News

Society for Neuroscience

posted Nov 9, 2017, 6:32 PM by Bionic Lab   [ updated Nov 9, 2017, 6:33 PM ]

Come see our posters (including a dynamic poster) Tuesday November 14, 2017, 1:00 - 5:00 PM

595.14 / DP10/KK17 - Multi-scale, multi-modal analysis of the brain tissue-implant interface reveals new depths of the biological research field at the neuroelectronic interface [LINK]

595.03 / KK6 - In vivo 2-photon microscopy mapping of acute mechanical damage due to neural electrode array implantation [LINK]

595.07 / KK10 - CLARITY based 3D histology assessment of neural electrodes with antifouling coating implanted in mouse cortex [LINK]

Multimodal Microelectrode Failure Analysis Reveals Complex Relationship at the Neural Interface @ ECS

posted Oct 2, 2017, 2:58 AM by Bionic Lab   [ updated Oct 2, 2017, 2:59 AM ]

http://ma.ecsdl.org/content/MA2017-02/55/2296.short

   Penetrating microelectrode arrays that can record extracellular action potentials from small, targeted groups of neurons are critical for basic neuroscience research and emerging clinical applications. However, these electrode devices suffer from reliability and variability issues which impact their performance on the order of months to years. The failure mechanisms of these electrodes are understood to be a complex combination of the biotic and abiotic failure modes.

The breaching of the blood–brain barrier (BBB) to insert devices triggers a cascade of biochemical pathways resulting in complex molecular and cellular responses to implanted devices. Molecular and cellular changes in the microenvironment surrounding an implant include the introduction of mechanical strain, BBB leakage, activation of glial cells, loss of perfusion, secondary metabolic injury, and neuronal degeneration. The resulting inflammation is a key hypothesized cause of neural recording failure. However, previous attempt so directly correlate recording performance, to impedance, and to histological outcomes have led counter-intuitive and sometimes conflicting outcomes.

One reason is that many neurons remain quiescent during anesthetized or resting-state conditions. We previously demonstrated this by visually evoked stimulation paradigms of the contralateral eye in order to evaluate chronic recording performance of linear silicon electrode in the primary visual cortex. Additional, multiphoton analysis using GCaMP6 transgenic animals further confirmed these results. More recently, there has been a growing interesting recording during awake free-roaming conditions in the primary motor cortex in order to avoid resting-state related quiescent activity. However, this in turn leads to increases in Lenz’s Law related artefacts that have the same time constants and waveform shapes as action potentials in rodents, but not NHP. While behaviorally training animals to remain immobile could improve outcomes, it also introduces the potential for Experimenter Expectancy Effect bias on the outcomes.

The visual stimulation paradigm enable the use of current source density analysis to electrophysiologically identify Layer II/III, IV, and V in the cortex. This, in turn, allowed correlation of electrophysiological layers to the histological layers based on section depth and the differences in neural morphology and density. Our findings from electrophysiology, impedance spectroscopy, and post-mortem histology demonstrate a very poor relationship between histology and impedance to electrophysiology. For example, tissue with low-levels of glial encapsulation, healthy neuronal proximity, and low impedance can still have poor recording performance, even with neural activity is behaviorally driven.

Even when histology confirms a perfect tissue interface, cracking or delamination of insulation on the microelectrode has been linked to a drop in impedance and a loss of recording failure. In contrast, cracking of the electrical trace and delamination of the recording site has been linked to recording failure through a jump in electrical impedance. As such, several modes of mechanical failure of chronically implanted planar silicon electrodes were found that result in degradation and/or loss of recording. Our findings highlight the importance of strains and material properties of various subcomponents within an electrode array and the poor reliability of determining electrode viability through electrochemical impedance spectroscopy.

