Electrical Stimulation Of Afferent Nerves Research Articles

A novel in vitro analog expressing learning-induced cellular correlates in distinct neural circuits.

When presented with noxious stimuli, Aplysia exhibits concurrent sensitization of defensive responses, such as the tail-induced siphon withdrawal reflex (TSWR) and suppression of feeding. At the cellular level, sensitization of the TSWR is accompanied by an increase in the excitability of the tail sensory neurons (TSNs) that elicit the reflex, whereas feeding suppression is accompanied by decreased excitability of B51, a decision-making neuron in the feeding neural circuit. The goal of this study was to develop an in vitro analog coexpressing the above cellular correlates. We used a reduced preparation consisting of buccal, cerebral, and pleural-pedal ganglia, which contain the neural circuits controlling feeding and the TSWR, respectively. Sensitizing stimuli were delivered in vitro by electrical stimulation of afferent nerves. When trained with sensitizing stimuli, the in vitro analog expressed concomitant increased excitability in TSNs and decreased excitability in B51, which are consistent with the occurrence of sensitization and feeding suppression induced by in vivo training. This in vitro analog expressed both short-term (15 min) and long-term (24 h) excitability changes in TSNs and B51, depending on the amount of training administered. Finally, in vitro application of serotonin increased TSN excitability without altering B51 excitability, mirroring the in vivo application of the monoamine that induces sensitization, but not feeding suppression.

MP68-15 ELECTRICAL STIMULATION OF AFFERENT NERVES IN THE FOOT WITH TRANSCUTANEOUS ADHESIVE PAD ELECTRODES IMPROVES OVERACTIVE BLADDER SYMPTOMS IN WOMEN

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology II1 Apr 2016MP68-15 ELECTRICAL STIMULATION OF AFFERENT NERVES IN THE FOOT WITH TRANSCUTANEOUS ADHESIVE PAD ELECTRODES IMPROVES OVERACTIVE BLADDER SYMPTOMS IN WOMEN Christopher Chermansky, Bing Shen, Jon Shepherd, Shachi Tyagi, Jeremy Reese, William de Groat, and Changfeng Tai Christopher ChermanskyChristopher Chermansky More articles by this author , Bing ShenBing Shen More articles by this author , Jon ShepherdJon Shepherd More articles by this author , Shachi TyagiShachi Tyagi More articles by this author , Jeremy ReeseJeremy Reese More articles by this author , William de GroatWilliam de Groat More articles by this author , and Changfeng TaiChangfeng Tai More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1352AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Treatments for refractory overactive bladder (OAB) include onabotulinumtoxinA, sacral neuromodulation, and tibial neuromodulation. Yet, a non-invasive and convenient OAB treatment with no major adverse events would be ideal. We previously showed that stimulation of foot afferents in normal humans without OAB increased bladder capacity by more than 50% (an average of 200 cc) without any adverse events. We sought to determine if electrical stimulation of afferent nerves in the foot with transcutaneous adhesive pad electrodes (FootStim) improves OAB symptoms. METHODS Women with UUI from OAB underwent FootStim for 3 hours every evening for 7 days. All patients stopped OAB drug therapy 2 weeks prior. A 3-week voiding diary was obtained, and FootStim was applied during week 2 (see Figure). Transcutaneous adhesive pad electrodes were attached to the bottom of the foot to activate the lateral and medial plantar nerves. These electrodes were connected to a transcutaneous electrical nerve stimulator. Stimulation parameters included a pulse frequency of 5 Hz, a pulse width of 0.2 ms, and an intensity of 2-4 times the minimal stimulation necessary to induce a toe twitch. Responder was defined as having a statistically significant improvement in 1 or more of the measured voiding parameters. RESULTS Nineteen women completed the study, of which 16/19 (84%) responded. Incontinence frequency in all 19 women decreased from 3.7 leaks/day at baseline to 2.8 leaks/day at baseline (p=0.04), and urgency frequency decreased from 7.6 episodes/day to 6.6 episodes/day (p=0.03). Statistically significant decreases were seen in daytime voiding frequency and nocturia in 8 and 7 subjects respectively, although these differences were not significant when analyzing the entire sample size. The FootStim effect persisted for 4 days after treatment was discontinued. There were no adverse events. CONCLUSIONS FootStim in women with UUI from OAB decreased incontinence frequency and urgency frequency, and these results are comparable with pharmacotherapy. Our results support further testing of FootStim to determine ideal stimulation schedule and to test against placebo. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e894-e895 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Christopher Chermansky More articles by this author Bing Shen More articles by this author Jon Shepherd More articles by this author Shachi Tyagi More articles by this author Jeremy Reese More articles by this author William de Groat More articles by this author Changfeng Tai More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Development of an in vitro analog concomitantly expressing the cellular correlates of sensitization and suppression of feeding in Aplysia californica

