scholarly journals Mid-Air Tactile Sensations Evoked by Laser-Induced Plasma: A Neurophysiological Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Hyung-Sik Kim ◽  
Kyu Beom Kim ◽  
Je-Hyeop Lee ◽  
Jin-Ju Jung ◽  
Ye-Jin Kim ◽  
...  
Keyword(s):  
Mechanical Stimulus ◽  
Tactile Sensation ◽  
Classification Error ◽  
Mechanical Stimuli ◽  
Long Distance ◽  
Laser Induced Plasma ◽  
Sensorimotor Area ◽  
Stimulation Method ◽  
Haptic Stimulation ◽  
Plasma Effect

This study demonstrates the feasibility of a mid-air means of haptic stimulation at a long distance using the plasma effect induced by laser. We hypothesize that the stress wave generated by laser-induced plasma in the air can propagate through the air to reach the nearby human skin and evoke tactile sensation. To validate this hypothesis, we investigated somatosensory responses in the human brain to laser plasma stimuli by analyzing electroencephalography (EEG) in 14 participants. Three types of stimuli were provided to the index finger: a plasma stimulus induced from the laser, a mechanical stimulus transferred through Styrofoam stick, and a sham stimulus providing only the sound of the plasma and mechanical stimuli at the same time. The event-related desynchronization/synchronization (ERD/S) of sensorimotor rhythms (SMRs) in EEG was analyzed. Every participant verbally reported that they could feel a soft tap on the finger in response to the laser stimulus, but not to the sham stimulus. The spectrogram of EEG evoked by laser stimulation was similar to that evoked by mechanical stimulation; alpha ERD and beta ERS were present over the sensorimotor area in response to laser as well as mechanical stimuli. A decoding analysis revealed that classification error increased when discriminating ERD/S patterns between laser and mechanical stimuli, compared to the case of discriminating between laser and sham, or mechanical and sham stimuli. Our neurophysiological results confirm that tactile sensation can be evoked by the plasma effect induced by laser in the air, which may provide a mid-air haptic stimulation method.

The initiation of nerve impulses by mesenteric Pacinian corpuscles

1950 ◽  
Vol 137 (886) ◽  
pp. 96-114 ◽  
Keyword(s):  
Conditioning Stimulus ◽  
Mechanical Stimulus ◽  
Constant Current ◽  
Mechanical Stimuli ◽  
Pacinian Corpuscles ◽  
Nerve Impulses ◽  
A Value ◽  
Test Shock ◽  
Long Duration ◽  
Refractory State

A preparation of a single Pacinian corpuscle in the cat’s mesentery has been used to study the initiation of nerve impulses in sensory endings. The minimum movement of a mechanical stimulator required to excite a single corpuscle has been found to be 0⋅5 μ in 100 μ sec. It has been difficult to produce repetitive discharges with rectangular pulses of long duration, either mechanical or of constant current. The latency between a mechanical stimulus and the initiation of an impulse has a value around 1⋅5 msec, for threshold stimuli, and this decreases to a minimum value around 0⋅5 msec, as the stimulus is increased; it is altered only slightly, if at all, by changes in the duration of the maintained displacement of the mechanical stimulator. Subthreshold mechanical stimuli have been shown to facilitate stimulation by electrical test shocks. The return of excitability at the ending is independent of the nature of the conditioning stimulus and varies but little with the nature of the test shock. The value of the latency at threshold is unaffected by the relatively refractory state. The relations of these results to various hypotheses are discussed, and it is suggested that these results can all be accounted for in terms of the known properties of axons.

Rapid Contractions and Associated Potentials in a Sand-Dwelling Anemone

1969 ◽  
Vol 51 (2) ◽  
pp. 513-528
Author(s):  
PETER E. PICKENS
Keyword(s):  
Maximum Size ◽  
Mechanical Stimulus ◽  
Retractor Muscle ◽  
Mechanical Stimuli ◽  
Nerve Impulses ◽  
Electrical Potentials ◽  
Spread Of Excitation ◽  
Electrical Stimuli ◽  
Withdrawal Response ◽  
Muscle Potential

