis I defined the role of 4-O-sulfation of the chondroitin sulfate proteoglycans in the learning and memory in the young and early adult animals. To do so I used Chondroitin sulfotransferase 11 knockout mice strain, which has decreased amount of 4-O-sulfation. I tested their long-term, short-term, and working memory using behavioural tests. I also monitored the morphological changes in the perineuronal nets and changes in the number of synapses using immunohistochemical methods and confocal microscopy