A new type of somatosensory organ in the nasolabial skin of the dog

A new morphological type of somatosensory organ is described. It is found in the glabrous skin of the dog nose (rhinarium or planum nasale) and situated in dermis papillae. The otherwise thick epidermis forms a thin window above the organ. There are only a few layers of keratinocytes in the window and the corneocytes are much thinner than elsewhere. The organ consists of highly branching cells that wrap naked nerve endings emanating from myelinated nerve fibers originating in the outer dermal nerve plexus. The structure entirely fills the top of the dermal papilla. The intercellular spaces of the organ and its surroundings are occupied by an extended areolar basal lamina.     

Striae albae: a morphological study on the human skin

Specimens of abdomen skin, comprising alternate areas of striae albae and healthy skin, were removed during surgical lipectomy from multiparous and obese women between the ages of 24 and 53 years. A flattening and thinning of the striae albae surface and the almost complete disappearance of dermal papillae was observed in paraffin and thin sections. The papillary dermis was found to be almost completely replaced by straight bundles of collagen fibres running parallel to the skin surface. Immunofluorescence data revealed in these bundles high positivity for type I collagen. The underlying reticular dermis was also found to contain large densely packed bundles of collagen fibres running parallel to the skin surface. Both papillary and reticular dermis collagen fibres were mainly arranged orthogonally to the main axis of the stria. Furthermore, the density of the collagen fibre bundles and the diameter of the collagen fibrils was found to be greater than that of the clinically healthy skin. A larger number of elastic fibres, which presented an abnormal ultrastructural appearance, were visible in pathological papillary and reticular dermis.     

Vitiligo-related neuropeptides in nerve fibers of the skin

Skin distribution of substance P (SP)-, somatostatin (SOM)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (LI) in vitiligo patients was studied by an indirect immunofluorescence technique. Immunocytochemical characteristics of the epidermis, dermal-epidermal junction, papillary and reticular dermis and skin appendages were analyzed in lesional and marginal vitiligo areas, as well as in healthy skin. In healthy pigmented skin, SP-, SOM-, CGRP-, and NPY-LI nerve fibers were observed with specific distributional patterns. In uninvolved vitiligo skin, thin SP-containing fibers were evident in dermal papillae, extending into the epidermis, and SP-LI fibers were seen around blood vessels and sweat glands. SOM-LI varicose nerve fibers were associated with Meissner corpuscles in the dermal papillae, while CGRP-LI was demonstrated in the free subepidermal nerve terminals and in sensory nerve fibers around blood vessels, hair follicles and sweat glands. Autonomic NPY-nerve fibers innervated the eccrine sweat glands and blood vessels. The distribution of these neuropeptides in both marginal and lesional areas of vitiliginous skin was the same as in the skin of healthy control subjects, except for an increased immunoreactivity against NPY and, to a lesser extent, against CGRP in the skin depigmentation lesions. The elevated NPY levels in skin affected by vitiligo suggest that this peptide may serve as a neurochemical marker in the pathogenesis of the disease, thus supporting the neuronal theory of vitiligo.     

Protein gene product 9.5-immunoreactive nerve fibres and cells in human skin

Summary Sections of human skin were processed according to the indirect immunofluorescence technique with a rabbit antiserum against human protein gene product 9.5 (PGP 9.5). Immunoreactivity was detected in intraepidermal and dermal nerve fibres and cells. The intraepidermal nerves were varicose or smooth with different diameters, running as single processes or branched, straight or bent, projecting in various directions and terminating in the stratum basale, spinosum or granulosum. The density of the intraepidermal nerves varied between the different skin areas investigated. PGP 9.5-containing axons of the lower dermis were found in large bundles. They separated into smaller axon bundles within the upper dermis, entering this portion of the skin perpendicular to the surface. Then they branched into fibres mainly arranged parallel to the epidermal-dermal junctional zone. However, the fibres en route to the epidermis traversed the upper dermis more or less perpendicularly. Furthermore, immunoreactive dermal nerve fibres were found in the Meissner corpuscles, the arrector pili muscles, hair follicles, around the eccrine and apocrine sweat glands and around certain blood vessels. Such fibres were also observed around most subcutaneous blood vessels, sometimes heavily innervating these structures. Numerous weakly-to-strongly PGP 9.5-immunoreactive cells were found both in the epidermis and in the dermis.     