Interestingly, we discovered in a number of situations that even with good neural density, uncompromised electrode material, and good impedances, recording performance can sometimes completely degrade. New multimodal analysis demonstrates the importance of capturing dynamic information, such as with in vivo multiphoton study, and that the presence of neurons does not guarantee functional neural activity over time. We further demonstrate that the foundation of assumptions and simplification made in the field for neural interface research are not true or incomplete. To solve the longstanding chronic neural interface problem, we need to first understand the complexity of the problem.

  • © 2017 ECS - The Electrochemical Society

ACS Chemical Neuroscience: Most Cited Papers from 2015

posted Aug 22, 2017, 11:57 AM by Bionic Lab   [ updated Aug 22, 2017, 11:58 AM ]

"The most cited paper from 2015 thus far, is a review article from Kozai and co-workers at the University of Pittsburgh and the McGowan Center for Regenerative Medicine entitled “Brain tissue responses to neural implants impact signal sensitivity and intervention strategies” (DOI: 10.1021/cn500256e).(2) This review was in the biannual special issue on Monitoring Molecules, edited by Prof. Anne Andrews. The review focused on the complex molecular and cellular changes that occur when a device breaches the blood-brain barrier and is implanted. The review does a fantastic job summarizing the magnitude, variability, and time course (of acute, seconds to minutes, and chronic, week to months) of injuries and responses to the introduction of foreign bodies into the brain. The review ends with reflections on how and deeper understanding of these complex issues might lead to devices with improved sensitivity and longevity.(2) This is truly a must read."

http://pubs.acs.org/doi/10.1021/acschemneuro.7b00246

Save the Date: GRC on Neuroelectronic Interfaces

posted Apr 19, 2017, 1:50 PM by Bionic Lab   [ updated Apr 19, 2017, 1:51 PM ]


1st Gordon Research Conference on Neuroelectronic Interfaces

posted Apr 4, 2017, 2:02 PM by Bionic Lab   [ updated Apr 4, 2017, 2:02 PM ]

https://www.grc.org/programs.aspx?id=17731

Beyond Feasibility - Bridging the Gap in Neuroelectronic Interfaces

Dates

March 25-30, 2018

Location

Hotel Galvez

Galveston, TX
  Site Information

Organizers

Chairs:
Ulrich Hofmann &
Jeffrey R. Capadona

Vice Chairs:
Thomas Stieglitz &
Takashi Kozai

Application Deadline

Applications for this meeting must be submitted by February 25, 2018. Please apply early, as some meetings become oversubscribed (full) before this deadline. If the meeting is oversubscribed, it will be stated here. Note: Applications for oversubscribed meetings will only be considered by the Conference Chair if more seats become available due to cancellations.

Please note: The online application form for 2018 meetings will be available in April.

Meeting Description

Neuroelectronic interfaces bridge the central nervous system to the outside world and hold great potential for functional restoration in persons with paralysis, other forms of motor dysfunction, or limb loss. Such rehabilitative applications are commonly referred to as brain machine (or brain computer) interfaces. With a variety of signal transducing systems and processing algorithms, extracted neural signals were shown to be useful to drive external devices such as limb prostheses or computers. A number of types of recording electrode devices have been developed to access different forms of neural information through varying levels of invasiveness. However, many researchers believe that recording devices that penetrate into specific regions of the brain will provide the most useful control signals for complex BMI applications. Despite the potential that penetrating intracortical microelectrodes have shown, widespread implementation is impeded by the inability to consistently record high quality neural signals over clinically relevant time frames.

The last years showed both an increasing interest into the cellular reasons and pathological causes for this slow-down in bridging the translational gap on one side and a new range of materials and methods appearing from the developmental pipelines like Graphene and Nanomaterials on the other side. Therefore, our inaugural Gordon Research Conference (GRC) on Neuroelectronic Interfaces will challenge the international field to turn back to the drawing board of basic materials research armed with emerging fundamental neurosciences knowledge, and bring together a multi-disciplinary team of leading experts in cellular neuroscience, brain pathology, neuro-technology and materials science in order to discuss and eventually solve or discard the obstacles on the quest for a chronically useful and reliable neural interface.

