1
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Suematsu N, Vazquez AL, Kozai TDY. Activation and depression of neural and hemodynamic responses induced by the intracortical microstimulation and visual stimulation in the mouse visual cortex. J Neural Eng 2024; 21:026033. [PMID: 38537268 PMCID: PMC11002944 DOI: 10.1088/1741-2552/ad3853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/28/2024] [Accepted: 03/27/2024] [Indexed: 04/09/2024]
Abstract
Objective. Intracortical microstimulation (ICMS) can be an effective method for restoring sensory perception in contemporary brain-machine interfaces. However, the mechanisms underlying better control of neuronal responses remain poorly understood, as well as the relationship between neuronal activity and other concomitant phenomena occurring around the stimulation site.Approach. Different microstimulation frequencies were investigatedin vivoon Thy1-GCaMP6s mice using widefield and two-photon imaging to evaluate the evoked excitatory neural responses across multiple spatial scales as well as the induced hemodynamic responses. Specifically, we quantified stimulation-induced neuronal activation and depression in the mouse visual cortex and measured hemodynamic oxyhemoglobin and deoxyhemoglobin signals using mesoscopic-scale widefield imaging.Main results. Our calcium imaging findings revealed a preference for lower-frequency stimulation in driving stronger neuronal activation. A depressive response following the neural activation preferred a slightly higher frequency stimulation compared to the activation. Hemodynamic signals exhibited a comparable spatial spread to neural calcium signals. Oxyhemoglobin concentration around the stimulation site remained elevated during the post-activation (depression) period. Somatic and neuropil calcium responses measured by two-photon microscopy showed similar dependence on stimulation parameters, although the magnitudes measured in soma was greater than in neuropil. Furthermore, higher-frequency stimulation induced a more pronounced activation in soma compared to neuropil, while depression was predominantly induced in soma irrespective of stimulation frequencies.Significance. These results suggest that the mechanism underlying depression differs from activation, requiring ample oxygen supply, and affecting neurons. Our findings provide a novel understanding of evoked excitatory neuronal activity induced by ICMS and offer insights into neuro-devices that utilize both activation and depression phenomena to achieve desired neural responses.
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Affiliation(s)
- Naofumi Suematsu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Alberto L Vazquez
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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2
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van der Grinten M, de Ruyter van Steveninck J, Lozano A, Pijnacker L, Rueckauer B, Roelfsema P, van Gerven M, van Wezel R, Güçlü U, Güçlütürk Y. Towards biologically plausible phosphene simulation for the differentiable optimization of visual cortical prostheses. eLife 2024; 13:e85812. [PMID: 38386406 PMCID: PMC10883675 DOI: 10.7554/elife.85812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/21/2024] [Indexed: 02/23/2024] Open
Abstract
Blindness affects millions of people around the world. A promising solution to restoring a form of vision for some individuals are cortical visual prostheses, which bypass part of the impaired visual pathway by converting camera input to electrical stimulation of the visual system. The artificially induced visual percept (a pattern of localized light flashes, or 'phosphenes') has limited resolution, and a great portion of the field's research is devoted to optimizing the efficacy, efficiency, and practical usefulness of the encoding of visual information. A commonly exploited method is non-invasive functional evaluation in sighted subjects or with computational models by using simulated prosthetic vision (SPV) pipelines. An important challenge in this approach is to balance enhanced perceptual realism, biologically plausibility, and real-time performance in the simulation of cortical prosthetic vision. We present a biologically plausible, PyTorch-based phosphene simulator that can run in real-time and uses differentiable operations to allow for gradient-based computational optimization of phosphene encoding models. The simulator integrates a wide range of clinical results with neurophysiological evidence in humans and non-human primates. The pipeline includes a model of the retinotopic organization and cortical magnification of the visual cortex. Moreover, the quantitative effects of stimulation parameters and temporal dynamics on phosphene characteristics are incorporated. Our results demonstrate the simulator's suitability for both computational applications such as end-to-end deep learning-based prosthetic vision optimization as well as behavioral experiments. The modular and open-source software provides a flexible simulation framework for computational, clinical, and behavioral neuroscientists working on visual neuroprosthetics.
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Affiliation(s)
| | | | - Antonio Lozano
- Netherlands Institute for Neuroscience, Vrije Universiteit, Amsterdam, Netherlands
| | - Laura Pijnacker
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Bodo Rueckauer
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Pieter Roelfsema
- Netherlands Institute for Neuroscience, Vrije Universiteit, Amsterdam, Netherlands
| | - Marcel van Gerven
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Richard van Wezel
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
- Biomedical Signals and Systems Group, University of Twente, Enschede, Netherlands
| | - Umut Güçlü
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Yağmur Güçlütürk
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
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3
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Suematsu N, Vazquez AL, Kozai TD. Activation and depression of neural and hemodynamic responses induced by the intracortical microstimulation and visual stimulation in the mouse visual cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.01.573814. [PMID: 38260671 PMCID: PMC10802282 DOI: 10.1101/2024.01.01.573814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Objective . Intracortical microstimulation can be an effective method for restoring sensory perception in contemporary brain-machine interfaces. However, the mechanisms underlying better control of neuronal responses remain poorly understood, as well as the relationship between neuronal activity and other concomitant phenomena occurring around the stimulation site. Approach . Different microstimulation frequencies were investigated in vivo on Thy1-GCaMP6s mice using widefield and two-photon imaging to evaluate the evoked excitatory neural responses across multiple spatial scales as well as the induced hemodynamic responses. Specifically, we quantified stimulation-induced neuronal activation and depression in the mouse visual cortex and measured hemodynamic oxyhemoglobin and deoxyhemoglobin signals using mesoscopic-scale widefield imaging. Main results . Our calcium imaging findings revealed a preference for lower-frequency stimulation in driving stronger neuronal activation. A depressive response following the neural activation preferred a slightly higher frequency stimulation compared to the activation. Hemodynamic signals exhibited a comparable spatial spread to neural calcium signals. Oxyhemoglobin concentration around the stimulation site remained elevated during the post-activation (depression) period. Somatic and neuropil calcium responses measured by two-photon microscopy showed similar dependence on stimulation parameters, although the magnitudes measured in soma was greater than in neuropil. Furthermore, higher-frequency stimulation induced a more pronounced activation in soma compared to neuropil, while depression was predominantly induced in soma irrespective of stimulation frequencies. Significance . These results suggest that the mechanism underlying depression differs from activation, requiring ample oxygen supply, and affecting neurons. Our findings provide a novel understanding of evoked excitatory neuronal activity induced by intracortical microstimulation and offer insights into neuro-devices that utilize both activation and depression phenomena to achieve desired neural responses.
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4
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Margalit SN, Slovin H. Spatio-temporal activation patterns of neuronal population evoked by optostimulation and the comparison to electrical microstimulation. Sci Rep 2023; 13:12689. [PMID: 37542091 PMCID: PMC10403613 DOI: 10.1038/s41598-023-39808-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
Optostimulation and electrical microstimulation are well-established techniques that enable to artificially stimulate the brain. While the activation patterns evoked by microstimulation in cortical network are well characterized, much less is known for optostimulation. Specifically, the activation maps of neuronal population at the membrane potential level and direct measurements of these maps were barely reported. In addition, only a few studies compared the activation patterns evoked by microstimulation and optostimulation. In this study we addressed these issues by applying optostimulation in the barrel cortex of anesthetized rats after a short (ShortExp) or a long (LongExp) opsin expression time and compared it to microstimulation. We measured the membrane potential of neuronal populations at high spatial (meso-scale) and temporal resolution using voltage-sensitive dye imaging. Longer optostimulation pulses evoked higher neural responses spreading over larger region relative to short pulses. Interestingly, similar optostimulation pulses evoked stronger and more prolonged population response in the LongExp vs. the ShortExp condition. Finally, the spatial activation patterns evoked in the LongExp condition showed an intermediate state, with higher resemblance to the microstimulation at the stimulation site. Therefore, short microstimulation and optostimulation can induce wide spread activation, however the effects of optostimulation depend on the opsin expression time.
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Affiliation(s)
| | - Hamutal Slovin
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel.
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5
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Denyer R, Greenhouse I, Boyd LA. PMd and action preparation: bridging insights between TMS and single neuron research. Trends Cogn Sci 2023; 27:759-772. [PMID: 37244800 DOI: 10.1016/j.tics.2023.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/29/2023]
Abstract
Transcranial magnetic stimulation (TMS) research has furthered understanding of human dorsal premotor cortex (PMd) function due to its unrivalled ability to measure the inhibitory and facilitatory influences of PMd over the primary motor cortex (M1) in a temporally precise manner. TMS research indicates that PMd transiently modulates inhibitory output to effector representations within M1 during motor preparation, with the direction of modulation depending on which effectors are selected for response, and the timing of modulations co-varying with task selection demands. In this review, we critically assess this literature in the context of a dynamical systems approach used to model nonhuman primate (NHP) PMd/M1 single-neuron recordings during action preparation. Through this process, we identify gaps in the literature and propose future experiments.
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Affiliation(s)
- Ronan Denyer
- Department of Physical Therapy, University of British Columbia, Vancouver, BC, V6T1Z3, Canada; Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, V6T1Z3, Canada.
| | - Ian Greenhouse
- Department of Human Physiology, University of Oregon, Eugene, OR 97401, USA
| | - Lara A Boyd
- Department of Physical Therapy, University of British Columbia, Vancouver, BC, V6T1Z3, Canada
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6
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Lycke R, Kim R, Zolotavin P, Montes J, Sun Y, Koszeghy A, Altun E, Noble B, Yin R, He F, Totah N, Xie C, Luan L. Low-threshold, high-resolution, chronically stable intracortical microstimulation by ultraflexible electrodes. Cell Rep 2023; 42:112554. [PMID: 37235473 PMCID: PMC10592461 DOI: 10.1016/j.celrep.2023.112554] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/08/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Intracortical microstimulation (ICMS) enables applications ranging from neuroprosthetics to causal circuit manipulations. However, the resolution, efficacy, and chronic stability of neuromodulation are often compromised by adverse tissue responses to the indwelling electrodes. Here we engineer ultraflexible stim-nanoelectronic threads (StimNETs) and demonstrate low activation threshold, high resolution, and chronically stable ICMS in awake, behaving mouse models. In vivo two-photon imaging reveals that StimNETs remain seamlessly integrated with the nervous tissue throughout chronic stimulation periods and elicit stable, focal neuronal activation at low currents of 2 μA. Importantly, StimNETs evoke longitudinally stable behavioral responses for over 8 months at a markedly low charge injection of 0.25 nC/phase. Quantified histological analyses show that chronic ICMS by StimNETs induces no neuronal degeneration or glial scarring. These results suggest that tissue-integrated electrodes provide a path for robust, long-lasting, spatially selective neuromodulation at low currents, which lessens risk of tissue damage or exacerbation of off-target side effects.
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Affiliation(s)
- Roy Lycke
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Robin Kim
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Pavlo Zolotavin
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Jon Montes
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA; Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Yingchu Sun
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Aron Koszeghy
- Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00790 Helsinki, Finland
| | - Esra Altun
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA; Material Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Brian Noble
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA; Applied Physics Program, Rice University, Houston, TX 77005, USA
| | - Rongkang Yin
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Fei He
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA
| | - Nelson Totah
- Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00790 Helsinki, Finland; Faculty of Pharmacy, University of Helsinki, 00790 Helsinki, Finland
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA; Department of Bioengineering, Rice University, Houston, TX 77005, USA.
| | - Lan Luan
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA; Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, USA; Department of Bioengineering, Rice University, Houston, TX 77005, USA.
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7
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Claar LD, Rembado I, Kuyat JR, Russo S, Marks LC, Olsen SR, Koch C. Cortico-thalamo-cortical interactions modulate electrically evoked EEG responses in mice. eLife 2023; 12:RP84630. [PMID: 37358562 DOI: 10.7554/elife.84630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023] Open
Abstract
Perturbational complexity analysis predicts the presence of consciousness in volunteers and patients by stimulating the brain with brief pulses, recording EEG responses, and computing their spatiotemporal complexity. We examined the underlying neural circuits in mice by directly stimulating cortex while recording with EEG and Neuropixels probes during wakefulness and isoflurane anesthesia. When mice are awake, stimulation of deep cortical layers reliably evokes locally a brief pulse of excitation, followed by a biphasic sequence of 120 ms profound off period and a rebound excitation. A similar pattern, partially attributed to burst spiking, is seen in thalamic nuclei and is associated with a pronounced late component in the evoked EEG. We infer that cortico-thalamo-cortical interactions drive the long-lasting evoked EEG signals elicited by deep cortical stimulation during the awake state. The cortical and thalamic off period and rebound excitation, and the late component in the EEG, are reduced during running and absent during anesthesia.
