Touch sensitivity in oligochaete giant fibers is transiently enhanced by a single spike

1996 ◽  
Vol 74 (5) ◽  
pp. 841-844
Author(s):  
David E. Turnbull ◽  
Charles D. Drewes
Keyword(s):  
Tactile Stimulation ◽  
Lumbriculus Variegatus ◽  
Giant Fiber ◽  
Non Invasive ◽  
Touch Sensitivity ◽  
Single Spike ◽  
Weak Stimulus ◽  
Site Of Stimulation ◽  
Stimulation Of ◽  
Touch Stimulus

Weak tactile stimulation of posterior segments in the freshwater oligochaete Lumbriculus variegatus evokes a single lateral giant fiber (LGF) spike but no overt escape shortening. After initiation of a single spike, giant-fiber excitability is increased, as reflected by a period of enhanced conduction velocity for a second LGF spike that follows 5–50 ms after the first. Using non-invasive recordings from intact worms and a biofeedback arrangement for stimulus delivery, it was shown that the period of enhanced velocity is associated with a marked increase in sensitivity to a second touch stimulus. Enhanced touch sensitivity is distributed within the LGF sensory field to loci remote from the original site of stimulation, leading to an increased likelihood that a second, weak stimulus will elicit rapid escape withdrawal.

scholarly journals Electro-haptic hearing: Speech-in-noise performance in cochlear implant users is enhanced by tactile stimulation of the wrists

2019 ◽  
Author(s):  
Mark D. Fletcher ◽  
Amatullah Hadeedi ◽  
Tobias Goehring ◽  
Sean R Mills
Keyword(s):  
Cochlear Implant ◽  
Speech Intelligibility ◽  
Tactile Stimulation ◽  
Electrical Signal ◽  
Noise Performance ◽  
Speech In Noise ◽  
Non Invasive ◽  
Real World Application ◽  
Before And After ◽  
Stimulation Of

Cochlear implant (CI) users receive only limited sound information through their implant, which means that they struggle to understand speech in noisy environments. Recent work has suggested that combining the electrical signal from the CI with a haptic signal that provides crucial missing sound information (“electro-haptic stimulation”; EHS) could improve speech-in-noise performance. The aim of the current study was to test whether EHS could enhance speech-in-noise performance in CI users using: (1) a tactile signal derived using an algorithm that could be applied in real time, (2) a stimulation site appropriate for a real-world application, and (3) a tactile signal that could readily be produced by a compact, portable device. We measured speech intelligibility in multi-talker noise with and without vibro-tactile stimulation of the wrist in CI users, before and after a short training regime. No effect of EHS was found before training, but after training EHS was found to improve the number of words correctly identified by an average of 8.3 %-points, with some users improving by more than 20 %-points. Our approach could offer an inexpensive and non-invasive means of improving speech-in-noise performance in CI users.

A visually elicited escape response in the fly that does not use the giant fiber pathway

1994 ◽  
Vol 11 (6) ◽  
pp. 1149-1161 ◽  
Author(s):  
Mats H. Holmqvist
Keyword(s):  
Escape Response ◽  
Compound Eye ◽  
Visual Stimulation ◽  
Giant Fiber ◽  
Single Spike ◽  
Freely Behaving ◽  
Freely Moving ◽  
Escape Responses ◽  
The Brain ◽  
Stimulation Of

AbstractA housefly elicits an escape in response to an approaching target (Holmqvist & Srinivasan, 1991). This study tests if the giant fiber pathway, which mediates a light-off escape response in a fruitfly (Wyman et al., 1985), also mediates escape to an approaching target in a housefly. Visual stimuli simulating an approaching or receding dark disk were presented to houseflies, Musca domestica, in both behavioral and physiological experiments. Freely behaving flies escaped in response to an expanding dark disk but not to a contracting dark disk. In restrained flies, the giant fiber, here called the giant descending neuron (GDN), was recorded from intracellularly and the tergotrochanteral muscle (TTM), which provides the main thrust in an escape jump, was recorded from extracellularly. During electrical stimulation of the brain, by means of stimulating electrodes inserted into the ventral part of each compound eye, a single spike in the GDN drives the TTM. However, when the TTM responds to visual stimulation that elicits an escape response in a behaving fly, the GDN shows no activity. Similarly to the behavioral results, the TTM of restrained flies showed muscle potentials in response to an expanding dark disk, but not to a contracting disk. However, freely moving flies elicit escapes more than 100 ms on average before the first TTM spike, suggesting that this type of escape does not start with a jump powered by the TTM. In conclusion, this visually evoked escape response in the housefly is not likely to be mediated by the giant fiber pathway. The findings suggest that there exist at least two pathways mediating visually evoked escape responses in flies.

