Neurophysiological markers of central sensitisation in the trigeminal pathway and their modulation by the cyclo-oxygenase inhibitor ketorolac

Cephalalgia ◽  
2010 ◽  
Vol 30 (10) ◽  
pp. 1241-1249 ◽  
Author(s):  
Alexey Y Sokolov ◽  
Olga A Lyubashina ◽  
Sergey S Panteleev ◽  
Boris A Chizh
Keyword(s):  
Electrical Stimulation ◽  
Dynamic Range ◽  
Preclinical Model ◽  
Neuronal Responses ◽  
Ongoing Activity ◽  
Central Sensitisation ◽  
Before And After ◽  
Electrical Stimuli ◽  
Mechanical Thresholds ◽  
Suitable Marker

Central sensitisation is a key mechanism of migraine; understanding its modulation by anti-migraine drugs is essential for rationalising treatment. We used an animal model of central trigeminal sensitisation to investigate neuronal responses to dural electrical stimulation as a putative electrophysiological marker of sensitisation and its modulation by ketorolac. In anaesthetised rats, responses of single convergent wide-dynamic range neurons of the spinal trigeminal nucleus to dural electrical simulation were recorded in parallel to their ongoing activity and responses to facial mechanical stimulation before and after a short-term dural application of an IS. Both ongoing activity and responses to dural electrical stimuli were enhanced by the inflammatory challenge, whereas neuronal thresholds to mechanical skin stimulation were reduced ( p < .05, N = 12). Intravenous ketorolac (2 mg/kg, N = 6) reduced ongoing activity and responses to dural electrical stimulation, and increased mechanical thresholds versus vehicle controls ( p < .05, N = 6). We conclude that neuronal responses to dural electrical stimulation can serve as a suitable marker which together with admitted electrophysiological signs can objectively detect central trigeminal sensitisation and its modulation by anti-migraine treatments in this preclinical model of migraine.

scholarly journals Repeated Galvanic Vestibular Stimulation Modified the Neuronal Potential in the Vestibular Nucleus

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Gyutae Kim ◽  
Sangmin Lee ◽  
Kyu-Sung Kim
Keyword(s):  
Glutamate Receptors ◽  
Vestibular Nucleus ◽  
Vestibular Stimulation ◽  
Neural Recording ◽  
Galvanic Vestibular Stimulation ◽  
Neuronal Responses ◽  
Cerebellar Flocculus ◽  
Before And After ◽  
Ampa And Nmda Receptors ◽  
Electrical Stimuli

Vestibular nucleus (VN) and cerebellar flocculus are known as the core candidates for the neuroplasticity of vestibular system. However, it has been still elusive how to induce the artificial neuroplasticity, especially caused by an electrical stimulation, and assess the neuronal information related with the plasticity. To understand the electrically induced neuroplasticity, the neuronal potentials in VN responding to the repeated electrical stimuli were examined. Galvanic vestibular stimulation (GVS) was applied to excite the neurons in VN, and their activities were measured by an extracellular neural recording technique. Thirty-eight neuronal responses (17 for the regular and 21 for irregular neurons) were recorded and examined the potentials before and after stimulation. Two-third of the population (63.2%, 24/38) modified the potentials under the GVS repetition before stimulation (p=0.037), and more than half of the population (21/38, 55.3%) changed the potentials after stimulation (p=0.209). On the other hand, the plasticity-related neuronal modulation was hardly observed in the temporal responses of the neurons. The modification of the active glutamate receptors was also investigated to see if the repeated stimulation changed the number of both types of glutamate receptors, and the results showed that AMPA and NMDA receptors decreased after the repeated stimuli by 28.32 and 16.09%, respectively, implying the modification in the neuronal amplitudes.

scholarly journals Changes in Responses of Neurons in Spinal and Medullary Subnucleus Reticularis Dorsalis to Acupoint Stimulation in Rats with Visceral Hyperalgesia

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ling-Ling Yu ◽  
Liang Li ◽  
Pei-Jing Rong ◽  
Bing Zhu ◽  
Qing-Guang Qin ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Neuronal Responses ◽  
Sprague Dawley ◽  
Visceral Hyperalgesia ◽  
Facilitation Effect ◽  
Visceral Nociception ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Wdr Neurons ◽  
Sensitizing Effect

The purpose of this study was to explore the mechanism of acupoints sensitization phenomenon at the spinal and medulla levels. Experiments were performed on adult male Sprague-Dawley rats and visceral noxious stimuli was generated by colorectal distension (CRD). The activities of wide dynamic range (WDR) and subnucleus reticularis dorsalis (SRD) neurons were recorded. The changes of the reactions of WDR and SRD neurons to electroacupuncture (EA) on acupoints of “Zusanli-Shangjuxu” before and after CRD stimulation were observed. The results showed that visceral nociception could facilitate the response of neurons to acupoints stimulation. In spinal dorsal horn, EA-induced activation of WDR neurons further increased to 106.84 ± 17.33% (1.5 mA) (P<0.001) and 42.27 ± 13.10% (6 mA) (P<0.01) compared to the neuronal responses before CRD. In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P<0.001) and 25.02 ± 7.47% (6 mA) (P<0.01) compared to that before CRD. Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization. But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

scholarly journals Insights into the combination of neuromuscular electrical stimulation and motor imagery in a training-based approach