1. Two kinds of electrical potentials can be recorded from the surface of the. retractor muscle of the anemone, Calamactis, during rapid contraction. These are large muscle action potentials and smaller pulses which are thought to be nerve spikes The latter resemble nerve impulses of higher organisms in that they are all-or-none and of short duration. 2. A nerve spike follows each of a pair of electrical stimuli, but the muscle potential and contraction occur only after the second shock, indicating that facilitation is required at the neuromuscular junction. 3. The size of the muscle potential and of the contraction are correlated with the interval between paired electrical stimuli. Maximum size is reached when stimuli are zoo msec. apart even though the minimum effective interval is 30 msec. 4. A muscle potential precedes contraction only along the upper part of the retractor muscle and this is the part that contracts rapidly during the withdrawal response. The lower retractor does not contract. 5. Conduction velocity along the upper retractor is higher than along the lower. The histological correlate of rapid conduction is a nerve net with large, long, longitudinally oriented fibres. 6. The refractory period of the conducting system of the upper retractor is shorter than that of the lower retractor. Consequently, spread of excitation toward the aboral end is limited if paired stimuli are further apart than 250-300 msec. 7. A mechanical stimulus which is just strong enough to elicit a withdrawal response evokes a single muscle potential of maximum size, suggesting that two nerve impulses closer together than 200 msec. precede the muscle potential. Stronger mechanical stimuli evoke a burst of muscle potentials.

Parallel processing of tactile information in the cerebral cortex of the cat: effect of reversible inactivation of SI on responsiveness of SII neurons

1992 ◽  
Vol 67 (2) ◽  
pp. 411-429 ◽  
Author(s):  
A. B. Turman ◽  
D. G. Ferrington ◽  
S. Ghosh ◽  
J. W. Morley ◽  
M. J. Rowe
Keyword(s):  
Phase Locking ◽  
Receptive Fields ◽  
Mechanical Stimulus ◽  
Glabrous Skin ◽  
Mechanical Stimuli ◽  
Sinusoidal Vibration ◽  
Response Level ◽  
Reversible Inactivation ◽  
Stimulus Response ◽  
Cortical Cooling

1. Localized cortical cooling was employed in anesthetized cats for the rapid reversible inactivation of the distal forelimb region within the primary somatosensory cortex (SI). The aim was to examine the responsiveness of individual neurons in the second somatosensory area (SII) in association with SI inactivation to evaluate the relative importance for tactile processing of the direct thalamocortical projection to SII and the indirect projection from the thalamus to SII via an intracortical path through SI. 2. Response features were examined quantitatively before, during, and after SI inactivation for 29 SII neurons, the tactile receptive fields of which were on the glabrous or hairy skin of the distal forelimb. Controlled mechanical stimuli that consisted of l-s trains of either sinusoidal vibration or rectangular pulses were delivered to the skin by means of small circular probes (4- to 8-mm diam). 3. Twenty-three of the 29 SII neurons (80%) showed no change in response level (in impulses per second) as a result of SI inactivation. These included seven neurons activated exclusively or predominantly by Pacinian corpuscle (PC) receptors, six that received hair follicle input, four activated by convergent input from hairy and glabrous skin, and six driven by dynamically sensitive but non-PC inputs from the glabrous skin. 4. Six SII neurons (20%), also made up of different functional classes, displayed a reduction in response to cutaneous stimuli when SI was inactivated. 5. Stimulus-response relations, constructed by plotting response level in impulses per second against the amplitude of the mechanical stimulus, showed that the effect of SI inactivation on individual neurons was consistent over the whole response range. 6. The reduced response level seen in 20% of SII neurons in association with SI inactivation cannot be attributed to direct spread of cooling from SI to the forelimb area of SII, as there was no evidence for a cooling-induced prolongation in SII spike waveforms, an effect that is known to precede any cooling-induced reduction in responsiveness. 7. As SI inactivation produced a fall in spontaneous activity in the affected SII neurons, we suggest that the inactivation removes a source of background facilitatory influence that arises in SI and affects a small proportion of SII neurons. 8. Phase-locking and therefore the precision of impulse patterning were unchanged in the responses of SII neurons to vibration during SI inactivation. This was the case whether response levels of neurons were reduced or unchanged by SI inactivation.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparative study of the changes in receptive-field properties of multireceptive and nocireceptive rat dorsal horn neurons following noxious mechanical stimulation

1989 ◽  
Vol 62 (4) ◽  
pp. 854-863 ◽  
Author(s):  
J. M. Laird ◽  
F. Cervero
Keyword(s):  
Dorsal Horn ◽  
Mechanical Stimulation ◽  
Receptive Fields ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Dorsal Horn Neurons ◽  
Mechanical Threshold ◽  
Before And After ◽  
Low Threshold ◽  
Noxious Mechanical Stimulation

