Font Size

HOME > No.25, May 2021 > MicroLED neural probe for neuroscience

MicroLED neural probe for neuroscience

Optogenetic control and recording technology for elucidation of brain functionBy Hiroto Sekiguchi
Hiroto Sekiguchi

Associate Professor Hiroto Sekiguchi and Ph.D. candidate Hiroki Yasunaga in the Department of Electrical and Electronic Information Engineering at Toyohashi University of Technology have developed a MicroLED neural probe for use in neuroscience. This MicroLED neural probe can optogenetically control and observe neural activity in the brain. Neural activity was successfully recorded using this neural probe, and confirmed that the MicroLED provided sufficient light output to activate neural activity. The developed MicroLED neural probe is expected to contribute to the development of optogenetic technology in the field of neuroscience, where light can be used to control neurons.

Information processes of advanced brain functions are known to result from complex interactions of interconnected neurons. Optogenetic technology is expected to contribute to elucidating how neural activity and animal behaviors are linked because it uses light to precisely target specific cells for manipulation without affecting other cells in the brain. Previously optical fibers have been inserted in to the brain tissue of mice to control neurons by optical stimulation, there were some issues with damage to the brain tissue as well as some difficulty in stimulating multiple locations.

Neural probe integrated with MicroLEDs and neural recording electrodes
Neural probe integrated with MicroLEDs and neural recording electrodes

In the field of engineering, microLEDs, which vary from around one tenth to a hundredth the size of a conventional LED, are increasingly garnering attention thanks to the possibilities they are opening up through the development of high-brightness, highly efficient, and high resolution displays. These displays are created by arranging millions of microLEDs in a single 1cm square. In this study, the research team has fabricated a new device that applies this tiny LED in the field of neuroscience. The micro-LEDs are very small, only a few tens of micrometers square, but they can produce light bright enough to activate nerve cells. This new type of neural probe tool can overcome many of the problems presented by conventional neuroscience tools, and its high spatiotemporal resolution enables us to control and record complex neural activity control.

(a) 3D schematic and (b) cross-sectional structure of the proposed integrated Micro LED and neural electrode probe. (c) a MicroLED neural probe mounted on a PCB board and (d) optical microscope images of a neural robe before and during LED operation.
(a) 3D schematic and (b) cross-sectional structure of the proposed integrated Micro LED and neural electrode probe. (c) a MicroLED neural probe mounted on a PCB board and (d) optical microscope images of a neural robe before and during LED operation.

Associate Professor Hiroto Sekiguchi said, “We have been developing LED materials and researching LED micro-integration technology for more than 10 years. As the industrialization of LEDs progressed, I have been looking for new research fields to utilize these new types of LEDs. In the midst of this, I happened by chance to meet a Pharmacology researcher, and we ended up chatting about our research. Six months later, I received a consultation from the Pharmacology researcher, which led to of this research result. I believe that my simple and easy-to-understand explanations, as well as my active interest in discussing topics across different fields, contributed to the development of this interdisciplinary research project combining pharmacology and engineering.”

The research team hopes to contribute to the development of neuroscience by applying the developed MicroLED neural probe to animal experiments related to in vivo optogenetics research. If the understanding of brain functions is advanced using this tool, it is expected to be utilized for developing treatments for various conditions, such as cancer, psychiatric disorders, and epilepsy. In addition, it is expected to have applications for brain-machine interfaces, and in the field of AI concerned with the development of new algorithms based on brain functions.

This study was partially supported by the Precursory Research for Embryonic Science and Technology Agency (JPMJPR1885), Research Foundation for OptoScience and Technology, and the Nitto Foundation.


Hiroki Yasunaga, Toshihiro Takagi, Diasuke Shinko, Yusei Nakayama, Yuichi Takeuchi, Atsushi Nishikawa, Alexander Loesing, Mashiro Ohsawa, and Hiroto Sekiguchi (2021). Development of a neural probe integrated with high-efficiency MicroLEDs for in vivo application.


By 関口 寛人




「10年以上LEDのための材料開発やLEDの微細集積化技術の研究を進めていましたが、すでに産業化が進みつつあるLEDにおいて、このLEDを発展的に活用するための新たな研究分野を模索していました。そうした中、研究とは関係のない出会いの中で薬学の研究者と出会い、何気ない会話の中で研究の話をしました。半年後、その薬学の研究者から相談をいただき、今回の研究成果につながりました。簡単にわかりやすく説明したことや、異分野のテーマでも積極的に興味を持って話をしたことが、医薬学と工学との融合領域研究に繋がったのではないかと考えています。」 と、関口寛人准教授はこの研究に至った経緯を語っています。



Share this story

Researcher Profile

Hiroto Sekiguchi
Name Hiroto Sekiguchi
Affiliation Department of Electrical and Electronic Information Engineering
Title Associate Professor
Fields of Research Light-Emitting device, Semiconductor Engineering
Degree Ph. D. (Engineering), Sophia University