When presented with aversive stimuli, the marine mollusk Aplysia californica shows increased defensive responses (sensitization) and suppression of feeding. The cellular correlates of sensitization and suppression of feeding include increased excitability of the tail sensory neurons (TSNs, which mediate defensive responses) and decreased excitability in neuron B51 (a cell critical to the Aplysia feeding circuit), respectively. The goal of this project was to develop a reduced preparation of the isolated Aplysia nervous system (buccal, pleural‐pedal, and cerebral ganglia) in which the effects of aversive stimuli within the defense and feeding neural circuits could be mimicked in vitro by electrical stimulation of afferent nerves. We successfully observed significant concomitant increase in excitability of the TSNs (measured by spikes evoked) and decrease in excitability of B51 (increase in the burst threshold) 15 min post stimulation. Currently, we are examining whether this in vitro analog expresses long term (24 h) correlates. This in vitro analog will facilitate further analyses of cellular and molecular modifications resulting from aversive stimulation, as it would allow manipulations not feasible in vivo. Supported by NSF Grant IOS 1120304 to RM.

Development of a neurotechnological system for relieving phantom limb pain using transverse intrafascicular electrodes (TIME)

Phantom limb pain (PLP) is a chronic condition that develops in the majority of amputees. The underlying mechanisms are not completely understood, and thus, no treatment is fully effective. Based on recent studies, we hypothesize that electrical stimulation of afferent nerves might alleviate PLP by giving sensory input to the patient if nerve fibers can be activated selectively. The critical component in this scheme is the implantable electrode structure. We present a review of a novel electrode concept to distribute highly selective electrode contacts over the complete cross section of a peripheral nerve to create a distributed activation of small nerve fiber ensembles at the fascicular level, the transverse intrafascicular multichannel nerve electrode (TIME). The acute and chronic implantations in a small animal model exhibited a good surface and structural biocompatibility as well as excellent selectivity. Implantation studies on large animal models that are closer to human nerve size and anatomical complexity have also been conducted. They proved implant stability and the ability to selectively activate nerve fascicles in a limited proximity to the implant. These encouraging results have opened the way forward for human clinical trials in amputees to investigate the effect of selective electrical stimulation on PLP.

Oscillations trumped by behavior: a link between sensory and direct electrical stimulation of cortical activity

Oscillations trumped by behavior: a link between sensory and direct electrical stimulation of cortical activity

The use of transcutaneous electrical nerve stimulation (TENS) to aid perceptual embodiment of prosthetic limbs

