Sphingosine kinase 2-deficiency mediated changes in spinal pain processing.

Chronic pain is one of the most burdensome health issues facing the planet (as costly as diabetes and cancer combined), and in desperate need for new diagnostic targets leading to better therapies. The bioactive lipid sphingosine 1-phosphate (S1P) and its receptors have recently been shown to modulate nociceptive signaling at the level of peripheral nociceptors and central neurons. However, the exact role of S1P generating enzymes, in particular sphingosine kinase 2 (Sphk2), in nociception remains unknown.

Conscious voiding during bladder obstruction in guinea pigs correlates with contractile activity of isolated bladders.

Purpose: There are many hypotheses accounting for detrusor overactivity; however, the exact mechanisms are still incompletely understood. We used a model of bladder outlet obstruction in male guinea pigs as a way to produce detrusor overactivity. The objective was to determine whether changes in voiding of obstructed guinea pigs correlates with specific changes in contractile activity of their isolated bladders in vitro.

Primary afferent neurons containing calcitonin gene-related peptide but not substance P in forepaw skin, dorsal root ganglia, and spinal cord of mice.

In mice dorsal root ganglia (DRG), some neurons express calcitonin gene-related peptide (CGRP) without substance P (SP; CGRP(+) SP(-) ). The projections and functions of these neurons are unknown. Therefore, we combined in vitro axonal tracing with multiple-labeling immunohistochemistry to neurochemically define these neurons and characterize their peripheral and central projections.

Sensory nerve fibers containing calcitonin gene-related peptide in gastrocnemius, latissimus dorsi and erector spinae muscles and thoracolumbar fascia in mice.

Chronic pain is a significant burden and much is attributed to back muscles. Back muscles and their associated fasciae make important and distinct contributions to back pain. Peptidergic nociceptors innervating these structures contribute to central transmission and pain modulation by peripheral and central actions.

Novel spinal pathways identified by neuronal c-Fos expression after urethrogenital reflex activation in female guinea pigs.

Pudendal nerve-spinal pathways are involved in urethrogenital sensation, pain and sexual activity. However, details of these pathways and their modulation are unclear. We examined spinal pathways activated by the urethrogenital reflex (UGR) and visualized by c-Fos immunoreactivity in reflexly activated neurons within spinal cord.

Quantification of in vivo colonic motor patterns in healthy humans before and after a meal revealed by high-resolution fiber-optic manometry.

Background: Until recently, investigations of the normal patterns of motility of the healthy human colon have been limited by the resolution of in vivo recording techniques.

Methods: We have used a new, high-resolution fiber-optic manometry system (72 sensors at 1-cm intervals) to record motor activity from colon in 10 healthy human subjects.

Key Results: In the fasted colon, on the basis of rate and extent of propagation, four types of propagating motor pattern could be identified: (i) cyclic motor patterns (at 2-6/min); (ii) short single motor patterns; (iii) long single motor patterns; and (iv) occasional retrograde, slow motor patterns.

The neurochemical changes in the innervation of human colonic mesenteric and submucosal blood vessels in ulcerative colitis and Crohn's disease.

Background: Neurogenic inflammation involves vasodilation, oedema and sensory nerve hypersensitivity. Extrinsic sensory nerves to the intestinal wall mediate these effects and functional subsets of these extrinsic nerves can be characterized by immunohistochemical profiles. In this study such profiles were examined in samples from patients with inflammatory bowel disease (IBD), in particular ulcerative colitis (UC) and Crohn's disease (CD).

Functional organization of autonomic neural pathways.

There is now abundant functional and anatomical evidence that autonomic motor pathways represent a highly organized output of the central nervous system. Simplistic notions of antagonistic all-or-none activation of sympathetic or parasympathetic pathways are clearly wrong. Sympathetic or parasympathetic pathways to specific target tissues generally can be activated tonically or phasically, depending on current physiological requirements.

Low-resolution colonic manometry leads to a gross misinterpretation of the frequency and polarity of propagating sequences: Initial results from fiber-optic high-resolution manometry studies.

Background: High-resolution manometry catheters are now being used to record colonic motility. The aim of this study was to determine the influence of pressure sensor spacing on our ability to identify colonic propagating sequences (PS).

Methods: Fiber-optic catheters containing 72-90 sensors spaced at 1 cm intervals were placed colonoscopically to the cecum in 11 patients with proven slow transit constipation, 11 patients with neurogenic fecal incontinence and nine healthy subjects.

Comparison of Stain-Free gels with traditional immunoblot loading control methodology.

Loading controls are necessary for semiquantitative Western blotting to compensate for loading errors. Loading control methods include the reprobing of membranes with an antibody against a constitutively expressed protein or staining the membrane with a total protein stain. We compared the loading control performance of recently released Stain-Free (SF) gels with Sypro Ruby (SR) and reprobing using β-actin.

Non-peptidergic small diameter primary afferents expressing VGluT2 project to lamina I of mouse spinal dorsal horn.

Background: Unmyelinated primary afferent nociceptors are commonly classified into two main functional types: those expressing neuropeptides, and non-peptidergic fibers that bind the lectin IB4. However, many small diameter primary afferent neurons neither contain any known neuropeptides nor bind IB4. Most express high levels of vesicular glutamate transporter 2 (VGluT2) and are assumed to be glutamatergic nociceptors but their terminations within the spinal cord are unknown.

MicroRNA-143 expression in dorsal root ganglion neurons.

The unpleasant sensory and emotional experience of pain is initiated by excitation of primary afferent nociceptive neurons. Nerve damage or inflammation induces changes in nociceptive DRG neurons which contribute to both peripheral and central sensitization of pain-sensitive pathways. Recently, blockade of microRNA synthesis has been found to modulate the response of nociceptive neurons to inflammatory stimuli.

