Distribution Of Nerve Endings Research Articles

Distribution of nerve endings in human thumb interphalangeal joint.

This study aims to quantitatively analyze the distribution of encapsulated nerve endings in the human thumb interphalangeal (IP) joint capsule. There are three types of nerve endings. Type-I nerve endings (Ruffini-like ending) sense pressure changes, Type II (Pacini-like ending) nerve endings contribute to the kinesthetic sense, and Type III (Golgi-like ending) nerve ending provides proprioceptive information. We dissected five right thumbs IP joints from freshly frozen cadavers (5 men). The mean age of the cadavers at the time of death was 63.4 years (55-73). Sections were stained with the hematoxylin-eosin and antiprotein gene product 9.5 (PGP9.5) to identify encapsulated nerve endings. Transverse sections were cut and divided into volar, dorsal, and then into two equal parts, proximal and distal. The density of encapsulated nerve endings compared to volar versus dorsal and proximal versus distal regions was examined. This study showed that type 1 nerve endings were more common in the distal parts of the IP joint (p < 0.05). Also, type 3 nerve endings were observed in the thumb IP joint. There was no difference between regions in type II and type III nerve endings. The current study demonstrates that the distribution of encapsulated nerve endings in the IP joint is different from the PIP and DIP joints. Moreover, further studies are required to understand the thumb's physiology.

The size, number, and distribution of nerve endings around and within the human epiglottis, focusing on tracheal intubation maneuvers.

The aim of this study was to examine the distribution of nerve endings in the mucosa, submucosa, and cartilage of the epiglottis and the vallecula area and to quantify them. The findings could inform the choice of laryngoscope blades for intubation procedures. Fourteen neck slices from seven unembalmed, cryopreserved human cadavers were analyzed. The slices were stained, and cross and longitudinal sections were obtained from each. The nerve endings and cartilage were identified. The primary metrics recorded were the number, area, and circumference of nerve endings located in the mucosa and submucosa of the pharyngeal and laryngeal sides of the epiglottis, epiglottis cartilage, and epiglottic vallecula zone. The length and thickness of the epiglottis and cartilage were also measured. The elastic cartilage of the epiglottis was primarily continuous; however, it contained several fragments. It was covered with dense collagen fibers and surrounded by adipose cells from the pharyngeal and laryngeal submucosa. Nerve endings were found within the submucosa of pharyngeal and laryngeal epiglottis and epiglottic vallecula. There were significantly more nerve endings on the posterior surface of the epiglottis than on the anterior surface. The epiglottic cartilage was twice the length of the epiglottis. The study demonstrated that the distribution of nerve endings in the epiglottis differed significantly between the posterior and anterior sides; there were considerably more in the former. The findings have implications for tracheal intubation and laryngoscope blade selection and design.

Analysis of Nerve Endings in the Superior Labrum-Biceps Complex by Fluorescence Immunohistochemistry and Confocal Laser Microscopy.

Objectives  The capsuloligamentous structures of the shoulder work as static stabilizers, together with the biceps and rotator cuff muscles, increasing the contact surface of the glenoid cavity. Free nerve endings and mechanoreceptors have been identified in the shoulder; however, there are a few studies that describe the presence of these nerves in the biceps' insertion. The present study aimed to describe the morphology and distribution of nerve endings using immunofluorescence with protein gene product 9.5 (PGP 9.5) and confocal microscopy. Methods  Six labrum-biceps complexes from six fresh-frozen cadavers were studied. The specimens were coronally cut and prepared using the immunofluorescence technique. In both hematoxylin and eosin (H&E) and immunofluorescence, the organization of the connective tissue with parallel collagen fibers was described. Results  In the H&E study, vascular structures and some nerve structures were visualized, which were identified by the elongated presence of the nerve cell. All specimens analyzed with immunofluorescence and confocal microscopy demonstrated poor occurrence of morphotypes of sensory corpuscles and free nerve endings. We identified free nerve endings located in the labrum and in the bicipital insertion, and sparse nerve endings along the tendon. Corpuscular endings with fusiform, cuneiform, and oval aspect were identified in the tendon. Conclusion  These findings support the hypothesis that the generation of pain in the superior labral tear from Anterior to posterior (SLAP) lesions derives from the more proximal part of the long biceps cord and even more from the upper labrum. Future quantitative studies with a larger number of specimens may provide more information on these sensory systems.

