Aged somatosensory cortex displays increased densities of perineuronal nets that are not associated with GAD-positive neurons

• Autorzy: Nowicka D. , Karetko-Sysa M. , Skangiel-Kramska J.
• Języki publikacji: EN

Abstrakty

EN

Ageing of the brain results in some degree of decline in a number of functions, one of which is neuronal plasticity. Recently, perineuronal nets (PNNs), a structuralized form of the brain extracellular matrix observed around some neurons (often GABAergic) have been postulated as a molecular brake, actively preventing plasticity in the adult brain. Removal of PNNs in visual cortex results in the restoration of ocular dominance plasticity in adult mice, and knockout mice with attenuated PNNs retain juvenile levels of ocular dominance plasticity. Little data, however, exist on the expression and function of PNNs in aged animals. We examined whether the decrease in neuronal plasticity during ageing could be the result of gradual increase in PNN density. To this aim we investigated PNNs across the layers of the somatosensory cortex of the adult (3 months) and aged (1 year) mouse. To visualize PNNs we employed Wisteria floribunda (WFA) lectin, binding to the sugar epitopes of PNNs, and CAT315 antibody recognizing a specific glycoform of PNN constituent, aggrecan. GAD and parvalbumin (PV) antibodies were used to stain GABAergic neurons. Detailed microscopic analysis revealed that in aged animals the density of WFA-positive PNNs increased significantly in layers IV and V-VI. At the same time the density of CAT-315-positive PNNs decreased slightly, thus suggesting changes in PNN composition. Co-localization studies revealed that the observed increase was mostly confined to WFA+/CAT-315 neurons that did not contain PV. Moreover, this increase in enveloping was characteristic for neurons that were GAD-negative. Ageing had no influence on the density of GADpositive or PV-positive cells. Our results suggest that in aged animals some additional set of neurons was enveloped by PNNs, possibly contributing to further limiting of cortical plasticity. Interestingly, these neurons are not necessarily GABAergic.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2011
• Tom: 71
• Numer: S
• Opis fizyczny: p.76

Twórcy

autor

Nowicka D.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland

autor

Karetko-Sysa M.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland

autor

Skangiel-Kramska J.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland

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