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PubMed1990

Sensory nerve endings in puborectalis and anal region: normal findings in the newborn and changes in anorectal anomalies.

This study was carried out in five full-term newborn babies and 11 patients with anorectal anomalies (five of whom had high deformity, five had intermediate, and one had low), using the modified Bielschowsky method. The following four kinds of sensory nerve ending were found: muscle spindle in the puborectalis and the external anal sphincter, Pacinian corpuscle in the plane between the internal anal sphincter and the external anal sphincter and in the presacral space, globular ending in the presacral space, and free nerve ending in the epithelium of the anal canal and in the perianal skin. It was found that there were significantly fewer muscle spindles in the puborectalis and many fewer Pacinian corpuscles and globular endings in the presacral space of high and intermediate deformities than normal. No spindle was found in the external sphincteric muscles of the deformities. On the other hand, the Pacinian corpuscles and the globular endings of high and intermediate deformities lagged behind normal in development. The densities of the nerve bundles in the subepidermis and the nerve fibers in the dermis of perineal region in high and intermediate deformities were much lower than normal, and the decrease in density corresponded to the levels of the rectal pouch. The observation showed that the agenesis of sensory nerve endings in the puborectalis and the anal region was one of the most significant pathological features in high and intermediate types of anorectal anomalies, and might be responsible for the abnormalities of the reflex of the anal sphincter and the anal sensation in such patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Canal↗
PubMed1979

Detection of tactile stimuli. Thresholds of afferent units related to psychophysical thresholds in the human hand.

1. Psychophysical thresholds were determined at 162 points in the glabrous skin area of the human hand when slowly rising, triangular indentations of controlled amplitudes were delivered with a small probe. The method of constant stimuli was used with either the two alternative forced choice or the yes-no procedure. It was found that the distribution of the psychophysical thresholds varied with the skin region. Thresholds from the volar aspect of the fingers and the peripheral parts of the palm were low and their distribution was unimodal with a median of 11.2 micrometers. In contrast, there was an over-representation of high thresholds when observations from the centre of the palm, the lateral aspects of the fingers and the regions of the creases were pooled, and the distribution was slightly bimodal with a median of 36.0 micrometers. 2. Nerve impulses were recorded from single fibres in the median nerve of human subjects with percutaneously inserted tungsten needle electrodes. The thresholds of 128 mechanosensitive afferent units in the glabrous skin area of the hand were determined when stimuli were delivered to partly the same points as stimulated for the assessment of the psychophysical thresholds. Of the four types of units present in this area the Pacinian corpuscle (PC) and rapidly adapting (RA) units had the lowest thresholds with medians of 9.2 and 13.8 micrometers, followed by the slowly adapting type I and slowly adapting type II units with medians of 56.5 and 33.1 micrometers. There was no indication of a difference between thresholds of units located in different skin areas. 3. In the region of low psychophysical thresholds there was good agreement between the thresholds of the rapidly adapting and Pacinian corpuscle units and the psychophysical thresholds, particularly at the lower ends of the samples. In the skin regions of high thresholds, on the other hand, practically all psychophysical thresholds were higher than the thresholds of the most sensitive afferent units. Moreover, simultaneous recording of nerve impulses during a detection task indicated that subjects did not detect stimuli strong enough to elicit several impulses in afferent units in this region. 4. Circumstantial evidence led to the conclusion that detection was dependent on one impulse in one or a few rapidly adapting units under optimal conditons in the region of low psychophysical thresholds, whereas it seemed unlikely that activity in Pacinian corpuscle units was crucial. 5. The findings are consistent with the interpretation that human subjects are able to detect an input consisting of a single impulse in a single rapidly adapting unit.

Adolescent↗
PubMed1975

Human middle ear corpuscles -- A light and electron microscopic study.

