家鸽Herbst小体对振动的反应特征

鸟类的Herbst小体是一种形态特殊的感觉性神经末梢器官.本文利用电生理学方法,研究了家鸽腿部胫骨-腓骨之间的Herbst小体对振动刺激的反应特征.这种小体对振动刺激非常敏感,当振动频率在600—800赫时,它们有反应的最低阈值约为0.3微米.不同的Herbst小体的反应阈值与频率的关系曲线表明:这种小体具有明显的带通滤波的特征,对振动反应的最佳频率范围为400—1000赫.在适宜频率、超阈值强度的振动刺激下,Herbst小体能以1:1的方式作出反应,即相对于每次正弦波振动刺激都有一个锁相的神经脉冲产生.在背根脊神经节内的细胞外记录表明:对振动敏感的神经节细胞具有和Herbst小体完全相似的反应特征.     

Analysis of the mechanism of amplitude change in Pacinian corpuscle receptor potential in a solution with a decreased calcium ion concentration

The effect of Ca2+-free solution on the amplitude increase in the receptor potential (RP) of Pacinian corpuscles was studied using external perfusion technique. The RP amplitude increased in Ca2+-free solution. It was blocked after addition of 10-20 mM of tetraethylamonium. A temporary increase in the RP amplitude is seen in the solution with 0.2 mM of 2.4-dinitrophenol. Sensitivity of the receptor membrane to mechanical stimuli does not change in Ca2+-free solution. It is suggested that near the mechanosensitive ionic canal of Pacinian corpuscle receptor membrane the fixed negative charges which could influence the "gate" system state of the mechanosensitive canal are absent.     

Differential Localization of Acid-Sensing Ion Channels 1 and 2 in Human Cutaneus Pacinian Corpuscles

Acid-sensing ion channels (ASICs) are the members of the degenerin/epithelial sodium channel (Deg/ENaC) superfamily which mediate different sensory modalities including mechanosensation. ASICs have been detected in mechanosensory neurons as well as in peripheral mechanoreceptors. We now investigated the distribution of ASIC1, ASIC2, and ASIC3 proteins in human cutaneous Pacinian corpuscles using immunohistochemistry and laser confocal-scanner microscopy. We detected different patterns of expression of these proteins within Pacinian corpuscles. ASIC1 was detected in the central axon co-expressed with RT-97 protein, ASIC2 was expressed by the lamellar cells of the inner core co-localized with S100 protein, and ASIC3 was absent. These results demonstrate for the first time the differential distribution of ASIC1 and ASIC2 in human rapidly adapting low-threshold mechanoreceptors, and suggest specific roles of both proteins in mechanotransduction.     

The number and kind of leukocytes in the saliva (salivary corpuscles) in healthy subjects and in patients]

In the form of a survey a report is given on the concept of the saliva corpuscle, its origin, composition, different degree of damage, its number and function. The quantitative behaviour enables a statement to be made about the actual unspecific cellular defence in parodontopathy (increased number of saliva corpuscles) and in various blood diseases (decreased number of saliva corpuscles. This has a particular diagnostic value.     

Ovoid geometry of the Pacinian corpuscle is not the determining factor for mechanical excitation

Static displacements in Pacinian corpuscles (PCs) were measured using video microscopy. Mechanical stimuli of 10-40 microm steps were applied to the PC capsule surfaces using cylindrical contacts with different diameters. Displacements parallel to the stimulation axis were measured at various locations in the focal plane of the optical setup. In contrast to previous data in the literature, the displacements within the corpuscle were found to be linearly related to the indentation amplitude. Displacements decreased as a function of lamella depth, with a more negative slope close to the surface and less negative slope at deeper locations. The experimental data were compared to the predictions of a previous mechanical model, and to the results of two new models: (1) elastic semi-infinite continuum model; (2) ovoid isotropic finite-element model. Although the previous model did not specify displacement boundary conditions, it predicted the current experimental results well. On the other hand, the experimental displacements were found to be smaller than those predicted by the semi-infinite continuum and finite-element models. However, both semi-infinite continuum and finite-element models yielded close results, which show that the three-dimensional ovoid geometry of the corpuscle is not the primary factor for determining the displacements in physiological conditions. Furthermore, simulations with the finite-element model using a wide range of material properties yielded similar results. This supports the hypothesis that a homogeneous isotropic model for the PC cannot predict experimental results. The modeling analyses suggest that the experimental results are largely affected by the displacement of the incompressible interlamellar fluid and the layered structure of the corpuscle.     

