scholarly journals Activation and inhibition of the micturition reflex by penile afferents in the cat

2008 ◽  
Vol 294 (6) ◽  
pp. R1880-R1889 ◽  
Author(s):  
John P. Woock ◽  
Paul B. Yoo ◽  
Warren M. Grill
Keyword(s):  
Electrical Stimulation ◽  
De Novo ◽  
Bladder Capacity ◽  
Functional Restoration ◽  
External Urethral Sphincter ◽  
Micturition Reflex ◽  
Cuff Electrode ◽  
Evoked Contractions ◽  
Stimulation Of ◽  
40 Hz

Coordination of the urinary bladder and the external urethral sphincter is controlled by descending projections from the pons and is also subject to modulation by segmental afferents. We quantified the effects on the micturition reflex of sensory inputs from genital afferents traveling in the penile component of the somatic pudendal nerve by electrical stimulation of the dorsal nerve of the penis (DNP) in α-chloralose anesthetized male cats. Depending on the frequency of stimulation (range, 1–40 Hz), activation of penile afferents either inhibited contractions of the bladder and promoted urine storage or activated the bladder and produced micturition. Stimulation of the DNP at 5–10 Hz inhibited distension-evoked contractions and increased the maximum bladder capacity before incontinence. Conversely, stimulation at 33 and 40 Hz augmented distension-evoked contractions. When the bladder was filled above a threshold volume (70% of the volume necessary for distension-evoked contractions), stimulation at 20–40 Hz activated de novo the micturition reflex and elicited detrusor contractions that increased voiding efficiency compared with distension-evoked voiding. Electrical stimulation of the DNP with a cuff electrode or percutaneous wire electrode produced similar results. The ability to evoke detrusor contractions by activation of the DNP was preserved following acute spinal cord transection. These results demonstrate a clear role of genital afferents in modulating the micturition reflex and suggest the DNP as a potential target for functional restoration of bladder control using electrical stimulation.

Modulation of the spinobulbospinal micturition reflex pathway in cats

1992 ◽  
Vol 262 (3) ◽  
pp. R478-R484 ◽  
Author(s):  
M. N. Kruse ◽  
B. S. Mallory ◽  
H. Noto ◽  
J. R. Roppolo ◽  
W. C. de Groat
Keyword(s):  
Electrical Stimulation ◽  
Bladder Capacity ◽  
Recurrent Inhibition ◽  
Afferent Feedback ◽  
Descending Pathways ◽  
Reflex Pathway ◽  
Micturition Reflex ◽  
Long Duration ◽  
Cervical Stimulation ◽  
Stimulation Of

Micturition, which is mediated by a spinobulbospinal reflex pathway, can be modulated by various spinal and supraspinal mechanisms. This study examined modulation of the micturition reflex in decerebrate unanesthetized cats. Electrical stimulation of the pontine micturition center (PMC) elicited two types of bladder responses: small-amplitude short-duration responses due to direct activation of the bulbospinal pathway (PS-direct contractions) and large-amplitude long-duration reflex responses induced by PS-direct contractions but maintained by afferent feedback (PS-reflex contractions). Rectal and vaginal-cervical stimulation inhibited the PS-direct contractions, indicating inhibition of the descending or efferent limb of the micturition pathway. Stimulation of the central end of a transected S2 ventral root elicited recurrent inhibition of PS-reflex contractions but not of PS-direct contractions, indicating that recurrent inhibition does not directly affect the descending pathway. Continuous electrical stimulation (20 Hz) of the PMC decreased (53 +/- 21%) bladder capacity, presumably by affecting transmission in the pons or ascending input to the pons. Thus the micturition reflex could be modulated at several sites: the pons, the ascending or descending pathways, or spinal interneuronal sites.

scholarly journals NEURONAL-GLIAL MEMBRANE CONTACTS DURING PESSIMAL ELECTRICAL STIMULATION

2020 ◽  
Vol 28 (3) ◽  
pp. 35-50
Author(s):  
Oleg S. Sotnikov ◽  
Svetlana S. Sergeeva ◽  
Tat'yana I. Vasyagina
Keyword(s):  
Electrical Stimulation ◽  
Gap Junctions ◽  
De Novo ◽  
Laboratory Rats ◽  
Transmission Electron ◽  
Layer Structures ◽  
Dense Substance ◽  
Membrane Contacts ◽  
Glial Membrane ◽  
Stimulation Of