The human middle ear corpuscles originally described by von Troeltsch are examined by means of light microscopy in 124 subjects, and electron microscopy in 27 subjects. While the corpuscles are not observed in all 19 individuals under age six, and in all 20 adults who had a history of suppurative otitis media, an average of six corpuscles per temporal bone is found in 98 percent of 83 adult subjects who had no history of middle ear disease. Two-thirds of the corpuscles are located in the mastoid, and the remainder in the middle ear. Often, they become bifurcated or trifurcated. Although light microscopy shows that the corpuscle is formed by lamellar capsules and a central core resembling pacinian corpuscles, electron microscopic study failed to confirm that this structure is a typical pacinian corpuscle. Subsequently, possible physiological significance of this corpuscle is discussed.

Adolescent↗
PubMed1976

Innervation of the synovial membrane of the cats joint capsule.

Results of investigations on the occurrence of nerve fibres and endings in the synovial membrane of the knee and elbow joint in the cat are reported. The stratum synoviale contains only autonomic fibres, running in the adventitia of arteries. Free nerve endings are lacking in the stratum synoviale. Simple Pacinian corpuscles with an inner core are occasionally observed in the border zone between the stratum synoviale and fibrosum. The ultrastructure of these endorgans resembles that of Pacinian corpuscles in the hairless and hairy skin of the cat.

Animals↗
PubMed1993

Structural and histochemical similarities in three principal sites of sensory axons with the presence of excitable activities.

In the present paper the ultrastructural similarities among the terminal portions of Pacinian corpuscles, the nodes of Ranvier, and the initial segments of primary sensory neurons are pointed out. Our conclusion is based on our observations of cat Pacinian corpuscles and other general knowledge of the node of Ranvier and the initial segment published elsewhere. The morpho-functional similarities of three principal excitable regions of the sensory nerve fibres (the initial segments, the node of Ranvier, and the terminal portions of sensory nerve formations) are illustrated by identical distribution of the enzymes which are associated with ionic transport (alkaline phosphatase, Mg(2+)-ATPase), and non-specific cholinesterase. Furthermore, the polyanionic material revealed by Alcian blue staining in three excitable sites of the sensory axon confirms the supposition that excitable axolemma cannot be considered in the isolation of its surroundings produced by Schwann cells.

Animals↗
PubMed1994

Immunohistochemical localization of calcium-binding proteins in the human cutaneous sensory corpuscles.

The localization of the calcium-binding proteins (CaBP) calbindin-D28k (CB), parvalbumin (PV) and S-100 protein (S100P) in the human cutaneous sensory corpuscles was studied by immunohistochemical procedure using monoclonal antibodies. Occurrence of CB, PV and S100P immunoreactivity (IR) was observed in the lamellar cells of Meissner's corpuscles. In the pacinian corpuscles, S100P IR was restricted to the inner-core cells whereas CB and PV IR were found labelling the axon, inner core, outer core and capsule. At the light-microscope level of resolution, the presence of IR in the axon of Meissner's corpuscles cannot be ensured. Since calcium ions (Ca2+) seem to participate in the mechanoreceptor electrogenesis, present results suggest that CaBP could be involved in buffering and/or transport of Ca2+ within the specialized cells surrounding the axon tips of sensory corpuscles, thus, maintaining the periaxonal microenvironment.

Adult↗
PubMedDate not supplied

[Peripheral nerve lesions of experimental leprosy in monkeys. V. Histopathological finding of cutaneous nerves and cutaneous sensory organs].