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Affiliation(s)
- Leslie D Claar
- MindScope Program, Allen Institute, Seattle, United States
| | - Irene Rembado
- MindScope Program, Allen Institute, Seattle, United States
| | | | - Simone Russo
- MindScope Program, Allen Institute, Seattle, United States
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Lydia C Marks
- MindScope Program, Allen Institute, Seattle, United States
| | - Shawn R Olsen
- MindScope Program, Allen Institute, Seattle, United States
| | - Christof Koch
- MindScope Program, Allen Institute, Seattle, United States
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8
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Chong I, Ramezanpour H, Thier P. Causal Manipulation of Gaze-Following in the Macaque Temporal Cortex. Prog Neurobiol 2023; 226:102466. [PMID: 37211234 DOI: 10.1016/j.pneurobio.2023.102466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 05/23/2023]
Abstract
Gaze-following, the ability to shift one's own attention to places or objects others are looking at, is essential for social interactions. Single unit recordings from the monkey cortex and neuroimaging work on the human and monkey brain suggest that a distinct region in the temporal cortex, the gaze-following patch (GFP), underpins this ability. Since previous studies of the GFP have relied on correlational techniques, it remains unclear whether gaze-following related activity in the GFP indicates a causal role rather than being just a reverberation of behaviorally relevant information produced elsewhere. To answer this question, we applied focal electrical and pharmacological perturbation to the GFP. Both approaches, when applied to the GFP, disrupted gaze-following if the monkeys had been instructed to follow gaze, along with the ability to suppress it if vetoed by the context. Hence the GFP is necessary for gaze-following as well as its cognitive control.
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Affiliation(s)
- Ian Chong
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
| | - Hamidreza Ramezanpour
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Centre for Vision Research, York University, Toronto, Ontario, Canada
| | - Peter Thier
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany.
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9
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Canales A, Scheuer KS, Zhao X, Jackson MB. Unitary synaptic responses of parvalbumin interneurons evoked by excitatory neurons in the mouse barrel cortex. Cereb Cortex 2023; 33:5108-5121. [PMID: 36227216 PMCID: PMC10151880 DOI: 10.1093/cercor/bhac403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian cortex integrates and processes information to transform sensory inputs into perceptions and motor outputs. These operations are performed by networks of excitatory and inhibitory neurons distributed through the cortical layers. Parvalbumin interneurons (PVIs) are the most abundant type of inhibitory cortical neuron. With axons projecting within and between layers, PVIs supply feedforward and feedback inhibition to control and modulate circuit function. Distinct populations of excitatory neurons recruit different PVI populations, but the specializations of these synapses are poorly understood. Here, we targeted a genetically encoded hybrid voltage sensor to PVIs and used fluorescence imaging in mouse somatosensory cortex slices to record their voltage changes. Stimulating a single visually identified excitatory neuron with small-tipped theta-glass electrodes depolarized multiple PVIs, and a common threshold suggested that stimulation elicited unitary synaptic potentials in response to a single excitatory neuron. Excitatory neurons depolarized PVIs in multiple layers, with the most residing in the layer of the stimulated neuron. Spiny stellate cells depolarized PVIs more strongly than pyramidal cells by up to 77%, suggesting a greater role for stellate cells in recruiting PVI inhibition and controlling cortical computations. Response half-width also varied between different excitatory inputs. These results demonstrate functional differences between excitatory synapses on PVIs.
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Affiliation(s)
- Alejandra Canales
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Katherine S Scheuer
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
| | - Xinyu Zhao
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, United States
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10
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Halgren AS, Siegel Z, Golden R, Bazhenov M. Multielectrode Cortical Stimulation Selectively Induces Unidirectional Wave Propagation of Excitatory Neuronal Activity in Biophysical Neural Model. J Neurosci 2023; 43:2482-2496. [PMID: 36849415 PMCID: PMC10082457 DOI: 10.1523/jneurosci.1784-21.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/27/2022] [Accepted: 01/13/2023] [Indexed: 03/01/2023] Open
Abstract
Cortical stimulation is emerging as an experimental tool in basic research and a promising therapy for a range of neuropsychiatric conditions. As multielectrode arrays enter clinical practice, the possibility of using spatiotemporal patterns of electrical stimulation to induce desired physiological patterns has become theoretically possible, but in practice can only be implemented by trial-and-error because of a lack of predictive models. Experimental evidence increasingly establishes traveling waves as fundamental to cortical information-processing, but we lack an understanding of how to control wave properties despite rapidly improving technologies. This study uses a hybrid biophysical-anatomical and neural-computational model to predict and understand how a simple pattern of cortical surface stimulation could induce directional traveling waves via asymmetric activation of inhibitory interneurons. We found that pyramidal cells and basket cells are highly activated by the anodal electrode and minimally activated by the cathodal electrodes, while Martinotti cells are moderately activated by both electrodes but exhibit a slight preference for cathodal stimulation. Network model simulations found that this asymmetrical activation results in a traveling wave in superficial excitatory cells that propagates unidirectionally away from the electrode array. Our study reveals how asymmetric electrical stimulation can easily facilitate traveling waves by relying on two distinct types of inhibitory interneuron activity to shape and sustain the spatiotemporal dynamics of endogenous local circuit mechanisms.SIGNIFICANCE STATEMENT Electrical brain stimulation is becoming increasingly useful to probe the workings of brain and to treat a variety of neuropsychiatric disorders. However, stimulation is currently performed in a trial-and-error fashion as there are no methods to predict how different electrode arrangements and stimulation paradigms will affect brain functioning. In this study, we demonstrate a hybrid modeling approach, which makes experimentally testable predictions that bridge the gap between the microscale effects of multielectrode stimulation and the resultant circuit dynamics at the mesoscale. Our results show how custom stimulation paradigms can induce predictable, persistent changes in brain activity, which has the potential to restore normal brain function and become a powerful therapy for neurological and psychiatric conditions.
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Affiliation(s)
- Alma S Halgren
- Department of Medicine, University of California - San Diego, La Jolla, California 92093-7374
- Department of Integrative Biology, University of California - Berkeley, Berkeley, California 94720
| | - Zarek Siegel
- Department of Medicine, University of California - San Diego, La Jolla, California 92093-7374
- Neurosciences Graduate Program, University of California - San Diego, La Jolla, California 92093-7374
| | - Ryan Golden
- Department of Medicine, University of California - San Diego, La Jolla, California 92093-7374
- Neurosciences Graduate Program, University of California - San Diego, La Jolla, California 92093-7374
| | - Maxim Bazhenov
- Department of Medicine, University of California - San Diego, La Jolla, California 92093-7374
- Neurosciences Graduate Program, University of California - San Diego, La Jolla, California 92093-7374
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11
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Fine I, Boynton GM. Pulse trains to percepts: A virtual patient describing the perceptual effects of human visual cortical stimulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.532424. [PMID: 36993519 PMCID: PMC10055195 DOI: 10.1101/2023.03.18.532424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The field of cortical sight restoration prostheses is making rapid progress with three clinical trials of visual cortical prostheses underway. However, as yet, we have only limited insight into the perceptual experiences produced by these implants. Here we describe a computational model or 'virtual patient', based on the neurophysiological architecture of V1, which successfully predicts the perceptual experience of participants across a wide range of previously published cortical stimulation studies describing the location, size, brightness and spatiotemporal shape of electrically induced percepts in humans. Our simulations suggest that, in the foreseeable future the perceptual quality of cortical prosthetic devices is likely to be limited by the neurophysiological organization of visual cortex, rather than engineering constraints.
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12
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Yun R, Mishler JH, Perlmutter SI, Rao RPN, Fetz EE. Responses of Cortical Neurons to Intracortical Microstimulation in Awake Primates. eNeuro 2023; 10:ENEURO.0336-22.2023. [PMID: 37037604 PMCID: PMC10135083 DOI: 10.1523/eneuro.0336-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 03/19/2023] [Accepted: 03/31/2023] [Indexed: 04/12/2023] Open
Abstract
Intracortical microstimulation (ICMS) is commonly used in many experimental and clinical paradigms; however, its effects on the activation of neurons are still not completely understood. To document the responses of cortical neurons in awake nonhuman primates to stimulation, we recorded single-unit activity while delivering single-pulse stimulation via Utah arrays implanted in primary motor cortex (M1) of three macaque monkeys. Stimuli between 5 and 50 μA delivered to single channels reliably evoked spikes in neurons recorded throughout the array with delays of up to 12 ms. ICMS pulses also induced a period of inhibition lasting up to 150 ms that typically followed the initial excitatory response. Higher current amplitudes led to a greater probability of evoking a spike and extended the duration of inhibition. The likelihood of evoking a spike in a neuron was dependent on the spontaneous firing rate as well as the delay between its most recent spike time and stimulus onset. Tonic repetitive stimulation between 2 and 20 Hz often modulated both the probability of evoking spikes and the duration of inhibition; high-frequency stimulation was more likely to change both responses. On a trial-by-trial basis, whether a stimulus evoked a spike did not affect the subsequent inhibitory response; however, their changes over time were often positively or negatively correlated. Our results document the complex dynamics of cortical neural responses to electrical stimulation that need to be considered when using ICMS for scientific and clinical applications.
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Affiliation(s)
- Richy Yun
- Departments of Bioengineering
- Center for Neurotechnology
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| | - Jonathan H Mishler
- Departments of Bioengineering
- Center for Neurotechnology
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| | - Steve I Perlmutter
- Physiology and Biophysics
- Center for Neurotechnology
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| | - Rajesh P N Rao
- Allen School for Computer Science and Engineering
- Center for Neurotechnology
| | - Eberhard E Fetz
- Departments of Bioengineering
- Physiology and Biophysics
- Center for Neurotechnology
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
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13
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Ersöz A, Kim I, Han M. Charge Injection Enhancement Comparisons of Iridium Oxide Microelectrodes In Vitro and In Vivo Using a Portable Neurostimulator. INTERNATIONAL IEEE/EMBS CONFERENCE ON NEURAL ENGINEERING : [PROCEEDINGS]. INTERNATIONAL IEEE EMBS CONFERENCE ON NEURAL ENGINEERING 2023; 2023:10.1109/ner52421.2023.10123832. [PMID: 38590827 PMCID: PMC11000213 DOI: 10.1109/ner52421.2023.10123832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Microelectrodes are desired to deliver more charges to neural tissues while under electrochemical safety limits. Applying anodic bias potential during neurostimulation is a known technique for charge enhancement. Here, we investigated the levels of charge enhancement with anodic bias potential in vitro and in vivo using a custom-designed portable neurostimulator. We immersed our custom microelectrode probe in saline and measured voltage transients in response to constant current stimulation with and without a 500 mV anodic bias potential. We then inserted the same microelectrode probe into the primary motor cortex of the rat brain and measured voltage transients with the same electronics. Results showed that the charge injection capacity of the activated iridium oxide microelectrode site (with 2000 μm2 geometric surface areas (GSAs)) increased by the use of the anodic bias potentials in both in vitro and in vivo: from 10 nC/phase to 32 nC/phase for 200 μs pulse widths, and from 2 nC/phase to 8 nC/phase, respectively. Thus, the order of charge injection capacities of the four cases tested in this study is as follows (from the lowest to the highest): in vivo without anodic bias, in vivo with anodic bias, in vitro without anodic bias, and in vitro with anodic bias. This work also validated in vivo use of our new portable neurostimulator which received stimulation waveforms wirelessly.
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Affiliation(s)
- Alpaslan Ersöz
- A. Ersӧz is with the Mechanical Engineering Department, Carnegie Mellon University, Pittsburgh, PA 15213 USA
| | - Insoo Kim
- I. Kim is with the Department of Medicine and Division of Occupational and Environmental Medicine, University of Connecticut, Farmington, CT 06030 USA
| | - Martin Han
- M. Han is with the Biomedical Engineering Department, University of Connecticut, Storrs, CT 06269 USA
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14
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Lycke R, Kim R, Zolotavin P, Montes J, Sun Y, Koszeghy A, Altun E, Noble B, Yin R, He F, Totah N, Xie C, Luan L. Low-threshold, high-resolution, chronically stable intracortical microstimulation by ultraflexible electrodes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.20.529295. [PMID: 36865195 PMCID: PMC9980065 DOI: 10.1101/2023.02.20.529295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Intracortical microstimulation (ICMS) enables applications ranging from neuroprosthetics to causal circuit manipulations. However, the resolution, efficacy, and chronic stability of neuromodulation is often compromised by the adverse tissue responses to the indwelling electrodes. Here we engineer ultraflexible stim-Nanoelectronic Threads (StimNETs) and demonstrate low activation threshold, high resolution, and chronically stable ICMS in awake, behaving mouse models. In vivo two-photon imaging reveals that StimNETs remain seamlessly integrated with the nervous tissue throughout chronic stimulation periods and elicit stable, focal neuronal activation at low currents of 2 μA. Importantly, StimNETs evoke longitudinally stable behavioral responses for over eight months at markedly low charge injection of 0.25 nC/phase. Quantified histological analysis show that chronic ICMS by StimNETs induce no neuronal degeneration or glial scarring. These results suggest that tissue-integrated electrodes provide a path for robust, long-lasting, spatially-selective neuromodulation at low currents which lessen risks of tissue damage or exacerbation of off-target side-effects.
