About

Dr. Yurii Vlasov is a John Bardeen Endowed Chair in Electrical and Computer Engineering and Physics at the University of Illinois at Urbana-Champaign. He holds tenured positions across multiple departments including Electrical and Computer Engineering, Physics, Materials Science and Engineering, and Bio-Engineering, as well as the Carle Illinois College of Medicine. His research focuses on the development of advanced engineering approaches for reverse engineering brain circuits, including silicon-based nanofluidic and nanophotonic neural probes, in-vivo neurobiological experiments involving large-scale recording and manipulation of brain activity, and the application of machine-learning algorithms to analyze neural datasets. Prior to his current appointment, Dr. Vlasov held significant research and managerial roles at IBM T.J. Watson Research Center, where he led efforts in integrated silicon nanophotonics and neuromorphic computing architectures, initiating projects that advanced the technology from fundamental research to commercial manufacturing. His earlier work includes semiconductor nanophotonics development at the N.E.C. Research Institute and the Strasbourg IPCMS Institute, as well as extensive research at the Ioffe Institute of Physics and Technology in Russia. Dr. Vlasov has published over 300 papers, filed more than 100 patents, and delivered over 100 invited talks. He is a member of the National Academy of Engineering and a Fellow of the APS, IEEE, and OSA, recognized for his contributions to the fields of nanophotonics and neurotechnology.

Research topics

• Computer Science
• Materials science
• Nanotechnology
• Chemistry
• Chromatography
• Engineering
• Optoelectronics
• Organic chemistry
• Data science
• Optics
• Human–computer interaction

Selected publications

• Probabilistic Perceptual Decisions during Navigation Are Driven by a Small Subpopulation of Neurons in a Single Cortical Column of the Primary Somatosensory Cortex

  Journal of Neuroscience · 2026-03-02

  articleOpen accessSenior author

  Perceptually driven behavioral choices are thought to develop gradually from sensation to perception in the somatosensory cortex to guide decision-making in higher-order cortical areas. The primary somatosensory cortex (wS1) of rodents related to their mystacial whiskers has been a model system to study this information flow. However, the role of wS1 in this process is often debated based on controversial results of loss-of-function behavioral experiments that often require prolonged training and movement restraints. Here, to elucidate the role of wS1 in decision-making, we developed an ethological whisker-guided virtual reality (VR) paradigm that closely mimics natural navigation in underground burrows. Untrained mice of either sex navigate left and right turns at high speed by sensing VR walls with just a pair of their C2 whiskers. Inactivating layer 4 of C2 barrel results in a loss of the ability to produce turns contralateral to the lesion. Using a probabilistic model of collision avoidance in the presence of noise and uncertainties, we hypothesize that wS1 is involved in a feedback control loop that requires continuous updates and predictions to infer the optimal path for collision avoidance.

  PublisherOA PDFDOI

• Local chemical compartments in a mammalian cortex measured in-vivo with silicon nanodialysis mass spectrometry platform

  ChemRxiv · 2025-09-11

  preprintOpen accessSenior author

  Chemical signaling in the mammalian brain is involved in control of behavior via modulation of neural activity, in wiring the brain by directing the axonal growth, in localization of pharmacological effects of drugs, and in directing immune cell migration in neuroinflammatory response. Local gradients of various neurochemicals in the brain are difficult to study in-vivo due to their complex spatiotemporal dynamics induced by intricate interactions between neurons and glial cells that are not well understood. Here, to directly measure in-vivo gradients of multiple neurochemicals and metabolites simultaneously, we utilize an open-flow silicon nanodialysis sampling platform coupled with sensitive mass spectrometry. Results reveal strong millimeter-scale spatial gradients in concentration of neurotransmitters, neuromodulators, and astroglial modulators in a mouse cortex. Formation and maintenance of such local chemical compartments indicate strong regulation of brain neurochemistry by glial-neuron interactions that may heavily influence physiological and pathophysiological modulation of brain functions.