Hindleg targeting during scratching in the locust

1997 ◽  
Vol 200 (1) ◽  
pp. 93-100 ◽  
Author(s):  
T Matheson
Keyword(s):  
Tactile Stimulation ◽  
Schistocerca Gregaria ◽  
Sensory Information ◽  
Sensory Receptors ◽  
Mechanical Constraints ◽  
Metathoracic Ganglion ◽  
The Central Nervous System ◽  
Stimulus Site ◽  
Site Of Stimulation ◽  
Stimulation Of

Intact locusts (Schistocerca gregaria) respond to tactile stimulation of their folded wings with rhythmic scratching movements of the ipsilateral hindleg that are directed towards the site of stimulation. For example, sites near the base of a wing elicit anteriorly directed scratches, whereas sites near the distal end of a wing elicit posteriorly directed scratches. Locusts also scratch in response to tactile stimulation of a wing that is held outstretched in a posture similar to that normally adopted during flight, but they fail to alter their leg targeting to compensate for this changed position of the stimulus site. Instead, they scratch at an empty point in space near the abdomen, where the stimulus site would have been if the wing was folded in the resting posture. This inappropriate scratching does not result from mechanical constraints on the hindleg's movement, from stimulation of abdominal sensory receptors, or from an absence of sensory information from the outstretched wing. It also persists when the metathoracic ganglion that controls movements of the hindlegs is isolated from the remainder of the central nervous system (CNS). Targeted scratching of sites on the wings of locusts therefore appears to be fixed relative to body coordinates and does not take into account alterations of the target wing's position.

Non-invasive electrical stimulation of oropharyngeal muscles in obstructive sleep apnoea

2021 ◽  
Author(s):  
Juan Luis RodrÍguez Hermosa ◽  
Myriam Calle ◽  
Ina Guerassimova ◽  
Baldomero FernÁndez ◽  
Víctor Javier Montero ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Obstructive Sleep Apnoea ◽  
Sleep Apnoea ◽  
Non Invasive ◽  
Obstructive Sleep ◽  
Stimulation Of

scholarly journals Non-invasive stimulation of the motor cerebellum has potential cognitive confounds

2021 ◽  
Author(s):  
Robert M. Hardwick ◽  
Amanda S. Therrien ◽  
Elise Lesage
Keyword(s):  
Non Invasive ◽  
Stimulation Of

Control of feeding motor output by paracerebral neurons in brain of Pleurobranchaea californica

1982 ◽  
Vol 47 (5) ◽  
pp. 885-908 ◽  
Author(s):  
R. Gillette ◽  
M. P. Kovac ◽  
W. J. Davis
Keyword(s):  
Feeding Behavior ◽  
Action Potentials ◽  
Tactile Stimulation ◽  
Natural Food ◽  
Buccal Ganglion ◽  
Pleurobranchaea Californica ◽  
Feeding Rhythm ◽  
Intracellular Stimulation ◽  
Motor Rhythm ◽  
Stimulation Of

