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Nerve Density (nerve + density)

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Medical Sciences	100%

Selected Abstracts

ORIGINAL RESEARCH,BASIC SCIENCE: A Prospective Study Examining the Anatomic Distribution of Nerve Density in the Human Vagina

THE JOURNAL OF SEXUAL MEDICINE, Issue 6 2006
Rachel Pauls MD
ABSTRACT Introduction., Women possess sufficient vaginal innervation such that tactile stimulation of the vagina can lead to orgasm. However, there are few anatomic studies that have characterized the distribution of nerves throughout the human vagina. Aim., The aim of this prospective study was to better characterize the anatomic distribution of nerves in the adult human vagina. A secondary aim was to assess whether vaginal innervation correlates with the subject's demographic information and sexual function. Methods., Full-thickness biopsies of anterior and posterior vagina (proximal and distal), cuff, and cervix were taken during surgery in a standardized manner. Specimens were prepared with hematoxylin and eosin, and S100 protein immunoperoxidase. The total number of nerves in each specimen was quantified. Enrolled patients completed a validated sexual function questionnaire (Female Sexual Function Index, FSFI) preoperatively. Main Outcome Measures., A description of vaginal innervation by location and an assessment of vaginal innervation in association with the subject's demographic information and sexual function. Results., Twenty-one patients completed this study, yielding 110 biopsy specimens. Vaginal innervation was somewhat regular, with no site consistently demonstrating the highest nerve density. Nerves were located throughout the vagina, including apex and cervix. No significant differences were noted in vaginal innervation based on various demographic factors, including age, vaginal maturation index, stage of prolapse, number of vaginal deliveries, or previous hysterectomy. There were no correlations between vaginal nerve quantity and FSFI domain and overall scores. Fifty-seven percent of the subjects had female sexual dysfunction; when compared to those without dysfunction, there were no significant differences in total or site-specific nerves. Conclusions., In a prospective study, vaginal nerves were located regularly throughout the anterior and posterior vagina, proximally and distally, including apex and cervix. There was no vaginal location with increased nerve density. Vaginal innervation was not associated with demographic information or sexual function. Pauls R, Mutema G, Segal J, Silva WA, Kleeman S, Dryfhout V, and Karram M. A prospective study examining the anatomic distribution of nerve density in the human vagina. J Sex Med 2006;3:979,987. [source]

Variance of Peptidic Nerve Innervation in a Canine Model of Atrial Fibrillation Produced by Prolonged Atrial Pacing

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2008
XIUFEN QU Ph.D.
Background:Long-term rapid atrial pacing may result in nerve sprouting and sympathetic hyperinnervation in atrial fibrillation (AF) in dogs. Whether peptidic nerve is involved in neural remodeling is unclear. Method and Results:We performed rapid left atrial pacing in six dogs to induce sustained AF. Tissues from six healthy dogs were used as controls. Nerve was identified by immunocytochemical techniques. The degree of nerve innervation was quantified by measuring the amount of staining area for each antibody and the heterogeneity of nerve distribution was qualitatively studied. In dogs with AF, the density of growth-associated protein 43 (GAP43) immunopositivenerve fibers in the left atrium (LA), atrial septum (AS), and right atrium (RA) was significantly (19,454.31 ± 1,592.81 ,m2/mm2 vs 1,673.41 ± 142.62 ,m2/mm2P < 0.001, 3,931.26 ± 361.78 ,m2/mm2 vs 1,614.20 ± 140. 41 ,m2/mm2 P < 0.05 and 2,324.15 ± 1,123.77 ,m2/mm2 vs 1,620.47 ± 189.05 ,m2/mm2 P < 0.05, respectively) higher than the nerve density in control tissues. The density of (neuropeptide Y) NPY-positive nerves in the, AS, and RA was (13,547.62 ± 2,983.37 ,m2/mm2 vs 703.72 ± 287.52 ,m2/mm2 P < 0.01, 2,689.22 ± 340.93 ,m2/mm2 vs 651.7 ± 283.02 ,m2/mm2 P < 0.01 and 1,574.70 ± 424.37 ,m2/mm2 vs 580.42 ± 188.12 ,m2/mm2 P < 0.001, respectively) higher than the nerve density in control tissues. At the same time, vasoactive intestinal polypeptide (VIP) positive nerve innervation shrank in dogs with AF. The density of VIP positive in LA, AS, and RA was statistically lower than the nerve density in control tissues, respectively. (110.48 ± 45.63,m2/mm2 vs 1679.32 ± 1020.34,m2/mm2 P < 0.01, 265.92 ± 52.51 ,m2/mm2 vs 2602.68 ± 1257.16,m2/mm2 P < 0.001 and 609.56 ± 139.75,m2/mm2 vs 2771.68 ± 779.08,m2/mm2 P < 0.01, respectively) Conclusions:Combined with VIP-ergic nerve denervation, significant nerve sprouting and NPY-ergic nerve hyperinnervation are present in a canine model of sustained AF produced by prolonged atrial pacing. [source]

