Michigan µLED Probes

Type: Electrophysiology / Probes,

Keywords: MiniSTAR optoelectrode, Opto-electrophysiology, BRAIN Initiative

High-density recording micro-LED optoelectrodes

Our goal is to disseminate high-density micro-LED optoelectrodes for mapping circuits in the brain.

* Optoelectrodes are fabricated on a GaN-on-silicon substrate with precisely defined, cellular size recording sites and μLEDs for simultaneous recording and local optogenetic stimulation with virtually no artifact
* The implementation of multi-metal-layer structure, the high-density boron doping of silicon substrate, and the transient pulse shaping of stimulation waveform contribute in no stimulation artifact higher than 50 uV pk-pk
* With nearly zero amplitude artifact, miniSTAR optoelectrodes can be readily utilized for functional dissection of neural circuits, multiple cell type manipulation, and many other experiments that require real-time event detection and closed-loop perturbation of neural circuits with <1ms temporal resolution
* Recent advances in genetic engineering allow for targeting neuron somas instead of neuron axons, further increasing the number of experiments possible with MINT uLED probes
* Demonstrates high fidelity electrical and optical signals, adequate light irradiance, heat removal and environmental protection for longevity, and re-usability

* Optogenetic-control of local neural circuits in awake, behaving studies.
* Square-wave excitation for precise timing control
* Sine-wave excitation for graded modulation. *Chronic optogenetics where a microdrive is used for fine-tune positioning
* These novel optoelectrodes can be used for neural circuit interrogation that requires the parametric control of two types of neurons in awake mammals
* Our principal in vivo result is intensity modulated optical excitation of pyramidal cells and PV interneurons in the same volume of densely populated CA1 of hippocampus of awake mice
* Validated the packaged devices in the intact brain of anesthetized mice co-expressing Channelrhodopsin-2 and Archaerhodopsin in pyramidal cells in the hippocampal CA1 region, achieving high quality recording, activation and silencing of the exact same neurons in a given local region.
* Present high-density four-shank optoelectrodes with integrated 405 and 635nm injection laser diode (ILD) light sources for dual color local circuit analysis. Multiple-shank probes with multi-optical/electrode sites can be fabricated using the same fabrication process flow

* With an in vivo experiment using a miniSTAR optoelectrode implanted in a mouse brain, demonstrate the absence of distortion in the recorded neuronal signals during precise in situ optical stimulation
* Implanted the packaged devices into the CA1 pyramidal layer of awake mice, expressing Channelrhodopsin-2 in pyramidal cells and ChrimsonR in paravalbumin-expressing interneurons, and achieved optical excitation of each cell type using sub-mW illumination

* Mice and rats

* No artifact, precise optical stimulation and recording with high temporal resolution

* Wu et al, “Monolithically Integrated mLEDs on Silicon Neural Probes for High-Resolution Optogenetic Studies in Behaving Animals,” Neuron, 88, pp. 1136-1148, doi: 10.1016, 2015.
Kim et al, “”Artifact-free and high-temporal-resolution in vivo opto-electrophysiology with microLED optoelectrodes.”” Nat Commun 11, 2063 (2020). https://doi.org/10.1038/s41467-020-15769-w

* English et al, “”Pyramidal Cell-Interneuron Circuit Architecture and Dynamics in Hippocampal Networks.”” Neuron, vol. 96, no. 2, pp. 505-520, Oct. 2017

* Navas-Olive et al. “”Multimodal determinants of phase-locked dynamics across deep-superficial hippocampal sublayers during theta oscillations.”” Nat Commun 11, 2217 (2020). https://doi.org/10.1038/s41467-020-15840-6


Euisik Yoon (Professor)
Jose Roberto Lopez Ruiz (Program Manager)


University of Michigan



Euisik Yoon (U-M Professor of Electrical Engineering and Computer Science)
György Buzsáki (Professor of Neuroscience at New York University)
Dawen Cai (Assistant Professor of Cell and Developmental Biology at U-M)
Cynthia Chestek (Associate Professor of Biomedical Engineering at U-M)
Viviana Gradinaru (Professor of Biology and Biological Engineering at California Institute of Technology)
John Seymour (Assistant Research Scientist in Electrical Engineering and Computer Science at U-M)
James Weiland (Professor of Biomedical Engineering at U-M)
Ken Wise (the William Gould Dow Distinguished University Professor Emeritus of Electrical Engineering and Computer Science at U-M)



NIH #1OT2OD024907
NINDS #UF1NS107659
NSF DBI-1707316
NINDS #U01NS094375