Researchers have designed silicon nanowires that allow modulation neuronal activity using light, allowing manipulation of specific neural circuits without genetic engineering for the first time.
Light-controlled neuron activation using optogenetics allows modulation of specific circuits but is invasive and requires genetic engineering. Researchers from the University of Chicago have developed a silicon-based nanowire that allows light modulation of neurons without genetic engineering, paving the way for optical control of neural activity to other neurological models. Image credit: Gerry Shaw / CC BY-SA 3.0.
Modern technologies have revolutionized our understanding of the neural basis of human cognition.
Nevertheless, fundamental aspects of the brain remain obscure as scientists have been limited in their ability to precisely manipulate neural circuits.
These difficulties were partially resolved by the arrival of optogenetics, an approach that allows researchers to turn specific neurons on or off with light.
Although optogenetics is a powerful system that already has yielded impressive findings, it is limited in its applicability because of its invasiveness and dependence on genetic engineering.
Researchers from the University of Chicago have developed a method based on silicon nanowiring that circumvents this need for genetic engineering while still utilizing the precision of light for specific neuron-targeting.
The atomic gold in the wire allows production of an electrical current along the wiring after exposure to light.
The group of researchers report in the journal Nature Nanotechnology that when this nanowiring is applied to rat neurons light could stimulate electrical signals within the neurons.
“When the wire is in place and illuminated, the voltage difference between the inside and outside of the cell is slightly reduced. This lowers the barrier for the neuron to fire an electrical signal to its neighboring cells,” said Bozhi Tian, the leader of the study.
“It’s a fundamental but very promising approach.”
“The nice thing about it is that both gold and silicon are biologically compatible materials,” said graduate student Ramya Parameswaran, the first author of the article.
“Also, after they’re injected into the body, structures of this size would degrade naturally within a couple of months.”
Their work provides a powerful method that allows manipulation of specific neuronal circuit activity without genetic engineering and surely has a bright future in neurological research.
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Ramya Parameswaran et al. Photoelectrochemical modulation of neuronal activity with free-standing coaxial silicon nanowires. Nature Nanotechnology, published online February 19, 2018; doi: 10.1038/s41565-017-0041-7