FINE STRUCTURE OF PACINIAN CORPUSCLES IN THE MESENTERY OF THE CAT

Pacinian corpuscles in the mesentery of adult cats were fixed with either glutaraldehyde, osmium tetroxide or permanganate solutions by close intra-arterial injection through the mesenteric artery, and were processed, after electron staining and Epon embedding, for electron microscopy. Better resolution of the corpuscle's ultrastructure was obtained than available heretofore. The myelinated segment of the corpuscle contains blood vessels separated from the axon by collagen fibers and 3 to 4 layers of lamellae. No blood vessels are found in the central core, though access from the vessels is afforded by diffusion through the "cleft" of the inner core. Two cell types are discernible in the inner core hemilamellae; the "clear cells" in which pinocytotic vesicles and organelles abound and reflect the greater metabolic activity of these cells, in contrast to the "dark cells." The ultraterminal is ellipsoidal in form with projections into the "cleft" which give this portion an irregular appearance in section. The terminal and ultraterminal are packed with mitochondria, and "synaptic" vesicles are seen in the ultraterminal. The innermost laminae of the inner core cells are in close apposition to the terminal and break their regular pattern of hemilamellation to surround the small ultraterminal projections at the apical part of the corpuscle.     

Macrophages in Pacinian corpuscles

The presence of macrophages in the outer bulb region of mouse, monkey and human Pacinian corpuscles was demonstrated by light and electron microscopy. In the normal, nontreated, Pacinian corpuscles, a few particular cells were located in the spaces between lamellae of the outer bulb. These cells contained numerous vesicles and vacuoles, and various cytoplasmic processes. When horseradish peroxidase (HRP) was injected locally or systemically, many HRP-positive cells, which were considered to be similar to the particular cells described above, were found in the outer bulb region of the corpuscles. Electron microscopy revealed that these cells contained HRP in vesicles and vacuoles, suggesting that they were macrophages vigorously taking up exogenous HRP. Macrophages in the Pacinian corpuscles are considered to work as scavengers to keep the inner environment of the corpuscles clear and constant with regard to its macromolecular content.     

Ovoid geometry of the Pacinian corpuscle is not the determining factor for mechanical excitation

Static displacements in Pacinian corpuscles (PCs) were measured using video microscopy. Mechanical stimuli of 10–40?µm steps were applied to the PC capsule surfaces using cylindrical contactors with different diameters. Displacements parallel to the stimulation axis were measured at various locations in the focal plane of the optical setup. In contrast to previous data in the literature, the displacements within the corpuscle were found to be linearly related to the indentation amplitude. Displacements decreased as a function of lamella depth, with a more negative slope close to the surface and less negative slope at deeper locations. The experimental data were compared to the predictions of a previous mechanical model, and to the results of two new models: () elastic semi-infinite continuum model; () ovoid isotropic finite-element model. Although the previous model did not specify displacement boundary conditions, it predicted the current experimental results well. On the other hand, the experimental displacements were found to be smaller than those predicted by the semi-infinite continuum and finite-element models. However, both semi-infinite continuum and finite-element models yielded close results, which show that the three-dimensional ovoid geometry of the corpuscle is not the primary factor for determining the displacements in physiological conditions. Furthermore, simulations with the finite-element model using a wide range of material properties yielded similar results. This supports the hypothesis that a homogeneous isotropic model for the PC cannot predict experimental results. The modeling analyses suggest that the experimental results are largely affected by the displacement of the incompressible interlamellar fluid and the layered structure of the corpuscle.     