1. Single-unit electrical activity has been recorded from 42 dorsal horn neurons in the sacral segments of the rat's spinal cord. The sample consisted of 20 multireceptive (class 2) cells with both A- and C-fiber inputs and 22 nocireceptive (class 3) cells. All neurons had cutaneous receptive fields (RFs) on the tail. 2. The RF sizes of the cells and their response thresholds to mechanical stimulation of the skin were determined before and after each of a series of 2-min noxious mechanical stimuli. Up to five such stimuli were delivered at intervals ranging from 10 to 60 min. In most cases, only one cell per animal was tested. 3. The majority of neurons were tested in barbiturate-anesthetized animals. However, to test whether or not this anesthetic influenced the results obtained, experiments were also performed in halothane-anesthetized and decerebrate-spinal preparations. The results from these experiments are considered separately. 4. All of the neurons responded vigorously to the first noxious pinch stimulus and all but one to the rest of the stimuli in the series. The responses of the neurons varied from stimulus to stimulus, but there were no detectable trends in the two groups of cells. 5. The RFs of the class 2 cells showed large increases (624.3 +/- 175.8 mm2, mean +/- SE) after the application of the pinch stimuli. The RFs of the class 3 neurons, which were initially smaller than those of the class 2 cells, either did not increase in size or showed very small increases after the pinch stimuli (38.3 +/- 11.95 mm2, mean +/- SE). 6. Some cells in both groups (6/10 class 2 cells and 7/16 class 3 cells) showed a decrease in mechanical threshold as a result of the noxious mechanical stimulus, but none of the class 3 cells' thresholds dropped below 20 mN into the low-threshold range. 7. The results obtained in the halothane-anesthetized and decerebrate-spinal animals were very similar to those seen in the barbiturate-anesthetized experiments, with the exception that in the decerebrate-spinal animals, the RFs of the class 2 cells were initially larger and showed only small increases.(ABSTRACT TRUNCATED AT 400 WORDS)

INK-JET PRINTED STRETCHABLE SENSORS FOR CELL MONITORING UNDER MECHANICAL STIMULI: A FEASIBILITY STUDY

2019 ◽  
Vol 19 (06) ◽  
pp. 1950049 ◽  
Author(s):  
SARAH TONELLO ◽  
MICHELA BORGHETTI ◽  
NICOLA F. LOPOMO ◽  
MAURO SERPELLONI ◽  
EMILIO SARDINI ◽  
...  
Keyword(s):  
Cyclic Strain ◽  
Mechanical Stimulus ◽  
Research Field ◽  
Stretchable Electronics ◽  
Present System ◽  
Mechanical Stimuli ◽  
Ink Jet ◽  
Cell Monitoring ◽  
Cell Concentrations ◽  
Stretchable Sensors

Impedance-based sensors represent a promising tool for cell monitoring to improve current invasive biological assays. A novel research field is represented by measurements performed in dynamic conditions, monitoring cells (e.g., myocytes) for which the mechanical stimulus plays an important role for promoting maturation. In this picture, we applied printed and stretchable electronics principles, developing a system able to evaluate cells adhesion during substrate cyclic strain. Cytocompatible and stretchable sensors were ink-jet printed using carbon-based ink on crosslinked poly([Formula: see text]-caprolactone) electrospun mats. Moreover, a customized stretching device was produced, with a complete user interface to control testing condition, validated in order to correlate impedance changes with myoblasts — i.e., myocytes precursors — adhesion. Overall system sensitivity was evaluated using three different cell concentrations and DAPI imaging assay was performed to confirm myoblast adhesion. Preliminary results showed the possibility to correlate an average increase of impedance magnitude of 1[Formula: see text]k[Formula: see text] every 15,000 cells/cm2 seeded, suggesting the possibility to discriminate between different cell concentrations, with a sensitivity of 80[Formula: see text]m[Formula: see text]/(cells/cm2). In conclusion, the present system might be generalized in the development of future applications, including the differentiation process of cardiac myocytes with the aid of mechanical stimuli.