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Affiliation(s)
- Roy Lycke
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Robin Kim
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Pavlo Zolotavin
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Jon Montes
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
- Department of Bioenginering; Rice University; Houston; Texas; 77005, United States
| | - Yingchu Sun
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Aron Koszeghy
- Helsinki Institute of Life Science (HiLIFE); University of Helsinki; Helsinki; 00790; Finland
| | - Esra Altun
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
- Material Science and NanoEngineering; Rice University; Houston; Texas; 77005, United States
| | - Brian Noble
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
- Applied Physics Program; Rice University; Houston; Texas; 77005, United States
| | - Rongkang Yin
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Fei He
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
| | - Nelson Totah
- Helsinki Institute of Life Science (HiLIFE); University of Helsinki; Helsinki; 00790; Finland
- Faculty of Pharmacy; University of Helsinki; Helsinki; 00790; Finland
| | - Chong Xie
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
- Department of Bioenginering; Rice University; Houston; Texas; 77005, United States
| | - Lan Luan
- Department of Electrical and Computer Engineering; Rice University; Houston; Texas; 77005, United States
- Rice Neuroengineering Initiative; Rice University; Houston; Texas; 77005, United States
- Department of Bioenginering; Rice University; Houston; Texas; 77005, United States
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15
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Advances in applications of head mounted devices (HMDs): Physical techniques for drug delivery and neuromodulation. J Control Release 2023; 354:810-820. [PMID: 36709924 DOI: 10.1016/j.jconrel.2023.01.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
Head-mounted medical devices (HMDs) are disruptive inventions representing laboratories and clinical institutions worldwide are climbing the apexes of brain science. These complex devices are inextricably linked with a wide range knowledge containing the Physics, Imaging, Biomedical engineering, Biology and Pharmacology, particularly could be specifically designed for individuals, and finally exerting integrated bio-effect. The salient characteristics of them are non-invasive intervening in human brain's physiological structures, and alterating the biological process, such as thermal ablating the tumor, opening the BBB to deliver drugs and neuromodulating to enhance cognitive performance or manipulate prosthetic. The increasing demand and universally accepted of them have set off a dramatic upsurge in HMDs' studies, seminal applications of them span from clinical use to psychiatric disorders and neurological modulation. With subsequent pre-clinical studies and human trials emerging, the mechanisms of transcranial stimulation methods of them were widely studied, and could be basically came down to three notable approach: magnetic, electrical and ultrasonic stimulation. This review provides a comprehensive overviews of their stimulating mechanisms, and recent advances in clinic and military. We described the potential impact of HMDs on brain science, and current challenges to extensively adopt them as promising alternative treating tools.
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16
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Bundy DT, Barbay S, Hudson HM, Frost SB, Nudo RJ, Guggenmos DJ. Stimulation-Evoked Effective Connectivity (SEEC): An in-vivo approach for defining mesoscale corticocortical connectivity. J Neurosci Methods 2023; 384:109767. [PMID: 36493978 DOI: 10.1016/j.jneumeth.2022.109767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/07/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Cortical electrical stimulation is a versatile technique for examining the structure and function of cortical regions and for implementing novel therapies. While electrical stimulation has been used to examine the local spread of neural activity, it may also enable longitudinal examination of mesoscale interregional connectivity. NEW METHOD Here, we sought to use intracortical microstimulation (ICMS) in conjunction with recordings of multi-unit action potentials to assess the mesoscale effective connectivity within sensorimotor cortex. Neural recordings were made from multielectrode arrays placed into sensory, motor, and premotor regions during surgical experiments in three squirrel monkeys. During each recording, single-pulse ICMS was repeatably delivered to a single region. Mesoscale effective connectivity was calculated from ICMS-evoked changes in multi-unit firing. RESULTS Multi-unit action potentials were able to be detected on the order of 1 ms after each ICMS pulse. Across sensorimotor regions, short-latency (< 2.5 ms) ICMS-evoked neural activity strongly correlated with known anatomical connections. Additionally, ICMS-evoked responses remained stable across the experimental period, despite small changes in electrode locations and anesthetic state. COMPARISON WITH EXISTING METHODS Previous imaging studies investigating cross-regional responses to stimulation are limited to utilizing indirect hemodynamic responses and thus lack the temporal specificity of ICMS-evoked responses. CONCLUSIONS These results show that monitoring ICMS-evoked neural activity, in a technique we refer to as Stimulation-Evoked Effective Connectivity (SEEC), is a viable way to longitudinally assess effective connectivity, enabling studies comparing the time course of connectivity changes with the time course of changes in behavioral function.
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Affiliation(s)
- David T Bundy
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA
| | - Scott Barbay
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA
| | - Heather M Hudson
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA
| | - Shawn B Frost
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA
| | - Randolph J Nudo
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA; Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, USA.
| | - David J Guggenmos
- Departiment of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, KS, USA
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17
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Uguz I, Shepard KL. Spatially controlled, bipolar, cortical stimulation with high-capacitance, mechanically flexible subdural surface microelectrode arrays. SCIENCE ADVANCES 2022; 8:eabq6354. [PMID: 36260686 PMCID: PMC9581492 DOI: 10.1126/sciadv.abq6354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Most neuromodulation approaches rely on extracellular electrical stimulation with penetrating electrodes at the cost of cortical damage. Surface electrodes, in contrast, are much less invasive but are challenged by the lack of proximity to axonal processes, leading to poor resolution. Here, we demonstrate that high-density (40-μm pitch), high-capacitance (>1 nF), single neuronal resolution PEDOT:PSS electrodes can be programmed to shape the charge injection front selectively at depths approaching 300 micrometers with a lateral resolution better than 100 micrometers. These electrodes, patterned on thin-film parylene substrate, can be subdurally implanted and adhere to the pial surface in chronic settings. By leveraging surface arrays that are optically transparent with PEDOT:PSS local interconnects and integrated with depth electrodes, we are able to combine surface stimulation and recording with calcium imaging and depth recording to demonstrate these spatial limits of bidirectional communication with pyramidal neurons in mouse visual cortex both laterally and at depth from the surface.
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18
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Hayashida Y, Kameda S, Umehira Y, Ishikawa S, Yagi T. Multichannel stimulation module as a tool for animal studies on cortical neural prostheses. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:927581. [PMID: 36176924 PMCID: PMC9513350 DOI: 10.3389/fmedt.2022.927581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Intracortical microstimulation to the visual cortex is thought to be a feasible technique for inducing localized phosphenes in patients with acquired blindness, and thereby for visual prosthesis. In order to design effective stimuli for the prosthesis, it is important to elucidate relationships between the spatio-temporal patterns of stimuli and the resulting neural responses and phosphenes through pre-clinical animal studies. However, the physiological basis of effective spatial patterns of the stimuli for the prosthesis has been little investigated in the literature, at least partly because that the previously developed multi-channel stimulation systems were designed specifically for the clinical use. In the present, a 64-channel stimulation module was developed as a scalable tool for animal experiments. The operations of the module were verified by not only dry-bench tests but also physiological animal experiments in vivo. The results demonstrated its usefulness for examining the stimulus-response relationships in a quantitative manner, and for inducing the multi-site neural excitations with a multi-electrode array. In addition, this stimulation module could be used to generate spatially patterned stimuli with up to 4,096 channels in a dynamic way, in which the stimulus patterns can be updated at a certain frame rate in accordance with the incoming visual scene. The present study demonstrated that our stimulation module is applicable to the physiological and other future studies in animals on the cortical prostheses.
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Affiliation(s)
- Yuki Hayashida
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
- Department of Information Engineering, Graduate School of Engineering, Mie University, Tsu, Japan
| | - Seiji Kameda
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Yuichi Umehira
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Shinnosuke Ishikawa
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Tetsuya Yagi
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
- Department of Electrical and Electronic Engineering, School of Engineering, Fukui University of Technology, Fukui, Japan
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19
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Fiocchi S, Chiaramello E, Marrella A, Bonato M, Parazzini M, Ravazzani P. Modelling of magnetoelectric nanoparticles for non-invasive brain stimulation: a computational study. J Neural Eng 2022; 19. [PMID: 36075197 DOI: 10.1088/1741-2552/ac9085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 09/08/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Recently developed magnetoelectric nanoparticles (MENPs) provide a potential tool to enable different biomedical applications. They could be used to overcome the intrinsic constraints posed by traditional neurostimulation techniques, namely the invasiveness of electrodes-based techniques, the limited spatial resolution, and the scarce efficiency of magnetic stimulation. APPROACH By using computational electromagnetic techniques, we modelled the behavior of recently designed biocompatible MENPs injected, in the shape of clusters, in specific cortical targets of a highly detailed anatomical head model. The distributions and the tissue penetration of the electric fields induced by MENPs clusters in each tissue will be compared to the distributions induced by traditional TMS coils for non-invasive brain stimulation positioned on the left prefrontal cortex of a highly detailed anatomical head model. MAIN RESULTS MENPs clusters can induce highly focused electric fields with amplitude close to the neural activation threshold in all the brain tissues of interest for the treatment of most neuropsychiatric disorders. Conversely, TMS coils can induce electric fields of several tens of V/m over a broad volume of the prefrontal cortex, but they are unlikely able to efficiently stimulate even small volumes of subcortical and deep tissues. SIGNIFICANCE Our numerical results suggest that the use of MENPs for brain stimulation may potentially led to a future pinpoint treatment of neuropshychiatric disorders, in which an impairment of electric activity of specific cortical and subcortical tissues and networks has been assumed to play a crucial role.
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Affiliation(s)
- Serena Fiocchi
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milan, 20133, ITALY
| | - Emma Chiaramello
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milan, 20133, ITALY
| | - Alessandra Marrella
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Area della Ricerca, via de Marini 6, Genova, 16149, ITALY
| | - Marta Bonato
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milan, 20133, ITALY
| | - Marta Parazzini
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milan, 20133, ITALY
| | - Paolo Ravazzani
- Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milan, 20133, ITALY
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20
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Sawada M, Adolphs R, Dlouhy BJ, Jenison RL, Rhone AE, Kovach CK, Greenlee JDW, Howard Iii MA, Oya H. Mapping effective connectivity of human amygdala subdivisions with intracranial stimulation. Nat Commun 2022; 13:4909. [PMID: 35987994 PMCID: PMC9392722 DOI: 10.1038/s41467-022-32644-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 08/08/2022] [Indexed: 01/21/2023] Open
Abstract
The primate amygdala is a complex consisting of over a dozen nuclei that have been implicated in a host of cognitive functions, individual differences, and psychiatric illnesses. These functions are implemented through distinct connectivity profiles, which have been documented in animals but remain largely unknown in humans. Here we present results from 25 neurosurgical patients who had concurrent electrical stimulation of the amygdala with intracranial electroencephalography (electrical stimulation tract-tracing; es-TT), or fMRI (electrical stimulation fMRI; es-fMRI), methods providing strong inferences about effective connectivity of amygdala subdivisions with the rest of the brain. We quantified functional connectivity with medial and lateral amygdala, the temporal order of these connections on the timescale of milliseconds, and also detail second-order effective connectivity among the key nodes. These findings provide a uniquely detailed characterization of human amygdala functional connectivity that will inform functional neuroimaging studies in healthy and clinical populations.
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Affiliation(s)
- Masahiro Sawada
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Department of Neurosurgery, Tazuke Kofukai Medical Research Institute and Kitano Hospital, Osaka, Japan
| | - Ralph Adolphs
- Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Brian J Dlouhy
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Rick L Jenison
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI, USA
| | - Ariane E Rhone
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Christopher K Kovach
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Jeremy D W Greenlee
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Matthew A Howard Iii
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA, USA
| | - Hiroyuki Oya
- Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA.