The skin samples of each palm side and dorsum side of finger, nose and peripheral nerves running under the finger skin at the area between proximal phalanx and distal phalanx of mangabey monkey A022 and rhesus monkey A125 were studied by histopathological methods (semithin section and light microscopic findings). Results found about this study were as follows. 1. In spite of the existence of a large amount of leprosy bacilli at the areas of corium and subcutis, some of Meissner's corpuscles, Vater-Pacinian corpuscles (or Golgi-Mazzoni's corpuscles) and Krauze's end bulbs-like structures were observed. 2. Occasionally, several intracytoplasmic foamy structures containing a large amount of leprosy bacilli were observed at the shallow and deep layers of stratum papillare of corium, where leprosy bacilli were not so remarkable as shown on Figure 4. So, it was thought that the affinity of leprosy bacilli to free nerve endings should be exist there. 3. Some of M. arrector pili were kept in good condition in spite of the existence of multiplying leprosy bacilli around the hair follicles. 4. It was thought that the histopathological findings of the fascicles of cutaneous nerves were classified to 4 patterns. The first pattern of histopathological finding of the cutaneous nerve was shown as A on Figure 25. In this pattern observed in almost of all the fascicles locating at the subcutis, no leprosy bacillus was observed inside the fascicles, and the nerve fibers were kept in good condition. The second pattern observed in almost of all the fascicles located at the corium, was shown as B on Figure 25. In this pattern, a large amount of leprosy bacilli were observed inside the fascicles, and the nerve fibers were often kept in good condition. The third pattern observed in almost of all the fascicles located at the deep layer of corium and subcutis, was shown as C on Figure 25. In this pattern, not only multiplying leprosy bacilli but also remarkable fibrosis were found inside one fascicle, and many nerve fibers disappeared by the existence of the bacilli and fibrosis. The final pattern observed in almost of all the fascicles located at the deep layer of corium and subcutis, was shown as D on Figure 25. In this pattern, remarkable fibrosis was observed inside the fascicles, and the nerve fibers often disappeared by the existence of fibrosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1978

Effect of vagotomy on the afferent innervation of cat pancreas.

The afferent innervation of the pancreas was studied with Holme's silver technique in normal and vagotomized cats 24, 48 and 72 hours after sectioning the vagus. Pacinian corpuscles were found in the interlobular and periductal connective tissue. After right vagotomy, degenerative changes were noticed among some of the nerve fibres entering the formation of the perivascular, periacinar, peri-insular and periductal plexuses. Moreover, degenerative changes were noticed in most of the Pacinian corpuscles while others remained unaffected, thus denoting that the right vagus was not the only pathway of the afferent nerve fibres from the pancreas and probably the left vagus contributed in that domain.

Animals↗
PubMed1988

Neurohistology of lumbar spine ligaments.

A study was conducted to identify neural elements in the posterior ligaments of the lumbar spine by using a modified gold-chloride method. Three morphologic types of mechanoreceptors were identified: Ruffini corpuscles, Ruffini end organs, and pacinian corpuscles. Free nerve endings, which are thought to be responsible for pain production, were also demonstrated within the ligaments.

Adolescent↗
PubMed1977

Inhibition of cuneate neurones: its afferent source and influence on dynamically sensitive "tactile" neurones.

1. Responses were recorded in decereberate, unanaesthetized cats from individual cuneate neurones in order to determine firstly, the afferent sources of inhibition on cuneate neurones and secondly, the influence of afferent-induced inhibition on those response features of dynamically sensitive tactile neurones which determine their capacity to code information about parameters of tactile stimuli.2. For all cuneate neurones which displayed afferent-induced inhibition from areas surrounding or within their excitatory receptive field (71% of the sample) it was consistently found that 300 Hz vibration at low amplitudes (< 25-50 mum) which selectively engages Pacinian corpuscles was an effective source of inhibition. In contrast, steady indentation which activates slowly adapting tactile afferents was quite ineffective, as was low frequency vibration (30 Hz) at amplitudes of < 50-100 mum. The latter stimulus can be used to engage rapidly adapting receptors either within glabrous skin (presumed to be Meissners corpuscles) or in association with hair follicles. It is concluded that afferents from Pacinian corpuscles are the dominant or exclusive source of afferent-induced inhibition of cuneate neurones.3. For dynamically sensitive neurones responsive to low frequency cutaneous vibration (30 Hz) there was a reduction in the slope of stimulus-response relations with afferent-induced inhibition, but no expansion of the range of stimulus amplitudes over which the neurone responded.4. The influence of afferent-induced inhibition on the phase-locking of impulse activity to a cutaneous vibratory wave form was examined by constructing post-stimulus time histograms and cycle histograms. Measures of dispersion of impulse activity around the preferred point of firing in the vibratory waveform indicated that the capacity of individual cuneate neurones to code information about the frequency of the cutaneous vibration was not systematically changed in the presence of afferent-induced inhibition.

Adaptation, Physiological↗
PubMed1993

Examination of distal involvement in cisplatin-induced neuropathy in man. An electrophysiological and histological study with particular reference to touch receptor function.