Mechanisms determining cholinergic neural responses in airways of young and mature rabbits,

PEDIATRIC PULMONOLOGY, Issue 2 2004
Gary L. Larsen MD
Abstract Neural pathways help control airway caliber and responsiveness. Yet little is known of how neural control changes as a function of development. In rabbits, we found electrical field stimulation (EFS) of airway nerves led to more marked contractile responses in 2- vs. 13-week-old animals. This enhanced response to EFS may be due to prejunctional, junctional, and/or postjunctional neural mechanisms. We assessed these mechanisms in airways of 2- and 13-week-old rabbits. The contractile responses to methacholine did not differ in the groups, suggesting postjunctional neural events are not primarily responsible for differing responses to EFS. To address junctional events, acetylcholinesterase (AChE) was measured (spectrophotometry). AChE was elevated in 2-week-olds. However, this should lead to less and not greater responses. Prejunctionally, EFS-induced acetylcholine (ACh) release was assessed by HPLC. Airways of 2-week-old rabbits released significantly more ACh than airways from mature rabbits. Choline acetyltransferase, a marker of cholinergic nerves, was not different between groups, suggesting that more ACh release in young rabbits was not due to increased nerve density. ACh release in the presence of polyarginine increased significantly in both groups, supporting the presence of functional muscarinic autoreceptors (M2) at both ages. Because substance P (SP) increases release of ACh, SP was measured by ELISA. This neuropeptide was significantly elevated in airways of younger rabbits. Nerve growth factor (NGF) increased SP and was also significantly increased in airways from younger rabbits. This work suggests that increases in EFS-induced responsiveness in young rabbits are likely due to prejunctional events with enhanced release of ACh. Increases in NGF and SP early in life may contribute to this increased responsiveness. Pediatr Pulmonol. 2004; 38:97,106. © 2004 Wiley-Liss, Inc. [source]

Mechanisms of cholinergic dysfunction in rabbits following recurrent aspiration of cow's milk,

PEDIATRIC PULMONOLOGY, Issue 6 2001
Gary L. Larsen MD
Abstract Recurrent aspiration of cow's milk has been shown to alter neural control of airways in young rabbits (Gelfand et al., 1997). The purpose of this study was to define the mechanisms responsible for in vitro cholinergic hyperresponsiveness in this model. Beginning at 1 week of age, rabbits received either 0.5 mL/kg whole cow's milk or sterile saline intranasally while under light anesthesia. This was repeated each weekday for 2 weeks. At 8 weeks of age, rabbits were sacrificed. Portions of lungs underwent lavage with sterile saline. Tracheal smooth muscle (TSM) segments were also removed. Segments were assessed for acetylcholine (ACh) release by high-performance liquid chromatography ( HPLC) with electrochemical detection or acetylcholinesterase (AChE) kinetic activity by spectrophotometry. Substance P (SP), a neuropeptide that can increase ACh release from nerves, was also assessed using an enzyme immunoassay to define the content in lavage and TSM segments. Immunohistochemistry for SP within airways was also assessed. We found that recurrent aspiration of milk led to statistically significant alterations in many parameters. Acetylcholine release was significantly greater in segments of airways from rabbits that had aspirated cow's milk (27.5,±,1.7 vs. 20.1,±,1.6 pmol/min/g tissue) than saline. At the same time, AChE activity was less in the group that aspirated milk (8.7,±,0.4 vs. 10.2,±,0.5 nmol/min/mg protein) compared to saline. The amount of SP within both lavage as well as tissue homogenates was greater in the group that had aspirated the foreign protein (159.1,±,28.9 vs. 41.9,±,5.2 pmol/mg protein in lavage; 158.7,±,31.9 vs. 80.5,±,7.8 pmol/mg protein in tissues) than saline controls. While total cholinergic nerve density as assessed by choline acetyltransferase was not significantly different between groups, SP-positive immunoreactive nerves were easily identified in the group that aspirated cow's milk. This study suggests that cholinergic hyperresponsiveness caused by repeated aspiration of milk is due to several abnormalities, including prejunctional (increase in ACh release) as well as junctional (decrease in AChE) mechanisms within the airways. In addition, an upregulation of SP within airways is part of this process. Pediatr Pulmonol. 2001; 32:409,417. © 2001 Wiley-Liss, Inc. [source]

