The Relationship Between Cortical Activation in Response to Anorectal Stimuli and Continence Behavior in Freely Behaving Rats Before and After Application of Sacral Nerve Stimulation.

Background: Changes in anorectal sensation have been reported in patients with fecal incontinence, and there is limited evidence that sacral nerve stimulation can restore normal sensation.

Objective: The aims of the present study were to investigate changes in the transmission of sensory anorectal stimuli in a rodent model of fecal incontinence and to study the effects of sacral nerve stimulation on defecation behavior.

Design: An established model of fecal incontinence was utilized for this study.

Electrophysiological characterisation of atrial volume receptors using ex vivo models of isolated rat cardiac atria.

New Findings: What is the central question of this study? What ex vivo preparation of the rat's cavoatrial junction is efficient for characterising atrial mechanoreceptors? What is the main finding and its importance? Of four different ex vivo preparations, static pressure, flow, open and euthermic, the optimal preparation was the euthermic one and involved direct recording from the right cardiac vagal branch with a Langendorff style perfusion at 37°C. Type A receptors were most common, and appeared insensitive to stretch and sensitive to atrial contraction. Type B and intermediate receptors were not isolated at 20°C but were observed closer to 37°C.

Distribution and morphology of sensory and autonomic fibres in the subendocardial plexus of the rat heart.

Cardiac reflexes originating from sensory receptors in the heart ensure blood supply to vital tissues and organs in the face of constantly changing demands. Atrial volume receptors are mechanically sensitive vagal afferents which relay to the medulla and hypothalamus, affecting vasopressin release and renal sympathetic activity. To date, two anatomically distinct sensory endings have been identified which may subserve cardiac mechanosensation: end-nets and flower-spray endings.

Design and implementation of a low cost, modular, adaptable and open-source XYZ positioning system for neurophysiology.

In recent years, open-source 3D printing technologies have become increasingly applied to biological research. We have created a fully open-source, versatile and low cost XYZ positioning system using 3D printer components. As this system is controlled by a Python3 based operating system running on a Raspberry Pi 3 Model B, its behaviour can be adapted to meet multiple needs in neurophysiology.

The projection of anorectal afferents to cortex of the rat: Comparison of two methods of cortical mapping.

Background: The rat has served usefully as a model for fecal incontinence and exploration of the mechanism of action of sacral neuromodulation. However, there is a gap in knowledge concerning representation(s) on the primary sensory cortex of this anatomical region.

Methods: Multi-electrode array (32 channels) and intrinsic optical signal (IOS) processing were used to map cortical activation sites following anorectal electrical stimulation in the rat.

The projection of anorectal afferents to spinal cord and effect of sacral neuromodulation on dorsal horn neurons which receive such input in the rat.

Background: The rat has served usefully as a model for fecal incontinence and exploration of the mechanism of action of sacral neuromodulation (SNM). There remains a deficit in information regarding the location and type of spinal neurons which receive anorectal input and the effect of SNM on those neurons.

Methods: Single neuronal extracellular recordings of neurons receiving anorectal input were made at the S1 level of the spinal cord using sharp glass electrodes.

Bands of Fontana are caused exclusively by the sinusoidal path of axons in peripheral nerves and predict axon path; evidence from rodent nerves and physical models.

The precise cause of the bands of Fontana, striations on peripheral nerves visible to the naked eye, has been the subject of debate for hundreds of years. Some researchers have described them as reflecting the sinuous course of nerve fibres passing through nerves, and others have proposed that endoneurial collagen and sheaths surrounding nerves play a role in their appearance. We hypothesised that the bands are caused exclusively by reflection of light from the surfaces of nerve fibres travelling in phase in sinusoidal waveforms through peripheral nerves.

Additive Manufacture of Composite Soft Pneumatic Actuators.

This article presents a direct additive manufacturing method for composite material soft pneumatic actuators that are capable of performing a range of programmable motions. Commonly, molding is the method used to manufacture soft fluidic actuators. This is material, labor, and time intensive and lacks the design freedom to produce custom actuators efficiently.

Efficacy and mechanism of sub-sensory sacral (optimised) neuromodulation in adults with faecal incontinence: study protocol for a randomised controlled trial.

Background: Faecal incontinence (FI) is a substantial health problem with a prevalence of approximately 8% in community-dwelling populations. Sacral neuromodulation (SNM) is considered the first-line surgical treatment option in adults with FI in whom conservative therapies have failed. The clinical efficacy of SNM has never been rigorously determined in a trial setting and the underlying mechanism of action remains unclear.

An animal model of faecal incontinence and sacral neuromodulation.