Cisplatin is a widely used anti-neoplastic agent with dose-dependent sensory neuropathy as a major side-effect. The mechanism for the neuropathy is poorly understood; it may be caused by a lesion of the dorsal root ganglion cells or by a distal axonopathy. This distinction is important since regeneration in a neuronopathy is impossible, whereas recovery may occur if the axon is affected only distally. The most distal part of the sensory nerve fibre is, however, not accessible for conventional electrophysiological examination. To ascertain whether the distal receptor-associated part of the fibre is involved, we have used a method previously untested in patients with neuropathy. In 26 males treated with cisplatin for testicular cancer 3-6.5 years previously, and in 22 normal males, the compound sensory action potentials evoked by a tactile probe were recorded through needle electrodes placed close to the sural and median nerves. The responses were compared with action potentials evoked by electrical stimulation of the same nerves. Biopsies from the distal sural nerve at the dorsolateral aspect of the foot were obtained in three patients and in four subjects not treated with cisplatin. Sixteen patients had received a conventional dose (307-435 mg/m2) of cisplatin and 10 patients had received a high dose (553-1197 mg/m2). Two-thirds of the conventional dose patients and all the high dose patients had mild to severe sensory loss and reduced or absent tendon reflexes. The amplitude of the electrically evoked sensory action potential decreased with increasing dose of cisplatin and was correlated with the reduction of vibration sense. Tactile responses, probably originating mainly from Pacinian corpuscles, were, with the exception of two high dose patients, recorded from all sural and median nerves. The two high dose patients without a tactile response had a severely reduced or no electrically evoked response at the sural nerve. The sural nerve biopsies from high dose patients showed loss of large fibres; Pacinian corpuscles were obtained in two of these patients and contained normal axons. Our findings do not suggest that cisplatin causes a primarily distal lesion with sparing of more proximal parts of the peripheral nerve. We interpret the results as being consistent with a neuronopathy affecting primarily large sensory neurons. Brainstem and somatosensory evoked potentials and H-reflexes suggested that the spinal cord and brainstem were affected as well.

Action Potentials↗
PubMed1989

Mechano-receptors in the flexor tendons of the hand.

Flexor tendons of the hand obtained fresh at autopsy were studied histologically for free nerves and mechano-receptors. In addition to free nerves, Ruffini endings, Pacinian corpuscles and Golgi tendon organs were found throughout the tendons. Golgi tendon organs and Pacinian corpuscles were subjectively in greater numbers than Ruffini endings. The predominance of these two mechano-receptors indicates that position sense and kinetic activities of the fingers are well-served, as evidenced in hand movements.

Hand↗
PubMed2001

Neural anatomy of the transverse carpal ligament.

Carpal tunnel syndrome is one of the most commonly diagnosed disorders of the upper extremity. The etiology of the neuropathy is known to be associated with many disorders, with the etiology of carpal tunnel syndrome mainly attributable to ischemia of the median nerve. The purpose of this study was to determine the presence of neural elements within the transverse carpal ligament. Fourteen transverse carpal ligaments were harvested from seven male and seven female fresh frozen cadavers with an average age of 76 years. The tissues were stained with S-100 using a standard immunoperoxidase technique used to localize neural tissue. The transverse carpal ligament consisted of interwoven bundles of fibrous connective tissue. It was found to have an intraligamentous and extraligamentous neural network consisting mostly of free nerve endings and pacinian corpuscles. Ruffini's corpuscles were not identified. This study showed that there is neural innervation to the transverse carpal ligament. Pacinian corpuscles have been shown to be mechanoreceptors which respond to changes in joint position, whereas free nerve endings have been identified as nociceptors. Neural innervation were present in the transverse carpal ligament, and the nociceptive information relayed by these neural elements may contribute to the pain associated with carpal tunnel syndrome. In addition to being a mechanical wrist stabilizer, the transverse carpal ligament also may play a role in proprioception of the wrist.

Aged↗
PubMed1986

Vibration-evoked responses from lamellated corpuscles in the legs of kangaroos.