Skin structure in the snout of the Australian lungfish,Neoceratodus forsteri (Osteichthyes: Dipnoi)

Many fossil lungfish have a system of mineralised tubules in the dermis of the snout, branching extensively and radiating towards the epidermis. The tubules anastomose in the superficial layer of the dermis, forming a plexus consisting of two layers of vessels, with branches that expand into pore canals and flask organs, flanked by cosmine nodules where these are present. Traces of this system are found in the Australian lungfish, Neoceratodus forsteri, consisting of branching tubules in the dermis, a double plexus below the epidermis and dermal papillae entering the epidermis without reaching the surface. In N. forsteri, the tubules, the plexus and the dermal papillae consist of thick, unmineralised connective tissue, enclosing fine blood vessels packed with lymphocytes. Tissues in the epidermis and the dermis of N. forsteri are not associated with deposits of calcium, which is below detectable limits in the skin of the snout at all stages of the life cycle. Canals of the sensory line system, with mechanoreceptors, are separate from the tubules, the plexus and the dermal papillae, as are the electroreceptors in the epidermis. The system of tubules, plexus, dermal papillae and lymphatic capillaries may function to protect the tissues of the snout from infection.     

The skin of primates. XXXVII. The skin of the pig-tail macaque (Macaca nemestrina)

The skin of the pig-tail macaque is basically similar to that of the rhesus monkey and the stump-tail macaque. The epidermis is thin and contains occasional basal melanocytes. The dermis, rich in elastic fibers, is practically free of pigment-containing cells. The upper dermis is highly vascular in the perianal region and sex skin. Cholinesterase-reactive nerve endings are plentiful beneath the friction surfaces of the pes and manus, mucous membranes, and junction of the hairy gluteus and glabrous ischial callosity. Hederiform-like endings are present in the eyelid, pinna, and frontal scalp. Apocrine and eccrine sweat glands occur throughout the hairy skin in a 2–3: 1 ratio. Both types are invested by nerves reactive for acetyl- and butyrylcholinesterase.     

Melanin and dopa-positive cells in the skin of tropical cattle.

Various histochemical and histological techniques were used to study the melanin and dopa-positive cell distribution in the skin of some tropical and temperate breeds of cattle in Nigeria. Melanin pigments were concentrated in the basal and lower spinous layers of the epidermis and in the hair cortex, follicle sheaths and papillae of the various breeds. In the White Fulani and N'Dama breeds, melanin pigments were however found in all layers of the epidermis. Dopa-positive cells (melanocytes) were observed in the epidermis, dermis and hair follicles; the distribution pattern varied among breeds, being copiously disposed in the basal epidermis and papillary dermis in the White Fulani and Muturu and, except in areas of thick epidermal ridges, scanty in the epidermis and dermis of the Friesian and N'Dama. Mast cell distribution pattern in the various breeds was similar to that of the dopa-positive cells. Peroxidase-positive cells were present in the basal epidermis and upper dermis of the Muturu, widespread in the subepidermal layer of the N'Dama and very scanty in the dermis of the White Fulani and Friesian. Acid phosphatase activity was intense in the granular layer of the Muturu and N'Dama breeds and also in the papillary dermis and hair follicles, whereas alkaline phosphatase-positive dendritic cells, and 'clear' cells were also observed in the basal and upper epidermis.     

江豚皮肤的超微结构及其与其它豚类的比较

江豚皮肤的超微结构与海洋豚类相同,但在各层表皮细胞中存在大量的膜被颗粒,这很可能与江豚适应从海水进入淡水的生活方式有关。大量成束的张力原纤维的存在,有利于江豚在水中深潜和快速游泳,可适应来自各方面的压力,加强细胞之间的联接。在上下颌皮肤的乳头层基部大量被囊神经末梢和有鞘神经纤维束的分布、与江豚水底觅食方式有关。白鱀豚和条纹原海豚皮肤的超微结构与江豚大致相同,但亦有其各自的特点。     

Neuro-histochemical study of the tongue of Gallus domesticus (White Leghorn)

An investigation was undertaken to study the neuro-histochemistry of tonue of Gallus domesticus (white Leghorn) by cholinesterase technique under maintained pH of 5.2, temperature 40 degrees C and incubation period 20 h, and Ungewitter's silver impregnation method. Fungiform (8--16 in number), filiform (5--16 in number), circumvallate and foliate (numerous) were recorded profusely innervated in the various regions of the tongue. Neuro-muscular spindles related either with the non-myelinated, myelinated nerve fibres or with the ganglia via pre- or postganglionic nerve fibre showed cholinesterase (AChE) positive activity in the form of dark brown patches. Neural network over the glands, formed the basket envelope likestructures. Glands showed positive cholinesterase (AChE) reaction on the periphery. Dot-like nerve endings were connected with the neural terminal network in the foliate papillae region and motor end plate like endings on blood vessel, were occasionally recorded. Parasympathetic ganglia of various shape and sizes, arranged in chain-like fashion were observed in the connective tissue space between the fungiform and circumvallate papillae and foliate papillae region. The pre- and postganglionic fibres of these ganglia were related with the anteriorly and posteriorly located papillae via the neural terminal network. Cholinesterase (AChE) activity was marked either in the centre, of the fungiform or on the periphery of the filiform, circumvallate and foliate papillae.     