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21
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Capaday C. Motor cortex outputs evoked by long-duration microstimulation encode synergistic muscle activation patterns not controlled movement trajectories. Front Comput Neurosci 2022; 16:851485. [PMID: 36062251 PMCID: PMC9434634 DOI: 10.3389/fncom.2022.851485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 07/15/2022] [Indexed: 11/29/2022] Open
Abstract
The effects of intracortical microstimulation (ICMS) parameters on the evoked electromyographic (EMG) responses and resulting limb movement were investigated. In ketamine-anesthetized cats, paw movement kinematics in 3D and EMG activity from 8 to 12 forelimb muscles evoked by ICMS applied to the forelimb area of the cat motor cortex (MCx) were recorded. The EMG responses evoked by ICMS were also compared to those evoked by focal ictal bursts induced by the iontophoretic ejection of the GABAA receptor antagonist bicuculline methochloride (BIC) at the same cortical point. The effects of different initial limb starting positions on movement trajectories resulting from long-duration ICMS were also studied. The ICMS duration did not affect the evoked muscle activation pattern (MAP). Short (50 ms) and long (500 ms) stimulus trains activated the same muscles in the same proportions. MAPs could, however, be modified by gradually increasing the stimulus intensity. MAPs evoked by focal ictal bursts were also highly correlated with those obtained by ICMS at the same cortical point. Varying the initial position of the forelimb did not change the MAPs evoked from a cortical point. Consequently, the evoked movements reached nearly the same final end point and posture, with variability. However, the movement trajectories were quite different depending on the initial limb configuration and starting position of the paw. The evoked movement trajectory was most natural when the forelimb lay pendant ~ perpendicular to the ground (i.e., in equilibrium with the gravitational force). From other starting positions, the movements did not appear natural. These observations demonstrate that while the output of the cortical point evokes a seemingly coordinated limb movement from a rest position, it does not specify a particular movement direction or a controlled trajectory from other initial positions.
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Affiliation(s)
- Charles Capaday
- Brain and Movement Laboratory, Department of Bioengineering, McGill University, Montreal, QC, Canada
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, United States
- *Correspondence: Charles Capaday
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22
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Mojaverrostami S, Khadivi F, Zarini D, Mohammadi A. Combination effects of mesenchymal stem cells transplantation and anodal transcranial direct current stimulation on a cuprizone-induced mouse model of multiple sclerosis. J Mol Histol 2022; 53:817-831. [PMID: 35947228 DOI: 10.1007/s10735-022-10092-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 07/20/2022] [Indexed: 11/24/2022]
Abstract
Multiple sclerosis (MS) has no absolute treatment, and researchers are still exploring to introduce promising therapy for MS. Transcranial direct current stimulation (tDCS), is a safe, non-invasive procedure for brain stimulating which can enhance working memory, cognitive neurohabitation and motor recovery. Here, we evaluated the effects of tDCS treatment and Mesenchymal stem cells (MSCs) transplantation on remyelination ability of a Cuprizone (CPZ)-induced demyelination mouse model. tDCS significantly increased the motor coordination and balance abilities in CPZ + tDCS and CPZ + tDCS + MSCs mice in comparison to the CPZ mice. Luxol fast blue (LFB) staining showed that tDCS and MSCs transplantation could increase remyelination capacity in CPZ + tDCS and CPZ + MSCs mice compared to the CPZ mice. But, the effect of tDCS with MSCs transplantation on remyelination process was larger than each of treatment alone. Immunofluorescence technique indicated that the numbers of Olig2+ cells were increased by tDCS and MSCs transplantation in CPZ + tDCS and CPZ + MSCs mice compared to the CPZ mice. Interestingly, the combination effect of tDCS and MSCs was larger than each of treatment alone on Oligodendrocytes population. MSCs transplantation significantly decreased the TUNEL+ cells in CPZ + MSCs and CPZ + tDCS + MSCs mice in comparison to the CPZ mice. Also, the combination effects of tDCS and MSCs transplantation was much larger than each of treatment alone on increasing the mRNA expression of BDNF and Sox2, while decreasing P53 as compared to CPZ mice. It can be concluded that the combination usage of tDCS and MSCs transplantation enhance remyelination process in CPZ-treated mice by increasing transplanted stem cell homing, oligodendrocyte generation and decreasing apoptosis.
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Affiliation(s)
- Sina Mojaverrostami
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.,Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Farnaz Khadivi
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Davood Zarini
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Mohammadi
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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23
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Meikle SJ, Hagan MA, Price NSC, Wong YT. Intracortical current steering shifts the location of evoked neural activity. J Neural Eng 2022; 19. [PMID: 35688125 DOI: 10.1088/1741-2552/ac77bf] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 06/10/2022] [Indexed: 11/12/2022]
Abstract
Objective.Intracortical visual prostheses are being developed to restore sight in people who are blind. The resolution of artificial vision is dictated by the location, proximity and number of electrodes implanted in the brain. However, increasing electrode count and proximity is traded off against tissue damage. Hence, new stimulation methods are needed that can improve the resolution of artificial vision without increasing the number of electrodes. We investigated whether a technique known as current steering can improve the resolution of artificial vision provided by intracortical prostheses without increasing the number of physical electrodes in the brain.Approach.We explored how the locus of neuronal activation could be steered when low amplitude microstimulation was applied simultaneously to two intracortical electrodes. A 64-channel, four-shank electrode array was implanted into the visual cortex of rats (n= 7). The distribution of charge ranged from single-electrode stimulation (100%:0%) to an equal distribution between the two electrodes (50%:50%), thereby steering the current between the physical electrodes. The stimulating electrode separation varied between 300 and 500μm. The peak of the evoked activity was defined as the 'virtual electrode' location.Main results.Current steering systematically shifted the virtual electrode on average between the stimulating electrodes as the distribution of charge was moved from one stimulating electrode to another. This effect was unclear in single trials due to the limited sampling of neurons. A model that scales the cortical response to each physical electrode when stimulated in isolation predicts the evoked virtual electrode response. Virtual electrodes were found to elicit a neural response as effectively and predictably as physical electrodes within cortical tissue on average.Significance.Current steering could be used to increase the resolution of intracortical electrode arrays without altering the number of physical electrodes which will reduce neural tissue damage, power consumption and potential heat dispersion issues.
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Affiliation(s)
- Sabrina J Meikle
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic 3800, Australia.,ARC Centre of Excellence for Integrative Brain Function, Clayton, Vic, 3800, Australia.,Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Vic, 3800, Australia.,Monash Vision Group, Monash University, Clayton, Vic 3800, Australia
| | - Maureen A Hagan
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic 3800, Australia.,ARC Centre of Excellence for Integrative Brain Function, Clayton, Vic, 3800, Australia
| | - Nicholas S C Price
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic 3800, Australia.,ARC Centre of Excellence for Integrative Brain Function, Clayton, Vic, 3800, Australia
| | - Yan T Wong
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic 3800, Australia.,ARC Centre of Excellence for Integrative Brain Function, Clayton, Vic, 3800, Australia.,Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Vic, 3800, Australia.,Monash Vision Group, Monash University, Clayton, Vic 3800, Australia
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24
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State-dependent effects of neural stimulation on brain function and cognition. Nat Rev Neurosci 2022; 23:459-475. [PMID: 35577959 DOI: 10.1038/s41583-022-00598-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2022] [Indexed: 01/02/2023]
Abstract
Invasive and non-invasive brain stimulation methods are widely used in neuroscience to establish causal relationships between distinct brain regions and the sensory, cognitive and motor functions they subserve. When combined with concurrent brain imaging, such stimulation methods can reveal patterns of neuronal activity responsible for regulating simple and complex behaviours at the level of local circuits and across widespread networks. Understanding how fluctuations in physiological states and task demands might influence the effects of brain stimulation on neural activity and behaviour is at the heart of how we use these tools to understand cognition. Here we review the concept of such 'state-dependent' changes in brain activity in response to neural stimulation, and consider examples from research on altered states of consciousness (for example, sleep and anaesthesia) and from task-based manipulations of selective attention and working memory. We relate relevant findings from non-invasive methods used in humans to those obtained from direct electrical and optogenetic stimulation of neuronal ensembles in animal models. Given the widespread use of brain stimulation as a research tool in the laboratory and as a means of augmenting or restoring brain function, consideration of the influence of changing physiological and cognitive states is crucial for increasing the reliability of these interventions.
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Wu CY, Melaku AZ, Ilhami FB, Chiu CW, Cheng CC. Conductive Supramolecular Polymer Nanocomposites with Tunable Properties to Manipulate Cell Growth and Functions. Int J Mol Sci 2022; 23:ijms23084332. [PMID: 35457150 PMCID: PMC9032009 DOI: 10.3390/ijms23084332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/01/2023] Open
Abstract
Synthetic bioactive nanocomposites show great promise in biomedicine for use in tissue growth, wound healing and the potential for bioengineered skin substitutes. Hydrogen-bonded supramolecular polymers (3A-PCL) can be combined with graphite crystals to form graphite/3A-PCL composites with tunable physical properties. When used as a bioactive substrate for cell culture, graphite/3A-PCL composites have an extremely low cytotoxic activity on normal cells and a high structural stability in a medium with red blood cells. A series of in vitro studies demonstrated that the resulting composite substrates can efficiently interact with cell surfaces to promote the adhesion, migration, and proliferation of adherent cells, as well as rapid wound healing ability at the damaged cellular surface. Importantly, placing these substrates under an indirect current electric field at only 0.1 V leads to a marked acceleration in cell growth, a significant increase in total cell numbers, and a remarkable alteration in cell morphology. These results reveal a newly created system with great potential to provide an efficient route for the development of multifunctional bioactive substrates with unique electro-responsiveness to manipulate cell growth and functions.
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Affiliation(s)
- Cheng-You Wu
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; (C.-Y.W.); (A.Z.M.); (F.B.I.)
| | - Ashenafi Zeleke Melaku
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; (C.-Y.W.); (A.Z.M.); (F.B.I.)
| | - Fasih Bintang Ilhami
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; (C.-Y.W.); (A.Z.M.); (F.B.I.)
| | - Chih-Wei Chiu
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan;
| | - Chih-Chia Cheng
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; (C.-Y.W.); (A.Z.M.); (F.B.I.)
- Advanced Membrane Materials Research Center, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
- Correspondence:
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Sombeck J, Heye J, Kumaravelu K, Goetz S, Peterchev AV, Grill WM, Bensmaia SJ, Miller LE. Characterizing the short-latency evoked response to intracortical microstimulation across a multi-electrode array. J Neural Eng 2022; 19. [PMID: 35378515 PMCID: PMC9142773 DOI: 10.1088/1741-2552/ac63e8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/04/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Persons with tetraplegia can use brain-machine interfaces to make visually guided reaches with robotic arms. Without somatosensory feedback, these movements will likely be slow and imprecise, like those of persons who retain movement but have lost proprioception. Intracortical microstimulation (ICMS) has promise for providing artificial somatosensory feedback. If ICMS can mimic naturally occurring neural activity, afferent interfaces may be more informative and easier to learn than interfaces that evoke unnaturalistic activity. To develop such biomimetic stimulation patterns, it is important to characterize the responses of neurons to ICMS. APPROACH Using a Utah multi-electrode array, we recorded activity evoked by single pulses and trains of ICMS at a wide range of amplitudes and frequencies in two rhesus macaques. As the electrical artifact caused by ICMS typically prevents recording for many milliseconds, we deployed a custom rapid-recovery amplifier with nonlinear gain to limit signal saturation on the stimulated electrode. Across all electrodes after stimulation, we removed the remaining slow return to baseline with acausal high-pass filtering of time-reversed recordings. MAIN RESULTS After single pulses of stimulation, we recorded what was likely transsynaptically-evoked activity even on the stimulated electrode as early as ~0.7 ms. This was immediately followed by suppressed neural activity lasting 10-150 ms. After trains, this long-lasting inhibition was replaced by increased firing rates for ~100 ms. During long trains, the evoked response on the stimulated electrode decayed rapidly while the response was maintained on non-stimulated channels. SIGNIFICANCE The detailed description of the spatial and temporal response to ICMS can be used to better interpret results from experiments that probe circuit connectivity or function of cortical areas. These results can also contribute to the design of stimulation patterns to improve afferent interfaces for artificial sensory feedback.