Integration of prosthetic limb awareness into body schema is likely to aid manual control of the prosthesis. Physiotherapists and prosthetists use techniques to generate mechanical, visual and/or auditory feedback related to stimulation of the stump and proximal residual limb to improve prosthetic limb awareness. Electrical stimulation of afferent nerves using implanted electrodes can generate sensations of touch, joint movement, and position, in the missing, phantom limbs of amputees. We report here a novel hypothesis that non-invasive transcutaneous electrical nerve stimulation (TENS) could be used to facilitate the process of perceptual embodiment of a prosthesis into the body schema of amputees. Using a modified version of the rubber hand illusion (RHI), we have found that TENS paraesthesiae can be made to feel like it is emanating from a prosthetic hand in healthy participants with intact limbs. In addition, participants reported perceptual embodiment of the prosthetic hand into their body schema, i.e. it felt as if it is part of their body. We predict that projecting TENS paraesthesiae into the prosthetic limb(s) of amputees will provide sufficient sensory input to facilitate perceptual embodiment. This could prove to be a simple and inexpensive training aid to improve ambulation and prosthesis success.

Discharge characteristics of sympathetic efferents to the knee joint of the cat

Sympathetic postganglionic neurons to the knee joint of the cat were studied to characterize the nerve supply and response to somatic stimulation. In halothane anesthetized cats, the sympathetic postganglionic units from a branch of medial articular nerve (MAN) were dissected. The other branch of MAN was left intact. Most of the central filaments of MAN showed spontaneous discharge. The frequency of the spontaneous discharge of single units ranged from 0.2 to 2.9 impulses per second. Cardiovascular rhythmic modulation was observed in most of the filaments tested. Phenylephrine-induced baroreceptor stimulation caused inhibition of the discharges. Repetitive stimulation of the lumbar sympathetic trunk or the peripheral cut end of MAN led to a decrease in the local temperature inside the joint. The frequency threshold for decreasing the temperature of the joint was approximately 1 Hz. Maximum effects were obtained with 5 Hz stimulation. Histograms of MAN sympathetic efferent fibre activity following electrical stimulation of afferent nerve fibres in the MAN exhibited two response periods. The first, of about 280 ms latency, was elicited by myelinated fibre excitation (the A-reflex) and the second, with a latency of approximately 700 ms, was evoked by unmyelinated fibre excitation (the C-reflex). Electrical stimulation of radial afferent nerve produced similar A- and C-reflex discharges in sympathetic fibres of MAN. Passive movement of the knee joint within its normal working range (flexion, extension or outward rotation) had very little effect on sympathetic efferent nerve activity in MAN, whereas noxious outward rotation of the joint produced a reflex increase in activity to about 140% of the prestimulus control level. In some cats efferent units to the knee were analyzed after inducing an experimental inflammation in the joint. The characteristics of the efferent activity were qualitatively similar to those of normal joints. This finding is discussed in regard to different results in other sympathetic subsystems.

Reflex responses evoked in the adrenal sympathetic nerve to electrical stimulation of somatic afferent nerves in the rat

The present study was initiated to determine the role of somatic A (myelinated) and C (unmyelinated) afferent fibers in both responses of increases and decreases in adrenal sympathetic nerve activities during repetitive mechanical pinching and brushing stimulations of the skin in anesthetized rats with central nervous system (CNS) intact. Accordingly, changes in adrenal sympathetic nerve activity resulting from repetitive and single shock electrical stimulation of various spinal afferent nerves, especially the 13th thoracic (Th13) spinal nerve and the sural nerve, were examined in urethane/chloralose-anesthetized rats. Repetitive electrical stimulation of A afferent fibers in Th13 spinal or sural nerve decreased the adrenal nerve activity similarly as brushing stimulation of skin of the lower chest or hindlimb did, while repetitive stimulation of A plus C afferent fibers of those nerves increased the adrenal nerve activity as pinching stimulation of those skins did. Single shock stimulation of spinal afferent nerves evoked various reflex components in the adrenal nerve: (1) an initial depression of spontaneous activity (the early depression); (2) the following reflex discharge due to activation of A afferent fibers (the A-reflex); (3) a subsequent reflex discharge due to activation of C afferent fibers (the C-reflex); and (4) following postexcitatory depressions. These reflexes seem to be mediated mainly via supraspinal pathways since they were abolished by spinal transection at the C1-2 level. Although the supraspinal A- and C-reflexes could be elicited from stimulation of a wide variety of spinal segmental afferent levels, the early depression was more prominent when afferents at spinal segments closer to the level of adrenal nerve outflow were excited. It is suggested that the decreased responses of the adrenal nerve during repetitive electrical stimulation of A afferent nerve fibers are attributable to summation of both the early depression and postexcitatory depression evoked by single shock stimulation, while the increased responses during repetitive stimulation of A plus C afferent fibers are attributable to summation of the C-reflex after single shock stimulation. In spinalized rats, repetitive stimulation of Th13 always increased the adrenal nerve activities regardless of whether A fibers alone or A plus C fibers were stimulated, just as brushing and pinching of the lower chest skin always increased them. The increased responses in spinal animals seem to be related to the fact that single electrical stimuli of Th13 produced A- and C-reflexes of spinal origin without clear depressions.

