Topic: chondroitin sulfate proteoglycans

Learning and memory formation require activity-dependent rearrangements of neuronal networks driven by structural plasticity. The brain's perineuronal extracellular matrix (ECM), composed mainly of chondroitin sulfate proteoglycans from the lectican family, suppresses structural plasticity in the mature brain. Several members of this family, such as aggrecan and brevican, undergo proteolytic cleavage by proteases from the ADAMTS family, which may loosen the ECM structure. Therefore, we hypothesize that activity-dependent extracellular proteolysis weakens the ECM, supporting neuronal plasticity

Axonal growth cones mediate axonal guidance and growth regulation and their activities are crucial for neuronal circuit development. However, the function of growth-cone-like structure at the tip of leading process of migrating neurons is largely unknown. Here, using live imaging analyses, we show that migrating neurons in mice possess a growth cone at the tip of their leading process, similar to that of axons, in terms of the cytoskeletal dynamics and functional responsivity through protein tyrosine phosphatase receptor type sigma (PTPσ). Migrating-neuron growth cones respond to chondroitin s

Synaptic homeostatic plasticity maintains firing of neuronal networks within physiological range, by adjusting synaptic strength via molecular and morphological changes in the synapse. The perineuronal extracellular matrix (ECM), which is mainly composed of chondroitin sulfate proteoglycans such as brevican, stabilizes synapses and reduces their plasticity. Previous data indicated that brevican is cleaved during homeostatic plasticity, which may facilitate synapse remodeling. The proteases ADAMTS4, -5 and the closely related ADAMTS8 and -15 may share brevican as substrate for ECM regulation. T

Perineuronal nets (PNNs), a specialized form of the extracellular matrix, enwrap subtypes of neurons and have many proposed functions including regulating adult brain plasticity. Removal of PNNs in adult mice by the bacterial enzyme chondroitinase ABC restores brain plasticity levels to that of juveniles. However, chondroitinase ABC indiscriminately degrades all chondroitin sulfate proteoglycans in the extracellular matrix, its effect is not restricted to PNNs. In contrast, several endogenous metalloproteinases specifically target PNN components. Some of these are selectively expressed in PNN-