Differential growth of sensory neurons in vitro in presence of dermis and epidermis. A quantitative time-lapse analysis

The influence of dermal and epidermal cells on the growth of nerve fibres from chick embryo sensory neurons was investigated in vitro. A previous quantitative analysis showed that the growth of nerve fibres is profoundly modified in the close vicinity of epidermis. This change is mainly characterized by erratic trajectories of nerve fibres resulting from numerous lateral displacements of the growth cones. In contrast, no such behaviour is observed far away from the epidermis or in the presence of dermis. In this latter case, neurites exhibit a straighter direction of extension. These observations suggest that the epidermis exerts some kind of control on the establishment of nerve fibre pattern in the dermis.     

Innervation der unbehaarten Nasenhaut des Maulwurfs (Talpa europaea)

Zusammenfassung Die Epidermis der unbehaarten Nasenhaut des Maulwurfs bildet regelmäßig angeordnete, einzeln stehende Papillen, die sich über die Epitheloberfläche erheben. Jede dieser Papillen entspricht einem Epithelzapfen, der sich pufferförmig verdickend in das Corium einsenkt. Diese epidermale Einheit wird als Eimersches Organ bezeichnet.Die Eimerschen Organe werden von 2 Typen von Nervenendigungen versorgt, von Merkelschen Endigungen und von freien Nervenfasern. Die Merkelschen Endigungen sind in das Stratum basale der Epidermis eingelagert und bestehen aus Merkelschen Zellen und kelchförmig verdickten Nervenfasern, die den basalen Teil der Zellen umfassen. Die zuführenden Nervenfasern sind myelinisiert, solange sie im dermalen Nervenplexus verlaufen. Jeder Epithelzapfen enthält 3–5 Merkelsche Endigungen. Die freien Nervenfasern treten in 2 Typen auf. In der Mitte jedes Epithelzapfens läuft eine etwas stärkere Nervenfaser, ca. 2,5 stark. Zirkulär umgeben sie ungefähr 20 schwächere Nervenfasern, 1–1,5 stark, die senkrecht gegen die Epitheloberfläche ziehen und mit einer knopfartigen Erweiterung im Stratum granulosum enden. Beide Fasertypen werden vom Eintritt in die Epidermis an in Epidermiszellen invaginiert. Infolgedessen umhüllen die Zellen der Epidermis die Nervenfaser ähnlich wie Schwannsche Zellen. Mit dem Interzellularraum ist das Axon mit einer dem Mesaxon ähnlichen Spalte verbunden. In der Peripherie der Epidermispapillen sind vereinzelte Nervenfasern in gleicher Weise angeordnet.

---

Innervation of hairless skin of the nose of moleI. Intraepidermal nerve endings

Summary The epidermis of the hairless skin of the mole's nose forms regularly arranged separate papillae which protrude above the surface of the epithelium. An individual epithelial peg which penetrates with a buffer-shaped thickening into the corium conforms to each papilla. This epidermal unit is called Eimer's organ.These Eimer's organs are provided with two types of nerve terminals: Merkel's corpuscles and free nerve endings. The Merkel's corpuscles are embedded in the stratum basale of the epidermis and consist of cells and nerve fibres which encircle the basal part of the cells. The afferent (dendritic) nerve fibres are myelinated as long as run in the dermal nerve plexus. Every epidermal peg contains 3 to 5 Merkel's corpuscles.In addition to nerve fibres connected to corpuscles, there are two types of free nerve endings. A thick nerve fibre, about 2.5 in diameter, runs in the centre of each epidermal peg. About 20 thin nerve fibres, 1 to 1.5 in diameter, encircle the thick central axon, running perpendicularly to the epidermal surface. Both types of nerve fibres end with knob-like thickening in the stratum granulosum. When entering the epidermis both types of nerve fibres become invaginated into cytoplasm of the epidermal cells. Thus the nerve fibres are ensheathed by the cells of the epidermis in the same manner as by Schwann's cells. The axon has access to the intercellular space by a gap resembling the situation in mesaxons. Sporadic nerve fibres occur in the periphery of the epidermal papillae which are aranged in the same pattern.

