Thanks to a three-year long collaborative effort by researchers from South Korea and the United States, and dozens of design iterations, individual neurons are now eligible for targeted manipulation through a tiny, minimally invasive brain implant that can be controlled by a consumer-grade smartphone.
“The wireless neural device enables chronic chemical and optical neuromodulation that has never been achieved before,” said Raza Qazi, a researcher with the Korea Advanced Institute of Science and Technology (KAIST) and University of Colorado Boulder, and the lead author on the study published in Nature Biomedical Engineering.
According to Qazi, the new set-up vastly outperforms conventional methods currently used by neuroscientists, which typically involve rigid metal tubes and optical fibres to deliver drugs and light, and have other disadvantages, such as limitations imposed on subjects’ movement due to bulky equipment, the development of brain lesions upon repeated exposure, and the inability to deliver drugs for long periods of time.
A key virtue of the new technique is its reliance on replaceable – ‘plug-n-play’ – drug cartridges which allow researchers to study the same brain circuits for weeks and months on end without having to worry about the drugs running out.
Once the drug cartridges were slotted into the neural device using a soft, ultrathin probe, which consists of microfluidic channels and tiny LEDs, the researchers were able to easily control the locomotor activity of mice for over four weeks via an elegant, easy-to-use smartphone interface.
Due to its ability to release drugs and emit light in any specific combination or sequence, it could eventually be used for highly complex and fully automated in vivo experiments, as well as help speed up research into the neural underpinnings of different brain disorders, such as Parkinson’s disease, drug addiction, depression, and many others.
“This revolutionary device is the fruit of advanced electronics design and powerful micro and nanoscale engineering,” said Jae-Woong Jeong, Professor of Electrical Engineering at KAIST. “We are interested in further developing this technology to make a brain implant for clinical applications.”