ANGIOTENSIN CONVERTING ENZYME AND SUBSTANCE P CHANGES IN BLISTER FLUID FOLLOWING AFFERENT NERVE STIMULATION IN THE RAT

We have examined the effect of electrical nerve stimulation on substance P and angiotensin converting enzyme activity in the interstitial fluid of rat skin using a blister model. Following sciatic nerve stimulation, blister fluid immunoreactive substance P (fmol/ml) was increased from 118 (unstimulated side, s.e.m. = 13, n = 15) to 197 (stimulated side, s.e.m. = 26, n = 15, P less than 0.0125, paired t-test, 14 d.f.). Angiotensin converting enzyme (ACE) activity (nmol HL/ml per h) was reduced in blister fluid from 26.5 (unstimulated side, s.e.m. = 2.4, n = 12) to 22.4 (stimulated side, s.e.m. = 1.4, P less than 0.05, paired t-test, 11 d.f.). Electrical stimulation of afferent nerves inhibits angiotensin converting enzyme activity in vivo. This may contribute to the process of neurogenic inflammation.

The use of a four-channel electrical stimulator as an ambulatory aid for paraplegic patients.

This article reports the use of electrical stimulation to provide paraplegic patients with complete lesions of the spinal cord the ability to rise from sitting to standing, to maintain a standing position, and to walk with a reciprocal gait. Four channels of electrical stimulation are sufficient for synthesis of a simple reciprocal gait pattern in these patients. During the double-stance phase, knee extensor muscles of both knees are stimulated, providing sufficient support for the body. Only one knee extensor muscle group is excited during the single-stance phase. The swing phase of the contralateral lower extremity is accomplished by eliciting the synergistic flexor muscle response through electrical stimulation of afferent nerves. The transition from the double-stance phase to the swing phase is controlled by two hand switches used by the therapist or built into the handles of the walking frame or crutches for use by the patient.

The role of the lateral-line efferent system in Xenopus laevis.

ABSTRACT Efferent impulses have been recorded from branches of lateral-line nerves. The functional significance of the efferent innervation and its action on afferent impulse activity has been examined. Neither mechanical stimulation of the lateral-line receptors nor electrical stimulation of afferent nerves excites lateral-line efferent activity. Trains of efferent impulses accompany all active movements for their duration. In immobilized animals a close correlation exists between impulses in lateral-line efferent nerve fibres and motor impulses in ‘large’ nerves innervating ‘twitch’ muscles, but not with impulses in nerves innervating ‘slow’ muscles. A close similarity also exists between impulse activity in different lateral-line efferent fibres. Whereas electrical stimulation of ascending tracts in the spinal cord fails to excite lateral-line efferent fibres, stimulation of the spinal cord in the region of descending reticular motor axons causes efferent impulses to follow each pulse after brief, constant, latencies. It is suggested that the efferent neurones may be innervated by axon collaterals from reticular cells. Electrical stimulation of efferent fibres innervating a lateral-line receptor produces transitory inhibition of impulse activity in the afferent nerve fibres. The inhibition has a long variable latency (11-30 ms) and persists for 40-60 ms. Upon cessation of inhibition, caused by a train of efferent impulses, afferent impulses reappear at an accelerated frequency (after-discharge), and quickly return to resting frequency. A role of the lateral-line efferent neurones during active movement is discussed.