1. A population of interneurons that control feeding behavior in the mollusk Pleurobranchaea has been analyzed by dye injection and intracellular stimulation/recording in whole animals and reduced preparations. The population consists of 12-16 somata distributed in two bilaterally symmetrical groups on the anterior edge of the cerebropleural ganglion (brain). On the basis of their position adjacent to the cerebral lobes, these cells have been named paracerebral neurons (PCNs). This study concerns pme subset pf [MCs. the large, phasic ones, which have the strongest effect on the feeding rhythm (21). 2. Each PCN sends a descending axon via the ipsilateral cerebrobuccal connective to the buccal ganglion. Axon branches have not been detected in other brain or buccal nerves and hence the PCNs appear to be interneurons. 3. In whole-animal preparations, tonic intracellular depolarization of the PNCs causes them to discharge cyclic bursts of action potentials interrupted by a characteristic hyperpolarization. In all specimens that exhibit feeding behavior, the interburst hyperpolarization is invariably accompanied by radula closure and the beginning of proboscis retraction (the "bite"). No other behavorial effect of PCN stimulation has been observed. 4. In whole-animal preparations, the PCNs are excited by food and tactile stimulation of the oral veil, rhinophores, and tentacles. When such stimuli induce feeding the PCNs discharge in the same bursting pattern seen during tonic PCN depolarization, with the cyclic interburst hyperpolarization phase locked to the bit. When specimens egest an unpalatable object by cyclic buccal movements, however, the PCNs are silent. The PCNs therefore exhibit properties expected of behaviorally specific "command" neurons for feeding. 5. Silencing one or two PCNs by hyperpolarization may weaken but does not prevent feeding induced by natural food stimuli. Single PCNs therefore can be sufficient but are not necessary to induction of feeding behavior. Instead the PCNs presumably operate as a population to control feeding. 6. In isolated nervous system preparations tonic extracellular stimulation of the stomatogastric nerve of the buccal ganglion elicits a cyclic motor rhythm that is similar in general features to the PNC-induced motor rhythm. Bursts of PCN action potentials intercalated at the normal phase position in this cycle intensify the buccal rhythm. Bursts of PCN impulses intercalated at abnormal phase positions reset the buccal rhythm. The PCNs, therefore, also exhibit properties expected of pattern-generator elements and/or coordinating neurons for the buccal rhythm. 7. The PCNs are recruited into activity when the buccal motor rhythm is elicited by stomatogastric nerve stimulation or stimulation of the reidentifiable ventral white cell. The functional synergy between the PCNs and the buccal rhythm is therefore reciprocal. 8...

A methodological reappraisal of non invasive high voltage electrical stimulation of lumbosacral nerve roots

2011 ◽  
Vol 122 (10) ◽  
pp. 2071-2080 ◽  
Author(s):  
Walter Troni ◽  
Alessia Di Sapio ◽  
Eliana Berra ◽  
Sergio Duca ◽  
Aristide Merola ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
High Voltage ◽  
Nerve Roots ◽  
Non Invasive ◽  
Stimulation Of

Structure and Function of the Lateral Giant Neurone of the Primitive Crustacean Anaspides Tasmaniae

1979 ◽  
Vol 78 (1) ◽  
pp. 121-136
Author(s):  
GERALD E. SILVEY ◽  
IAN S. WILSON
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Large Diameter ◽  
Whole Body ◽  
Giant Fibre ◽  
Single Action ◽  
Giant Neurone ◽  
And Function ◽  
Thoracic And Abdominal ◽  
Stimulation Of

The syncarid crustacean Anaspides tasmaniae rapidly flexes its free thoracic and abdominal segments in response to tactile stimulation of its body. This response decrements but recovers in slightly more than one hour. The fast flexion is evoked by single action potentials in the lateral of two large diameter fibres (40 μm) which lie on either side of the cord. The lateral giant fibre is made up of fused axons of 11 neurones, one in each of the last 5 thoracic and 6 abdominal ganglia. The soma of each neurone lies contralateral to the axon. Its neurite crosses that of its counterpart in the commissure and gives out dendrites into the neuropile of each hemiganglion. The lateral giant neurone receives input from the whole body but fires in response only to input from the fourth thoracic segment posteriorly. Both fibres respond with tactile stimulation of only one side. Since neither current nor action potentials spread from one fibre to the other, afferents must synapse with both giant neurones. The close morphological and physiological similarities of the lateral giant neurone in Anaspides to that in the crayfish (Eucarida) suggest that the lateral giant system arose in the ancestor common to syncarids and eucarids, prior to the Carboniferous.

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