Medicosnext
Perineuronal nets (PNNs) are cartilage-like structures that surround inhibitory neurons in the brain, and their primary function is to control the level of plasticity in the brain. They contain chondroitin sulphates, some of which—like chondroitin 4-sulphate—inhibit neuroplasticity, while others like chondroitin 6-sulphate promote neuroplasticity. The balance of these compounds changes with growing age, and decreasing levels of chondroitin 6-sulphate results in age-related memory decline.
A team at the University of Cambridge and University of Leeds did research on whether manipulating the chondroitin sulphate composition could restore neuroplasticity and prevent age-related memory loss. The study, conducted on 20-month old mice (which are considered very old), used a variety of tests to demonstrate that they exhibited memory deficit compared to six-month old mice. When they were treated with a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs, the researchers found that this completely restored memory in the older mice, comparable to that seen in the younger mice.
Dr. Jessica Kwok of the University of Leeds said that the results were remarkable, with the memory and ability to learn restored to levels they would not have seen since they were much younger. Professor James Fawcett of the University of Cambridge said that the same mechanism should operate in humans, since the molecules and structures in the human brain are the same as those in rodents. A potential oral drug, licensed for human use, which inhibits the formation of PNNs, has already been identified by the team. It has been shown to restore memory in ageing mice and rats, besides also improving recovery in spinal cord injury.