Morphology of nerve endings in vocal fold of human newborn

Sensory receptors are distributed throughout the oral cavity, pharynx, and larynx. Laryngeal sensitivity is crucial for maintaining safe swallowing, thus avoiding silent aspiration. Morphologic description of different receptor types present in larynx vary because of the study of many different species, from mouse to humans. The most commonly sensory structures described in laryngeal mucosa are free nerve endings, taste buds, muscle spindles, glomerular and corpuscular receptors. This study aimed at describing the morphology and the distribution of nerve endings in premature newborn glottic region. Transversal serial frozen sections of the whole vocal folds of three newborns were analyzed using an immuno-histochemical process with a pan-neuronal marker anti-protein gene product 9.5 (PGP 9.5). Imaging was done using a confocal laser microscope. Nerve fiber density in vocal cord was calculated using panoramic images in software Morphometric Analysis System v1.0. Some sensory structures, i.e. glomerular endings and intraepithelial free nerve endings were found in the vocal cord mucosa. Muscle spindles, complex nerve endings (Meissner-like, spherical, rectangular and growing) spiral-wharves nerve structures were identified in larynx intrinsic muscles. Nervous total mean density in vocal cord was similar in the three newborns, although they had different gestational age. The mean nerve fiber density was higher in the posterior region than anterior region of vocal cord. The present results demonstrate the occurrence of different morphotypes of sensory corpuscles and nerve endings premature newborn glottic region and provide information on their sensory systems.

Nerve endings in rat periodontal ligament: an immunofluorescence study

Periodontal ligament is a structure between tooth root and alveolar bone. A few morphological study on the sensory innervation of periodontal ligament are available. Although there has been controversy over the distribution and shape of the sensory nerve terminals, researchers largely agree on the presence of two types of nerve endings: free endings and organized structures as Ruffini-like and Meissner corpuscles. Ruffini-like are slowly adapting receptors and give informations about the intensity and duration of the mechanical stimulus applied to the periodontal ligament; Meissner’s corpuscles are rapidly adapting receptors and give informations about direction of mechanical stimuli to the tissue. In the present study we investigated, by immunofluorescence for protein gene product PGP 9.5, the distribution of nerve endings among the different regions of periodontal ligament both of incisors and molars of rat. We found a variety of nerve endings morphology and several difference about their distribution between incisors and molars periodontal ligament. Moreover, we found that the morphology of nerve endings changes depending on the modification of the force applied to periodontal ligament, highlighting its importance in regulation of muscle activity.

Distribution of Nerve Endings in Human Distal Interphalangeal Joint and Surrounding Structures

To examine the distribution of encapsulated nerve endings called mechanoreceptors in the human distal interphalangeal (DIP) joint and surrounding structures. We processed 12 right index finger DIP joints and surrounding structures from fresh cadavers for immunohistochemistry of the anti-protein gene product 9.5 (PGP9.5) and silver staining to detect encapsulated nerve endings. Serial transverse sections were cut throughout the whole specimen and divided into 3 regions along the longitudinal axis: distal, middle, and proximal. Each of the transverse sections was partitioned into dorsal capsule (DC), radial capsule (RC), ulnar capsule (UC), volar plate (VP), and radial and ulnar assemblage nuclei (RAN and UAN); the RAN and UAN are located on both the radial and ulnar side of the VP. The C3 pulley contained the proximal region of the RAN and UAN, whereas the A5 pulley contained the middle and distal. The accessory collateral ligament contained all the regions of the RAN and UAN. We analyzed and compared the density of encapsulated nerve endings among the 18 different regions. According to the modified Freeman and Wyke classification, we identified type I (eg, Ruffini-like endings) and type II (eg, Pacini-like endings) nerve endings. The density of type II nerve endings in the proximal region of the RAN and UAN was considerably higher than that in the proximal region of the VP, RC, UC and DC, and that in the proximal region of the VP, RC, UC, and DC, respectively. Our examination of the distribution of type I and type II nerve endings provides new information on the sensory systems of the DIP joints and surrounding structures.