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Affiliation(s)
- Joseph Sombeck
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, UNITED STATES
| | - Juliet Heye
- Department of Neuroscience, Northwestern University, 310 E. Superior St, Chicago, Illinois, 60202, UNITED STATES
| | - Karthik Kumaravelu
- Biomedical Engineering, Duke University, 2080 Duke University Road, Durham, North Carolina, 27708-0187, UNITED STATES
| | - Stefan Goetz
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, 2080 Duke University Road, Durham, North Carolina, 27708, UNITED STATES
| | - Angel V Peterchev
- Psychiatry & Behavioral Sciences, Duke University School of Medicine, 40 Duke Medicine Circle, Durham, North Carolina, 27710, UNITED STATES
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Hudson Hall 136, Box 90281, Durham, North Carolina, 27708-0281, UNITED STATES
| | - Sliman J Bensmaia
- Organismal Biology and Anatomy, University of Chicago, 1027 E 57th St, Chicago, IL 60637, USA, Chicago, Illinois, 60637, UNITED STATES
| | - Lee E Miller
- Neuroscience, Northwestern University Feinberg School of Medicine, 303 East Chicago Ave, Chicago, Illinois, 60611-3008, UNITED STATES
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Pandarinath C, Bensmaia SJ. The science and engineering behind sensitized brain-controlled bionic hands. Physiol Rev 2022; 102:551-604. [PMID: 34541898 PMCID: PMC8742729 DOI: 10.1152/physrev.00034.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/07/2021] [Accepted: 09/13/2021] [Indexed: 12/13/2022] Open
Abstract
Advances in our understanding of brain function, along with the development of neural interfaces that allow for the monitoring and activation of neurons, have paved the way for brain-machine interfaces (BMIs), which harness neural signals to reanimate the limbs via electrical activation of the muscles or to control extracorporeal devices, thereby bypassing the muscles and senses altogether. BMIs consist of reading out motor intent from the neuronal responses monitored in motor regions of the brain and executing intended movements with bionic limbs, reanimated limbs, or exoskeletons. BMIs also allow for the restoration of the sense of touch by electrically activating neurons in somatosensory regions of the brain, thereby evoking vivid tactile sensations and conveying feedback about object interactions. In this review, we discuss the neural mechanisms of motor control and somatosensation in able-bodied individuals and describe approaches to use neuronal responses as control signals for movement restoration and to activate residual sensory pathways to restore touch. Although the focus of the review is on intracortical approaches, we also describe alternative signal sources for control and noninvasive strategies for sensory restoration.
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Affiliation(s)
- Chethan Pandarinath
- Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia
- Department of Neurosurgery, Emory University, Atlanta, Georgia
| | - Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois
- Committee on Computational Neuroscience, University of Chicago, Chicago, Illinois
- Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, Illinois
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Fifer MS, McMullen DP, Osborn LE, Thomas TM, Christie B, Nickl RW, Candrea DN, Pohlmeyer EA, Thompson MC, Anaya MA, Schellekens W, Ramsey NF, Bensmaia SJ, Anderson WS, Wester BA, Crone NE, Celnik PA, Cantarero GL, Tenore FV. Intracortical Somatosensory Stimulation to Elicit Fingertip Sensations in an Individual With Spinal Cord Injury. Neurology 2022; 98:e679-e687. [PMID: 34880087 PMCID: PMC8865889 DOI: 10.1212/wnl.0000000000013173] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/19/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The restoration of touch to fingers and fingertips is critical to achieving dexterous neuroprosthetic control for individuals with sensorimotor dysfunction. However, localized fingertip sensations have not been evoked via intracortical microstimulation (ICMS). METHODS Using a novel intraoperative mapping approach, we implanted electrode arrays in the finger areas of left and right somatosensory cortex and delivered ICMS over a 2-year period in a human participant with spinal cord injury. RESULTS Stimulation evoked tactile sensations in 8 fingers, including fingertips, spanning both hands. Evoked percepts followed expected somatotopic arrangements. The subject was able to reliably identify up to 7 finger-specific sites spanning both hands in a finger discrimination task. The size of the evoked percepts was on average 33% larger than a finger pad, as assessed via manual markings of a hand image. The size of the evoked percepts increased modestly with increased stimulation intensity, growing 21% as pulse amplitude increased from 20 to 80 µA. Detection thresholds were estimated on a subset of electrodes, with estimates of 9.2 to 35 µA observed, roughly consistent with prior studies. DISCUSSION These results suggest that ICMS can enable the delivery of consistent and localized fingertip sensations during object manipulation by neuroprostheses for individuals with somatosensory deficits. CLINICALTRIALSGOV IDENTIFIER NCT03161067.
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Affiliation(s)
- Matthew S Fifer
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL.
| | - David P McMullen
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Luke E Osborn
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Tessy M Thomas
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Breanne Christie
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Robert W Nickl
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Daniel N Candrea
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Eric A Pohlmeyer
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Margaret C Thompson
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Manuel A Anaya
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Wouter Schellekens
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Nick F Ramsey
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Sliman J Bensmaia
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - William S Anderson
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Brock A Wester
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Nathan E Crone
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Pablo A Celnik
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Gabriela L Cantarero
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
| | - Francesco V Tenore
- From the Research and Exploratory Development Department (M.S.F., L.E.O., B.P.C., E.A.P., M.C.T., F.V.T.), Johns Hopkins University Applied Physics Laboratory, Laurel; National Institute of Mental Health (D.P.M.), NIH, Bethesda; Department of Biomedical Engineering (T.M.T., D.N.C.), Department of Physical Medicine and Rehabilitation (R.W.N., M.A.A., P.A.C., G.L.C.), Department of Neurosurgery (W.S.A.), and Department of Neurology (B.A.W., N.E.C.), Johns Hopkins University, Baltimore, MD; UMC Utrecht Brain Center (W.S., N.F.R.), the Netherlands; and Department of Organismal Biology and Anatomy (S.J.B.), University of Chicago, IL
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Kaji M, Yamada Y, Kitazumi Y, Shirai O. Severe Problems of the Voltage‐Clamp Method in Concurrent Monitoring of Membrane Potentials. ELECTROANAL 2022. [DOI: 10.1002/elan.202100508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Maiko Kaji
- Division of Applied Life Sciences, Graduate School of Agriculture Kyoto University Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 Japan
| | - Yusuke Yamada
- Division of Applied Life Sciences, Graduate School of Agriculture Kyoto University Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 Japan
| | - Yuki Kitazumi
- Division of Applied Life Sciences, Graduate School of Agriculture Kyoto University Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 Japan
| | - Osamu Shirai
- Division of Applied Life Sciences, Graduate School of Agriculture Kyoto University Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 Japan
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Schelles M, Wouters J, Asamoah B, Mc Laughlin M, Bertrand A. Objective evaluation of stimulation artefact removal techniques in the context of neural spike sorting. J Neural Eng 2022; 19. [DOI: 10.1088/1741-2552/ac4ecf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 01/25/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective - We present a framework to objectively test and compare stimulation artefact removal techniques in the context of neural spike sorting. Approach - To this end, we used realistic hybrid ground-truth spiking data, with superimposed artefacts from in vivo recordings. We used the framework to evaluate and compare several techniques: blanking, template subtraction by averaging, linear regression, and a multi-channel Wiener filter (MWF). Main results - Our study demonstrates that blanking and template subtraction result in a poorer spike sorting performance than linear regression and MWF, while the latter two perform similarly. Finally, to validate the conclusions found from the hybrid evaluation framework, we also performed a qualitative analysis on in vivo recordings without artificial manipulations. Significance - Our framework allows direct quantification of the impact of the residual artefact on the spike sorting accuracy, thereby allowing for a more objective and more relevant comparison compared to indirect signal quality metrics that are estimated from the signal statistics. Furthermore, the availability of a ground truth in the form of single-unit spiking activity also facilitates a better estimation of such signal quality metrics.
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Kunigk NG, Urdaneta ME, Malone IG, Delgado F, Otto KJ. Reducing Behavioral Detection Thresholds per Electrode via Synchronous, Spatially-Dependent Intracortical Microstimulation. Front Neurosci 2022; 16:876142. [PMID: 35784835 PMCID: PMC9247280 DOI: 10.3389/fnins.2022.876142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/31/2022] [Indexed: 12/04/2022] Open
Abstract
Intracortical microstimulation (ICMS) has shown promise in restoring quality of life to patients suffering from paralysis, specifically when used in the primary somatosensory cortex (S1). However, these benefits can be hampered by long-term degradation of electrode performance due to the brain's foreign body response. Advances in microfabrication techniques have allowed for the development of neuroprostheses with subcellular electrodes, which are characterized by greater versatility and a less detrimental immune response during chronic use. These probes are hypothesized to enable more selective, higher-resolution stimulation of cortical tissue with long-term implants. However, microstimulation using physiologically relevant charges with these smaller-scale devices can damage electrode sites and reduce the efficacy of the overall device. Studies have shown promise in bypassing this limitation by spreading the stimulation charge between multiple channels in an implanted electrode array, but to our knowledge the usefulness of this strategy in laminar arrays with electrode sites spanning each layer of the cortex remains unexplored. To investigate the efficacy of simultaneous multi-channel ICMS in electrode arrays with stimulation sites spanning cortical depth, we implanted laminar electrode arrays in the primary somatosensory cortex of rats trained in a behavioral avoidance paradigm. By measuring detection thresholds, we were able to quantify improvements in ICMS performance using a simultaneous multi-channel stimulation paradigm. The charge required per site to elicit detection thresholds was halved when stimulating from two adjacent electrode sites, although the overall charge used by the implant was increased. This reduction in threshold charge was more pronounced when stimulating with more than two channels and lessened with greater distance between stimulating channels. Our findings suggest that these improvements are based on the synchronicity and polarity of each stimulus, leading us to conclude that these improvements in stimulation efficiency per electrode are due to charge summation as opposed to a summation of neural responses to stimulation. Additionally, the per-site charge reductions are seen regardless of the cortical depth of each utilized channel. This evocation of physiological detection thresholds with lower stimulation currents per electrode site has implications for the feasibility of stimulation regimes in future advanced neuroprosthetic devices, which could benefit from reducing the charge output per site.
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Affiliation(s)
- Nicolas G. Kunigk
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Morgan E. Urdaneta
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Ian G. Malone
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, United States
| | - Francisco Delgado
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Kevin J. Otto
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, United States
- Department of Materials Science and Engineering, University of Florida, Gainesville, FL, United States
- Department of Neurology, University of Florida, Gainesville, FL, United States
- McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- *Correspondence: Kevin J. Otto,
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Kumaravelu K, Sombeck J, Miller LE, Bensmaia SJ, Grill WM. Stoney vs. Histed: Quantifying the spatial effects of intracortical microstimulation. Brain Stimul 2022; 15:141-151. [PMID: 34861412 PMCID: PMC8816873 DOI: 10.1016/j.brs.2021.11.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Intracortical microstimulation (ICMS) is used to map neural circuits and restore lost sensory modalities such as vision, hearing, and somatosensation. The spatial effects of ICMS remain controversial: Stoney and colleagues proposed that the volume of somatic activation increased with stimulation intensity, while Histed et al., suggested activation density, but not somatic activation volume, increases with stimulation intensity. OBJECTIVE We used computational modeling to quantify the spatial effects of ICMS intensity and unify the apparently paradoxical findings of Histed and Stoney. METHODS We implemented a biophysically-based computational model of a cortical column comprising neurons with realistic morphology and representative synapses. We quantified the spatial effects of single pulses and short trains of ICMS, including the volume of activated neurons and the density of activated neurons as a function of stimulation intensity. RESULTS At all amplitudes, the dominant mode of somatic activation was by antidromic propagation to the soma following axonal activation, rather than via transsynaptic activation. There were no occurrences of direct activation of somata or dendrites. The volume over which antidromic action potentials were initiated grew with stimulation amplitude, while the volume of somatic activation increased marginally. However, the density of somatic activation within the activated volume increased with stimulation amplitude. CONCLUSIONS The results resolve the apparent paradox between Stoney and Histed's results by demonstrating that the volume over which action potentials are initiated grows with ICMS amplitude, consistent with Stoney. However, the volume occupied by the activated somata remains approximately constant, while the density of activated neurons within that volume increase, consistent with Histed.
