Aging somatosensory cortex displays increased density of WFA-binding perineuronal nets associated with GAD-negative neurons.

The mechanisms of aging in the brain and the subsequent decrease in cognitive abilities remain elusive. While most studies refer to research conducted in old and senile animals, little is known about the early symptoms of normal, healthy aging. In this study, we examined whether perineuronal nets (PNNs), a special form of extracellular matrix (ECM) tightly associated with neurons that is thought to be involved in limiting neuronal plasticity, undergo changes in density during early aging.

Comparison of matrix metalloproteinase activation after focal cortical ischemia in young adult and aged mice.

Matrix metalloproteinase (MMP) activity is implicated in the degradation of the extracellular matrix during cerebral ischemia. Although many studies have demonstrated spatiotemporal patterns of activation of gelatinases (MMP-9 and MMP-2) after ischemic stroke in young adult rodents, no data exist on MMP activity in old brains. In this study, we investigated the gelatinolytic activity in young adult (3-month-old) and aged (1-year-old) mice subjected to photothrombotic stroke.

Disturbance of perineuronal nets in the perilesional area after photothrombosis is not associated with neuronal death.

Perineuronal nets (PNNs) are a condensed form of extracellular matrix that covers the surface of a subset of neurons. Their presence limits neuronal plasticity and may protect neurons against harmful agents. Here we analyzed the relationship between spatiotemporal changes in PNN expression and cell death markers after focal cortical photothrombotic stroke in rats.

Matrix metalloproteinase inhibition counteracts impairment of cortical experience-dependent plasticity after photothrombotic stroke.

Matrix metalloproteinases (MMPs) are fine modulators of brain plasticity and pathophysiology. The inhibition of MMPs shortly after ischaemic stroke reduces the infarct size and has beneficial effects on post-stroke behavioural recovery. Our previous studies have shown that photothrombotic cortical stroke disrupts use-dependent plasticity in the neighbouring cortex.

Effect of focal cerebral ischaemia on modulatory neurotransmitter receptors in the rat brain: an autoradiographic study.

Neurotransmission is strongly affected after ischaemic insult. It is postulated that modulatory neurotransmitter systems and their receptors play a role in experience-dependent and restoration plasticity. In this study, muscarinic cholinergic, serotonergic 5-HT(2A/2C), dopaminergic D(1) and noradrenergic beta(1) receptors were examined after focal cerebral ischaemia in different brain regions, using quantitative in vitro autoradiography.