LONDON (Dispatches) -- Age-related memory loss in mice has been successfully reversed and the discovery can lead to the development of treatments to prevent memory loss in people as they age, Cambridge and Leeds scientists report.
Scientists at the University of Cambridge and University of Leeds investigated whether manipulating the chondroitin sulphate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.
To do this, the team looked at 20-month old mice -- considered very old -- and using a suite of tests showed that the mice exhibited deficits in their memory compared to six-month old mice.
The results of the study show that changes in the extracellular matrix of the brain -- ‘scaffolding’ around nerve cells -- lead to loss of memory with ageing, but that it is possible to reverse these using genetic treatments.
The team has shown that recent evidence has emerged of the role of perineuronal nets (PNNs) in neuroplasticity -- the ability of the brain to learn and adapt -- and to make memories. PNNs are cartilage-like structures that mostly surround inhibitory neurons in the brain. Their main function is to control the level of plasticity in the brain. They appear at around five years old in humans, and turn off the period of enhanced plasticity during which the connections in the brain are optimised. Then, plasticity is partially turned off, making the brain more efficient but less plastic
The team treated the ageing mice using a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs and found that this completely restored memory in the older mice, to a level similar to that seen in the younger mice.