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Affiliation(s)
| | - Joseph Sombeck
- Department of Physiology, Northwestern University, Chicago, IL,Department of Biomedical Engineering, Northwestern University, Chicago, IL
| | - Lee E. Miller
- Department of Physiology, Northwestern University, Chicago, IL,Department of Biomedical Engineering, Northwestern University, Chicago, IL,Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL
| | - Sliman J. Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL,Committee on Computational Neuroscience, University of Chicago, Chicago, IL,Neuroscience Institute, University of Chicago, Chicago, IL
| | - Warren M. Grill
- Department of Biomedical Engineering, Duke University, Durham, NC,Department of Electrical and Computer Engineering, Duke University, Durham, NC,Department of Neurobiology, Duke University, Durham, NC,Department of Neurosurgery, Duke University, Durham, NC,Correspondence: Warren M. Grill, Ph.D., Duke University, Department of Biomedical Engineering, Rm. 1427, Fitzpatrick CIEMAS, 101 Science Drive, Campus Box 90281, Durham, NC, 27708, USA, , 919 660-5276 Phone, 919 684-4488 FAX
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What déjà vu and the “dreamy state” tell us about episodic memory networks. Clin Neurophysiol 2022; 136:173-181. [DOI: 10.1016/j.clinph.2022.01.126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 01/04/2022] [Accepted: 01/11/2022] [Indexed: 11/22/2022]
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Meikle SJ, Wong YT. Neurophysiological considerations for visual implants. Brain Struct Funct 2021; 227:1523-1543. [PMID: 34773502 DOI: 10.1007/s00429-021-02417-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 10/17/2021] [Indexed: 11/26/2022]
Abstract
Neural implants have the potential to restore visual capabilities in blind individuals by electrically stimulating the neurons of the visual system. This stimulation can produce visual percepts known as phosphenes. The ideal location of electrical stimulation for achieving vision restoration is widely debated and dependent on the physiological properties of the targeted tissue. Here, the neurophysiology of several potential target structures within the visual system will be explored regarding their benefits and downfalls in producing phosphenes. These regions will include the lateral geniculate nucleus, primary visual cortex, visual area 2, visual area 3, visual area 4 and the middle temporal area. Based on the existing engineering limitations of neural prostheses, we anticipate that electrical stimulation of any singular brain region will be incapable of achieving high-resolution naturalistic perception including color, texture, shape and motion. As improvements in visual acuity facilitate improvements in quality of life, emulating naturalistic vision should be one of the ultimate goals of visual prostheses. To achieve this goal, we propose that multiple brain areas will need to be targeted in unison enabling different aspects of vision to be recreated.
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Affiliation(s)
- Sabrina J Meikle
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
| | - Yan T Wong
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
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35
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Innocenti GM, Schmidt K, Milleret C, Fabri M, Knyazeva MG, Battaglia-Mayer A, Aboitiz F, Ptito M, Caleo M, Marzi CA, Barakovic M, Lepore F, Caminiti R. The functional characterization of callosal connections. Prog Neurobiol 2021; 208:102186. [PMID: 34780864 PMCID: PMC8752969 DOI: 10.1016/j.pneurobio.2021.102186] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022]
Abstract
The functional characterization of callosal connections is informed by anatomical data. Callosal connections play a conditional driving role depending on the brain state and behavioral demands. Callosal connections play a modulatory function, in addition to a driving role. The corpus callosum participates in learning and interhemispheric transfer of sensorimotor habits. The corpus callosum contributes to language processing and cognitive functions.
The brain operates through the synaptic interaction of distant neurons within flexible, often heterogeneous, distributed systems. Histological studies have detailed the connections between distant neurons, but their functional characterization deserves further exploration. Studies performed on the corpus callosum in animals and humans are unique in that they capitalize on results obtained from several neuroscience disciplines. Such data inspire a new interpretation of the function of callosal connections and delineate a novel road map, thus paving the way toward a general theory of cortico-cortical connectivity. Here we suggest that callosal axons can drive their post-synaptic targets preferentially when coupled to other inputs endowing the cortical network with a high degree of conditionality. This might depend on several factors, such as their pattern of convergence-divergence, the excitatory and inhibitory operation mode, the range of conduction velocities, the variety of homotopic and heterotopic projections and, finally, the state-dependency of their firing. We propose that, in addition to direct stimulation of post-synaptic targets, callosal axons often play a conditional driving or modulatory role, which depends on task contingencies, as documented by several recent studies.
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Affiliation(s)
- Giorgio M Innocenti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Signal Processing Laboratory (LTS5), École Polytechnique Fédérale (EPFL), Lausanne, Switzerland
| | - Kerstin Schmidt
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Chantal Milleret
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, Label Memolife, PSL Research University, Paris, France
| | - Mara Fabri
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Maria G Knyazeva
- Laboratoire de Recherche en Neuroimagerie (LREN), Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Leenaards Memory Centre and Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | | | - Francisco Aboitiz
- Centro Interdisciplinario de Neurociencias and Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maurice Ptito
- Harland Sanders Chair in Visual Science, École d'Optométrie, Université de Montréal, Montréal, Qc, Canada; Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, Qc, Canada; Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Matteo Caleo
- Department of Biomedical Sciences, University of Padua, Italy; CNR Neuroscience Institute, Pisa, Italy
| | - Carlo A Marzi
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Muhamed Barakovic
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale (EPFL), Lausanne, Switzerland
| | - Franco Lepore
- Department of Psychology, Centre de Recherche en Neuropsychologie et Cognition, University of Montréal, Montréal, QC, Canada
| | - Roberto Caminiti
- Department of Physiology and Pharmacology, University of Rome SAPIENZA, Rome, Italy; Neuroscience and Behavior Laboratory, Istituto Italiano di Tecnologia, Rome, Italy.
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36
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Herrero JL, Smith A, Mishra A, Markowitz N, Mehta AD, Bickel S. Inducing neuroplasticity through intracranial θ-burst stimulation in the human sensorimotor cortex. J Neurophysiol 2021; 126:1723-1739. [PMID: 34644179 PMCID: PMC8782667 DOI: 10.1152/jn.00320.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/20/2021] [Accepted: 10/08/2021] [Indexed: 01/04/2023] Open
Abstract
The progress of therapeutic neuromodulation greatly depends on improving stimulation parameters to most efficiently induce neuroplasticity effects. Intermittent θ-burst stimulation (iTBS), a form of electrical stimulation that mimics natural brain activity patterns, has proved to efficiently induce such effects in animal studies and rhythmic transcranial magnetic stimulation studies in humans. However, little is known about the potential neuroplasticity effects of iTBS applied through intracranial electrodes in humans. This study characterizes the physiological effects of intracranial iTBS in humans and compare them with α-frequency stimulation, another frequently used neuromodulatory pattern. We applied these two stimulation patterns to well-defined regions in the sensorimotor cortex, which elicited contralateral hand muscle contractions during clinical mapping, in patients with epilepsy implanted with intracranial electrodes. Treatment effects were evaluated using oscillatory coherence across areas connected to the treatment site, as defined with corticocortical-evoked potentials. Our results show that iTBS increases coherence in the β-frequency band within the sensorimotor network indicating a potential neuroplasticity effect. The effect is specific to the sensorimotor system, the β band, and the stimulation pattern and outlasted the stimulation period by ∼3 min. The effect occurred in four out of seven subjects depending on the buildup of the effect during iTBS treatment and other patterns of oscillatory activity related to ceiling effects within the β band and to preexistent coherence within the α band. By characterizing the neurophysiological effects of iTBS within well-defined cortical networks, we hope to provide an electrophysiological framework that allows clinicians/researchers to optimize brain stimulation protocols which may have translational value.NEW & NOTEWORTHY θ-Burst stimulation (TBS) protocols in transcranial magnetic stimulation studies have shown improved treatment efficacy in a variety of neuropsychiatric disorders. The optimal protocol to induce neuroplasticity in invasive direct electrical stimulation approaches is not known. We report that intracranial TBS applied in human sensorimotor cortex increases local coherence of preexistent β rhythms. The effect is specific to the stimulation frequency and the stimulated network and outlasts the stimulation period by ∼3 min.
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Affiliation(s)
- Jose L Herrero
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
| | - Alexander Smith
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
| | - Akash Mishra
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
| | - Noah Markowitz
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
| | - Ashesh D Mehta
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
| | - Stephan Bickel
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
- Department of Neurology, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York
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37
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Shupe LE, Miles FP, Jones G, Yun R, Mishler J, Rembado I, Murphy RL, Perlmutter SI, Fetz EE. Neurochip3: An Autonomous Multichannel Bidirectional Brain-Computer Interface for Closed-Loop Activity-Dependent Stimulation. Front Neurosci 2021; 15:718465. [PMID: 34489634 PMCID: PMC8417105 DOI: 10.3389/fnins.2021.718465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
Toward addressing many neuroprosthetic applications, the Neurochip3 (NC3) is a multichannel bidirectional brain-computer interface that operates autonomously and can support closed-loop activity-dependent stimulation. It consists of four circuit boards populated with off-the-shelf components and is sufficiently compact to be carried on the head of a non-human primate (NHP). NC3 has six main components: (1) an analog front-end with an Intan biophysical signal amplifier (16 differential or 32 single-ended channels) and a 3-axis accelerometer, (2) a digital control system comprised of a Cyclone V FPGA and Atmel SAM4 MCU, (3) a micro SD Card for 128 GB or more storage, (4) a 6-channel differential stimulator with ±60 V compliance, (5) a rechargeable battery pack supporting autonomous operation for up to 24 h and, (6) infrared transceiver and serial ports for communication. The NC3 and earlier versions have been successfully deployed in many closed-loop operations to induce synaptic plasticity and bridge lost biological connections, as well as deliver activity-dependent intracranial reinforcement. These paradigms to strengthen or replace impaired connections have many applications in neuroprosthetics and neurorehabilitation.
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Affiliation(s)
- Larry E Shupe
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, United States.,Washington National Primate Research Center, University of Washington, Seattle, WA, United States
| | - Frank P Miles
- Washington National Primate Research Center, University of Washington, Seattle, WA, United States
| | - Geoff Jones
- Independent Researcher, Seattle, CA, United States
| | - Richy Yun
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Jonathan Mishler
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Irene Rembado
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, United States
| | - R Logan Murphy
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, United States
| | - Steve I Perlmutter
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, United States.,Washington National Primate Research Center, University of Washington, Seattle, WA, United States
| | - Eberhard E Fetz
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, United States.,Washington National Primate Research Center, University of Washington, Seattle, WA, United States.,Department of Bioengineering, University of Washington, Seattle, WA, United States
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38
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Kudela P, Anderson WS. Impact of gyral geometry on cortical responses to surface electrical stimulation: insights from experimental and modeling studies. J Neural Eng 2021; 18. [PMID: 34407519 DOI: 10.1088/1741-2552/ac1ed3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 08/18/2021] [Indexed: 11/11/2022]
Abstract
Objective.Invasive simultaneous stimulation and recording from intracranial electrodes and microwire arrays were used to investigate direct cortical responses to single pulses of electrical stimulation in humans.Approach.Microwire contacts measured surface potentials in cortical microdomains at a distance of 2-6 mm from the intracranial electrode. Direct cortical responses to stimulation (<20 ms) consisted of a larger surface negative potentials.Main results. The latencies of these responses were directly or inversely correlated with distances between the intracranial electrode and microwire contacts. We hypothesize that surface negative potentials reflected local synchronous depolarization of apical dendrites of pyramidal neurons in cortical microdomains in the superficial cortical layer and resulted from the activation of gray matter axons that delivered excitatory inputs to apical dendrites after cortical stimulation. We further hypothesized that the positive or inverse distance-latency correlations of the recorded negative responses were measured depending on whether activation of neurons originated at one (crown) or multiple (crown, lip, bank) sites throughout the gyrus simultaneously. The inverse distance-latency correlations then reflected the spatiotemporal superposition of different nearby sources of neuronal recruitment in the gyrus. To prove this hypothesis, we built an anatomically informed and biophysically realistic cortical network model and simulated early responses of cortical neurons to electrical stimulation in this cortical network model. The model simulations yielded negative potentials in simulated microdomains in the cortical model consistent with those recorded from humans. The model predicted sensitivity of cortical responses to the alignment of the stimulating electrode and microwire array with respect to the cortical gyrus and confirmed that gyral geometry has a major impact on direct neuronal recruitment, the timing, and the time course of neuronal activation in cortical microdomains.Significance.In this work, we demonstrated how the high-resolution forward network models can be used for better understanding and detailed prediction of cortical stimulation effects. Accurate predictive modeling tools are needed for the progress of brain stimulation therapies.
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Affiliation(s)
- Pawel Kudela
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Meyer 8-181, 600 North Wolfe St, Baltimore, MD 21287, United States of America
| | - William S Anderson
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Meyer 8-181, 600 North Wolfe St, Baltimore, MD 21287, United States of America
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39
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Han MJ, Park CU, Kang S, Kim B, Nikolaidis A, Milham MP, Hong SJ, Kim SG, Baeg E. Mapping functional gradients of the striatal circuit using simultaneous microelectric stimulation and ultrahigh-field fMRI in non-human primates. Neuroimage 2021; 236:118077. [PMID: 33878384 DOI: 10.1016/j.neuroimage.2021.118077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/26/2021] [Accepted: 04/07/2021] [Indexed: 02/07/2023] Open
Abstract
Advances in functional magnetic resonance imaging (fMRI) have significantly enhanced our understanding of the striatal system of both humans and non-human primates (NHP) over the last few decades. However, its circuit-level functional anatomy remains poorly understood, partly because in-vivo fMRI cannot directly perturb a brain system and map its casual input-output relationship. Also, routine 3T fMRI has an insufficient spatial resolution. We performed electrical microstimulation (EM) of the striatum in lightly-anesthetized NHPs while simultaneously mapping whole-brain activation, using contrast-enhanced fMRI at ultra-high-field 7T. By stimulating multiple positions along the striatum's main (dorsal-to-ventral) axis, we revealed its complex functional circuit concerning mutually connected subsystems in both cortical and subcortical areas. Indeed, within the striatum, there were distinct brain activation patterns across different stimulation sites. Specifically, dorsal stimulation revealed a medial-to-lateral elongated shape of activation in upper caudate and putamen areas, whereas ventral stimulation evoked areas confined to the medial and lower caudate. Such dorsoventral gradients also appeared in neocortical and thalamic activations, indicating consistent embedding profiles of the striatal system across the whole brain. These findings reflect different forms of within-circuit and inter-regional neuronal connectivity between the dorsal and ventromedial striatum. These patterns both shared and contrasted with previous anatomical tract-tracing and in-vivo resting-state fMRI studies. Our approach of combining microstimulation and whole-brain fMRI mapping in NHPs provides a unique opportunity to integrate our understanding of a targeted brain area's meso- and macro-scale functional systems.
