Optogenetics has established that light-sensitive proteins can be used to control gene expression. It is also well-known that electrical activity in brain can be converted in to a physical output . Combining these two streams can pave the way for new gene and cell based treatments.
Swiss scientists led by Folcher has done exactly that.The work is the accumulation of efforts to control cell gene expressions remotely.Light inducible transgenes ( that can produce proteins to influence the cell functioning) can be introduced to cells and these can be switched on using light of a particular frequency. What this group has now done is capturing the electrical activity in brain (electrical activity in brain is already used to control prosthetics) and relay that to a light source which can then switch on the light-sensitive genes.
Researchers created a small, implantable device that contained cells responsive to near-infrared light, and a light-emitting diode (LED) that produced this wavelength. This was placed under the skin of a mouse. When stimulated by the light, these cells produced a bacterial molecule that induced the synthesis of interferons and these diffused in to animals body. The implant was wirelessly connected to a monitor that captured a human subjects brainwaves with an EEG sensor placed on their foreheads. Different mental activity of the human participant can produce different EEG signatures. These eeg signatures were then converted to threshold values for stimulating the LED .When the light was turned on, genes within the implant cells were expressed and proteins secreted into the mouse circulation.
What application might this have?
Diseases where brain activity can be distinct and pathological ( e.g. epilepsy ) might benefit from this i.e. the early brain waves are detected and control substance is released by the cells. Chronic pain is another candidate condition. Mental illness? When brain electrical signature studies reach a stage where differentiation of different mental states are possible, may be then, such devices may regulate neurochemicals or functional circuits to bring the pathological states back to normalcy. But it is a big if..
Summary of the article
Folcher M, Oesterle S, Zwicky K, Thekkottil T, Heymoz J, Hohmann M, Christen M, Daoud El-Baba M, Buchmann P, Fussenegger M. Nat Commun. 2014