P148: Air puff evoked potentials. Short latency response and long latency vertex response. Normative values

The earliest neural response to a mechanical perturbation, the short-latency stretch response (R1: 20–45 ms), is known to exhibit “automatic gain-scaling” whereby its magnitude is proportional to preperturbation muscle activity. Because gain-scaling likely reflects an intrinsic property of the motoneuron pool (via the size-recruitment principle), counteracting this property poses a fundamental challenge for the nervous system, which must ultimately counter the absolute change in load regardless of the initial muscle activity (i.e., show no gain-scaling). Here we explore the temporal evolution of gain-scaling in a simple behavioral task where subjects stabilize their arm against different background loads and randomly occurring torque perturbations. We quantified gain-scaling in four elbow muscles (brachioradialis, biceps long, triceps lateral, triceps long) over the entire sequence of muscle activity following perturbation onset—the short-latency response, long-latency response (R2: 50–75 ms; R3: 75–105 ms), early voluntary corrections (120–180 ms), and steady-state activity (750–1250 ms). In agreement with previous observations, we found that the short-latency response demonstrated substantial gain-scaling with a threefold increase in background load resulting in an approximately twofold increase in muscle activity for the same perturbation. Following the short-latency response, we found a rapid decrease in gain-scaling starting in the long-latency epoch (∼75-ms postperturbation) such that no significant gain-scaling was observed for the early voluntary corrections or steady-state activity. The rapid decrease in gain-scaling supports our recent suggestion that long-latency responses and voluntary control are inherently linked as part of an evolving sensorimotor control process through similar neural circuitry.

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Differentiated short latency response increases after conditioning in inferior colliculus neurons of alert rat

Brain Research ◽

10.1016/0006-8993(77)90278-5 ◽

1977 ◽

Vol 130 (2) ◽

pp. 315-333 ◽

Cited By ~ 42

Author(s):

John F. Disterhoft ◽

Duncan K. Stuart

Keyword(s):

Inferior Colliculus ◽

Short Latency ◽

Alert Rat ◽

Short Latency Response ◽

Latency Response

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Impact of Experimental Tonic Pain on Corrective Motor Responses to Mechanical Perturbations

Neural Plasticity ◽

10.1155/2020/8864407 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Elodie Traverse ◽

Clémentine Brun ◽

Émilie Harnois ◽

Catherine Mercier

Keyword(s):

Sensory Feedback ◽

Pain Model ◽

Voluntary Response ◽

Long Latency ◽

Short Latency Response ◽

Latency Response ◽

Tonic Pain ◽

Underlying Mechanisms ◽

The Impact ◽

Muscle Responses

Movement is altered by pain, but the underlying mechanisms remain unclear. Assessing corrective muscle responses following mechanical perturbations can help clarify these underlying mechanisms, as these responses involve spinal (short-latency response, 20-50 ms), transcortical (long-latency response, 50-100 ms), and cortical (early voluntary response, 100-150 ms) mechanisms. Pairing mechanical (proprioceptive) perturbations with different conditions of visual feedback can also offer insight into how pain impacts on sensorimotor integration. The general aim of this study was to examine the impact of experimental tonic pain on corrective muscle responses evoked by mechanical and/or visual perturbations in healthy adults. Two sessions (Pain (induced with capsaicin) and No pain) were performed using a robotic exoskeleton combined with a 2D virtual environment. Participants were instructed to maintain their index in a target despite the application of perturbations under four conditions of sensory feedback: (1) proprioceptive only, (2) visuoproprioceptive congruent, (3) visuoproprioceptive incongruent, and (4) visual only. Perturbations were induced in either flexion or extension, with an amplitude of 2 or 3 Nm. Surface electromyography was recorded from Biceps and Triceps muscles. Results demonstrated no significant effect of the type of sensory feedback on corrective muscle responses, no matter whether pain was present or not. When looking at the effect of pain on corrective responses across muscles, a significant interaction was found, but for the early voluntary responses only. These results suggest that the effect of cutaneous tonic pain on motor control arises mainly at the cortical (rather than spinal) level and that proprioception dominates vision for responses to perturbations, even in the presence of pain. The observation of a muscle-specific modulation using a cutaneous pain model highlights the fact that the impacts of pain on the motor system are not only driven by the need to unload structures from which the nociceptive signal is arising.