2021 ◽  
Author(s):  
Amandine Bouguetoch ◽  
Alain Martin ◽  
Sidney Grosprêtre
Keyword(s):  
Electrical Stimulation ◽  
Motor Imagery ◽  
Neural Plasticity ◽  
Neuromuscular Electrical Stimulation ◽  
Voluntary Contraction ◽  
Muscle Architecture ◽  
Fascicle Length ◽  
Before And After ◽  
V Wave ◽  
And Control

Abstract Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.

Cross-talk along gastrointestinal tract during electrical stimulation: effects and mechanisms of gastric/colonic stimulation on rectal tone in dogs

2005 ◽  
Vol 288 (6) ◽  
pp. G1195-G1198 ◽  
Author(s):  
Shi Liu ◽  
Lijie Wang ◽  
J. D. Z. Chen
Keyword(s):  
Electrical Stimulation ◽  
Inhibitory Effect ◽  
Adrenergic Blockade ◽  
Rectal Compliance ◽  
Rectal Tone ◽  
Before And After ◽  
Sensory Functions ◽  
Sympathetic Pathway ◽  
Colonic Electrical Stimulation ◽  
Stimulation Of

Gastric electrical stimulation (GES) has been shown to alter motor and sensory functions of the stomach. However, its effects on other organs of the gut have rarely been investigated. The study was performed in 12 dogs implanted with two pairs of electrodes, one on the serosa of the stomach and the other on the colon. The study was composed of two experiments. Experiment 1 was designed to study the effects of GES on rectal tone and compliance in nine dogs compared with colonic electrical stimulation (CES). Rectal tone and compliance were assessed before and after GES or CES. Experiment 2 was performed to study the involvement of sympathetic pathway in 8 of the 12 dogs. The rectal tone was recorded for 30–40 min at baseline and 20 min after intravenous guanethidine. GES or CES was given for 20 min 20 min after the initiation of the infusion. It was found that both GES and CES reduced rectal tone with comparable potency. Rectal compliance was altered neither with GES, nor with CES. The inhibitory effect of GES but not CES on rectal tone was abolished by an adrenergic blockade, guanethidine. GES inhibited rectal tone with a comparable potency with CES but did not alter rectal compliance. The inhibitory effect of GES on rectal tone is mediated by the sympathetic pathway. It should be noted that electrical stimulation of one organ of the gut may have a beneficial or adverse effect on another organ of the gut.

Effect of Speech Processor Program Modifications on Cochlear Implant Recipients’ Threshold and Maximum Acceptable Loudness Levels

1999 ◽  
Vol 8 (2) ◽  
pp. 128-136 ◽  
Author(s):  
John C. Sun ◽  
Margarate W. Skinner ◽  
S. Y. Liu ◽  
T. S. Huang
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Everyday Life ◽  
Dynamic Range ◽  
Active Electrode ◽  
Speech Processor ◽  
Significant Change ◽  
Upper Boundary

This study’s purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients’ thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants’ threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Attempts to Suppress Tinnitus with Transcutaneous Electrical Stimulation

1985 ◽  
Vol 93 (3) ◽  
pp. 385-389 ◽  
Author(s):  
Jack A. Vernon ◽  
James A. Fenwick
Keyword(s):  
Electrical Stimulation ◽  
Positive Response ◽  
Transcutaneous Electrical Stimulation ◽  
Therapeutic Procedure ◽  
Placebo Trial ◽  
Electrical Stimuli ◽  
Severe Tinnitus

Various electrical stimuli were tested for their ability to suppress or relieve severe tinnitus. Stimulation was applied transdermally by electrodes placed on the preauricular and postauricular regions and on the two mastoids. Of the 50 patients tested, only 14 (28%) obtained relief that met the criterion of a reduction in the tinnitus by 40% or more. When relief was obtained, it usually extended for several hours into the poststimulation period. There was only one positive response (2%) In the placebo trial, which was administered to all patients. It was concluded that transdermal electrical stimulation such as that used in this research Is not a practical therapeutic procedure for the relief of tinnitus.