ORIGINAL RESEARCH,BASIC SCIENCE: A Prospective Study Examining the Anatomic Distribution of Nerve Density in the Human Vagina

In vitro model for penetration of sensory nerve fibres on a Matrigel basement membrane: implications for possible application to intractable pruritus

BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2009
M. Tominaga
Summary Background, Epidermal hyperinnervation occurs in dermatoses with intractable pruritus, such as atopic dermatitis, suggesting that the hyperinnervation is partly responsible for abnormal itch perception. Objectives, To investigate the mechanisms of penetration of sensory nerve fibres into the basement membrane of the skin. Methods, A rat dorsal root ganglion neurone culture system consisting of Matrigel and a Boyden chamber containing a nerve growth factor (NGF) concentration gradient was used. In some experiments, matrix metalloproteinase (MMP) blockers and semaphorin 3A (Sema3A) were added to the culture system. Matrigel-coated membranes were stained with anti-Tau antibody, and the number of nerve fibres that crossed the membrane was counted. Expression of MMPs in the cultured neurones was examined at mRNA and protein levels by quantitative reverse transcription,polymerase chain reaction and immunocytochemistry, respectively. The activity was also examined by zymography. Results, Nerve fibres penetrated into Matrigel in the presence of an NGF concentration gradient, which was dose-dependently inhibited by GM6001, a broad-spectrum MMP inhibitor. Transcripts for MMP2, but not MMP9, were increased in the cultured neurones, and the penetration was dose-dependently inhibited by MMP-2 blockers. MMP-2 and its activity were partially localized on the NGF-responsive growth cones. NGF also upregulated pro-MMP-2 activation molecules in the cultured neurones. Sema3A stimulation showed the opposite effects on these NGF-dependent events. Interestingly, MMP2 expression was modulated by extracellular matrix (ECM) substrates for this enzyme. Conclusions, Membrane-associated MMP-2 contributes to penetration of nerve fibres into Matrigel through modulation by axonal guidance molecules and/or ECM. These findings provide insight for understanding the development of intractable pruritus involving epidermal nerve density. [source]

4131: Pathologic epithelial and anterior corneal nerve morphology in congenital aniridic keratopathy

ACTA OPHTHALMOLOGICA, Issue 2010
P FAGERHOLM
Purpose To document corneal morphology in Swedish families with congenital aniridia. Methods Detailed ophthalmic examinations were conducted in a number of affected and unaffected members. Digital slit lamp photography, anterior segment optical coherence tomography (ASOCT) and in-vivo confocal microscopy (IVCM) examinations were performed bilaterally to document corneal morphology. Results Affected family members presented with different stages of aniridic keratopathy, with a corneal appearance varying from totally transparent to opaque and highly vascularised. Increased corneal thickness in affected members, particularly those with severe keratopathy, was noted by ASOCT. By IVCM, opaque corneas were characterized by active vessels and dense inflammatory cell infiltration. In corneas with milder keratopathy, pathologic epithelial findings included epithelial pleomorphism, focal epithelial opacities, and an absence of limbal epithelial crypts and focal stromal projections at the limbus. Nerves of the anterior cornea exhibited several distinct features, including an unusually close association of subbasal nerves with epithelial cells, an unusually high subbasal nerve density with highly branched nerves, and a prominent whorl region. Additionally, abnormally dense and tortuous anterior stromal nerves, attached to stromal keratocytes, were noted in unaffected members. Conclusion Altered epithelial morphology and a vigorous innervation of the anterior cornea were the most pronounced corneal findings in family members with milder forms of aniridic keratopathy. Further findings confirmed the known increase in corneal thickness and limbal stem cell abnormality in aniridia. [source]