Controlling brain cells using quantum dots
Our current methods of stimulating the brain are crude, either being invasive (like placing electrodes inside the head) or imprecise (like magnetic stimulation from outside the head). Recently, Lih Lin and her colleagues at the University of Washington have found a more promising method that involves quantum physics, utilising light-sensitive semi-conductive nanoparticles called quantum dots. Their potential was realised after an experiment on prostate cancer cells, where quantum dots were positioned next to cell membranes and then exposed to light. The energy excited the quantum dots’ electrons and the area then became negatively charged, which caused the cancer cells’ ion channels to open, allowing ions to rush in or out. Since this is essentially how brain cells communicate, the researchers repeated the experiment on nerve cells and found that individual cells can be controlled at a level of precision beyond that of alternative brain-stimulation techniques. Quantum dots can be delivered to the brain cells relatively easily through an injection, but the real problem is how to then expose them to light. For this reason, it’s likely that their first uses will be in the human eye, since the retina naturally absorbs light—and if they can reactivate damaged cells, they could potentially treat blindness. Because many brain disorders are caused by imbalanced neural activity, quantum dots could eventually be used to treats conditions such as Alzheimer’s disease, depression, and epilepsy—thankfully without cracking open your skull.
(Image Credit: 1, 2)