Aggregation of chondroitin sulphate proteoglycans into perineuronal nets control plasticity in the adult central nervous system

Date

Nov 27, 2013

Time

1:00 PM - 2:00 PM

Speaker

Jessica Kwok, John van Geest Centre for Brain Repair Cambridge

Language

en

Main Topic

Biologie

Other Topics

Biologie

Host

Gilbert Ng / Jochen Guck

Description

The glial scar that forms after a CNS injury contains molecules that are inhibitory to axon. The up-regulation of these molecules, which normally help to maintain stable connections and ensure proper functions of the CNS, in the glial scar hinders the CNS from recovery. One of the key inhibitory molecules presents in the glial scar is chondroitin sulphate proteoglycans (CSPGs). Enzymatic removal of the CSPGs in the lesion area enhances both structural and functional recovery in the CNS. Apart from enhancing regeneration, we recently discover that removing CSPGs around the lesion core re-activates plasticity, a process which allows re-routing of neural pathways and connections. This increase in plasticity is mainly attributed to the removal of CSPGs in a structure called perineuronal nets (PNNs). PNNs are mainly composed of CSPGs, hyaluronan, link proteins, and tenascin R. In contrast to the loose extracellular matrix present in the brain, the supramolecular interactions between these molecules lead to the formation of a compact pericellular complex which surrounds synapses on the neuronal surface. We have developed an in vitro model for the PNNs and identified the key molecules involved in the formation of the PNNs. Knocking out these molecules reverts the compact matrix into loose extracellular matrix. Transgenic mice with attenuated PNNs, due to a lack of molecular aggregation, showed enhanced plasticity and regeneration. We are currently looking into methods to manipulate the extracellular matrix aggregation which may benefit recovery after CNS injury.

Links

• to announcement of the organizer

Last modified: Nov 27, 2013, 8:37:06 AM