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Air puff evoked potentials. Short latency responses. Normative values

Neurophysiologie Clinique ◽

10.1016/j.neucli.2013.10.028 ◽

2013 ◽

Vol 43 (5-6) ◽

pp. 321

Author(s):

C. Prieur ◽

P. Convers ◽

C. Créac’h ◽

R. Peyron

Keyword(s):

Evoked Potentials ◽

Short Latency ◽

Normative Values

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A novel long-latency response of locus coeruleus neurons to noxious stimuli: mediation by peripheral C-fibers

Journal of Neurophysiology ◽

10.1152/jn.1994.71.5.1752 ◽

1994 ◽

Vol 71 (5) ◽

pp. 1752-1761 ◽

Cited By ~ 58

Author(s):

H. Hirata ◽

G. Aston-Jones

Keyword(s):

Sciatic Nerve ◽

Locus Coeruleus ◽

Short Latency ◽

Late Response ◽

Excitatory Response ◽

C Fibers ◽

Long Latency ◽

C Fiber ◽

Latency Response ◽

Noxious Stimuli

1. Extracellular recordings were obtained from single presumed noradrenergic neurons in the nucleus locus coeruleus (LC) in response to percutaneous electrical foot shock (FS) stimulation in the rat. We employed long-duration stimulus pulses to examine the possible contribution of peripheral C-fibers to evoked activity in LC. 2. As in previous studies, 0.5-ms FS stimuli produced a short-latency excitatory response (onset 20.8 ms) followed by a prolonged postactivation inhibition. However, 2.0- or 5.0-ms FS stimuli yielded an additional late excitatory response. 3. The onset and termination latency of this late excitatory response were approximately 200 and 400 ms, respectively, after the FS. The conduction velocity for this late response (peripheral plus central pathway) was estimated to be < 1.2 m/s. 4. The percentages of LC neurons that exhibited a significant late response was 4% (3/85) with 0.5-ms stimuli, 53% (31/59) with 2.0-ms stimuli, and 73% (47/64) with 5.0-ms FS stimuli. 5. The average number of spikes evoked per FS stimulus (presented at 0.5 Hz) increased from the 1st to the 21st FS stimulus. This increased response occurred selectively in the late, not in the early, response. This result was interpreted to represent a “windup” phenomenon reflected at the level of LC. 6. Direct application of capsaicin onto the sciatic nerve reduced the average magnitude of the late response of LC neurons to 17% of control 42.5 min after application. The magnitude of the short-latency response components showed little or no change. 7. Averaged compound action potential (cAP) recordings from the sciatic nerve revealed that C-fiber responses were more consistently observed and much larger with 5.0-ms compared with 0.5-ms FS stimuli. 8. C-fiber cAPs were reduced or eliminated after application of capsaicin distal to the recording site with a time course similar to that of the late response of LC neurons, with little or no effect on A-fiber cAPs. 9. These data show that a previously undescribed long-latency response of LC neurons to noxious FS stimulation in rat results from C-fiber activation in the sciatic nerve. This late response may be involved in generating descending noradrenergic analgesia induced by electrical stimulation of the foot pad or other body regions. Future studies of the pharmacology of this late response to noxious stimuli in LC may aid in developing new therapies for the treatment of acute or chronic pain.