After the creation of a method for obtaining inter-neuronal gap junctions in a nervous system devoid of glia, it is expedient to reproduce gap neuronal-glial contacts on a model that also contains hybrid neuronal-glial gap junctions, which, as you know, are functionally fundamentally different from inter-neuronal contacts. The experiments were carried out on the truncus sympathicus ganglia of laboratory rats using pessimal electrical stimulation and transmission electron microscopy. Electrical activation of ganglia with a frequency of up to 100 Hz revealed local and widespread variants of various neuronal-glial connections (contacts, bridges), fringed with peri-membrane filamentous proteins. They had a blurred veil that masked two-layer neuro-membranes. Some of the contacts resembled slit or dense 5-layer structures without a visible inter-neuronal slit, but with an extreme decrease in the thickness of the contact slit. The main result of the experiments was the formation, in addition to slotted, multiple septate (ladder) contacts. Relatively independent aggregates of the electron-dense substance of the septa were located inside the intercellular gaps, crossing both adjacent membranes, and, possibly, permeate of them. Near-membrane, poorly outlined pyramid-like protein cones associated with both cell membranes were also formed. Such membranes appeared to be dotted-dashed, that is, not continuous. A significant number of septic contact membranes had endocytic invaginations (invaginations) facing neuroplasm with pyramid-like marginal projections. All reactive altered structures that have arisen de novo are considered by the authors as developed under the influence of frequency electrical stimulation of denaturation and aggregation of intrinsic and perimembrane proteins.

Micturition reflexes in the in vitro neonatal rat brain stem-spinal cord-bladder preparation

1994 ◽  
Vol 266 (3) ◽  
pp. R658-R667 ◽  
Author(s):  
K. Sugaya ◽  
W. C. De Groat
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Brain Stem ◽  
Rat Brain ◽  
Bladder Wall ◽  
Spinal Reflex ◽  
Neonatal Rat ◽  
Evoked Contractions ◽  
Stimulation Of

An in vitro neonatal (1-7 day) rat brain stem-spinal cord-bladder (BSB) preparation was used to examine the central control of micturition. Isovolumetric bladder contractions occurred spontaneously or were induced by electrical stimulation of the ventrolateral brain stem, spinal cord, bladder wall (ES-BW), or by perineal tactile stimulation (PS). Transection of the spinal cord at the L1 segment increased the amplitude of ES-BW- and PS-evoked contractions, and subsequent removal of the spinal cord further increased spontaneous and ES-BW-evoked contractions but abolished PS-evoked contractions. Hexamethonium (1 mM), a ganglionic blocking agent, mimicked the effect of cord extirpation. Tetrodotoxin (1 microM) blocked ES-BW- and PS-evoked contractions but enhanced spontaneous contractions. Bicuculline methiodide (10-50 microM), a gamma-aminobutyric acid A receptor antagonist, increased the amplitude of spontaneous, ES-BW- and PS-evoked contractions. These results indicate that PS-evoked contractions are mediated by spinal reflex pathways, whereas spontaneous and ES-BW-evoked contractions that are elicited by peripheral mechanisms are subject to a tonic inhibition dependent on an efferent outflow from the spinal cord. PS-evoked micturition is also subject to inhibitory modulation arising from sites rostral to the lumbosacral spinal cord. Although electrical stimulation of bulbospinal excitatory pathways can initiate bladder contractions in the neonatal rat, these pathways do not appear to have an important role in controlling micturition during the first postnatal week.

Effects of WAY100635, a selective 5-HT1A-receptor antagonist on the micturition-reflex pathway in the rat

2001 ◽  
Vol 280 (5) ◽  
pp. R1407-R1413 ◽  
Author(s):  
Hidehiro Kakizaki ◽  
Mitsuharu Yoshiyama ◽  
Tomohiko Koyanagi ◽  
William C. De Groat
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Receptor Antagonist ◽  
Intrathecal Injection ◽  
Cervical Cord ◽  
Dependent Manner ◽  
Reflex Pathway ◽  
Micturition Reflex ◽  
Female Wistar Rats ◽  
Stimulation Of

5-Hydroxytryptamine (5-HT) receptors in the central nervous system have been implicated in the control of micturition. The present study was undertaken to evaluate the effects of a selective 5-HT1A-receptor antagonist { N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]- N-(2-pyridinyl)cyclohexanecarboxamide trihydrochloride (WAY100635)} on the micturition-reflex pathway in urethane-anesthetized female Wistar rats. Rhythmic isovolumetric bladder contractions evoked by bladder distension were abolished by 0.3- to 3-mg/kg iv or 30- to 100-μg intrathecal (it) administration of WAY100635 in a dose-dependent manner for periods of 3–15 min. Intrathecal injection of WAY100635 was effective only if injected at the L6-S1 spinal cord level, but not at the thoracic or cervical cord levels. WAY100635 (30–100 μg it) significantly reduced the amplitude of bladder contractions evoked by electrical stimulation of the pontine micturition center. However, the field potentials in the rostral pons evoked by electrical stimulation of pelvic nerve were not affected by intrathecal or intravenous injection of WAY100635. These results suggest that 5-HT1A receptors at the L6-S1 level of the spinal cord have an important role in the tonic control of the descending limb of the micturition-reflex pathway in the rat.