Immunohistochemical localization of some extracellular molecules and their integrin receptors in the rat Pacinian corpuscles

The present results suggest that laminin-1 and 3 are localized in the specialized Schwann cells of Pacinian corpuscles, in spite of incomplete deposition of the basal lamina on the surface of their cytoplasmic processes. In addition, laminin-3 is concentrated and probably function as a stop protein not only in the neuromuscular junction, but also in the specialized Schwann cells enveloping the dendritic zone of the afferent axon. No significant changes of immunostaining for both laminins and their integrin receptors following denervation of Pacinian corpuscles indicate that their synthesis is independent to afferent axon as a prerequisite for successful reinnervation.     

Protein kinase C (alpha, beta, gamma) in Pacinian corpuscle.

Immunocytochemical demonstration of protein kinase C (PKC) subspecies (alpha, beta, gamma) was carried out in Pacinian corpuscles of rat hind feet using monoclonal or polyclonal antibodies against each of these subspecies. The inner core cells and lamellae and the Schwann cell cytoplasm of the nerve fiber innervating the corpuscle were strongly positive for PKC alpha-immunoreactivity (IR). In contrast, the axon terminal and the outer core did not display any positive alpha-IR. Very weak PKC beta-IR was detected in the ultraterminal region of the axon terminal, while the trunk region showed no immunoreactivity. Very faint PKC beta-IR was found also in the lamellar cells located at the periphery of the inner core and the endoneurial fibroblasts in the intermediate layer. PKC gamma-IR was not detected in any part of the corpuscle. The strong PKC alpha-IR in the inner core and the presence or absence of PKC alpha-, beta-, and gamma-IR in the axon terminal are discussed from the point of view of the functional aspects of each part.     

ELECTRON MICROSCOPY OF THE PACINIAN CORPUSCLE

The Pacinian corpuscle has a framework of cytoplasmic lamellae arranged concentrically in the outer zone, and bilaterally in the core. Between these is an intermediate growth zone. The inner core shows an unexpected complexity in that its component lamellae are arranged in two symmetrical groups of nested cytoplasmic sheets. Longitudinal tissue spaces form clefts separating the two groups. The perikarya of the core lamellae lie in or near the intermediate growth zone, and send arms into the clefts. The arms then branch and terminate as lamellae which interdigitate with those of neighboring cells. The single nerve fiber loses its myelin sheath just before it reaches the inner core but retains its Schwann cell cytoplasmic covering for a short additional distance. The Schwann sheath is not continuous with the lamellae of the inner core. Inside the core the fiber contains a striking circumferential palisade of radially disposed mitochondria. The fiber does not arborize. Vascular capillaries penetrate the hilar region of the corpuscle only as far as the myelinated sheath of the nerve, and they have not been seen elsewhere in the corpuscle. There is direct continuity between the clefts of the core and tissue spaces in the vicinity of the capillaries. It is likely that this provides a route whereby metabolites reach the active nerve ending, as well as the cells of the growth zone. The outer zone consists of at least 30 flattened concentric cytoplasmic lamellae separated from one another by relatively wide fluid-filled spaces. Collagenous fibrils are present, particularly on the outer surface of lamellae, and tend to be oriented circularly. The girdle of proliferating cells constituting the growth zone, which is prominent in corpuscles from young animals, is the layer from which the outer lamellae are derived. Osmotic forces probably elevate the lamellae, and maintain turgor pressure.     

LEVELS OF AMINO ACIDS AND PROTEINS IN PACINIAN CORPUSCLES OF THE CAT

Abstract— Paper chromatography of extracts from mesenteric Pacinian corpuscles of the cat revealed the presence of glutamic acid, glutamine, aspartic acid and alanine as major amino acids, and glycine, serine and threonine in traces; GABA was not detected. Levels of glutamic acid (0·75 μmol/g ' 0·37, s.d. ), glutamine (1·34 ± 0·55), and aspartic acid (0·32 ± 0·22) of mesenteric and pancreatic samples of Pacinian corpuscles were determined by separation on chromatographic columns. The protein values averaged 5·2 ± 0·66 per cant of the wet weight.
Treatment of the cats with reserpine or pargyline or deafferentation of the Pacinian corpuscles did not significantly alter these values.     

