perineuronal net
Specialized extracellular matrix structures surrounding certain neurons, involved in synaptic stabilization.
Full Definition
Perineuronal nets are specialized lattice-like extracellular matrix structures that ensheath the cell bodies and proximal dendrites of certain neurons, particularly fast-spiking interneurons and some projection neurons. These nets are composed of chondroitin sulfate proteoglycans, hyaluronic acid, and link proteins, and play crucial roles in regulating synaptic plasticity and neuronal excitability. Perineuronal nets can be visualized using specific lectins such as Wisteria floribunda agglutinin (WFA) and are altered in various neurological and psychiatric conditions. Their formation marks the end of critical period plasticity and their degradation has been implicated in cognitive dysfunction and neurodegeneration.
Usage
Usage note: Often abbreviated as PNN; requires special staining techniques for visualization.
In Context
- "WFA-positive perineuronal nets were reduced in number and intensity in the affected cortical areas." — Research findings
- "The integrity of perineuronal nets appeared preserved despite significant neuronal loss." — Histochemical analysis