scholarly journals Biological and bionic hands: natural neural coding and artificial perception

2015 ◽  
Vol 370 (1677) ◽  
pp. 20140209 ◽  
Author(s):  
Sliman J. Bensmaia
Keyword(s):  
Upper Limb ◽  
Neural Coding ◽  
Neural Circuits ◽  
Brain Activity ◽  
First Century ◽  
Somatosensory Feedback ◽  
Human Arm ◽  
Tactile Sensations ◽  
The Brain ◽  
Stimulation Of

The first decade and a half of the twenty-first century brought about two major innovations in neuroprosthetics: the development of anthropomorphic robotic limbs that replicate much of the function of a native human arm and the refinement of algorithms that decode intended movements from brain activity. However, skilled manipulation of objects requires somatosensory feedback, for which vision is a poor substitute. For upper-limb neuroprostheses to be clinically viable, they must therefore provide for the restoration of touch and proprioception. In this review, I discuss efforts to elicit meaningful tactile sensations through stimulation of neurons in somatosensory cortex. I focus on biomimetic approaches to sensory restoration, which leverage our current understanding about how information about grasped objects is encoded in the brain of intact individuals. I argue that not only can sensory neuroscience inform the development of sensory neuroprostheses, but also that the converse is true: stimulating the brain offers an exceptional opportunity to causally interrogate neural circuits and test hypotheses about natural neural coding.

scholarly journals Parylene photonics: a flexible, broadband optical waveguide platform with integrated micromirrors for biointerfaces

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jay W. Reddy ◽  
Maya Lassiter ◽  
Maysamreza Chamanzar
Keyword(s):  
Optical Waveguides ◽  
Brain Activity ◽  
Low Loss ◽  
Parylene C ◽  
Optogenetic Stimulation ◽  
Patterned Illumination ◽  
The Brain ◽  
532 Nm ◽  
Stimulation Of

Abstract Targeted light delivery into biological tissue is needed in applications such as optogenetic stimulation of the brain and in vivo functional or structural imaging of tissue. These applications require very compact, soft, and flexible implants that minimize damage to the tissue. Here, we demonstrate a novel implantable photonic platform based on a high-density, flexible array of ultracompact (30 μm × 5 μm), low-loss (3.2 dB/cm at λ = 680 nm, 4.1 dB/cm at λ = 633 nm, 4.9 dB/cm at λ = 532 nm, 6.1 dB/cm at λ = 450 nm) optical waveguides composed of biocompatible polymers Parylene C and polydimethylsiloxane (PDMS). This photonic platform features unique embedded input/output micromirrors that redirect light from the waveguides perpendicularly to the surface of the array for localized, patterned illumination in tissue. This architecture enables the design of a fully flexible, compact integrated photonic system for applications such as in vivo chronic optogenetic stimulation of brain activity.

scholarly journals Understanding the brain by controlling neural activity

2015 ◽  
Vol 370 (1677) ◽  
pp. 20140201 ◽  
Author(s):  
Kristine Krug ◽  
C. Daniel Salzman ◽  
Scott Waddell
Keyword(s):  
Brain Function ◽  
Brain Activity ◽  
Clinical Intervention ◽  
Technical Developments ◽  
Control Brain ◽  
Electrical Devices ◽  
Behavioural Experiments ◽  
Brain Processing ◽  
The Brain ◽  
Stimulation Of

Causal methods to interrogate brain function have been employed since the advent of modern neuroscience in the nineteenth century. Initially, randomly placed electrodes and stimulation of parts of the living brain were used to localize specific functions to these areas. Recent technical developments have rejuvenated this approach by providing more precise tools to dissect the neural circuits underlying behaviour, perception and cognition. Carefully controlled behavioural experiments have been combined with electrical devices, targeted genetically encoded tools and neurochemical approaches to manipulate information processing in the brain. The ability to control brain activity in these ways not only deepens our understanding of brain function but also provides new avenues for clinical intervention, particularly in conditions where brain processing has gone awry.