Distribution of Nerve Endings in the Human Proximal Interphalangeal Joint and Surrounding Structures

To examine the distribution of encapsulated nerve endings called mechanoreceptors in the human proximal interphalangeal (PIP) joint and surrounding structures. We processed 12 right index finger PIP joints and surrounding structures from fresh and dissecting-room cadavers for immunohistochemistry of the anti-protein gene product 9.5 and silver staining to detect encapsulated nerve endings. Serial transverse sections were cut throughout the whole specimen and divided into 3 regions along the longitudinal axis: distal, middle, and proximal. Each of the transverse sections was partitioned into dorsal capsule (DC), radial capsule (RC), ulnar capsule (UC), volar plate (VP), radial assemblage nuclei (RAN), and ulnar assemblage nuclei (UAN); the RAN and UAN are located on the radial and ulnar side of the VP. The C1 pulley contained the proximal region of the RAN and UAN, whereas the A3 pulley contained the middle and distal regions. The accessory collateral ligament contained all the regions of the RAN and UAN. The densities of encapsulated nerve endings in these 18 different regions were analyzed and compared. According to the modified Freeman and Wyke classification, type I (Ruffini-like endings) and type II (Pacini-like endings) nerve endings were identified. The density of type I nerve endings in the proximal region of the VP was substantially higher than that in the proximal region of the RAN, UAN, RC, UC, and DC. The density of type II nerve endings in the proximal region of the RAN and UAN was substantially higher than that in the proximal region of the VP, RC, UC and DC, and that in the proximal region of the VP and DC, respectively. Our examination of the distribution of type I and type II nerve endings provides information on the sensory systems of the PIP joints and surrounding structures.

Distribution of Nerve Endings in the Human Dorsal Radiocarpal Ligament

The purpose of this investigation was to evaluate the nerve-ending apparatus populations within a large number of adult human dorsal radiocarpal (DRC) ligaments to test the hypothesis that the majority of nerve endings could be grouped into established classifications and that the nerve endings could be found in predictable locations within the substance of the ligament. The DRC ligaments were harvested from 20 wrists of 10 fresh cadavers with an average age of 75.6 years within 12 to 18 hours of death. Before the tissues were harvested, radiographs were taken to exclude any arthritic conditions of the wrists. Tissues were fixed, sectioned with a cryostat, and serial sections were collected on glass slides. Slides were processed for fluorescence immunohistochemistry using antibody to protein gene product 9.5 and a secondary antibody conjugated to a fluorescent tag (Alexa Fluor 488). The sections were evaluated with an LSM-510 confocal laser microscope and a Kontron KS 400 image analyzer. Labeled nerve endings were counted, mapped, and reconstructed. The average number of nerve endings in each DRC ligament was 10.1+/-4.7. More than 76% of the nerve endings were found in the 2 ends of the ligament with 23.3% in the central third and approximately 80% distributed in the superficial layer. More than 80% of the nerve endings were discovered in the epiligamentous sheath rather than in the perifascicular spaces. The distribution of the nerve endings follows a consistent pattern. These results will provide a foundation of morphologic information useful in understanding normal and abnormal neural control of wrist joint mechanics.

Effects of anterior lumbar spinal fusion on the distribution of nerve endings and mechanoreceptors in the rabbit facet joint: quantitative histological analysis

AbstractThe purpose of this study was to investigate the density and distribution of neural endings in rabbit lumbar facet joints after anterior spinal fusion and to evaluate the effects of intervertebral immobilization. An extraperitoneal approach was applied, and L5/6 was fixed with a plate and screws. Bilateral L4/5, L5/6, and L6/7 facet joint capsules were harvested from the rabbits 4, 8, and 16 weeks postoperatively. Capsular tissues were processed using a modified gold chloride staining method, and the specimens were sliced into 15-μm sections. All sections were analyzed microscopically, and neural ending numbers per unit volume were calculated. Three types of neural ending were identified in each specimen: Pacinian corpuscles, Ruffini corpuscles, and free nerve endings. In the L5/6 fusion segment there was a significant decrease in the number of Pacinian corpuscles at 4 weeks and of Ruffini corpuscles at 4, 8, and 16 weeks after the fusion compared with the control; and in the L4/5 upper adjacent segment there was a significant increase in the number of free nerve endings. The number of Ruffini endings for the L6/7 lower adjacent segment was significantly lower more than 8 weeks after the fusion. These results suggest that immobilization of the intervertebral segment causes a reduction in the number of mechanoreceptors in the facet joint capsules because of the reduction in mechanical stimulation. Moreover, in the upper adjacent facet joint there may be neural sprouting caused by nociceptive stimulation.

