Research can pave the way for the treatment of various forms of epilepsy and seizures that occur as a result of brain lesions caused by trauma, infection or brain tumors.
Since 1893, scientists have learned about mysterious structures called perineuronal networks wrapped around neurons, but the function of these networks has remained unknown. A group of scientists from the University of Virginia, led by Harald Sontheimer (Harald Sontheimer), however, said these networks are modulating electrical impulses in the brain. In addition, they found that seizures occur in the event of network failure. The results of the work published in Nature Communications.
Initially, researchers have made this finding in mice suffering from epilepsy caused by lethal brain cancer, glioblastoma, the first sign of which is often seizures. Glioblastoma is the only tumor that is limited in space. Because the skull blocks cancer before expansion, the tumor produces an exaggerated excitatory chemical neurotransmitter (glutamate) that kills adjacent healthy cells to free up space for growth.
In addition to glutamate, the tumor excretes an enzyme aimed at destroying the surrounding extracellular matrix – a gel-like substance that holds the brain cells in place. Glioblastomas are very malignant and are known to spread throughout the body. Enzyme secreted is a type of knife that resolves cancer cells, allowing them to move freely.
To their surprise, scientists also observed how the enzyme attacks perineuronal nets wrapped around GABA-inhibiting neurons (gamma-aminobutyric acid) to help prevent seizures.
Italian neurologist Camillo Golgi (Camillo Golgi) first discovered the perineuronal network in 1893, but then misunderstood their function. Golgi called the "corset" network and said it most likely prevented the exchange of messages between neurons. The Sontheimer's study refutes it. The scientist, on the other hand, found that networks support messaging. Neurons covered with perineuronal nets have less membrane capacity and ability to store electrical charge, which means they can trigger the pulse and charge up to twice as fast as neuronal neurons.
When suddenly losing their perineural nets, the results may be catastrophic: the use of this enzyme in the brain-free brain, scientists have seen that the most enzymatic degradation of the perineuronal nets was enough to induce seizures – even though the neurons remained intact.
Now, researchers are focusing on the role that perineural networks can play in other forms of epilepsy – for example, as a result of head injuries or brain infections – which will bring them closer to creating an effective drug.
"We have solved the 125-year-old secret of neurology! This is what is basic science: keep open and attentive mind and answer old and new questions," says Sontheimer.
According to the World Health Organization, more than 50 million people worldwide suffer from epilepsy, one third of which is not susceptible to known antiepileptic procedures.
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