Morphological aspect of the skin terminal corpuscles, previous corrosion with pancreatin.

The capsulated corpuscles of the skin have been studied by pancreatin corrosion methods. With this corrosion, Meissner's corpuscles disappear while those, whose fundamental structure is collagenous, remain intact. We have observed structural differences in these collagenous corpuscles, some being formed as a fine reticulum or with longitudinal or concentric sheaths. Within the corpuscle, there is a totally vascular compartment, the 'vascular hill', which is easily differentiated from the other laminar or reticular segment which is the 'nerve hill'. We conclude that the connective tissue arrangement and the vascular content of the corpuscles contribute to the regulation of the different degrees of sensations perceived by these corpuscles. The tendency that these corpuscles show to unite may be caused because the places, where they are grouped, are the points of greatest sensory perception.     

Fluoride resistant acid phosphatase activity in pacinian corpuscles of the cat mesentery. Light microscope

Fluoride-resistant acid phosphatase (extralysosomal) activity has been investigated in Pacinian sensory corpuscles from cat's mesentery. The activity was found in the innermost and intermediate layers of the capsular system, but it is not possible to establish its exact localization. The central axon and the inner core were FRAP negative. The authors discuss the possible functional significance of FRAP activity in sensory corpuscles.     

Study of individual Pacinian corpuscle mechanoreceptors following application of colchicine to a nerve]

Colchicine application to the cat caudal mesenteric nerve containing sensory fibers for single mechanoreceptors (Pacinian corpuscles) causes degeneration of the axis cast of the nerve endings. Ultrastructural changes in the receptors showed no difference from the axonal degeneration after the nerve section but the rate of degeneration was considerably slower. Ultrastructural, electrophysiological, and biochemical changes occurring in the Pacinian corpuscles were not the result of direct action of colchicine, but appeared to be realized through the nerve by the axoplasmic transport block. It is suggested that the receptor's structure is under the sensory neuron neurotrophic control.     

A histological and anatomical profile of pacinian corpuscles from Dupuytren's contracture and the expression of nerve growth factor receptor

The etiology of Dupuytren's disease is unknown. The causes of the fibroplastic response of nodules, fibrosis of cords, and prominence of pacinian corpuscles are not evident. Histological and immunohistology differences in pacinian corpuscles from the hands of five patients with Dupuytren's disease compared with 17 Dupuytren's-free patients are presented. Histological sections of pacinian corpuscle specimens were stained with hematoxylin and eosin and immunostained for nerve growth factor receptor. The length and width of intact pacinian corpuscles were measured, and the number of layers within each corpuscle was counted and recorded. Grossly, the pacinian corpuscles from Dupuytren's patients were larger and more numerous compared with those from unaffected patients. When measured microscopically, the pacinian corpuscles from Dupuytren's diseased fascia were significantly larger (2.0 x 1.1 mm) compared with controls (1.5 x 0.78 mm). The pacinian corpuscles from Dupuytren's-affected patients had significantly more layers (64 +/- 14) compared with those from control patients (40 +/- 9). Nerve growth factor receptor staining of pacinian corpuscles from patients affected with Dupuytren's disease showed greater intensity and more area stained compared with unaffected controls. It is suggested that nerve growth factor may be involved in the increased size of pacinian corpuscles in Dupuytren's-affected fascia. It is proposed that the cellular outgrowth from pacinian corpuscles may generate the cells that develop into Dupuytren's nodules.     