Morphology and distribution of nerve endings in the human triangular fibrocartilage complex

We studied the morphology and distribution of nerve endings in the human triangular fibrocartilage complex using both silver staining and immunohistochemical staining using a protein specific to nerve fibres. Free nerve endings were found in the ulnar side of the triangular fibrocartilage complex, especially in the ulnar collateral ligament, meniscus homologue and the adjacent collagen fibre area of the peripheral part of the ulnar side of the articular disc. Meissner's and Krause's corpuscles were observed in the ulnar collateral ligament and meniscus homologue. The fact that free nerve endings were observed in the meniscus homologue and adjacent collagen fibre area of the peripheral part of the ulnar side of the articular disc suggests that this disc may be a source of wrist pain. The presence of nerve end bulbs in the triangular fibrocartilage complex also suggests a possible role for corpuscles as mechanoreceptors.

Occurrence of epidermal nerve endings in glabrous and hairy skin of the rat foot after sciatic nerve regeneration.

The occurrence and distribution of intraepidermal nerve endings in hairy and glabrous skin of the rat foot was examined in normal cases and three months after sciatic neurotomy/suture or a crush lesion. The nerve endings were visualized in cryostate sections with antibodies against protein gene product 9.5. Normal glabrous skin exhibited 23.3 endings/mm length. Neurotomy/suture cases had 6.1 endings/mm. In rats with nerve crush injury the occurrence was normal, but the intraepidermal nerve endings tended to be abnormally short and occurred mainly in the basal layer of the epidermis. In sections from hairy skin countings were not possible. Subjective evaluation indicated that the occurrence of dermal and epidermal axon profiles usually was very deficient after neurotomy/suture and essentially normal after crush. Skin samples from the contralateral side of operated animals showed a normal occurrence and distribution of nerve endings. We also noted that cases subjected to neurotomy/suture showed increased numbers of protein gene product 9.5-immunoreactive intraepidermal cells and an abnormally thin epidermis. We suggest that a highly deficient occurrence of intraepidermal nerve endings may be one factor behind the unsatisfactory restitution of the sensory function of the hand typically seen in patients subjected to neurotomy and suture.

Effect of cholecystokinin-octapeptide on dopamine release from slices of cat caudate nucleus

The cat caudate nucleus has been reported to possess a rich and fairly even distribution of nerve endings, containing both dopamine- and cholecystokinin-like peptides. In this study, the effect of cholecystokinin-octapeptide (CCK-8) on basal and electrically evoked tritium outflow from slices of cat caudate nucleus previously labeled with [3H]dopamine was examined. Evoked tritium outflow from slices of cat caudate nucleus was Ca2+ dependent and abolished by tetrodotoxin, suggesting that it reflects action potential-induced [3H]dopamine release. In the presence of bovine serum albumin and bacitracin, the sulfated but not the unsulfated form of CCK-8 inhibited both basal and electrically evoked tritium outflow from slices of cat caudate nucleus at very low concentrations. CCK-8 sulfate was efficient in causing this effect in concentrations down to 10(-14) M, and the maximum effect was obtained with 10(-11) M. In contrast, without bovine serum albumin and bacitracin, no inhibitory effect of CCK-8 sulfate was seen, but instead, a marked enhancement of tritium outflow at 10(-7) M was observed. The findings suggest that CCK-8 sulfate in dopamine/CCK coexistence regions is involved in regulating dopamine release.

Activation of groups III and IV sensory units in medial articular nerve by local mechanical stimulation of knee joint.