  PublisherDOI

• Neural Correlates of Perceptual Decision Making in Primary Somatosensory Cortex

  Proceedings of the National Academy of Sciences · 2025-04-03 · 1 citations

  preprintOpen accessSenior author

  Abstract The brain is thought to produce decisions by gradual accumulation of sensory evidence through a hierarchically organized feedforward cascade of neuronal activities that transforms early stimulus representations in the primary somatosensory cortex (S1) to a perceptual decision processed in pre-motor areas. Recently, this prevailing view has been challenged by observation of choice- correlated neural activity as early in the hierarchy as S1. Here, to reconcile these seemingly controversial observations, we employ ethological whisker-guided navigation of mice in a tactile virtual reality paradigm combined with dense electrophysiological recordings in whisker-related wS1. Leaving only a pair of C2 whiskers for mice to navigate with, we effectively designed an information bottleneck for sensory input to decision making. We show that neural activity during sensory evidence accumulation exhibits dramatic collapse of the high-dimensional spiking activity to just a single latent variable followed by a slower and almost synchronous ramping up across the whole cortical column. We show that this variable is consistent with models of gradual accumulation of noisy sensory evidence to a decision bound. These observations indicate that S1 may directly participate in a categorical coding of all-or-none decision variable via cortico-cortical feedback loops through which sensory information reverberates to be transformed into perception and action. Significance Statement By employing ethological whisker-guided navigation of mice in a tactile virtual reality paradigm combined with dense electrophysiological recordings in whisker-related wS1, we show that neural activity during sensory evidence accumulation exhibits dramatic collapse of the high-dimensional spiking activity to just a single latent variable followed by a slower and almost synchronous ramping up across the whole cortical column. We show that this variable is consistent with models of gradual accumulation of noisy sensory evidence to a decision bound. These observations indicate that wS1 may directly participate in a categorical coding of all-or-none decision variable. Naturalistic perceptual decisions during active whisker-guided navigation High-dimensional activity in S1 collapses to a single variable prior to decision This ramping spiking activity is consistent with drift-diffusion decision models Indicates direct involvement of S1 in evidence accumulation

  PublisherOA PDFDOI

• Probabilistic Perceptual Decisions During Navigation Are Driven by Small Subpopulation of Neurons in a Single Cortical Column of Primary Somatosensory Cortex

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-18 · 1 citations

  preprintOpen accessSenior authorCorresponding

  Abstract Perceptually driven behavioral choices are thought to develop gradually from sensation to perception in the somatosensory cortex to guide decision-making in higher order cortical areas. Primary somatosensory cortex (wS1) of rodents related to their mystacial whiskers has been a model system to study this information flow. However, the role of wS1 in this process is often debated based on controversial results of loss-of-function behavioral experiments that often require prolonged training and movement restraints. Here, to elucidate the role of wS1 in decision-making, we developed an ethological whisker-guided virtual reality (VR) paradigm that closely mimics natural navigation in underground burrows. Untrained mice navigate left and right turns at high speed by sensing VR walls with just a pair of their C2 whiskers. Inactivating layer 4 of C2 barrel results in loss of ability to produce turns contralateral to the lesion. Using probabilistic model of collision avoidance in the presence of noise and uncertainties we hypothesize that wS1 is involved in a feedback control loop that requires continuous updates and predictions to infer the optimal path for collision avoidance. Significance Perceptual decisions driven by sensing salient changes in the environment are thought to develop from sensation in primary cortex (S1) to decisions in pre-motor cortical areas. However, the role of S1 in this process is debated based on controversial results of loss-of-function behavioral experiments that often require prolonged training and movement restraints. Here, by utilizing an ethological whisker-guided virtual reality, we show that perceptual decisions causally depend on small subpopulation of neurons in layer 4 of a single cortical barrel. Whisker-guided navigation requires continuous updates and predictions of relative positions of the body and obstacles to infer the optimal path for collision avoidance. These complex computations are likely to rely on nested feedback loops that directly involve wS1 hence making it indispensable.