Histological and electrophysiological investigations on the vibration-sensitive receptors (Herbst corpuscles) in the wing of the pigeon (Columba livia)

Summary The Herbst corpuscles (HCs) of the pigeon's wing were investigated both histologically and electrophysiologically. All HCs found in the wing were lamellated, basic type corpuscles without any specialized structures. Their lengths ranged from 67 to 853 m (mean = 310 m). Unexpected findings were their large number (about 1000 in the manual part of the wing), their irregular distribution and their preferred orientation (approximately parallel or at right angles to the primary feather follicles). The HCs were highly sensitive to vibrational stimuli applied to wing feathers. Their electrophysiological behaviour has the following characteristics: no spontaneous activity, phase-locked nerve impulses, a 11 stimulus-response relation up to at least 660 Hz at sufficiently high stimulus amplitudes, and a sensitivity to stimulus frequencies up to 1800 Hz. The best frequencies of 52 receptive units for which complete threshold curves were obtained lay between 100 and 900 Hz, 67% of the best frequencies were between 200 and 400 Hz. The threshold amplitudes at best frequency ranged from 0.5 to 150 m. Two virtually non-overlapping mechanosensitive areas on the wing were identified. One is a very narrow band along the frontal edge and the other covers a large area of the remaining wing. They correspond with the two branches of the radial nerve. The histological and electrophysiological findings suggest that the HCs are part of a vibrational sensory system that is principally involved in flight control. The actual aerodynamic state during flight could be detected by the frontal receptive area, and flight behaviour could be adjusted accordingly. The effectiveness of these corrective reactions would then be assessed on the basis of air current changes along the caudal wing edge by the caudal receptive area. Despite some physiological differences considerable similarities between HCs and Pacinian corpuscles support the hypothesis that they evolved from a unique ancestral lamellar receptor.Abbreviations HC(s) Herbst corpuscle(s) - PC(s) Pacinian corpuscle(s) All experiments were carried out at the Ruhr-Universität Bochum, Lehrstuhl für Allgemeine Zoologie     

Corpuscular bodies in the palate of the rat. 1. Morphology and distribution

The morphology and the frequency distribution of corpuscular bodies in the palate was studied in rats using light and electron microscopy. The study extended from the day of birth through 180 days after birth. The corpuscles appeared as round (diameter 35-50 microns) to ovoid (width 40-60 microns, height 60-90 microns) bodies intercalated within the epithelium of the incisal papilla and the soft palate. A subepithelial nerve plexus surrounded the base of a corpuscle. For types of cells were identified within the corpuscle: basal, type I (dark), type II (pale) and type III cells. Some cells bore microvilli which protruded through a pore into the oral cavity. Numerous nerve endings terminated in close relation to the latter three types of cells. Two distinct types of membrane specializations were found representing axosomatic and axo-axonal contacts. On morphological grounds we interpret the structures described as receptors of taste. At birth, a mean total of 21 corpuscles was observed in the entire palate of which 31% was located on the incisal papilla and 68% was found in the soft palate. During the first 2 weeks (16 days) of postnatal life, the number of corpuscles increased. Thereafter, a significant decrease in corpuscle number occurred with increasing age. We speculate that the corpuscles are associated with the learning process of food selection.     

Immunohistochemical study of Pacinian corpuscles using monoclonal antibodies for neurofilament protein, glial fibrillary acidic protein and S-100 protein

The presence of neurofilament protein (NFP), glial fibrillary acidic protein (GFAP) and S-100 protein has been investigated in Pacinian corpuscles from cat's mesentery by means of immunohistochemical methods. The NFP-like positivity was found in the central axon of the corpuscles; the GFAP- and S-100 protein-like immunoreactivities were shown in the innermost layers of the differentiated cell of the inner core. No positive reaction was detected in the capsule. The authors discuss these findings.     

Hemolysis and the solar spectrum

Summary The curves of Fig. 1 show that the spectral distribution of efficiency of radiation in decreasing the stability of red blood corpuscles corresponds very closely to the spectral distribution of the power of oxyhemoglobin to absorb radiation. This correspondence clearly indicates that it is a chemical change in the hemoglobin which is responsible for the decrease of resistance of the corpuscles and hemolysis produced by light. In other words, hemolysis is not due to some change in the membrane of the red corpuscle, which is colorless, but to a chemical change in the hemoglobin; that is, in one of the components of the principal compounds constituting the protoplasm of erythrocytes (4). With 1 Text-figure