Relief for epilepsy at the scale of a single cell.

Epilepsy is a common neurological condition characterized by spontaneous, recurrent synchronous discharges of a population of neurons, unprovoked by a known proximal cause. Epilepsy is the second most common neurological pathology in the United States, behind only stroke.  Some oral medicines are available, however, these can cause adverse reactions.  Now, researchers led by Linköping University have developed a small device that both detects the initial signal of an epileptic attack and doses a substance that effectively stops it.  The team state that all this takes place where the signal arises, in an area of size of a single-cell, known as a ‘neural pixel’.  The study is published in the journal Proceedings of the National Academy of Sciences (PNAS).

Previous studies show that local control of neuronal activity is central to many therapeutic strategies aiming to treat neurological disorders. Arguably, the best solution would make use of endogenous highly localized and specialized regulatory mechanisms of neuronal activity, and an ideal therapeutic technology should sense activity and deliver endogenous molecules at the same site for the most efficient feedback regulation.  The current study develops an organic electronic multifunctional device that is capable of chemical stimulation and electrical sensing at the same site, at the single-cell scale.

The current study utilised slices of brains from mice to develop a small 20×20 μm device which can both capture signals, and stop them in the exact area of nerve cells where they arise. The device consists of a sensor that detects nerve signals, and a small ion pump that doses an exact amount of the neurotransmitter GABA, a substance the body itself uses to inhibit stimuli in the central nervous system.  The lab explain the same electrode that registers the activity in the cell can also deliver the transmitter, which they have named a bioelectronic ‘neural pixel’, since it imitates the functions of biological neurons.

The group state that signalling in biological systems is based on chemical signals in the form of cations, which are passed between transmitters and receptors, which consist of proteins. They go on to add that when a signal is transferred to another cell, the identification of the signal and the triggering of a new one occur within a very small distance, only a few nanometers or it happens at the same point. Results show that their device combines electronic detection and release in the same electrode, which is highly desirable.

The team surmise that their technology makes it possible to interact with both healthy and sick neurons. For the future, the researchers state that they can now start investigating opportunities for finding therapies for neurological illnesses that arise so rapidly and so locally that the patient doesn’t notice them.

Source: Linköping University