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Evoked potentials in the hypothalamus

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.6.1163 ◽

1959 ◽

Vol 196 (6) ◽

pp. 1163-1167 ◽

Cited By ~ 47

Author(s):

Shaul Feldman ◽

Charles S. Van der Heide ◽

Robert W. Porter

Keyword(s):

Sciatic Nerve ◽

Evoked Potentials ◽

Reticular Formation ◽

Short Latency ◽

High Frequency Stimulation ◽

Midbrain Reticular Formation ◽

Long Latency ◽

Prolonged Recovery ◽

Frequency Stimulation ◽

Stimulation Of

The distribution and some properties of the evoked potentials in the hypothalamus from stimulation of the sciatic nerve were investigated in 60 cats. In the posterior and lateral hypothalamus biphasic positive-negative responses of 7–10 msec. latency were found, while in the anterior and medial hypothalamus the stimuli evoked monophasic negative waves of 20–35 msec. latency. The threshold of activation of the hypothalamic potentials corresponded to the upper range of activation of group A fibers in the sciatic nerve. The hypothalamic evoked potentials had a very prolonged recovery time on double stimulation, were sensitive to pentobarbital even to a greater degree than the evoked potentials in the midbrain reticular formation, and were abolished by high frequency stimulation of the midbrain reticular formation. The long latency potentials in the hypothalamus were similar to those evoked in the midbrain reticular formation, while the short latency potentials had properties similar to those of the lemniscal potentials. This fact suggested that the short latency potentials signaled the arrival of impulses from lemniscal collaterals.

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The relationship in gating effects between short-latency and long-latency somatosensory-evoked potentials

Neuroreport ◽

10.1097/wnr.0b013e32834dc296 ◽

2011 ◽

Vol 22 (18) ◽

pp. 1000-1004 ◽

Cited By ~ 10

Author(s):

Hiroki Nakata ◽

Kiwako Sakamoto ◽

Masato Yumoto ◽

Ryusuke Kakigi

Keyword(s):

Evoked Potentials ◽

Somatosensory Evoked Potentials ◽

Short Latency ◽

Long Latency ◽

The Relationship

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Impact of Rhythmic Oral Activity on the Timing of Muscle Activation in the Swallow of the Decerebrate Pig

Journal of Neurophysiology ◽

10.1152/jn.90847.2008 ◽

2009 ◽

Vol 101 (3) ◽

pp. 1386-1393 ◽

Cited By ~ 25

Author(s):

Allan J. Thexton ◽

A. W. Crompton ◽

Tomasz Owerkowicz ◽

Rebecca Z. German

Keyword(s):

Brain Stem ◽

Muscle Activation ◽

Rhythmic Activity ◽

Emg Activity ◽

Long Latency ◽

Jaw Opening ◽

Short Latency Response ◽

Pharyngeal Swallow ◽

Latency Response ◽

Changeover Period

The pharyngeal swallow can be elicited as an isolated event but, in normal animals, it occurs within the context of rhythmic tongue and jaw movement (RTJM). The response includes activation of the multifunctional geniohyoid muscle, which can either protract the hyoid or assist jaw opening; in conscious nonprimate mammals, two bursts of geniohyoid EMG activity (GHemg) occur in swallow cycles at times consistent with these two actions. However, during experimentally elicited pharyngeal swallows, GHemg classically occurs at the same time as hyoglossus and mylohyoid activity (short latency response) but, when the swallow is elicited in the decerebrate in the absence of RTJM, GHemg occurs later in the swallow (long latency response). We tested the hypothesis that it was not influences from higher centers but a brain stem mechanism, associated with RTJM, which caused GHemg to occur earlier in the swallow. In 38 decerebrate piglets, RTJM occurred sporadically in seven animals. Before RTJM, GHemg had a long latency, but, during RTJM, swallow related GHemg occurred synchronously with activity in hyoglossus and mylohyoid, early in the swallow. Both early and late responses were present during the changeover period. During this changeover period, duplicate electrodes in the geniohyoid could individually detect either the early or the late burst in the same swallow. This suggested that two sets of geniohyoid task units existed that were potentially active in the swallow and that they were differentially facilitated or inhibited depending on the presence or absence of rhythmic activity originating in the brain stem.

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