Poststimulation Block of Pudendal Nerve Conduction by High-Frequency (kHz) Biphasic Stimulation in Cats.

Objective: To determine the relationship between various parameters of high-frequency biphasic stimulation (HFBS) and the recovery period of post-HFBS block of the pudendal nerve in cats.

Materials And Methods: A tripolar cuff electrode was implanted on the pudendal nerve to deliver HFBS in ten cats. Two hook electrodes were placed central or distal to the cuff electrode to stimulate the pudendal nerve and induce contractions of external urethral sphincter (EUS).

Thermal block of mammalian unmyelinated C fibers by local cooling to 15-25°C after a brief heating at 45°C.

The purpose of this study was to examine the changes in cold block of unmyelinated C fibers in the tibial nerve by preconditioning with heating and to develop a safe method for thermal block of C-fiber conduction. In seven cats under α-chloralose anesthesia, C-fiber-evoked potentials elicited by electrical stimulation were recorded on the tibial nerve during block of axonal conduction induced by exposing a small segment (9 mm) of the nerve to cooling (from 35°C to ≤5°C) or heating (45°C). Before heating, partial, reproducible, and reversible cold block was first detected at a threshold cold block temperature of 15°C and complete cold block occurred at a temperature of ≤5°C.

Additive Inhibition of Reflex Bladder Activity Induced by Bilateral Pudendal Neuromodulation in Cats.

Objective: To determine the inhibitory effect on bladder activity induced by bilateral pudendal neuromodulation.

Methods: In 10 cats under anesthesia, two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves for stimulation. A double lumen catheter was inserted into the bladder through the urethra to infuse saline and measure bladder pressure.

Prolonged nonobstructive urinary retention induced by tibial nerve stimulation in cats.

Nonobstructive urinary retention (NOUR) is a medical condition without an effective drug treatment, but few basic science studies have focused on this condition. In α-chloralose-anesthetized cats, the bladder was cannulated via the dome and infused with saline to induce voiding that could occur without urethral outlet obstruction. A nerve cuff electrode was implanted for tibial nerve stimulation (TNS).

Low pressure voiding induced by a novel implantable pudendal nerve stimulator.

Aim: To validate the functionality of an implantable pudendal nerve stimulator under development for Food and Drug Administration approval to restore bladder function after spinal cord injury.

Methods: In nine cats under anesthesia, two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves and one bipolar cuff electrode was implanted on the right pudendal nerve central to the tripolar cuff electrode. The pudendal nerve stimulator was implanted subcutaneously on the left lower back along the lumbosacral spine and connected to the cuff electrodes.

Sympathetic afferents in the hypogastric nerve facilitate nociceptive bladder activity in cats.

This study in α-chloralose-anesthetized cats revealed a role of hypogastric nerve afferent axons in nociceptive bladder activity induced by bladder irritation using 0.25% acetic acid (AA). In cats with intact hypogastric and pelvic nerves, AA irritation significantly ( P < 0.

Feline Interstitial Cystitis Enhances Mucosa-Dependent Contractile Responses to Serotonin.

Purpose: To determine whether responses to serotonin are altered in bladder strips from cats diagnosed with a naturally occurring form of bladder pain syndrome/interstitial cystitis termed feline interstitial cystitis (FIC).

Methods: Full thickness bladder strips were isolated from aged matched healthy control cats and cats with clinically verified FIC. Bladder strips were mounted in an organ bath and connected to a tension transducer to record contractile activity.

Corrigendum: Inflammation and Tissue Remodeling in the Bladder and Urethra in Feline Interstitial Cystitis.

[This corrects the article DOI: 10.3389/fnsys.2018.

Spinal interneuronal mechanisms underlying pudendal and tibial neuromodulation of bladder function in cats.

This study examined the mechanisms underlying pudendal and tibial neuromodulation of bladder function at the single neuron level in the spinal cord. A microelectrode was inserted into the S2 spinal cord of anesthetized cats to record single neuron activity induced by bladder distention over a range of constant intravesical pressures (10-40 cmHO). Pudendal nerve stimulation (PNS) or tibial nerve stimulation (TNS) was applied at 5 Hz frequency and 0.

Frequency Dependent Tibial Neuromodulation of Bladder Underactivity and Overactivity in Cats.

Objective: This study is aimed at determining if tibial nerve stimulation (TNS) can modulate both bladder underactivity and overactivity.

Methods: In α-chloralose anesthetized cats, tripolar cuff electrodes were implanted on both tibial nerves and TNS threshold (T) for inducing toe twitching was determined for each nerve. Normal bladder activity was elicited by slow intravesical infusion of saline; while bladder overactivity was induced by infusion of 0.

Inflammation and Tissue Remodeling in the Bladder and Urethra in Feline Interstitial Cystitis.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disease of unknown etiology. A naturally occurring disease termed feline interstitial cystitis (FIC) reproduces many features of IC/BPS patients. To gain insights into mechanisms underlying IC/BPS, we investigated pathological changes in the lamina propria (LP) of the bladder and proximal urethra in cats with FIC, using histological and molecular methods.

Bladder underactivity after prolonged stimulation of somatic afferent axons in the tibial nerve in cats.

Aims: To establish an animal model of bladder underactivity induced by prolonged and intense stimulation of somatic afferent axons in the tibial nerve.