A High Throughput System for Long Term Application of Intermittent Cyclic Hydrostatic Pressure on Cells in Culture

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Markus Rottmar ◽  
Sabine Ackerknecht ◽  
Peter Wick ◽  
Katharina Maniura-Weber
Keyword(s):  
Cell Proliferation ◽  
Hydrostatic Pressure ◽  
Cell Fate ◽  
High Throughput ◽  
Cell Response ◽  
Mechanical Stimulus ◽  
Bone Alkaline Phosphatase ◽  
Cell Counting ◽  
Present System ◽  
Mechanical Stimuli

The process of bone remodeling is governed by mechanical stresses and strains. Studies on the effects of mechanical stimulation on cell response are often difficult to compare as the nature of the stimuli and differences in parameters applied vary greatly. Experimental systems for the investigation of mechanical stimuli are mostly limited in throughput or flexibility and often the sum of several stimuli is applied. In this work, a flexible system that allows the investigation of cell response to isolated intermittent cyclic hydrostatic pressure (icHP) on a high throughput level is shown. Human bone derived cells were cultivated with or without mechanical stimulus in the presence or absence of chemical cues triggering osteogenesis for 7–10 days. Cell proliferation and osteogenic differentiation were evaluated by cell counting and immunohistochemical staining for bone alkaline phosphatase as well as collagen 1, respectively. In either medium, both cell proliferation and level of differentiation were increased when the cultures were mechanically stimulated. These initial results therefore qualify the present system for studies on the effects of isolated icHP on cell fate and encourage further investigations on the details behind the observed effects.

scholarly journals Knowledge of and Management Attitude regarding Dentin Hypersensitivity among Dentists from a West African Country

2014 ◽  
Vol 15 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Fatou Leye Benoist ◽  
Fatou Gaye Ndiaye ◽  
Babacar Faye ◽  
Khaly Bane ◽  
Papa Ibrahima Ngom ◽  
...  
Keyword(s):  
African Country ◽  
Mechanical Stimulus ◽  
West African ◽  
Dentin Hypersensitivity ◽  
Mechanical Stimuli ◽  
West African Country ◽  
Management Procedure ◽  
Private And Public ◽  
Triggering Factor ◽  
Management Attitude

ABSTRACT Aim The aim of the present study was to assess knowledge of, and management attitude of dentists regarding Dentin hypersensitivity. Materials and methods The study involved all the dentists from private and public sectors, exerting in Senegal. The following data were requested from the surveyed dentists using an anonymous questionnaire; sociodemographics (i.e. age, gender, area of activity, etc.) and knowledge on triggering factor, type of pain, diagnosis, preventive and curative procedures. Results Out of the 238 dentists who received the questionnaire, 68.9% returned properly filled forms. They were 116 males and 48 females with a mean age of 41.99 ± 8.50 years. Eighty three percent of the participants had a good understanding of the characteristics of pain related to DH and 92% recogni-zed chemical and thermal stimuli as triggering factor while mechanical stimulus was not evoked. Many responders (90.9%) did not have any idea of the mechanism for pain transmission across the dentin. Regarding diagnosis technique, 68% use mechanical stimuli to elicit DH pain. Regarding management procedure, the use of desensitizing tooth paste is the mostly chosen option followed by professional topical application of fluoride. More than 1/3rd of the surveyed dentists confess resorting to root canal to manage DH. Conclusion We recommend incorporation of basic science knowledge on orofacial pain and competencies to manage painful conditions like dentin hypersensitivity. Also, Health regulatory institutions should make continuing dental education a requirement to preserve the dental licensure. How to cite this article Benoist FL, Ndiaye FG, Faye B, Bane K, Ngom PI, Ndong PMK. Knowledge of and Management Attitude regarding Dentin Hypersensitivity among Dentists from a West African Country. J Contemp Dent Pract 2014;15(1):86-91.

scholarly journals Mechanosensitive recruitment of stator units promotes binding of the response regulator CheY-P to the flagellar motor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jyot D. Antani ◽  
Rachit Gupta ◽  
Annie H. Lee ◽  
Kathy Y. Rhee ◽  
Michael D. Manson ◽  
...  
Keyword(s):  
Adaptive Response ◽  
Mechanical Load ◽  
Response Regulator ◽  
Mechanical Stimulus ◽  
Viscous Resistance ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Flagellar Motor ◽  
Neuromuscular Systems ◽  
Bacterial Flagellar Motor