Statistical Evaluation of Polygraphic Investigations of Pentoxifylline

1976 ◽  
Vol 4 (4) ◽  
pp. 211-222 ◽  
Author(s):  
U J Jovanović
Keyword(s):  
Blood Pressure ◽  
Beneficial Effect ◽  
Statistical Evaluation ◽  
Brain Activity ◽  
Metabolic Effects ◽  
Electrical Brain Activity ◽  
Wave Patterns ◽  
The Brain ◽  
Electrical Skin ◽  
Stimulation Of

Changes in the electro-encephalogram, and in the electro-oculogram electromyogram, ECG, blood supply, blood pressure, electrical skin activity and neurological/psychiatric findings, were investigated in 100 patients given single administrations of 200 mg of pentoxifylline (BL 191). It is concluded from the changes in the EEG wave patterns that pentoxifylline produces a beneficial effect on the cerebral processes contributing to bio-electrical brain activity. Pentoxifylline can be classed as a substance with microcirculatory/metabolic effects on the brain, which lead to stimulation of psychomotor behaviour.

scholarly journals Span, CRUNCH, and Beyond: Working Memory Capacity and the Aging Brain

2010 ◽  
Vol 22 (4) ◽  
pp. 655-669 ◽  
Author(s):  
Nils J. Schneider-Garces ◽  
Brian A. Gordon ◽  
Carrie R. Brumback-Peltz ◽  
Eunsam Shin ◽  
Yukyung Lee ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Neural Circuits ◽  
Memory Span ◽  
Brain Activity ◽  
Memory Search ◽  
Brain Activation ◽  
Aging Brain ◽  
Younger Adults ◽  
The Brain

Neuroimaging data emphasize that older adults often show greater extent of brain activation than younger adults for similar objective levels of difficulty. A possible interpretation of this finding is that older adults need to recruit neuronal resources at lower loads than younger adults, leaving no resources for higher loads, and thus leading to performance decrements [Compensation-Related Utilization of Neural Circuits Hypothesis; e.g., Reuter-Lorenz, P. A., & Cappell, K. A. Neurocognitive aging and the compensation hypothesis. Current Directions in Psychological Science, 17, 177–182, 2008]. The Compensation-Related Utilization of Neural Circuits Hypothesis leads to the prediction that activation differences between younger and older adults should disappear when task difficulty is made subjectively comparable. In a Sternberg memory search task, this can be achieved by assessing brain activity as a function of load relative to the individual's memory span, which declines with age. Specifically, we hypothesized a nonlinear relationship between load and both performance and brain activity and predicted that asymptotes in the brain activation function should correlate with performance asymptotes (corresponding to working memory span). The results suggest that age differences in brain activation can be largely attributed to individual variations in working memory span. Interestingly, the brain activation data show a sigmoid relationship with load. Results are discussed in terms of Cowan's [Cowan, N. The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87–114, 2001] model of working memory and theories of impaired inhibitory processes in aging.

Teaching in Symbiosis with the Needs of the Brain

2013 ◽  
Vol 3 (2) ◽  
pp. 60-78
Author(s):  
Monika Máčajová
Keyword(s):  
Brain Activity ◽  
Life Quality ◽  
Educational Systems ◽  
Learning And Teaching ◽  
Effective Learning ◽  
Economic Problems ◽  
Evaluation Procedures ◽  
Learning Principles ◽  
The Brain ◽  
Stimulation Of

Despite of many worldwide economic problems, every developed society focuses its interest on education. This is undoubtedly caused by the fact that the societies have realized that education is the only way to progress and life quality improvement. Therefore, all educational systems in any period of their development have been making their efforts to seek and find newer approaches to more effective learning and teaching. The present study contributes to the line of works that look for new ways of education through discovering and learning principles of the functioning of the human brain. The paper introduces and explains teaching procedures which respect the needs of the brain. A specific emphasis is put on a) brain activity in various periods; b) evaluation procedures related to the theory of brain‑compatible learning; c) the need to articulate new knowledge and problem solving procedures with respect to optimal stimulation of the brain.