Epidural Electrical Stimulation on Neurogenic Bladder

1993 ◽  
Vol 60 (1) ◽  
pp. 87-89 ◽  
Author(s):  
C. Simeone ◽  
E. Frego ◽  
T. Zanotelli ◽  
R. Capra ◽  
A. Lenzi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Beneficial Effect ◽  
Bladder Dysfunction ◽  
Bladder Capacity ◽  
Bladder Function ◽  
Complete Relief ◽  
Detrusor Sphincter Dyssynergia ◽  
Thoracic Level ◽  
Stimulation Of

In 1967 Shealy first used electrical stimulation of the spinal cord to treat spasticity and pain. This therapy proved to be effective for bladder dysfunction too. The effect of electrical stimulation of the spinal cord at thoracic level has been evaluated in 18 neurogenic patients suffering from hyperreflexia with detrusor-sphincter dyssynergia. Bladder function improved significantly in 13 (73%). Partial or complete relief of bladder hyperreflexia, marked increased of bladder capacity and reduction of residual urine were recorded. The beneficial effect of stimulation indicates that it is a safe and effective alternative treatment for the neuropathic bladder and careful trials with further investigations should be carried out.

scholarly journals Exploring selective neural electrical stimulation for upper limb function restoration

2016 ◽  
Vol 26 (2) ◽  
Author(s):  
Wafa Tigra ◽  
David Guiraud ◽  
David Andreu ◽  
Bertrand Coulet ◽  
Anthony Gelis ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Upper Limb ◽  
Surgical Intervention ◽  
Video Recording ◽  
New Approach ◽  
Preliminary Results ◽  
Surface Electrodes ◽  
Cuff Electrode ◽  
Upper Limb Function ◽  
Stimulation Of

This article introduces a new approach of selective neural electrical stimulation of the upper limb nerves. Median and radial nerves of individuals with tetraplegia are stimulated via a multipolar cuff electrode to elicit movements of wrist and hand in acute conditions during a surgical intervention. Various configurations corresponding to various combinations of a 12-poles cuff electrode contacts are tested. Video recording and electromyographic (EMG) signals recorded via sterile surface electrodes are used to evaluate the selectivity of each stimulation configuration in terms of activated muscles. In this abstract we introduce the protocol and preliminary results will be presented during the conference.

scholarly journals Electrical stimulation of the pudendal nerve promotes neuroregeneration and functional recovery from stress urinary incontinence in a rat model

2018 ◽  
Vol 315 (6) ◽  
pp. F1555-F1564 ◽  
Author(s):  
Hai-Hong Jiang ◽  
Qi-Xiang Song ◽  
Bradley C. Gill ◽  
Brian M. Balog ◽  
Raul Juarez ◽  
...  
Keyword(s):  
Urinary Incontinence ◽  
Electrical Stimulation ◽  
Stress Urinary Incontinence ◽  
Rat Model ◽  
Pudendal Nerve ◽  
External Urethral Sphincter ◽  
Sham Stimulation ◽  
Point Pressure ◽  
Separate Cohort ◽  
Stimulation Of

The pudendal nerve can be injured during vaginal delivery of children, and slowed pudendal nerve regeneration has been correlated with development of stress urinary incontinence (SUI). Simultaneous injury to the pudendal nerve and its target muscle, the external urethral sphincter (EUS), during delivery likely leads to slowed neuroregeneration. The goal of this study was to determine if repeat electrical stimulation of the pudendal nerve improves SUI recovery and promotes neuroregeneration in a dual muscle and nerve injury rat model of SUI. Rats received electrical stimulation or sham stimulation of the pudendal nerve twice weekly for up to 2 wk after injury. A separate cohort of rats received sham injury and sham stimulation. Expression of brain-derived neurotrophic factor (BDNF) and βII-tubulin expression in Onuf’s nucleus were measured 2, 7, and 14 days after injury. Urodynamics, leak point pressure (LPP), and EUS electromyography (EMG) were recorded 14 days after injury. Electrical stimulation significantly increased expression of BDNF at all time points and βII-tubulin 1 and 2 wk after injury. Two weeks after injury, LPP and EUS EMG during voiding and LPP testing were significantly decreased compared with sham-injured animals. Electrical stimulation significantly increased EUS activity during voiding, although LPP did not fully recover. Repeat pudendal nerve stimulation promotes neuromuscular continence mechanism recovery possibly via a neuroregenerative response through BDNF upregulation in the pudendal motoneurons in this model of SUI. Electrical stimulation of the pudendal nerve may therefore improve recovery after childbirth and ameliorate symptoms of SUI by promoting neuroregeneration after injury.

Sign in / Sign up

Export Citation Format

Share Document