A group of lamellated corpuscles are present in the interosseous region of the legs of macropod marsupials. Structurally, they are similar to, but simpler than the Pacinian corpuscles of eutherian mammals, in having fewer lamellae. Responses of mechanoreceptors with axons coursing in the interosseous nerve were recorded from filaments, containing single functional units, dissected from the sciatic nerve of the wallaby Thylogale billardierii. The receptors were all maximally sensitive to stimuli applied in the interosseous region, where the cluster of lamellated corpuscles is located. Most units had low mechanical thresholds and were sensitive to sinusoidal vibration over a wide range of frequencies. Functional properties generally resembled those of eutherian Pacinian corpuscles, but the marsupial receptors were less rapidly adapting. The afferent nerve fibres conducted at 45 to 60 ms-1, while the diameter of axons in the osmium-stained interosseous nerve ranged between 7.5 and 12 micron. It is suggested that one important function of the receptors might be the detection of ground-borne vibration.

Adaptation, Physiological↗
PubMed2003

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

The 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-micro m 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.

Animals↗
PubMed1992

Neural elements in the human temporomandibular articular disc.

The purpose of this study was to determine the presence and describe the location of neural elements in the articular disc of the human temporomandibular joint. Six articular discs were obtained from three adult human subjects at autopsy. Four discs were cut into segments of known anterior-posterior orientation. The remaining two were processed intact. All tissues were stained in bulk with gold chloride, and frozen, sectioned on a sliding microtome at 70 to 100 microns, mounted on slides, dehydrated, and coverslipped. Nerve fibers were seen penetrating the discs from the pericapsular connective tissue. Structures resembling Ruffini endings, Pacinian corpuscles, and Golgi tendon organs were identified in the pericapsular connective tissue and within the disc. The population density of neural elements was the greatest at the periphery of the disc and progressively decreased towards the center, which was essentially devoid of them. The concentration of neural elements appeared to be greater at the anterior and posterior margins of the disc, with the greatest concentration being posteriorly. These findings support the theory that afferent nerves may arise from neural elements within the disc.

Adult↗
PubMed1992

Somatic afferent fibers which continuously discharge after being isolated from their receptors.

A previous study in our laboratory has shown that some afferent axons produce prolonged discharges after the axons have been completely isolated. We have attempted to identify the type of afferent fibers displaying such activity. Single unit activity was recorded from a filament dissected from the distal stump of the cut sural or plantar nerve of an anesthetized rat. After thorough identification of the receptor type, the nerve was cut at a site between the recording electrode and the receptive field, completely isolating the fiber being recorded. Unit activity was recorded up to 1 h after sectioning the nerve. Upon sectioning the nerve, most units showed brief injury discharges lasting only a few seconds. However, 21 of 70 units exhibited prolonged discharges lasting at least 30 min after having been isolated from their receptors. These 21 units included 8 slowly adapting type II cutaneous mechanoreceptors, 3 Pacinian corpuscles and 10 muscle spindle afferent units. These results suggest that prolonged injury discharges can be produced in the axons of the slowly adapting type II cutaneous mechanoreceptors, Pacinian corpuscles, and muscle spindle afferents. This phenomenon may have important clinical and experimental consequences.

Afferent Pathways↗
PubMed1980

[Splanchnic gall bladder mechanoreceptors (author's transl)].

The aim of the present paper is to study the electrophysiology of splanchnic gall bladder mechanoreceptors. The neurons unitary activity is recorded by means of glass extracellular microelectrodes implanted in the spinal ganglion (T6-L1). Two types of mechanoreceptors have been revealed by punctiform stimulations. 1. Muscular mechanoreceptors a) Slowly-adapting receptors, located in the whole biliary tract, sensitive to distension. b) Rapidly-adapting receptors, located in the gall bladder, recruited during the dynamic phases of stimulation. These receptors are connected with C fibers. II. Peritoneal Mechanoreceptors a) Pacinian corpuscles, located in the mesentery surrounding the biliary tract. b) Slowly-adapting receptors (movement receptors), located in the serosa of the gall bladder and the pericystic and pericholedochal peritoneum. Pacinian corpuscles are connected with A beta fibers, movement receptors with A gamma delta and B fibres.

Animals↗