Deep brain stimulation has achieved good results in the treatment of Parkinson’s disease and epilepsy. The therapy involves electrically stimulating the patient’s brain to produce neurotransmitters like dopamine. If a sensor were added to treatment devices installed in the brain, physicians would know in real time how the neurotransmitters were responding to treatment. Neurotransmitters are too small to be seen by the naked eye, and therefore no device can visusalise us how they function directly, forcing us to employ other means to gather information.
“A definite benefit of such sensors would be the real-time nature of the data they produce. Neurotransmitters move from cell to cell very rapidly, and only a real-time method can let us know how much of a specific substance is present at each given moment. Treatments would become more effective and the risk of adverse effects would reduce,” Peltola says.
In addition to neurotransmitter concentration, it is important to know the location in which neurotransmitters are being released, how rapidly cells are releasing the substance as well as how long it takes for the cell to uptake it. Existing methods are unable to gather this information.
The part of the brain in which the sensor is placed determines which neurotransmitter should be measured. The functioning of glutamate, the neurotransmitter that affects learning and memory, is studied in the hippocampus in particular. Local measurements yield fresh information on disease mechanisms as well as on the functioning of the brain and pharmaceuticals.
Peltola believes that if measurements inside the body were to become possible, researchers could develop new diagnostic and treatment methods. “We could have new treatments that would not only slow down diseases, but stop or even cure them.”
Researchers hope that sensors embedded into the body would become part of its tissue. This is what happens when nerve cells attach to sensors. But our body can send glial cells to surround sensors, and they form scar tissue that hampers measurements. In order for a sensor to attract the right kinds of cells, its surface must be of a specific type. But researchers have not yet determined what this type is like.