Release to the cerebral ventricles of substances with possible transmitter function in the caudate nucleus.

1. One caudate nucleus of the anaesthetized cat was superfused by perfusing the anterior horn of one lateral cerebral ventricle. The perfusates were examined for their content in acetylcholine (ACh), dopamine, homovanillic acid (HVA) and 5-hydroxytryptamine (5-HT), at rest and after a variety of stimuli.2. When prostigmine was added to the perfusion fluid, ACh appeared in the effluent; its concentration tended to rise in the course of an experiment. Various afferent stimuli, all of which caused evoked responses recorded from the contra-lateral caudate nucleus, increased the ACh content of the effluent. Effective stimuli were noise and electrical stimulation of afferent nerves or of certain regions of the brain including the ipsi-lateral substantia nigra.3. The dopamine content of the effluent was extremely low (of the order of 50 pg/min) at rest, but, on occasion, rose sharply when the substantia nigra was stimulated electrically with trains of pulses repeated once every 3 sec. The results were inconsistent.4. Since dopamine in tissue is rapidly transformed enzymically into HVA, the appearance of this acid in the perfusate was examined.5. At rest, HVA was found to appear in the effluent at a rate of 2-8 ng/min. Its concentration was rapidly depressed by increasing the depth of anaesthesia.6. Stimulation of the substantia nigra for periods of 3 or 4 min caused an increment in the HVA content of the effluent lasting 1 hr or more. It was frequently seen when two points of the substantia nigra were stimulated simultaneously, less regularly with only one stimulating electrode, and rarely if this was placed in the most caudal part of the substantia nigra.7. These results strongly support the view that there is a dopaminergic nigro-striatal pathway. The following assumption would explain the erratic appearance of dopamine and the long duration of increments in HVA: many of the axons originating in the substantia nigra end either in the putamen or in parts of the caudate nucleus which are far away from the ventricular surface; any dopamine released from these axons will not reach the ventricular surface at all, and HVA will, at best, reach it very slowly.8. Small amounts of 5-HT appeared in the ventricular perfusate, and the quantity rose after the administration of monoamine oxidase inhibitors. It was not increased by the type of stimuli used in this work to elicit the release of ACh or HVA.

The excitability change of motoneurones due to electrotonus and its relations to the effects of repetitive stimulation.

1. The ventral root potentials following an electrical stimulation of afferent nerve were recorded in toads and bull-frogs during the application of polarizing currents along spinal cord and ventral root.2. The motoneurone ceases to elicit an efferent impulse when its soma is polarized anelectrotonically as well as when polarized catelectrotonically to a considerable extent (cathodal depression). In the former case the slow potential shows retarded temporal decay, in contrast with its rapid decay observable in the latter case. The effects of the electrotonus on the motoneurone soma (including dendrites) and on the axon-hillock were considered separately and discussed for respective cases.3. Repetitive stimulation seems, when it gives rise to fatigue, to shift the resting status of polarization at synaptic membrane towards increasingly depolarized state, until finally it reaches what is similar to the state of cathodal depression. Currents applied in a direction to polarize motoneurone soma catelectrotonically accelerate and emphasize the above mentioned effect of repetitive stimulation, and hinder the motoneurone to recover during a pause of stimulation. Polarizing currents in reverse direction retard or prevent the occurrence of “fatigue” in the motoneurone.4. It is suggested that the resting status of polarization at synaptic membrane would be labile and alterable within a wide range, and that the failure of synaptic transmission under a state similar to that of cathodal depression may account for at least a certain kind of central fatigue in normal organisms.