Developmental patterns of proteoglycan-containing extracellular matrix in perineuronal nets and neuropil of the postnatal rat brain

Abstract

The extracellular matrix is involved in various morphogenetic processes which are accompanied by changes in its physicochemical properties and spatial organization. In the adult brain it contributes to cellular communication and the regulation of neuronal activity. The present study deals with the postnatal appearance and transformation into adult distribution patterns of extracellular matrix components related to chondroitin-sulphate proteoglycans (CSPGs) in the rat brain. The differential accumulation of these components in neuropil and in perineuronal nets (PNs) enriched in certain regions was examined in 0-, 7-, 14-, 21- and 35-day-old rats and adult animals using the N-acetylgalactosamine-binding Wisteria floribunda agglutinin (WFA) and immunocytochemical detection of CSPGs. The lectin stained the olfactory-bulb glomerular layer and layer Ia of piriform and entorhinal cortex already in newborn animals. On postnatal day 7 diffuse neuropil staining was additionally found in certain subcortical nuclei and in deep neocortical layers. The first sharply contoured PNs were detected at this age in the brain stem, indicating the more advanced maturation of matrix components in subcortical regions. CSPG immunoreactivity yielded staining patterns largely identical to WFA-binding patterns but appeared only between postnatal day 14 and 21. The adult-like stage was revealed with both methods between 21 and 35 days after birth. The results provide further evidence that the accumulation of certain CSPGs in the extracellular space is spatiotemporally related to distinct patterns of neuronal activity at the regional and cellular level.

Fixed negative charge and the Donnan effect: a description of the driving forces associated with brain tissue swelling and oedema

“…This assay has been used with success to measure FCD values for comparison with FCD predictions in tissues modelled as triphasic mixture materials, such as cartilage and aorta (Lu et al 2007;Azeloglu et al 2008). While GAGs may not represent the entirety of the FCD found within brain (other contributions may come from negatively charged DNA, proteins and matrix molecules), there is a significant amount of different sulphated proteglycans in brain, the majority of which contain chondroitin sulphate (Margolis et al 1975(Margolis et al , 1976Jenkins & Bachelard 1988;Lander 1993;Koppe et al 1997;Costa et al 2007). Much of this sulphated GAG, especially at later stages of development, has been localized within the cytoplasm of neurons and astrocytes (Margolis et al 1979;Alvarado & Castejon 1984;Aquino et al 1984;Sames & Hoyer 1992).…”

The Stop Signal Revised: Immature Cerebellar Granule Neurons in the External Germinal Layer Arrest Pontine Mossy Fiber Growth

“…To determine whether differences in expression of PGs on granule cells could explain the differences in pontine axon outgrowth, we analyzed PG expression using biotin-conjugated WFA, a lectin which binds specifically to N-acetylglycosamine (Koppe et al, 1997). PGs were present on both immature (0 div) and mature (4 div) granule cells ( In summary, pontine mossy fiber arrest at the inferior border of the EGL could be controlled by a specific ECM component and/or a guidance cue with a heparin-binding domain that is exclusively expressed in the EGL.…”

Regeneration beyond the glial scar

“…, which are produced as the animal passes through critical periods of central nervous system maturation 147,148 . Interestingly, dark-rearing prolongs the duration of the critical period and, in turn, development of the perineuronal net, implicating sensory experience in maturation of the net…”