Activation of groups III and IV sensory units in medial articular nerve by local mechanical stimulation of knee joint.H G Schaible, and R F SchmidtH G Schaible, and R F SchmidtPublished Online:01 Jan 1983https://doi.org/10.1152/jn.1983.49.1.35MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByRole of TRPV1 in acupuncture modulation of reflex excitatory cardiovascular responsesZhi-Ling Guo,* Liang-Wu Fu,* Hou-Fen Su, Stephanie C. Tjen-A-Looi, and John C. Longhurst1 May 2018 | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, Vol. 314, No. 5Subtypes of nociceptive units in the rat temporomandibular jointBrain Research Bulletin, Vol. 61, No. 6Effects of anterior lumbar spinal fusion on the distribution of nerve endings and mechanoreceptors in the rabbit facet joint: quantitative histological analysisJournal of Orthopaedic Science, Vol. 8, No. 4Functional maturation of periodontal mechanoreceptors during development in ratsDevelopmental Brain Research, Vol. 139, No. 2Chemical responsiveness and histochemical phenotype of electrophysiologically classified cells of the adult rat dorsal root ganglionNeuroscience, Vol. 115, No. 1How do you feel? Interoception: the sense of the physiological condition of the bodyNature Reviews Neuroscience, Vol. 3, No. 8Responses of Spinothalamic Lamina I Neurons to Maintained Noxious Mechanical Stimulation in the CatD. Andrew, and A. D. Craig1 April 2002 | Journal of Neurophysiology, Vol. 87, No. 4Subclassified Acutely Dissociated Cells of Rat DRG: Histochemistry and Patterns of Capsaicin-, Proton-, and ATP-Activated CurrentsJeffrey C. Petruska, Jintana Napaporn, Richard D. Johnson, Jianguo G. Gu, and Brian Y. Cooper1 November 2000 | Journal of Neurophysiology, Vol. 84, No. 5Mechanosensitive Afferent Units in the Shoulder and Adjacent TissuesClinical Orthopaedics and Related Research, Vol. 369Patient-controlled Analgesia in the Total Joint Arthroplasty PatientClinical Orthopaedics and Related Research, Vol. 335Neuroanatomy of the Pain System and of the Pathways That Modulate PainJournal of Clinical Neurophysiology, Vol. 14, No. 1The involvement of substance P and neurokinin-1 receptors in the responses of rat dorsal horn neurons to noxious but not to innocuous mechanical stimuli applied to the knee jointBrain Research, Vol. 666, No. 2Effects of a carrageenan-induced inflammation in rabbit lumbar facet joint capsule and adjacent tissuesNeuroscience Research, Vol. 20, No. 4Afferent and spinal mechanisms of joint painPain, Vol. 55, No. 1Ankle joint (artc. intertarsalis) receptors in the domestic fowlNeuroscience, Vol. 49, No. 4Topical anesthetic-induced improvements in the mobility of patients with muscular hypertonicity: Preliminary resultsJournal of Electromyography and Kinesiology, Vol. 1, No. 1Capsaicin inhibits responses of fine afferents from the knee joint of the cat to mechanical and chemical stimuliBrain Research, Vol. 530, No. 1Spinal sensorimotor systems and their supraspinal controlNeuroscience Research, Vol. 7, No. 4Response of hip joint afferent fibers to pressure and vibration in the catNeuroscience Letters, Vol. 90, No. 1-2Convergent inputs from articular, cutaneous and muscle receptors onto ascending tract cells in the cat spinal cordExperimental Brain Research, Vol. 66, No. 3Enhancement of the responses of ascending tract cells in the cat spinal cord by acute inflammation of the knee jointExperimental Brain Research, Vol. 66, No. 3Opiates inhibit the discharges of fine afferent units from inflamed knee joint of the catNeuroscience Letters, Vol. 76, No. 1Activation of fine articular afferent units by bradykininBrain Research, Vol. 327, No. 1-2Reactions of cardiac postganglionic sympathetic neurons to movements of normal and inflamed knee jointsJournal of the Autonomic Nervous System, Vol. 12, No. 1Changes in blood pressure and heart rate induced by movements of normal and inflamed knee jointsNeuroscience Letters, Vol. 52, No. 1-2Discharge characteristics of fine medial articular afferents at rest and during passive movements of inflamed knee jointsBrain Research, Vol. 272, No. 1Types of afferents from the knee joint evoking sympathetic reflexes in cat inferior cardiac nervesNeuroscience Letters, Vol. 39, No. 1 More from this issue > Volume 49Issue 1January 1983Pages 35-44 https://doi.org/10.1152/jn.1983.49.1.35PubMed6827302History Published online 1 January 1983 Published in print 1 January 1983 Metrics

Properties of Ruffini afferents revealed by stress analysis of isolated sections of cat knee capsule.