Preliminary Program

The topics and speakers for the conference sessions are displayed below (italics denote discussion leaders). The Conference Chair is currently developing their detailed program, which will include the complete meeting schedule, as well as the talk titles for all speakers. The detailed program will be available by November 25, 2017. Please check back for updates.

  • Brain-Machine Interfaces
    (A. Ajiboye / Richard Andersen / Robert Kirsch / Miguel Nicolelis)
  • Neuropathology – The Brain's Response to Injury
    (Maria Asplund / Carola Haas / Alex Huang / Marco Prinz)
  • Brain Implants – State of the Art
    (Kip Ludwig / Cindy Chestek / Stephanie Lacour / Patrick Ruther / Philip Troyk)
  • Functional Materials and Brain
    (Simon Thiele / Polina Anikeeva / Elisa Castagnola / Jurgen Ruhe / Walter Voit)
  • Neurophotonics and Brain Implants
    (Justin Williams / Ilka Diester / Erin Purcell / Daniel Razansky / Cristin Welle)
  • Biomechanics of the Device-Tissue Interface
    (Kevin Otto / James Fawcett / Ellen Kuhl / Jit Muthuswamy)
  • Soft Matter Interactions in Brain Implants
    (Manfred Radmacher / Xinyan Cui / Yael Hanein)
  • Device Biologisation and Stem Cells
    (Ana Paula / D. Kacy Cullen / Davide Ricci / John Wolf)
  • Nanotools in Neural Interfacing
    (Joseph Pancrazio / Edward Boyden / Hilton Kaplan / Chong Xie)   

See you at SfN

posted Nov 11, 2016, 7:11 AM by Bionic Lab   [ updated Nov 11, 2016, 7:11 AM ]

Nov. 13, 2016, 11:00 AM
Short talk at Blackrock Microsystem Booth  (#1129) at SfN
Preclinical assessment of bioactive coatings on Utah Arrays in rodents
http://blackrockmicro.com/ephys-lounge/

Nov. 14, 2016, 1:00 - 5:00 PM
438.07 / WW5 - Evaluation of neural cell adhesion molecule L1 coating for improved chronic recordings 
438.08 / WW6 - Dexamethasone retrodialysis attenuates microglial response to implanted probes In vivo
438.14 / WW12 - In vivo 2-photon imaging of neural implants: surface modification with L1CAM camouflages devices from microglial encapsulation 

Neuroadhesive L1 coating attenuates acute microglial attachment to neural electrodes as revealed by live two-photon microscopy. Biomaterials. (Accepted)

posted Nov 6, 2016, 12:56 PM by Bionic Lab   [ updated Nov 6, 2016, 12:57 PM ]

Eles JR, Vazquez AL, Snyder NR, Lagenaur C, Murphy MC, Kozai TDY*†, Cui XT*†. 
http://www.sciencedirect.com/science/article/pii/S0142961216306044

Implantable neural electrode technologies for chronic neural recordings can restore functional control to paralysis and limb loss victims through brain-machine interfaces. These probes, however, have high failure rates partly due to the biological responses to the probe which generates an inflammatory scar and subsequent neuronal cell death. L1 is a neuronal specific cell adhesion molecule and has been shown to minimize glial scar formation and promote electrode-neuron integration when covalently attached to the surface of neural probes. In this work, the acute microglial response to L1-coated neural probes was evaluated in vivo by implanting coated devices into the cortex of mice with fluorescently labeled microglia, and tracking microglial dynamics with multi-photon microscopy for the ensuing 6 h in order to understand L1's cellular mechanisms of action. Microglia became activated immediately after implantation, extending processes towards both L1-coated and uncoated control probes at similar velocities. After the processes made contact with the probes, microglial processes expanded to cover 47.7% of the control probes' surfaces. For L1-coated probes, however, there was a statistically significant 83% reduction in microglial surface coverage. This effect was sustained through the experiment. At 6 h post-implant, the radius of microglia activation was reduced for the L1 probes by 20%, shifting from 130.0 to 103.5 μm with the coating. Microglia as far as 270 μm from the implant site displayed significantly lower morphological characteristics of activation for the L1 group. These results suggest that the L1 surface treatment works in an acute setting by microglial mediated mechanisms.
http://www.sciencedirect.com/science/article/pii/S0142961216306044