Peripheral endotoxin causes long-lasting changes in locus coeruleus activity via IL-1 in the brain

2002 ◽  
Vol 14 (6) ◽  
pp. 303-321 ◽  
Author(s):  
Mark K. Borsody ◽  
Jay M. Weiss
Keyword(s):  
Locus Coeruleus ◽  
Bacterial Infections ◽  
Low Dose ◽  
Brain Activity ◽  
Interleukin 1 ◽  
Gram Positive Bacteria ◽  
Polycytidylic Acid ◽  
Increased Activity ◽  
The Brain ◽  
Stimulation Of

Activity of locus coeruleus (LC) neurons, the major noradrenergic cell-body group in the brain whose axons give rise to approximately 70% of norepinephrine (NE) in the brain, is believed to play an important role in attention/vigilance, cognitive functions and behavioral disorders, particularly depression. Results described here show that in the rat, intraperitoneal (i.p.) injection of lipopolysaccharide (LPS, a bacterial endotoxin) causes long-lasting changes in electrophysiological activity of LC neurons that are mediated by interleukin-1 (IL-1) acting locally in the LC region. First, it was found that IL-1, when microinjected into the LC region or stimulated/expressed in that brain region, increased activity of LC neurons. The only exception to this was that a very low dose of microinjected IL-1 (5 pg) decreased LC activity, which could be blocked by an antagonist to corticotropin-releasing hormone (CRH), thus suggesting that the decrease was due to IL-1 stimulation of CRH release. All of these effects could be blocked by injection and/or infusion of IL-1 receptor antagonist (IL-1RA) specifically into the LC region. Next, intraperitoneal (i.p.) injection of a low dose of LPS(10 µg/kg or 100 ng/kg) was also found to increase LC activity. The excitation of LC produced by 10 µg/kg i.p. LPS increased progressively for at least 1 week, with LC neurons firing at more than twice their normal rate at 1 week after the i.p. LPS injection. Alteration of LC activity lasted for 3 weeks after a single i.p. injection of 10 µg/kg LPS. The effects of i.p. LPS on LC activity at any time after i.p. injection could be blocked by a brief microinfusion of IL-1RA into the LC region, thereby indicating that changes in LC activity seen after the i.p. LPS were caused by IL-1 acting in the LC region. Finally, i.p. injection of peptidoglycan, representing gram-positive bacteria, and polyinsinic-polycytidylic acid [poly(I):(C)], representing viral infection, also caused increases in LC activity, and the effects of peptidoglycan [but not those of poly(I):(C)] were blocked by microinfusion of IL-1RA into LC. These findings suggest that bacterial infections can give rise to prolonged changes in brain activity through cytokine action in brain.

scholarly journals Review of Brain-Machine Interfaces Used in Neural Prosthetics with New Perspective on Somatosensory Feedback through Method of Signal Breakdown

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Gabriel W. Vattendahl Vidal ◽  
Mathew L. Rynes ◽  
Zachary Kelliher ◽  
Shikha Jain Goodwin
Keyword(s):  
Neural Control ◽  
Direct Stimulation ◽  
Neural Prosthetics ◽  
Somatosensory Feedback ◽  
Neuron Populations ◽  
Machine Interface ◽  
New Perspective ◽  
The Brain ◽  
Initial Focus ◽  
Stimulation Of

The brain-machine interface (BMI) used in neural prosthetics involves recording signals from neuron populations, decoding those signals using mathematical modeling algorithms, and translating the intended action into physical limb movement. Recently, somatosensory feedback has become the focus of many research groups given its ability in increased neural control by the patient and to provide a more natural sensation for the prosthetics. This process involves recording data from force sensitive locations on the prosthetics and encoding these signals to be sent to the brain in the form of electrical stimulation. Tactile sensation has been achieved through peripheral nerve stimulation and direct stimulation of the somatosensory cortex using intracortical microstimulation (ICMS). The initial focus of this paper is to review these principles and link them to modern day applications such as restoring limb use to those who lack such control. With regard to how far the research has come, a new perspective for the signal breakdown concludes the paper, offering ideas for more real somatosensory feedback using ICMS to stimulate particular sensations by differentiating touch sensors and filtering data based on unique frequencies.

scholarly journals Sensory restoration by epidural stimulation of the lateral spinal cord in upper-limb amputees

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Santosh Chandrasekaran ◽  
Ameya C Nanivadekar ◽  
Gina McKernan ◽  
Eric R Helm ◽  
Michael L Boninger ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Upper Limb ◽  
Sensory Feedback ◽  
Limb Amputation ◽  
Stimulus Amplitude ◽  
Major Barrier ◽  
Somatosensory Feedback ◽  
Upper Limb Amputation ◽  
Epidural Spinal Cord Stimulation ◽  
Stimulation Of