Ascending pathways in the spinal cord involved in the activation of subnucleus reticularis dorsalis neurons in the medulla of the rat

1990 ◽  
Vol 63 (3) ◽  
pp. 424-438 ◽  
Author(s):  
Z. Bing ◽  
L. Villanueva ◽  
D. Le Bars
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
The Body ◽  
Cervical Cord ◽  
Lateral Part ◽  
Neuronal Responses ◽  
C Fiber ◽  
Dorsal Columns ◽  
Dorsolateral Funiculus ◽  
The Right

1. Recordings were made from neurons in the left medullary subnucleus reticularis dorsalis (SRD) of anesthetized rats. Two populations of neurons were recorded: neurons with total nociceptive convergence (TNC), which gave responses to A delta- and C-fiber activation from the entire body after percutaneous electrical stimulation, and neurons with partial nociceptive convergence (PNC), which responded to identical stimuli with an A delta-peak regardless of which part of the body was stimulated and with a C-fiber peak of activation from some, mainly contralateral, parts of the body. 2. The effects of various, acute, transverse sections of the cervical (C4-C5) spinal cord on the A delta- and C-fiber-evoked responses were investigated by building poststimulus histograms (PSHs) after 50 trials of supramaximal percutaneous electrical stimulation of the extremity of either hindpaw (2-ms duration; 3 times threshold for C-fiber responses), before and 30-40 min after making the spinal lesion. 3. In the case of TNC neurons, hemisections of the left cervical cord blocked the responses elicited from the right hindpaw and slightly, but not significantly, diminished those evoked from the left hindpaw. Conversely, hemisections of the right cervical cord abolished TNC responses elicited from the left hindpaw without significantly affecting the responses elicited from the right hindpaw. 4. Lesioning the dorsal columns or the left dorsolateral funiculus was found not to affect the TNC neuronal responses elicited from either hindpaw. By contrast, lesioning the left lateral funiculus or the most lateral part of the ventrolateral funiculus, respectively, reduced and blocked the responses elicited from the right hindpaw without affecting those evoked from the left hindpaw. 5. After lesions that included the most lateral parts of the left ventral funiculus, PNC neuronal responses elicited from the right hindpaw were also abolished, whereas those elicited from the left hindpaw remained unchanged. 6. We conclude that the signals responsible for the activation of SRD neurons travel principally in the lateral parts of the ventrolateral quadrant, a region that classically has been implicated in the transmission of noxious information. Both a crossed and a double-crossed pathway are involved in this process. The postsynaptic fibers of the dorsal columns and the spinocervical and spinomesencephalic tracts do not appear to convey signals that activate SRD neurons. 7. The findings also suggest that lamina I nociceptive specific neurons, the axons of which travel within the dorsolateral funiculus, do not contribute very much to the activation of SRD neurons.

Influences from laryngeal afferents on expiratory bulbospinal neurons and motoneurons

1988 ◽  
Vol 64 (4) ◽  
pp. 1337-1345 ◽  
Author(s):  
J. S. Jodkowski ◽  
A. J. Berger
Keyword(s):  
Electrical Stimulation ◽  
Cold Water ◽  
Superior Laryngeal Nerve ◽  
Intercostal Nerve ◽  
Firing Frequency ◽  
Neuronal Responses ◽  
Water Infusion ◽  
Afferent Activation ◽  
Expiratory Neurons ◽  
Stimulation Of

The purpose of this study is to analyze the reflex effects of laryngeal afferent activation on respiratory patterns in anesthetized, vagotomized, paralyzed, ventilated cats. We recorded simultaneously from the phrenic nerve, T10 internal intercostal nerve, and single bulbospinal expiratory neurons of the caudal ventral respiratory group (VRG). Laryngeal afferents were activated by electrical stimulation of the superior laryngeal nerve (SLN) or by cold-water infusion into the larynx. Both types of stimuli caused inhibition of phrenic activity and facilitation of internal intercostal nerve activity, indicating expiratory effort. The activity of 46 bulbospinal expiratory cells was depressed during SLN electrical stimulation, and 13 of them were completely inhibited. In 44 of 56 neurons tested, mean firing frequency (FFmean) was decreased in response to cold-water infusion and 8 others responded with increased FFmean; in the remaining 4 neurons, FFmean was unchanged. Possible reasons for different neuronal responses to SLN electrical stimulation and water infusion are discussed. We conclude that bulbospinal expiratory neurons of VRG were not the source of the reflex motoneuronal expiratory-like activity produced by SLN stimulation. Other, not yet identified inputs to spinal expiratory motoneurons are activated during this experimental condition.

scholarly journals Evaluation of direct reading photoionization detector performance under various operational parameters

2021 ◽  
Vol 8 (2) ◽  
pp. 123-128
Author(s):  
Amir Hossein Khoshakhlagh ◽  
Farideh Golbabaei ◽  
Mojtaba Beygzadeh ◽  
Francisco Carrasco-Marín ◽  
Seyed Jamaleddin Shahtaheri
Keyword(s):  
Relative Humidity ◽  
Dynamic Range ◽  
Reference Method ◽  
Operational Parameters ◽  
Direct Reading ◽  
Detector Performance ◽  
Vapor Detection ◽  
Sample Concentration ◽  
Photoionization Detector ◽  
Before And After

Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40° C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the performance of the PID could be altered by the variables. The best performance of the PID was at temperature of 21° C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207.9 ± 8.7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203.5 ± 5.8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r2 = 0.93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency.

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