University of Pittsburgh Brain Institute: Brain Day Nov 4!

posted Nov 3, 2016, 2:41 PM by Bionic Lab   [ updated Nov 3, 2016, 2:42 PM ]

We hope you’ll join us at the scientific poster sessions tomorrow, Friday, November 4, when the University of Pittsburgh Brain Institute (UPBI) holds its second annual Brain Day on the main floor of the William Pitt Union, 3959 Fifth Avenue (parking is available in the Soldiers and Sailors Garage nearby).

 

This event brings together scientists, advocacy groups, and community members to talk about the importance of brain research in understanding and solving key health problems such as addiction, depression, and neurodegenerative disorders. The two sessions will showcase a total of 150 posters on research from departments across the university’s campus! We also anticipate attendance by representatives of 27 different advocacy groups, allowing Brain Institute members like you to talk with them about brain science, as well as listen to their concerns and interests. Additionally, the day provides an opportunity for scientists from a broad range of disciplines across campus to learn about each other’s research.

 

Please come hear several distinguished guests kick off the morning poster session. Remarks beginning at 9:30 a.m. are as follows:

 

  • Welcome by Peter Strick, Ph.D., Scientific Director of the Brain Institute, Thomas Detre Professor and Chair of Neurobiology, and Director of Systems Neuroscience Institute
  • Address by Patrick Gallagher, Ph.D., Chancellor of the University of Pittsburgh
  • Address by Congressman Tim Murphy, Representative of the 18th District of PA

 

Running from 9:30 a.m. to 12:00 p.m., the morning session will highlight work focusing on brain injury; neurodegenerative and neurological diseases; psychiatric disorders; and neurochemistry and pharmacology.

 

From 2:00 p.m. - 4:30 p.m., we will hold a second session with posters on brain function; sensory studies; brain models and neurotechnologies; imaging techniques; and brains and technology.  At 2:30 p.m., we will have a demonstration by Ted Huppert, Ph.D., associate professor of radiology at Pitt’s School of Medicine, of a novel electroencephalography (EEG) based technology designed to help image the brains of patients with traumatic brain injury.

 

Of special note, we will be awarding one “Peoples’ Choice” award - all attendees may cast their vote for their favorite poster! There will be judges assessing each session, and we will give two awards for best graduate poster and two awards for best poster by a post-doctoral fellow.

 

We hope to see you there!


http://www.pittbrainday.site/about

New Papers

posted Nov 1, 2016, 7:04 AM by Bionic Lab   [ updated Nov 1, 2016, 7:04 AM ]

Khilwani R, Gilgunn PJ, Kozai TDY, Ong XC, Korkmaz E, Gunalan P, Cui XT, Fedder GK, Ozdoganlar OB. Ultra-Miniature Ultra-Compliant Neural Probes with Dissolvable Delivery Needles: Design, Fabrication and Characterization. Biomedical Microdevices. 18(6), 97. [LINK]

Patel PR, Zhang H, Robbins M, Nofar J, Marshal S, Kobylarek M, Kozai TDY, Kotov NA, Chestek C. Chronic in vivo stability assessment of carbon fiber microelectrode arrays J Neural Eng. 2016. 13(6). 066022. [LINK]

BrainCAS Session

posted Oct 11, 2016, 7:50 AM by Bionic Lab   [ updated Oct 15, 2016, 10:49 PM ]

Kozai TDY, Biological Science Driven Future of Neural Interface Engineering. 2016 BrainCAS. Hangzhou. China. Oct 20-21.


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