  PublisherDOI

• Neuropeptides in the Extracellular Space of the Mouse Cortex Measured In Vivo by Nanodialysis Probe Coupled with LC‐MS

  Angewandte Chemie International Edition · 2025-08-11 · 2 citations

  articleOpen accessCorresponding

  Abstract Neuropeptides are key neuromodulators in the central nervous system that shape sensory processing, yet their extracellular dynamics in the somatosensory cortex (S1) remain poorly understood. This study applies an innovative membrane‐free silicon nanodialysis (ND) probe coupled with liquid chromatography‐mass spectrometry (LC‐MS) to analyze the extracellular neuropeptidome in the mouse S1 with spatial resolution down to 100 µm. Localized in vivo sampling identified extracellular peptides from secretogranin‐1, ProSAAS, pro‐opiomelanocortin (POMC), and others. Minimal tissue damage, enabled by probe dimensions of 75 × 15 µm 2 , resulted in an absence of structural peptides in the dialysate indicating low intracellular contamination. Many detected secretory peptides correlated with strong local mRNA expression; however, the detection of POMC‐derived peptides, despite negligible local expression, suggests long‐distance peptide transport or extracellular processing. To expand peptide identification, a discovery‐to‐targeted peptidomic approach was developed, revealing 46 peptides from 24 proteins in dialysate samples, including 10 proteins with low local expression. Complementary S1 tissue analysis confirmed POMC peptides and showed that 17% of 304 prohormone‐derived peptides had low local expression. These results uncover a complex extracellular peptide landscape shaped by both local and long‐distance signaling. By overcoming the limitations of traditional microdialysis, this approach advances the understanding of neuropeptide signaling in cortical function.

  PublisherOA PDFDOI

• Neuropeptides in the Extracellular Space of the Mouse Cortex Measured In Vivo by Nanodialysis Probe Coupled with LC‐MS

  Angewandte Chemie · 2025-08-11 · 1 citations

  articleOpen accessCorresponding

  Abstract Neuropeptides are key neuromodulators in the central nervous system that shape sensory processing, yet their extracellular dynamics in the somatosensory cortex (S1) remain poorly understood. This study applies an innovative membrane‐free silicon nanodialysis (ND) probe coupled with liquid chromatography‐mass spectrometry (LC‐MS) to analyze the extracellular neuropeptidome in the mouse S1 with spatial resolution down to 100 µm. Localized in vivo sampling identified extracellular peptides from secretogranin‐1, ProSAAS, pro‐opiomelanocortin (POMC), and others. Minimal tissue damage, enabled by probe dimensions of 75 × 15 µm 2 , resulted in an absence of structural peptides in the dialysate indicating low intracellular contamination. Many detected secretory peptides correlated with strong local mRNA expression; however, the detection of POMC‐derived peptides, despite negligible local expression, suggests long‐distance peptide transport or extracellular processing. To expand peptide identification, a discovery‐to‐targeted peptidomic approach was developed, revealing 46 peptides from 24 proteins in dialysate samples, including 10 proteins with low local expression. Complementary S1 tissue analysis confirmed POMC peptides and showed that 17% of 304 prohormone‐derived peptides had low local expression. These results uncover a complex extracellular peptide landscape shaped by both local and long‐distance signaling. By overcoming the limitations of traditional microdialysis, this approach advances the understanding of neuropeptide signaling in cortical function.

  PublisherDOI

• Neuropeptides in the Extracellular Space of the Mouse Cortex Measured by Nanodialysis Probe Coupled with LC-MS