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Affiliation(s)
- Min-Jun Han
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Chan-Ung Park
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Sangyun Kang
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea
| | - Byounghoon Kim
- Neuroscience, University of Wisconsin - Madison, Madison, WI, United States
| | - Aki Nikolaidis
- Center for the Developing Brain, Child Mind Institute, New York, NY, United States
| | - Michael P Milham
- Center for the Developing Brain, Child Mind Institute, New York, NY, United States; Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, New York, NY, United States
| | - Seok Jun Hong
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea,; Center for the Developing Brain, Child Mind Institute, New York, NY, United States
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea,.
| | - Eunha Baeg
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea,.
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40
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Zheng XS, Yang Q, Vazquez AL, Tracy Cui X. Imaging the Efficiency of Poly(3,4-ethylenedioxythiophene) Doped with Acid-Functionalized Carbon Nanotube and Iridium Oxide Electrode Coatings for Microstimulation. ADVANCED NANOBIOMED RESEARCH 2021; 1:2000092. [PMID: 34746928 PMCID: PMC8552016 DOI: 10.1002/anbr.202000092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/18/2021] [Indexed: 12/02/2022] Open
Abstract
Electrical microstimulation has shown promise in restoring neural deficits in humans. Electrodes coated with materials like the conducting polymer poly(3,4-ethylenedioxythiophene) doped with acid-functionalized carbon nanotubes (PEDOT/CNTs, or PC) exhibit superior charge injection than traditional metals like platinum. However, the stimulation performance of PC remains to be fully characterized. Advanced imaging techniques and transgenic tools allow for real-time observations of neural activity in vivo. Herein, microelectrodes coated with PC and iridium oxide (IrOx) (a commonly used high-charge-injection material) are implanted in GCaMP6s mice and electrical stimulation is applied while imaging neuronal calcium responses. Results show that PC-coated electrodes stimulate more intense and broader GCaMP responses than IrOx. Two-photon microscopy reveals that PC-coated electrodes activate significantly more neuronal soma and neuropil than IrOx-coated electrodes in constant-voltage stimulation and significantly more neuronal soma in constant-current stimulation. Furthermore, with the same injected charge, both materials activate more spatially confined neural elements with shorter pulses than longer pulses, providing a means to tune stimulation selectivity. Finite element analyses reveal that the PC coating creates a denser and nonuniform electric field, increasing the likelihood of activating nearby neural elements. PC coating can significantly improve energy efficiency for electrical stimulation applications.
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Affiliation(s)
- Xin S. Zheng
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Qianru Yang
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Alberto L. Vazquez
- Departments of Radiology and BioengineeringUniversity of Pittsburgh3025 E. Carson St.PittsburghPA15203USA
| | - Xinyan Tracy Cui
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
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41
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Kagan I, Gibson L, Spanou E, Wilke M. Effective connectivity and spatial selectivity-dependent fMRI changes elicited by microstimulation of pulvinar and LIP. Neuroimage 2021; 240:118283. [PMID: 34147628 DOI: 10.1016/j.neuroimage.2021.118283] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 05/04/2021] [Accepted: 06/16/2021] [Indexed: 11/30/2022] Open
Abstract
The thalamic pulvinar and the lateral intraparietal area (LIP) share reciprocal anatomical connections and are part of an extensive cortical and subcortical network involved in spatial attention and oculomotor processing. The goal of this study was to compare the effective connectivity of dorsal pulvinar (dPul) and LIP and to probe the dependency of microstimulation effects on task demands and spatial tuning properties of a given brain region. To this end, we applied unilateral electrical microstimulation in the dPul (mainly medial pulvinar) and LIP in combination with event-related BOLD fMRI in monkeys performing fixation and memory-guided saccade tasks. Microstimulation in both dPul and LIP enhanced task-related activity in monosynaptically-connected fronto-parietal cortex and along the superior temporal sulcus (STS) including putative face patch locations, as well as in extrastriate cortex. LIP microstimulation elicited strong activity in the opposite homotopic LIP while no homotopic activation was found with dPul stimulation. Both dPul and LIP stimulation also elicited activity in several heterotopic cortical areas in the opposite hemisphere, implying polysynaptic propagation of excitation. Despite extensive activation along the intraparietal sulcus evoked by LIP stimulation, there was a difference in frontal and occipital connectivity elicited by posterior and anterior LIP stimulation sites. Comparison of dPul stimulation with the adjacent but functionally dissimilar ventral pulvinar also showed distinct connectivity. On the level of single trial timecourses within each region of interest (ROI), most ROIs did not show task-dependence of stimulation-elicited response modulation. Across ROIs, however, there was an interaction between task and stimulation, and task-specific correlations between the initial spatial selectivity and the magnitude of stimulation effect were observed. Consequently, stimulation-elicited modulation of task-related activity was best fitted by an additive model scaled down by the initial response amplitude. In summary, we identified overlapping and distinct patterns of thalamocortical and corticocortical connectivity of pulvinar and LIP, highlighting the dorsal bank and fundus of STS as a prominent node of shared circuitry. Spatial task-specific and partly polysynaptic modulations of cue and saccade planning delay period activity in both hemispheres exerted by unilateral pulvinar and parietal stimulation provide insight into the distributed interhemispheric processing underlying spatial behavior.
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Affiliation(s)
- Igor Kagan
- Decision and Awareness Group, Cognitive Neuroscience Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Goettingen 37077, Germany; Department of Cognitive Neurology, University of Goettingen, Robert-Koch-Str. 40, Goettingen 37075, Germany; Leibniz ScienceCampus Primate Cognition, Kellnerweg 4, Goettingen 37077, Germany.
| | - Lydia Gibson
- Decision and Awareness Group, Cognitive Neuroscience Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Goettingen 37077, Germany; Department of Cognitive Neurology, University of Goettingen, Robert-Koch-Str. 40, Goettingen 37075, Germany
| | - Elena Spanou
- Decision and Awareness Group, Cognitive Neuroscience Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Goettingen 37077, Germany
| | - Melanie Wilke
- Decision and Awareness Group, Cognitive Neuroscience Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Goettingen 37077, Germany; Department of Cognitive Neurology, University of Goettingen, Robert-Koch-Str. 40, Goettingen 37075, Germany; Leibniz ScienceCampus Primate Cognition, Kellnerweg 4, Goettingen 37077, Germany
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Does the Prefrontal Cortex Play an Essential Role in Consciousness? Insights from Intracranial Electrical Stimulation of the Human Brain. J Neurosci 2021; 41:2076-2087. [PMID: 33692142 DOI: 10.1523/jneurosci.1141-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022] Open
Abstract
A central debate in philosophy and neuroscience pertains to whether PFC activity plays an essential role in the neural basis of consciousness. Neuroimaging and electrophysiology studies have revealed that the contents of conscious perceptual experience can be successfully decoded from PFC activity, but these findings might be confounded by postperceptual cognitive processes, such as thinking, reasoning, and decision-making, that are not necessary for consciousness. To clarify the involvement of the PFC in consciousness, we present a synthesis of research that has used intracranial electrical stimulation (iES) for the causal modulation of neural activity in the human PFC. This research provides compelling evidence that iES of only certain prefrontal regions (i.e., orbitofrontal cortex and anterior cingulate cortex) reliably perturbs conscious experience. Conversely, stimulation of anterolateral prefrontal sites, often considered crucial in higher-order and global workspace theories of consciousness, seldom elicits any reportable alterations in consciousness. Furthermore, the wide variety of iES-elicited effects in the PFC (e.g., emotions, thoughts, and olfactory and visual hallucinations) exhibits no clear relation to the immediate environment. Therefore, there is no evidence for the kinds of alterations in ongoing perceptual experience that would be predicted by higher-order or global workspace theories. Nevertheless, effects in the orbitofrontal and anterior cingulate cortices suggest a specific role for these PFC subregions in supporting emotional aspects of conscious experience. Overall, this evidence presents a challenge for higher-order and global workspace theories, which commonly point to the PFC as the basis for conscious perception based on correlative and possibly confounded information.
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Allison-Walker T, Hagan MA, Price NSC, Wong YT. Microstimulation-evoked neural responses in visual cortex are depth dependent. Brain Stimul 2021; 14:741-750. [PMID: 33975054 DOI: 10.1016/j.brs.2021.04.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 02/26/2021] [Accepted: 04/27/2021] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Cortical visual prostheses often use penetrating electrode arrays to deliver microstimulation to the visual cortex. To optimize electrode placement within the cortex, the neural responses to microstimulation at different cortical depths must first be understood. OBJECTIVE We investigated how the neural responses evoked by microstimulation in cortex varied with cortical depth, of both stimulation and response. METHODS A 32-channel single shank electrode array was inserted into the primary visual cortex of anaesthetized rats, such that it spanned all cortical layers. Microstimulation with currents up to 14 μA (single biphasic pulse, 200 μs per phase) was applied at depths spanning 1600 μm, while simultaneously recording neural activity on all channels within a response window 2.25-11 ms. RESULTS Stimulation elicited elevated neuronal firing rates at all depths of cortex. Compared to deep sites, superficial stimulation sites responded with higher firing rates at a given current and had lower thresholds. The laminar spread of evoked activity across cortical depth depended on stimulation depth, in line with anatomical models. CONCLUSION Stimulation in the superficial layers of visual cortex evokes local neural activity with the lowest thresholds, and stimulation in the deep layers evoked the most activity across the cortical column. In conjunction with perceptual reports, these data suggest that the optimal electrode placement for cortical microstimulation prostheses has electrodes positioned in layers 2/3, and at the top of layer 5.
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Affiliation(s)
- Tim Allison-Walker
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic, 3800, Australia; ARC Centre of Excellence for Integrative Brain Function, Australia; Monash Vision Group, Monash University, Clayton, Vic, 3800, Australia
| | - Maureen A Hagan
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic, 3800, Australia; ARC Centre of Excellence for Integrative Brain Function, Australia
| | - Nicholas S C Price
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic, 3800, Australia; ARC Centre of Excellence for Integrative Brain Function, Australia
| | - Yan T Wong
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic, 3800, Australia; ARC Centre of Excellence for Integrative Brain Function, Australia; Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Vic, 3800, Australia; Monash Vision Group, Monash University, Clayton, Vic, 3800, Australia.
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Klink PC, Aubry JF, Ferrera VP, Fox AS, Froudist-Walsh S, Jarraya B, Konofagou EE, Krauzlis RJ, Messinger A, Mitchell AS, Ortiz-Rios M, Oya H, Roberts AC, Roe AW, Rushworth MFS, Sallet J, Schmid MC, Schroeder CE, Tasserie J, Tsao DY, Uhrig L, Vanduffel W, Wilke M, Kagan I, Petkov CI. Combining brain perturbation and neuroimaging in non-human primates. Neuroimage 2021; 235:118017. [PMID: 33794355 DOI: 10.1016/j.neuroimage.2021.118017] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 03/07/2021] [Accepted: 03/22/2021] [Indexed: 12/11/2022] Open
Abstract
Brain perturbation studies allow detailed causal inferences of behavioral and neural processes. Because the combination of brain perturbation methods and neural measurement techniques is inherently challenging, research in humans has predominantly focused on non-invasive, indirect brain perturbations, or neurological lesion studies. Non-human primates have been indispensable as a neurobiological system that is highly similar to humans while simultaneously being more experimentally tractable, allowing visualization of the functional and structural impact of systematic brain perturbation. This review considers the state of the art in non-human primate brain perturbation with a focus on approaches that can be combined with neuroimaging. We consider both non-reversible (lesions) and reversible or temporary perturbations such as electrical, pharmacological, optical, optogenetic, chemogenetic, pathway-selective, and ultrasound based interference methods. Method-specific considerations from the research and development community are offered to facilitate research in this field and support further innovations. We conclude by identifying novel avenues for further research and innovation and by highlighting the clinical translational potential of the methods.