AbstractReversible switching of the bacterial flagellar motor between clockwise (CW) and counterclockwise (CCW) rotation is necessary for chemotaxis, which enables cells to swim towards favorable chemical habitats. Increase in the viscous resistance to the rotation of the motor (mechanical load) inhibits switching. However, cells must maintain homeostasis in switching to navigate within environments of different viscosities. The mechanism by which the cell maintains optimal chemotactic function under varying loads is not understood. Here, we show that the flagellar motor allosterically controls the binding affinity of the chemotaxis response regulator, CheY-P, to the flagellar switch complex by modulating the mechanical forces acting on the rotor. Mechanosensitive CheY-P binding compensates for the load-induced loss of switching by precisely adapting the switch response to a mechanical stimulus. The interplay between mechanical forces and CheY-P binding tunes the chemotactic function to match the load. This adaptive response of the chemotaxis output to mechanical stimuli resembles the proprioceptive feedback in the neuromuscular systems of insects and vertebrates.

Activity-dependent sensory signal processing in mechanically responsive slowly conducting meningeal afferents

2014 ◽  
Vol 112 (12) ◽  
pp. 3077-3085 ◽  
Author(s):  
Michael Uebner ◽  
Richard W. Carr ◽  
Karl Messlinger ◽  
Roberto De Col
Keyword(s):  
Action Potential ◽  
Conduction Velocity ◽  
Receptive Fields ◽  
Low Frequency ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Action Potential Firing ◽  
Afferent Fibers ◽  
Custom Made ◽  
Activity Dependent

Activity-dependent processes in slowly conducting afferents have been shown to modulate conduction and receptive properties, but it is not known how the frequency of action potential firing determines the responses of such fibers to mechanical stimulation. We examined the responses of slowly conducting meningeal afferents to mechanical stimuli and the influence of preceding action potential activity. In hemisected rat heads with adhering cranial dura mater, recordings were made from meningeal nerves. Dural receptive fields of mechanically sensitive afferent fibers were stimulated with a custom-made electromechanostimulator. Sinusoidal mechanical stimuli of different stimulus durations and amplitudes were applied to produce either high-frequency (phasic) or low-frequency (tonic) discharges. Most fibers showed slowing of their axonal conduction velocity on electrically evoked activity at ≥2 Hz. In this state, the peak firing frequency of phasic responses to a 250-ms mechanical stimulus was significantly reduced compared with control. In contrast, the frequency of tonic responses induced by mechanical stimuli of >500 ms did not change. In a rare subtype of afferents, which showed conduction velocity speeding during activity, an increase in the phasic responses to mechanical stimuli was observed. Depending on the axonal properties of the afferent fibers, encoding of phasic components of mechanical stimuli is altered according to the immediate firing history. Preceding activity in mechanoreceptors slowing their conduction velocity seems to provide a form of low-pass filtering of action potential discharges predominantly reducing the phasic component. This may improve discrimination between harmless and potentially harmful mechanical stimuli in normal tissue.

scholarly journals Simulations of Myenteric Neuron Dynamics in Response to Mechanical Stretch

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Donghua Liao ◽  
Jingbo Zhao ◽  
Hans Gregersen
Keyword(s):  
Large Scale ◽  
Visceral Pain ◽  
Mechanical Stretch ◽  
Compartment Model ◽  
Building Blocks ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Myenteric Neuron ◽  
Mechanoelectrical Transduction ◽  
Physiological Outcomes

Background. Intestinal sensitivity to mechanical stimuli has been studied intensively in visceral pain studies. The ability to sense different stimuli in the gut and translate these to physiological outcomes relies on the mechanosensory and transductive capacity of intrinsic intestinal nerves. However, the nature of the mechanosensitive channels and principal mechanical stimulus for mechanosensitive receptors are unknown. To be able to characterize intestinal mechanoelectrical transduction, that is, the molecular basis of mechanosensation, comprehensive mathematical models to predict responses of the sensory neurons to controlled mechanical stimuli are needed. This study aims to develop a biophysically based mathematical model of the myenteric neuron with the parameters constrained by learning from existing experimental data. Findings. The conductance-based single-compartment model was selected. The parameters in the model were optimized by using a combination of hand tuning and automated estimation. Using the optimized parameters, the model successfully predicted the electrophysiological features of the myenteric neurons with and without mechanical stimulation. Conclusions. The model provides a method to predict features and levels of detail of the underlying physiological system in generating myenteric neuron responses. The model could be used as building blocks in future large-scale network simulations of intrinsic primary afferent neurons and their network.

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