Properties of Ruffini afferents revealed by stress analysis of isolated sections of cat knee capsule.P Grigg, and A H HoffmanP Grigg, and A H HoffmanPublished Online:01 Jan 1982https://doi.org/10.1152/jn.1982.47.1.41MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByProprioceptive changes in the contralateral knee joint following anterior cruciate injuryThe Bone & Joint Journal, Vol. 95-B, No. 2Hamstring and Quadriceps Strength Balance in Normal and Hamstring Anterior Cruciate Ligament-Reconstructed SubjectsClinical Journal of Sport Medicine, Vol. 14, No. 5Encoding of tensile stress and strain during stretch by muscle mechano-nociceptors1 January 2004 | Muscle & Nerve, Vol. 30, No. 2Integrin α2β1 affects mechano-transduction in slowly and rapidly adapting cutaneous mechanoreceptors in rat hairy skinNeuroscience, Vol. 129, No. 2Knee joint proprioception in ACL-deficient knees is related to cartilage injury, laxity and ageA retrospective study of 54 patients8 July 2009 | Acta Orthopaedica Scandinavica, Vol. 75, No. 1Effects of anterior lumbar spinal fusion on the distribution of nerve endings and mechanoreceptors in the rabbit facet joint: quantitative histological analysisJournal of Orthopaedic Science, Vol. 8, No. 4Encoding of Compressive Stress During Indentation by Group III and IV Muscle Mechano-Nociceptors in Rat Gracilis MuscleWeiqing Ge, and Partap S. Khalsa1 February 2003 | Journal of Neurophysiology, Vol. 89, No. 2Reflex muscle contractions can be elicited by valgus positional perturbations of the human kneeJournal of Biomechanics, Vol. 36, No. 2Encoding of Compressive Stress During Indentation by Slowly Adapting Type I Mechanoreceptors in Rat Hairy SkinWeiqing Ge, and Partap S. Khalsa1 April 2002 | Journal of Neurophysiology, Vol. 87, No. 4Proprioception of the Ankle: A Comparison Between Female Teenaged Gymnasts and Controls26 June 2016 | Foot & Ankle International, Vol. 23, No. 2Role of Proprioception in Pathoetiology of Shoulder InstabilityClinical Orthopaedics and Related Research, Vol. 330Selective muscle activation following rapid varus/valgus perturbations at the kneeMedicine &amp Science in Sports &amp Exercise, Vol. 28, No. 7Knee effusion and quadriceps muscle strengthClinical Biomechanics, Vol. 9, No. 6Loading and deformation of the cat posterior knee joint capsule in axial and extension rotationsJournal of Biomechanics, Vol. 26, No. 11Peripheral projections of calretinin-immunoreactive primary sensory neurons in chick hindlimbsBrain Research, Vol. 622, No. 1-2Role of knee ligaments in proprioception and regulation of muscle stiffnessJournal of Electromyography and Kinesiology, Vol. 1, No. 3A neurosensory hypothesis of ligament functionMedical Hypotheses, Vol. 29, No. 4Sensory nerve endings in the cat cruciate ligaments: A morphological investigationNeuroscience Letters, Vol. 102, No. 1Proprioception in the anterior cruciate deficient knee23 April 2016 | The American Journal of Sports Medicine, Vol. 17, No. 1Response of hip joint afferent fibers to pressure and vibration in the catNeuroscience Letters, Vol. 90, No. 1-2A microprocessor-based tissue displacement monitor for in vitro quantification of knee capsule deformationJournal of Neuroscience Methods, Vol. 10, No. 2A method for measuring strains in soft tissueJournal of Biomechanics, Vol. 17, No. 10Parallel processing of somatosensory information: A theoryBrain Research Reviews, Vol. 6, No. 1Functional performance of the knee after intraarticular anesthesia23 April 2016 | The American Journal of Sports Medicine, Vol. 11, No. 4 More from this issue > Volume 47Issue 1January 1982Pages 41-54 https://doi.org/10.1152/jn.1982.47.1.41PubMed7057224History Published online 1 January 1982 Published in print 1 January 1982 Metrics

Properties of nerve endings with small granular vesicles in the distal colon and rectum of the guinea-pig

