Wireless, battery-free, subdermally implantable platforms for transcranial and long-range optogenetics in freely moving animals

Significance Delivery of light for optogenetic stimulation of the brain is challenging, especially in small animals, because of behavioral constraints associated with physical tethering by fiber optic cables. This limitation interferes with some classes of in vivo behavioral experiments and makes others impossible. Additionally, the penetrating probes associated with these and related technologies cause damage to targeted regions of neural tissues, thereby complicating experimental evaluation. Here, we introduce a wireless, battery-free system that interfaces to the animal as a minimally invasive, subdermal implant capable of delivering high-intensity optogenetic light stimulation directly through the skull, without penetrating the brain. This approach avoids damage to brain tissue, facilitates simple surgical implantation, and enables new, ethologically grounded neuroscience experiments, applicable over large experimental arenas.