The pudendal nerves can be injured during traumatic vaginal childbirth and result in faecal incontinence. Some of these incontinent patients benefit from chronic sacral neuromodulation and the mechanism of action of this therapy has been a focus of many studies. In 2008, a rodent model of neuropathic faecal incontinence was introduced and subsequently validated through a series of investigations.

Dual-extrusion 3D printing of anatomical models for education.

Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex flexible filament and polylactic acid (PLA) filament were extruded respectively via a single 0.

Systematic Review of Animal Models Used in Research of Origins and Treatments of Fecal Incontinence.

Background: Fecal incontinence is a common disorder, but its pathophysiology is not completely understood.

Objective: The aim of this review is to present animal models that have a place in the study of fecal incontinence.

Data Sources: A literature review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines performed in August 2016 revealed 50 articles of interest.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine.

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail.

A review of sacral nerve stimulation parameters used in the treatment of faecal incontinence.

Sacral nerve stimulation (SNS) was originally developed in the field of urinary incontinence. Without adaptation, it was subsequently applied to treat faecal incontinence. SNS has now become a first line therapy for this socially disabling condition, however the mechanism of action is unknown.

Increased cardiac output contributes to the development of chronic intermittent hypoxia-induced hypertension.

Chronic intermittent hypoxia (CIH) in animal models has been shown to result in hypertension and elevation of sympathetic nervous system activity. Sympathetically mediated vasoconstriction is believed to be the primary mechanism underpinning CIH-induced hypertension; however, the potential contribution of the heart is largely overlooked. We sought to determine the contribution of cardiac output (CO) and lumbar sympathetic control of the hindlimb circulation to CIH-induced hypertension.

Normal nerve striations are altered in the trembler-J mouse, a model of Charcot-Marie-Tooth disease.

Introduction: This study was initiated because it was noted that the peripheral nerves of Trembler-J mice (a model of human Charcot-Marie-Tooth disease) appear to lack normal striations.

Methods: We performed confocal microscopy of whole sciatic nerves and tested the effect of axial stress on impulse conduction.

Results: We found that the axons of mutant mice were longer than those of the wild-type (1.

Effect of chronic intermittent hypoxia on the reflex recruitment of the genioglossus during airway obstruction in the anesthetized rat.

We sought to test the hypothesis that chronic intermittent hypoxia (CIH)-a feature of sleep-disordered breathing in humans-impairs reflex recruitment of the genioglossus (GG, pharyngeal dilator) during obstructive airway events. Adult male Wistar rats were exposed to 20 cycles of normoxia and hypoxia (5% O2 at nadir) per hour, 8h a day for 7 days (CIH, N=7). The sham group (N=7) were exposed to normoxia in parallel.

Effects of sustained hypoxia on sternohyoid and diaphragm muscle during development.

Sustained hypoxia is a dominant feature of respiratory disease. Despite the clinical significance, the effects of sustained hypoxia on the form and function of respiratory muscle during development are relatively underexplored. Wistar rats were exposed to 1 week of sustained hypoxia (ambient pressure 450 mmHg) or normoxia at various time points during development.

Chronic intermittent hypoxia alters genioglossus motor unit discharge patterns in the anaesthetized rat.

The respiratory control system is subject to diverse and considerable plasticity in health and disease. Intermittent hypoxia elicits expression of intrinsic plasticity within sensory and motor pathways involved in the control of breathing with potentially adaptive and maladaptive consequences for respiratory homeostasis. We and others have shown that chronic intermittent hypoxia (CIH) - a major feature of sleep-disordered breathing - has deleterious effects on rat upper airway dilator muscle contractile function and motor control.

Pro-inflammatory cytokines do not affect basal or hypoxia-stimulated discharge of rat vagal paraganglia.

Vagal paraganglia are structurally similar to the carotid body and are chemosensitive to reduction in the P(O(2)). We hypothesized that they may also mediate communication between the immune system and the central nervous system via pro-inflammatory cytokines or endotoxin. In vitro experiments with isolated superior laryngeal nerve (SLN) paraganglia were performed to test this hypothesis.

Respiratory control and sternohyoid muscle structure and function in aged male rats: decreased susceptibility to chronic intermittent hypoxia.

Obstructive sleep apnoea syndrome (OSAS) is a common respiratory disorder characterized by chronic intermittent hypoxia (CIH). We have shown that CIH causes upper airway muscle dysfunction in the rat due to oxidative stress. Ageing is an independent risk factor for the development of OSAS perhaps due to respiratory muscle remodelling and increased susceptibility to hypoxia.