Methods: In seven cats under α-chloralose anesthesia, tibial nerve stimulation (TNS) of 30-min duration was repeatedly (3-8 times) applied at 4-6 times threshold (T) intensity for inducing a toe twitch to produce bladder underactivity determined by cystometry. Naloxone (1 mg/kg, i.

Saphenous nerve stimulation normalizes bladder underactivity induced by tibial nerve stimulation in cats.

This study in α-chloralose-anesthetized cats aimed at investigating the bladder responses to saphenous nerve stimulation (SNS). A urethral catheter was used to infuse the bladder with saline and to record changes in bladder pressure. With the bladder fully distended, SNS at 1-Hz frequency and an intensity slightly below the threshold (T) for inducing an observable motor response of the hindlimb muscles induced large amplitude (40-150 cmHO) bladder contractions.

Sacral neuromodulation blocks pudendal inhibition of reflex bladder activity in cats: insight into the efficacy of sacral neuromodulation in Fowler's syndrome.

This study tested the hypothesis that sacral neuromodulation, i.e., electrical stimulation of afferent axons in sacral spinal root, can block pudendal afferent inhibition of the micturition reflex.

An excitatory reflex from the superficial peroneal nerve to the bladder in cats.

This study in α-chloralose-anesthetized cats discovered an excitatory peroneal nerve-to-bladder reflex. A urethral catheter was used to infuse the bladder with saline and record bladder pressure changes. Electrical stimulation was applied to the superficial peroneal nerve to trigger reflex bladder activity.

Glutamatergic Mechanisms Involved in Bladder Overactivity and Pudendal Neuromodulation in Cats.

The involvement of ionotropic glutamate receptors in bladder overactivity and pudendal neuromodulation was determined in -chloralose anesthetized cats by intravenously administering MK801 (a NMDA receptor antagonist) or CP465022 (an AMPA receptor antagonist). Infusion of 0.5% acetic acid (AA) into the bladder produced bladder overactivity.

Sex difference in the contribution of GABA receptors to tibial neuromodulation of bladder overactivity in cats.

This study investigated the role of γ-aminobutyric acid subtype B (GABA) receptors in tibial and pudendal neuromodulation of bladder overactivity induced by intravesical administration of dilute (0.5%) acetic acid (AA) in α-chloralose-anesthetized cats. To inhibit bladder overactivity, tibial or pudendal nerve stimulation (TNS or PNS) was applied at 5 Hz and two or four times threshold (T) intensity for inducing toe or anal sphincter twitch.

Role of cannabinoid receptor type 1 in tibial and pudendal neuromodulation of bladder overactivity in cats.

The role of cannabinoid type 1 (CB1) receptors in tibial and pudendal neuromodulation of bladder overactivity induced by intravesical infusion of 0.5% acetic acid (AA) was determined in α-chloralose anesthetized cats. AA irritation significantly ( < 0.

Lumbosacral spinal segmental contributions to tibial and pudendal neuromodulation of bladder overactivity in cats.

Aims: To determine the spinal segmental afferent contributions to tibial and pudendal inhibition of bladder overactivity.

Methods: Intravesical infusion of 0.5% acetic acid was used to irritate the bladder and induce bladder overactivity in anesthetized cats.

Influence of urothelial or suburothelial cholinergic receptors on bladder reflexes in chronic spinal cord injured cats.

The effects of intravesical administration of a muscarinic receptor agonist (oxotremorine-M, OXO-M) and antagonist (atropine methyl nitrate, AMN) and of a nicotinic receptor agonist (nicotine) and antagonist (hexamethonium, C) on reflex bladder activity were investigated in conscious female chronic spinal cord injured (SCI) cats using cystometry. OXO-M (50μM) decreased bladder capacity (BC) for triggering micturition contractions, increased maximal micturition pressure (MMP), increased frequency and area under the curve of pre-micturition contractions (PMC-AUC). Nicotine (250μM) decreased BC, increased MMP, but did not alter PMC-AUC.

Neurotransmitter Mechanisms Underlying Sacral Neuromodulation of Bladder Overactivity in Cats.

Objective: To determine the role of opioid, β-adrenergic, and metabotropic glutamate 5 receptors in sacral neuromodulation of bladder overactivity.

Material And Methods: In α-chloralose anesthetized cats, intravesical infusion of 0.5% acetic acid (AA) irritated the bladder and induced bladder overactivity.

Contribution of GABAA, Glycine, and Opioid Receptors to Sacral Neuromodulation of Bladder Overactivity in Cats.

In α-chloralose-anesthetized cats, we examined the role of GABA, glycine, and opioid receptors in sacral neuromodulation-induced inhibition of bladder overactivity elicited by intravesical infusion of 0.5% acetic acid (AA). AA irritation significantly (P < 0.

Sacral neuromodulation of nociceptive bladder overactivity in cats.

Aims: To investigate the effects of electrical stimulation of sacral dorsal/ventral roots on irritation-induced bladder overactivity, reveal possible different mechanisms under nociceptive bladder conditions, and establish a large animal model of sacral neuromodulation.

Methods: Intravesical infusion of 0.5% acetic acid (AA) was used to irritate the bladder and induce bladder overactivity in cats under α-chloralose anesthesia.

Post-stimulation block of frog sciatic nerve by high-frequency (kHz) biphasic stimulation.

This study determined if high-frequency biphasic stimulation can induce nerve conduction block that persists after the stimulation is terminated, i.e., post-stimulation block.