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Affiliation(s)
- P Christiaan Klink
- Department of Vision & Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands.
| | - Jean-François Aubry
- Physics for Medicine Paris, Inserm U1273, CNRS UMR 8063, ESPCI Paris, PSL University, Paris, France
| | - Vincent P Ferrera
- Department of Neuroscience & Department of Psychiatry, Columbia University Medical Center, New York, NY, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Andrew S Fox
- Department of Psychology & California National Primate Research Center, University of California, Davis, CA, USA
| | | | - Béchir Jarraya
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France; Foch Hospital, UVSQ, Suresnes, France
| | - Elisa E Konofagou
- Ultrasound and Elasticity Imaging Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA; Department of Radiology, Columbia University, New York, NY, USA
| | - Richard J Krauzlis
- Laboratory of Sensorimotor Research, National Eye Institute, Bethesda, MD, USA
| | - Adam Messinger
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD, USA
| | - Anna S Mitchell
- Department of Experimental Psychology, Oxford University, Oxford, United Kingdom
| | - Michael Ortiz-Rios
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom; German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Hiroyuki Oya
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa, Iowa city, IA, USA
| | - Angela C Roberts
- Department of Physiology, Development and Neuroscience, Cambridge University, Cambridge, United Kingdom
| | - Anna Wang Roe
- Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | | | - Jérôme Sallet
- Department of Experimental Psychology, Oxford University, Oxford, United Kingdom; Univ Lyon, Université Lyon 1, Inserm, Stem Cell and Brain Research Institute, U1208 Bron, France; Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Michael Christoph Schmid
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom; Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland
| | - Charles E Schroeder
- Nathan Kline Institute, Orangeburg, NY, USA; Columbia University, New York, NY, USA
| | - Jordy Tasserie
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France
| | - Doris Y Tsao
- Division of Biology and Biological Engineering, Tianqiao and Chrissy Chen Institute for Neuroscience; Howard Hughes Medical Institute; Computation and Neural Systems, Caltech, Pasadena, CA, USA
| | - Lynn Uhrig
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France
| | - Wim Vanduffel
- Laboratory for Neuro- and Psychophysiology, Neurosciences Department, KU Leuven Medical School, Leuven, Belgium; Leuven Brain Institute, KU Leuven, Leuven Belgium; Harvard Medical School, Boston, MA, USA; Massachusetts General Hospital, Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Melanie Wilke
- German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany; Department of Cognitive Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Igor Kagan
- German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany.
| | - Christopher I Petkov
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom.
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Hussain I, Young S, Kim CH, Benjamin HCM, Park SJ. Quantifying Physiological Biomarkers of a Microwave Brain Stimulation Device. SENSORS (BASEL, SWITZERLAND) 2021; 21:1896. [PMID: 33800415 PMCID: PMC7962824 DOI: 10.3390/s21051896] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/25/2021] [Accepted: 03/04/2021] [Indexed: 11/23/2022]
Abstract
Physiological signals are immediate and sensitive to neural and cardiovascular change resulting from brain stimulation, and are considered as a quantifying tool with which to evaluate the association between brain stimulation and cognitive performance. Brain stimulation outside a highly equipped, clinical setting requires the use of a low-cost, ambulatory miniature system. The purpose of this double-blind, randomized, sham-controlled study is to quantify the physiological biomarkers of the neural and cardiovascular systems induced by a microwave brain stimulation (MBS) device. We investigated the effect of an active MBS and a sham device on the cardiovascular and neurological responses of ten volunteers (mean age 26.33 years, 70% male). Electroencephalography (EEG) and electrocardiography (ECG) were recorded in the initial resting-state, intermediate state, and the final state at half-hour intervals using a portable sensing device. During the experiment, the participants were engaged in a cognitive workload. In the active MBS group, the power of high-alpha, high-beta, and low-beta bands in the EEG increased, and the power of low-alpha and theta waves decreased, relative to the sham group. RR Interval and QRS interval showed a significant association with MBS stimulation. Heart rate variability features showed no significant difference between the two groups. A wearable MBS modality may be feasible for use in biomedical research; the MBS can modulate the neurological and cardiovascular responses to cognitive workload.
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Affiliation(s)
- Iqram Hussain
- Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science, Daejeon 34113, Korea; (I.H.); (S.Y.)
- Department of Medical Physics, University of Science & Technology, Daejeon 34113, Korea
| | - Seo Young
- Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science, Daejeon 34113, Korea; (I.H.); (S.Y.)
- Department of Medical Physics, University of Science & Technology, Daejeon 34113, Korea
| | | | | | - Se Jin Park
- Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science, Daejeon 34113, Korea; (I.H.); (S.Y.)
- Department of Medical Physics, University of Science & Technology, Daejeon 34113, Korea
- AI Research Group, Sewon Intelligence, Ltd., Seoul 04512, Korea;
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Rocchi F, Oya H, Balezeau F, Billig AJ, Kocsis Z, Jenison RL, Nourski KV, Kovach CK, Steinschneider M, Kikuchi Y, Rhone AE, Dlouhy BJ, Kawasaki H, Adolphs R, Greenlee JDW, Griffiths TD, Howard MA, Petkov CI. Common fronto-temporal effective connectivity in humans and monkeys. Neuron 2021; 109:852-868.e8. [PMID: 33482086 PMCID: PMC7927917 DOI: 10.1016/j.neuron.2020.12.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 10/02/2020] [Accepted: 12/30/2020] [Indexed: 01/24/2023]
Abstract
Human brain pathways supporting language and declarative memory are thought to have differentiated substantially during evolution. However, cross-species comparisons are missing on site-specific effective connectivity between regions important for cognition. We harnessed functional imaging to visualize the effects of direct electrical brain stimulation in macaque monkeys and human neurosurgery patients. We discovered comparable effective connectivity between caudal auditory cortex and both ventro-lateral prefrontal cortex (VLPFC, including area 44) and parahippocampal cortex in both species. Human-specific differences were clearest in the form of stronger hemispheric lateralization effects. In humans, electrical tractography revealed remarkably rapid evoked potentials in VLPFC following auditory cortex stimulation and speech sounds drove VLPFC, consistent with prior evidence in monkeys of direct auditory cortex projections to homologous vocalization-responsive regions. The results identify a common effective connectivity signature in human and nonhuman primates, which from auditory cortex appears equally direct to VLPFC and indirect to the hippocampus. VIDEO ABSTRACT.
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Affiliation(s)
- Francesca Rocchi
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK.
| | - Hiroyuki Oya
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA.
| | - Fabien Balezeau
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK
| | | | - Zsuzsanna Kocsis
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK; Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Rick L Jenison
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI, USA
| | - Kirill V Nourski
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | | | - Mitchell Steinschneider
- Departments of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yukiko Kikuchi
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK
| | - Ariane E Rhone
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Brian J Dlouhy
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Ralph Adolphs
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jeremy D W Greenlee
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | - Timothy D Griffiths
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK; Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Matthew A Howard
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA; Pappajohn Biomedical Institute, The University of Iowa, Iowa City, IA, USA
| | - Christopher I Petkov
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK.
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Modelling and prediction of the dynamic responses of large-scale brain networks during direct electrical stimulation. Nat Biomed Eng 2021; 5:324-345. [PMID: 33526909 DOI: 10.1038/s41551-020-00666-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/24/2020] [Indexed: 01/19/2023]
Abstract
Direct electrical stimulation can modulate the activity of brain networks for the treatment of several neurological and neuropsychiatric disorders and for restoring lost function. However, precise neuromodulation in an individual requires the accurate modelling and prediction of the effects of stimulation on the activity of their large-scale brain networks. Here, we report the development of dynamic input-output models that predict multiregional dynamics of brain networks in response to temporally varying patterns of ongoing microstimulation. In experiments with two awake rhesus macaques, we show that the activities of brain networks are modulated by changes in both stimulation amplitude and frequency, that they exhibit damping and oscillatory response dynamics, and that variabilities in prediction accuracy and in estimated response strength across brain regions can be explained by an at-rest functional connectivity measure computed without stimulation. Input-output models of brain dynamics may enable precise neuromodulation for the treatment of disease and facilitate the investigation of the functional organization of large-scale brain networks.
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Ibayashi K, Cardenas AR, Oya H, Kawasaki H, Kovach CK, Howard MA, Long MA, Greenlee JDW. Focal Cortical Surface Cooling is a Novel and Safe Method for Intraoperative Functional Brain Mapping. World Neurosurg 2020; 147:e118-e129. [PMID: 33307258 DOI: 10.1016/j.wneu.2020.11.164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/28/2020] [Accepted: 11/28/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Electric cortical stimulation (ECS) has been the gold standard for intraoperative functional mapping in neurosurgery, yet it carries the risk of induced seizures. We assess the safety of focal cortical cooling (CC) as a potential alternative to ECS. METHODS We reviewed 40 patients (13 with tumor and 27 with mesial temporal lobe epilepsy) who underwent intraoperative CC at the University of Iowa Hospital and Clinics (CC group), of whom 38 underwent ECS preceding CC. Intraoperative and postoperative seizure incidence, postoperative neurologic deficits, and new postoperative radiographic findings were collected to assess CC safety. Fifty-five patients who underwent ECS mapping without CC (ECS-alone group) were reviewed as a control cohort. Another 25 patients who underwent anterior temporal lobectomy (ATL) without CC or ECS (no ECS/no CC-ATL group) were also reviewed to evaluate long-term effects of CC. RESULTS Seventy-nine brain sites in the CC group were cooled, comprising inferior frontal gyrus (44%), precentral gyrus (39%), postcentral gyrus (6%), subcentral gyrus (4%), and superior temporal gyrus (6%). The incidence of intraoperative seizure(s) was 0% (CC group) and 3.6% (ECS-alone group). The incidence of seizure(s) within the first postoperative week did not significantly differ among CC (7.9%), ECS-alone (9.0%), and no ECS/no CC-ATL groups (12%). There was no significant difference in the incidence of postoperative radiographic change between CC (7.5%) and ECS-alone groups (5.5%). Long-term seizure outcome (Engel I+II) for mesial temporal epilepsy did not differ among CC (80%), ECS-alone (83.3%), and no ECS/no CC-ATL groups (83.3%). CONCLUSIONS CC when used as an intraoperative mapping technique is safe and may complement ECS.
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Affiliation(s)
- Kenji Ibayashi
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Araceli R Cardenas
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Hiroyuki Oya
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Christopher K Kovach
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Matthew A Howard
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Michael A Long
- Neuroscience Institute, New York University School of Medicine, New York, New York, USA
| | - Jeremy D W Greenlee
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
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Ryu SB, Paulk AC, Yang JC, Ganji M, Dayeh SA, Cash SS, Fried SI, Lee SW. Spatially confined responses of mouse visual cortex to intracortical magnetic stimulation from micro-coils. J Neural Eng 2020; 17:056036. [PMID: 32998116 DOI: 10.1088/1741-2552/abbd22] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Electrical stimulation via microelectrodes implanted in cortex has been suggested as a potential treatment for a wide range of neurological disorders. Despite some success however, the effectiveness of conventional electrodes remains limited, in part due to an inability to create specific patterns of neural activity around each electrode and in part due to challenges with maintaining a stable interface. The use of implantable micro-coils to magnetically stimulate the cortex has the potential to overcome these limitations because the asymmetric fields from coils can be harnessed to selectively activate some neurons, e.g. vertically-oriented pyramidal neurons while avoiding others, e.g. horizontally-oriented passing axons. In vitro experiments have shown that activation is indeed confined with micro-coils but their effectiveness in the intact brain of living animals has not been evaluated. APPROACH To assess the efficacy of stimulation, a 128-channel custom recording microelectrode array was positioned on the surface of the visual cortex (ECoG) in anesthetized mice and responses to magnetic and electric stimulation were compared. Stimulation was delivered from electrodes or micro-coils implanted through a hole in the center of the recording array at a rate of 200 pulses per second for 100 ms. MAIN RESULTS Both electric and magnetic stimulation reliably elicited cortical responses, although activation from electric stimulation was spatially expansive, often extending more than 1 mm from the stimulation site, while activation from magnetic stimulation was typically confined to a ∼300 µm diameter region around the stimulation site. Results were consistent for stimulation of both cortical layer 2/3 and layer 5 as well as across a range of stimulus strengths. SIGNIFICANCE The improved focality with magnetic stimulation suggests that the effectiveness of cortical stimulation can be improved. Improved focality may be particularly attractive for cortical prostheses that require high spatial resolution, e.g. devices that target sensory cortex, as it may lead to improved acuity.
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Affiliation(s)
- Sang Baek Ryu
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
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