Restoring somatosensory feedback to people with limb amputations is crucial to improve prosthetic control. Multiple studies have demonstrated that peripheral nerve stimulation and targeted reinnervation can provide somatotopically relevant sensory feedback. While effective, the surgical procedures required for these techniques remain a major barrier to translatability. Here, we demonstrate in four people with upper-limb amputation that epidural spinal cord stimulation (SCS), a common clinical technique to treat pain, evoked somatosensory percepts that were perceived as emanating from the missing arm and hand. Over up to 29 days, stimulation evoked sensory percepts in consistent locations in the missing hand regardless of time since amputation or level of amputation. Evoked sensations were occasionally described as naturalistic (e.g. touch or pressure), but were often paresthesias. Increasing stimulus amplitude increased the perceived intensity linearly, without increasing area of the sensations. These results demonstrate the potential of SCS as a tool to restore somatosensation after amputations.

scholarly journals Coordination of brain wide activity dynamics by dopaminergic neurons

2016 ◽  
Author(s):  
Garret Stuber ◽  
Heather Decot ◽  
Vijay Namboodiri ◽  
Wei Gao ◽  
Jenna McHenry ◽  
...  
Keyword(s):  
Dopaminergic Neurons ◽  
Large Scale ◽  
Cerebral Blood Volume ◽  
Brain Activity ◽  
Functional Magnetic Resonance ◽  
Transgenic Rats ◽  
Optogenetic Stimulation ◽  
The Brain ◽  
Neuropsychiatric Conditions ◽  
Stimulation Of

Several neuropsychiatric conditions, such as addiction, schizophrenia, and depression may arise in part from dysregulated activity of ventral tegmental area dopaminergic (THVTA) neurons, as well as from more global maladaptation in neurocircuit function. However, whether THVTA activity affects large-scale brain-wide function remains unknown. Here, we selectively activated THVTA neurons in transgenic rats and measured resulting changes in whole-brain activity using stimulus-evoked functional magnetic resonance imaging (fMRI). Selective optogenetic stimulation of THVTA neurons not only enhanced cerebral blood volume (CBV) signals in striatal target regions in a dopamine receptor dependent fashion, but also engaged many additional anatomically defined regions throughout the brain. In addition, repeated pairing of THVTA neuronal activity with forepaw stimulation, produced an expanded brain-wide sensory representation. These data suggest that modulation of THVTA neurons can impact brain dynamics across many distributed anatomically distinct regions, even those that receive little to no direct THVTA input.

Observation of neuronal activity using real-time voltage-sensitive dye imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 476-477
Author(s):  
John S. Kauer ◽  
Angel Cinelli ◽  
David Wellis ◽  
Joel White
Keyword(s):  
Neuronal Activity ◽  
Neural Circuits ◽  
Brain Activity ◽  
Single Cells ◽  
Pyramidal Cells ◽  
Optical Recording ◽  
Sensory Cells ◽  
Large Numbers ◽  
The Brain ◽  
Prepyriform Cortex

Sensory systems are confronted with the problem of taking “information” in the outside world and encoding and manipulating it in forms that can be used in the neuronal world. A major challenge is to document how the transition between these worlds takes place (transduction) and, once it has taken place, how the data are manipulated by neural circuits (integration). Since the brain is an intrinsically parallel device, carrying out many functions simultaneously, it would appear as important to record brain activity in a similarly parallel manner as to record events in single cells and membranes. Optical recording of neuronal events offers a first step toward thing to observe events that are distributed among the cells and processes of a neuronal network.In the sense of smell odors appear to be encoded by activity distributed across many neurons at each level of the system studied so far, from the sensory cells in the nose to the pyramidal cells in prepyriform cortex (for review see). Thus, to elucidate how the molecular properties of odorants are represented by neurons it is probably necessary to observe the patterns of distributed activation. The distribution of activity across many neuronal elements, in contrast to representing odor molecules by dedicated “labelled lines”, confers redundancy and fault tolerance on a system that is crucial for complex behaviors that underly survival for many animals species, as well as providing flexibility for being sensitive to large numbers of compounds.

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