Serotonergic paraneurones in the female mouse urethral epithelium and their potential role in peripheral sensory information processing.

AIM: The mechanisms underlying detection and transmission of sensory signals arising from visceral organs, such as the urethra, are poorly understood. Recently, specialized ACh-expressing cells embedded in the urethral epithelium have been proposed as chemosensory sentinels for detection of bacterial infection. Here, we examined the morphology and potential role in sensory signalling of a different class of specialized cells that express serotonin (5-HT), termed paraneurones. METHODS: Urethrae, dorsal root ganglia neurones and spinal cords were isolated from adult female mice and used for immunohistochemistry and calcium imaging. Visceromotor reflexes (VMRs) were recorded in vivo. RESULTS: We identified two morphologically distinct groups of 5-HT+ cells with distinct regional locations: bipolar-like cells predominant in the mid-urethra and multipolar-like cells predominant in the proximal and distal urethra. Sensory nerve fibres positive for calcitonin gene-related peptide, substance P, and TRPV1 were found in close proximity to 5-HT+ paraneurones. In vitro 5-HT (1 µm) stimulation of urethral primary afferent neurones, mimicking 5-HT release from paraneurones, elicited changes in the intracellular calcium concentration ([Ca2+ ]i ) mediated by 5-HT2 and 5-HT3 receptors. Approximately 50% of 5-HT responding cells also responded to capsaicin with changes in the [Ca2+ ]i . In vivo intra-urethral 5-HT application increased VMRs induced by urethral distention and activated pERK in lumbosacral spinal cord neurones. CONCLUSION: These morphological and functional findings provide insights into a putative paraneurone-neural network within the urethra that utilizes 5-HT signalling, presumably from paraneurones, to modulate primary sensory pathways carrying nociceptive and non-nociceptive (mechano-sensitive) information to the central nervous system.

A 2.5-Mb contig constructed from Angus, Longhorn and horned Hereford DNA spanning the polled interval on bovine chromosome 1.

The polled locus has been mapped by genetic linkage analysis to the proximal region of bovine chromosome 1. As an intermediate step in our efforts to identify the polled locus and the underlying causative mutation for the polled phenotype, we have constructed a BAC-based physical map of the interval containing the polled locus. Clones containing genes and markers in the critical interval were isolated from the TAMBT (constructed from Angus and Longhorn genomic DNA) and CHORI-240 (constructed from horned Hereford genomic DNA) BAC libraries and ordered based on fingerprinting and the presence or absence of 80 STS markers. A single contig spanning 2.5 Mb was assembled. Comparison of the physical order of STSs to the corresponding region of human chromosome 21 revealed the same order of genes within the polled critical interval. This contig of overlapping BAC clones from horned and polled breeds is a useful resource for SNP discovery and characterization of positional candidate genes.

A study of the prevalence and distribution of dentine sensitivity in a population of 17-58-year-old serving personnel on an RAF base in the Midlands.

Previous studies have reported on dentine sensitivity (DS) prevalence in hospital and general practice populations. Results from these studies indicate that perception and prevalence of DS vary depending on the population. The study aimed to determine any major differences in the perception and prevalence of DS in subjects in a military training establishment. Questionnaires from 228 subjects [188 completed by males, 39 completed by females, with one person not indicating their gender of mean age 24.0 years (s.d. 7.16)] were collected and analysed using the Statistical Package for the Social Sciences (SPSS). Fifty percent of the subjects (n=114) claimed to have DS. Yet approximately 30% of the subjects (29.8%, n=68) perceived the condition as a slight problem and approximately 40% of the subjects (40.8%, n=93) claimed it was an occasional problem and approximately 50% (49.1%, n=112) did not seek treatment. Seventeen subjects (7.5%) used a desensitizing paste during periods of discomfort. No clear pattern emerged with regard to seasonal variation in DS although 5.7% (n=13) subjects considered DS to be more of a problem in winter. Only 7.9% (n=18) reported any previous periodontal surgery, consistent with previous studies (12.6 and 15.5%). Of those who received regular scaling (27.2%, n=62), only 23 (10.1%) reported any discomfort following treatment, which did not last >or=5 days. The results indicate that self-reporting of DS was similar to previous reports, although it is of fundamental importance that such studies should be supplemented with a thorough clinical examination to determine more reliable prevalence data.