  ChemRxiv · 2025-05-01

  preprintOpen access

  Neuropeptides are key neuromodulators in the central nervous system that shape sensory processing, yet their extracellular dynamics in the somatosensory cortex (S1) remain poorly understood. This study applies an innovative membrane-free silicon nanodialysis (ND) probe coupled with liquid chromatography-mass spectrometry (LC-MS) to analyze the extracellular neuropeptidome in the mouse S1 with spatial resolution down to 100 μm. Localized in vivo sampling identified extracellular peptides from secretogranin-1, ProSAAS, pro-opiomelanocortin (POMC), and others. Minimal tissue damage, enabled by probe dimensions of 75×15 μm², resulted in the detection of only one structural peptide (JIP-2), indicating low intracellular contamination. Many detected secretory peptides correlated with strong local mRNA expression; however, the detection of POMC-derived peptides, despite negligible local expression, suggests long-distance peptide transport or extracellular processing. To expand peptide identification, a discovery-to-targeted peptidomics approach was developed, revealing 46 peptides from 24 proteins in dialysate samples, including 10 proteins with low local expression. Complementary S1 tissue analysis confirmed POMC peptides and showed that 17% of 304 prohormone-derived peptides had low local expression. These results uncover a complex extracellular peptide landscape shaped by both local and long-distance signaling. By overcoming the limitations of traditional microdialysis, this approach advances the understanding of neuropeptide signaling in cortical function.

  PublisherOA PDFDOI

• Integrated Photonic Meta Beam-Shaper For Single-Neuron Optogenetic Interrogation

  2025-01-01

  articleSenior author

  We experimentally demonstrate an integrated photonic meta beam-shaper that produces a focused spot smaller than a single-neuron at a 46μm depth inside a brain slice with over 10dB suppression of background intensity.

  PublisherDOI

• Ultra-high numerical aperture waveguide-integrated meta beam shaper

  Optica · 2024-11-19 · 4 citations

  articleOpen accessSenior author

  The integration of metasurfaces with guided mode sources like waveguides has opened new frontiers for on-chip optical integration. However, the state-of-the-art in the field has targeted applications where long focal distances over thousands of light wavelengths are needed. This regime where the paraxial approximation holds enables inverse design of metasurfaces with weakly confining elements that are typically thicker than the wavelength in the material. For short focal length applications at distances less than 100 λ , where the paraxial approximation fails and high numerical apertures (NAs) are necessary, a different approach is required. Here, we designed and experimentally demonstrated single-mode waveguide-integrated meta beam shapers capable of redirecting the confined light into the free space and focusing it at focal distances less than 100 λ above the chip surface into a tightly focused spot. Focal spot characteristics measured at 460 nm operating wavelength approach diffraction-limited focusing across a range of focal lengths, device footprints, and numerical apertures, demonstrating the robustness of the approach. Focal volumes smaller than 1µm 3 are demonstrated for a range of focal distances below 50 µm (100 λ ). For a device with NA of 0.95 that is one of the highest amongst integrated metasurfaces, the measured focal volume is as small as just 0.06µm 3 at a focal distance of 13µm (28 λ ). These on-chip integrated ultra-high NA meta beam shapers have the potential to unlock new applications in quantum optical computing with trapped ions, localized optogenetic neurostimulation, and high resolution in situ microscopy.

  PublisherDOI

• Waveguide-fed Metasurfaces for High NA Focusing at Ultrashort Distances

  2024-01-01

  articleSenior author

  We experimentally demonstrate high-confinement waveguide-fed metasurfaces that produce nearly diffraction-limited spots at numerical apertures (NAs) as high as 0.95 with focal lengths as small as 15λ and sustain their efficiencies through high NAs

  PublisherDOI

Frequent coauthors

• William M. J. Green

  Princeton University

  91 shared

• Solomon Assefa

  Ethiopian Public Health Institute

  91 shared

• Fengnian Xia

  Hebei Chemical and Pharmaceutical College

  43 shared

• Clint L. Schow

  University of California, Santa Barbara

  40 shared

• Alexander Rylyakov

  Nokia (United States)

  37 shared

• Richard M. Osgood

  36 shared

• Jerry I. Dadap

  36 shared

• Tymon Barwicz

  IBM (United States)

  36 shared

Education

• Ph.D., Computer Science

  University of Illinois at Urbana-Champaign

  2000

• M.S., Computer Science

  University of Illinois at Urbana-Champaign

  1996

• B.S., Computer Science

  University of Illinois at Urbana-Champaign

  1994

Awards & honors

• Member of the National Academy of Engineering
• Fellow of the APS
• Fellow of the IEEE
• Fellow of the OSA
• IBM CEO Corporate Award