Scientists at the Karolinska Institutet and Linköping University in Sweden say they are well on the way to creating the first artificial nerve cell that can communicate directly with nerve cells in the body using neurotransmitters.
Existing techniques for stimulating nerve signals in the nervous system rely on electrical stimulation. Examples include cochlear implants, which are surgically inserted into the cochlea in the inner ear, and electrodes that are used directly in the brain. One problem with this method is that all the different types of cells in the vicinity of the electrode are activated, which gives undesired effects.
The Swedish scientists have now used an electrically conducting plastic to create a new type of electrode that rather than sending electrical signals releases neurotransmitters that brain cells use to communicate naturally. The advantage of this is that only neighbouring cells that have receptors for the specific neurotransmitter, and that are thus sensitive to this substance, will be activated.
The scientists have demonstrated that the electrode can be used to control the hearing function in the brains of guinea pigs.
“The ability to deliver exact doses of neurotransmitters opens completely new possibilities for correcting the signalling systems that are faulty in a number of neurological disease conditions,” says Agneta Richter-Dahlfors, who led the work, together with Barbara Canlon.
The scientists intend to continue with the development of a small unit that can be implanted into the body. It will be possible to programme the unit so that the release of neurotransmitters takes place as required, in order to treat each individual patient. Research projects under way are targeted towards hearing, epilepsy and Parkinson’s disease.