Expression profile of the sphingosine kinase signalling system in the lung of patients with chronic obstructive pulmonary disease.

Aims: Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. Despite its importance, treatment methods are limited and restricted to symptomatic care, highlighting the urgent need for new treatment options. Tissue damage in COPD is thought to result from an inability of the normal repair processes with accumulation of apoptotic material and impaired clearance of this material by macrophages in the airways.

The cholinergic system in rat testis is of non-neuronal origin.

The cholinergic system consists of acetylcholine (ACh), its synthesising enzyme, choline acetyltransferase (CHAT), transporters such as the high-affinity choline transporter (SLC5A7; also known as ChT1), vesicular ACh transporter (SLC18A3; also known as VAChT), organic cation transporters (SLC22s; also known as OCTs), the nicotinic ACh receptors (CHRN; also known as nAChR) and muscarinic ACh receptors. The cholinergic system is not restricted to neurons but plays an important role in the structure and function of non-neuronal tissues such as epithelia and the immune system. Using molecular and immunohistochemical techniques, we show in this study that non-neuronal cells in the parenchyma of rat testis express mRNAs for Chat, Slc18a3, Slc5a7 and Slc22a2 as well as for the CHRN subunits in locations completely lacking any form of innervation, as demonstrated by the absence of protein gene product 9.

Sensory innervation of the external genital tract of female guinea pigs and mice.

Introduction: The structural and neurochemical characterization of the sensory innervation of the external genitalia of females is poorly known.

Aims:   To immunohistochemically map the sensory innervation of external genitalia and surrounding structures of female guinea pigs and mice.

Methods: Large-diameter sensory fibers, presumably mechanoreceptors, were identified by their immunoreactivity to neuron-specific enolase (NSE) or vesicular glutamate transporter 1 (VGluT1).

Sacro-lumbar intersegmental spinal reflex in autonomic pathways mediating female sexual function.

Introduction: Autonomic neurons in paracervical ganglia mediating vasodilation in the female reproductive tract receive inputs from both midlumbar and sacral spinal levels. However, it is not known how the lumbar pathways are activated.

Aim: This study tested whether stimulation of pudendal sensory nerve could activate lumbar spinal outflows to paracervical ganglia via a spinal reflex pathway.

Differential expression of microRNA-1 in dorsal root ganglion neurons.

Damage to sensory neurons induces neural repair, regrowth and hyperexcitability. The regulation of such responses to injury must be organized in some way by the neurons. Regulation can occur at the post-transcriptional level via microRNAs (miRNAs).

Role of sphingosine kinase 1 in allergen-induced pulmonary vascular remodeling and hyperresponsiveness.

Background: Immunologic processes might contribute to the pathogenesis of pulmonary arterial hypertension (PAH), a fatal condition characterized by progressive pulmonary arterial remodeling, increased pulmonary vascular resistance, and right ventricular failure. Experimental allergen-driven lung inflammation evoked morphologic and functional vascular changes that resembled those observed in patients with PAH. Sphingosine kinase 1 (SphK1) is the main pulmonary contributor to sphingosine-1-phosphate (S1P) synthesis, a modulator of immune and vascular functions.

A virtual reality 3D jigsaw for teaching anatomy.

Virtual Reality has some advantages over traditional teaching and learning media. Here we describe a VR Jigsaw which uses a novel interface to facilitate learning the anatomy of the skull. A small trial was performed which indicates that the software succeeds at engaging students and suggests that their comprehension of complex 3D structures was improved.

Properties of the major classes of mechanoreceptors in the guinea pig bladder.

Sensory neurons represent an attractive target for pharmacological treatment of various bladder disorders. However the properties of major classes of mechano-sensory neurons projecting to the bladder have not been systematically established. An in vitro bladder preparation was used to examine the effects of a range of mechanical stimuli (stretch, von Frey hair stroking and focal compression of receptive fields) and chemical stimuli (1 mm alpha,beta-methylene ATP, hypertonic solutions (500 mm NaCl) and 3 microm capsaicin) during electrophysiological recordings from guinea pig bladder afferents.

Kinetics of strain-dependent differential gene expression in oxygen-induced retinopathy in the rat.

Recent evidence suggests that retinopathy of prematurity, a potentially blinding condition of premature human neonates, has a genetically-determined component. Different inbred strains of rat exhibit differential susceptibility to oxygen-induced retinopathy (OIR), a well-established experimental model of retinopathy of prematurity. To explore the basis for this differential susceptibility, we quantified the retinal expression of 8 angiogenesis-related genes during early post-natal retinal development in rats with OIR.

Structure of peripheral synapses: autonomic ganglia.

Final motor neurons in sympathetic and parasympathetic ganglia receive synaptic inputs from preganglionic neurons. Quantitative ultrastructural analyses have shown that the spatial distribution of these synapses is mostly sparse and random. Typically, only about 1%-2% of the neuronal surface is covered with synapses, with the rest of the neuronal surface being closely enclosed by Schwann cell processes.

Post-stimulus potentiation of transmission in pelvic ganglia enhances sympathetic dilatation of guinea-pig uterine artery in vitro.

Vasodilatation produced by stimulation of preganglionic neurones in lumbar and sacral pathways to pelvic ganglia was studied using an in vitro preparation of guinea-pig uterine artery and associated nerves in a partitioned bath allowing selective drug application to the ganglia or artery. Arterial diameter was monitored using real time video imaging. Vasodilatations produced by hypogastric nerve stimulation (HN; 300 pulses, 10 Hz) were significantly larger and longer in duration than with pelvic nerve stimulation (N = 18).