The appearance and distribution of nerve endings (varicosities) containing small granular vesicles have been studied in the distal colon and rectum of the guinea-pig with the electron microscope. Two types of varicosity were recognised. They were distinguished by differences in their synaptic vesicles and in their distribution in the layers of the gut wall. The first type resembled noradrenergic nerves in having predominantly (92%) small vesicles and few (8%) large granular vesicles (90 nm diameter). This type was common in the plexuses and at the medial-adventitial border of arteries and arterioles but was sparsely distributed in the muscle coat. The second type had a lower proportion of small vesicles (69%) and a higher proportion (31%) of large granular vesicles (132 nm diameter). This type was absent in Auerbach's plexus, well represented in the muscle coat and Meissner's plexus and not associated with blood vessels. The first type was labelled with 5-hydroxydopamine, a specific marker for noradrenergic nerves, and disappeared after extrinsic denervation. a procedure which causes degeneration of noradrenergic nerves in the gut. The second type was unaffected by 5-hydroxydopamine and extrinsic denervation. It is concluded that the two types of small granular vesicle-containing varicosities belong to different axons and that the first type is noradrenergic. The second type of nerve axon has not been described in the gut before and is intrinsic to it. From the distribution and numbers of these axons in the circular muscle it would seem that they play an important role in gut motility.

Morphology and distribution of organized sensory nerve endings in the mandibular periosteum of the cat

The mandibular periostea of the labial-buccal and the lingual side of thecat were stained by the methylene blue immersion method and mounted wholly. The morphology and distribution of the nerve endings were studied with a light microscope.In the mandibular periostem, there were free nerve endings and two kinds of organized sensory nerve endings, bush-like nerve endings and small encapsulated corpuscles. The bush-like nerve endings were various in shape and size and not covered with capsule. The nerve fibers of these endings were 2.5-6.0μ in diameter. The small encapsulated corpuscles were almost oval in shape, 46-114μ in length and had a simple or branched axon. The fiber diameter of these endings were 2.5-7.5μ.Whereas the distribution area of the free nerve endings and the bush-like nerve endings extended throughout the periosteum, the small encapsulated corpuscles were localized in the anterior part of the labial side. The number of the bush-like nerve endings per half mandible was 137-423, and that of the small encapsulated corpuscles 31-79.Results of this experiment showed that, along with the organizing of the nerve ending, its fiber increases in dimeter, its number per idividual decreases and itdistribution localizes so as to receive external stimulation easily.

A functional taxonomy of epidermal appendages in mice based on the distribution of nerve endings.

AbstractExisting data on integumental nerve endings provide a basis for classification of the visible epidermal appendages (hairs and dermatoglyphic pads) in mice. Hairs that have long tips (tylotrichs and bristles) are surrounded by large encapsulated cylinders of coarse nerve fibers. Half of these hairs (tylotrichs) are associated with disk‐shaped dermatoglyphic pads, which contain innervated Merkel cells. Hairs that have short tips are surrounded by small cylinders of fine nerve fibers, but contiguous dermatoglyphic pads and dermal capsules are missing. Constrictions in the shafts of short‐tipped hairs vary unpredictably and are not readily correlated with nerve endings.Analysis of the distribution, structure and physiology of nerve endings and dermatoglyphic pads makes possible (1) the recognition of meaningful features of hair structure (e.g., contour of the tip) that are involved in the transmission of mechanical energy to tactile receptors, and (2) the disregard of equivocal features of hair structure (e.g., 1 constriction in the shaft), which vary between the sexes, among body regions and among inbred strains.

A study of the terminal innervation of a fast-acting fish muscle.

1. Histochemical localization of the enzyme, acetylcholinesterase (AChE) methylene blue perfusion, and gold chloride were employed in studying the motor nerve innervation of the intrinsic striated muscle located in the wall of the swimbladder of the toadfish, Opsanus tau.2. A plexiform pattern of multiple innervation was revealed.3. Both preterminal nerve fibers and nerve terminals showed acetylcholinesterase activity.4. A wide variation of shape, size and distribution of nerve endings was seen. The endplates ranged from 2 µ to 70 µ in length and were spaced from 20 µ to 480 µ along a muscle fiber.

Advances in the Neurophysiology and Neuroanatomy of the Cochlea

This review deals with a few selected areas in which significant advances have recently been made or are being made. The topics relate to the origin and significance of the dc polarization of scala media of the cochlea, to the variety and distribution of nerve endings, to the possible peripheral effects of the efferent nerve fibers, and to the pattern of activity of individual fibers of the auditory nerve.

Distribution of Nerve Endings in the Pulmonary Artery of the Cat

The density distribution of nerve endings in the wall of the extrapulmonary portion of the cat's pulmonary artery was studied in serial sections after staining by a supravital methylene blue procedure. The greatest concentration of endings occurred at the bifurcation, in the adjacent parts of the pulmonary artery, and in its right and left main branches. The morphology and distribution of these endings is consistent with a pressoreceptor function.