Für die sprachlichen Verbesserungen möchte ich mich besonders bei Herrn Prof. Dr. Dr. H.-R. Duncker bedanken.     

Barnacle bonding: Morphology of attachment of Xenobalanus globicipitis to its host Tursiops truncatus

Xenobalanus globicipitis, a unique type of small pseudo‐stalked barnacle occurs on the appendages of cetaceans, including the common bottlenose dolphin Tursiops truncatus. In this study, we examined attachment structures of X. globicipitis and modifications to the skin of T. truncatus in areas of attachment compared to skin nearby an attachment site. Barnacles and their six calcareous footplates were measured for their length and width. There was a positive correlation of barnacle width and length to footplate width and length. The thickness of the stratum corneum increased significantly in areas of attachment compared to skin nearby a footplate. The mitotic stratum germinativum at the base of the dermal papillae did not change significantly in areas of attachment compared to skin nearby a footplate. The stratum germinativum lining the lateral walls of the dermal papillae was significantly thicker in areas of skin nearby a footplate compared to in areas of attachment. Skin of T. truncatus nearby a footplate, displayed dermal papillae extending from the dermis and pointing roughly perpendicular to the epidermal stratum corneum. At sites of X. globicipitis attachment, the dermal papillae were forced to extend laterally, parallel to the stratum corneum, and the dermal papillae length to width ratio at an attachment site was significantly higher than on skin near an attachment site. Our results show that attachment of X. globicipitis through production of footplates organized into calcareous rings, leads to a thickened stratum corneum of the epidermis, a thinner lateral mitotic stratum germinativum and displaced structures of the upper dermis. These resulting modifications to the epidermis and dermis of the host may add to securing barnacle attachment to its host. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

Induction of follicle formation and hair growth by vibrissa dermal papillae implanted into rat ear wounds: vibrissa-type fibres are specified.

Adult vibrissa follicle dermal papillae have the capacity to induce hair growth and follicle formation when associated with epidermis from various sources. However, the range of conditions under which hair follicle induction will take place has not been established. The question of whether or not the adult papilla carries information to impose fibre-type specificity has also not been fully answered. This study describes how the implantation of isolated papillae into small incisional cuts on the rat ear pinna resulted in the subsequent emergence of abnormally large hair fibres from the wound sites. Many of these hairs were found to display vibrissa-type characteristics. Histological observations indicated that the papillae had interacted with the edges of the wound epidermis to produce new, and particularly large follicles, while immunohistochemical staining revealed that early follicle construction was accompanied by a profusion of the basement membrane constituents laminin and type IV collagen in the subjacent dermis. These findings show that adult rat papillae retain the capacity, as displayed by embryonic dermis, to determine vibrissa specificity in induced follicles.     

Distribution of neurofilament-immunoreactive nerve fibers in human skin

Neurofilament immunoreactive nerve fibers were demonstrated in human skin using indirect immunohistochemical technique with antibodies to neurofilament polypeptides. Neurofilament-positive fibers were seen as free nerve endings in the epidermis and in dermal papilla, in Meissner's corpuscles and as fibers crossing in the dermis. Strongly fluorescent nerve fibers were also seen around hair follicles, sweat gland ducts and sometimes in relation to blood vessels. From the distribution pattern it was concluded that predominantly sensory nerve fibers were labelled and that this technique may be used to study reinnervation of cutaneous sensory nerves following traumatic injuries and surgical procedures.     

Calcitonin gene-related peptide (CGRP) immunoreactivity in the neuroendocrine Merkel cells and nerve fibres of pig and human skin

Summary The presence of calcitonin gene-related peptide (CGRP) in the skin of pig snout and human fingertip was investigated using immunohistochemical techniques. CGRP immunoreactivity was found in Merkel cells and nerve fibres of both species. In pig snout skin, Merkel cells containing CGRP were seen forming clusters at the tips of rete ridge epidermis and in the external root sheath of sinus hair follicles (vibrissae). Human Merkel cells immunostained for CGRP were found isolated or forming small groups in the basal layer of glandular epidermal ridges. In all cases, immunoreactivity was more intense on the side of the Merkel cell facing the associated nerve terminal (which was never positive for CGRP). This part of the Merkel cell has the greatest density of dense-cored granules, suggesting that CGRP must be stored in these granules. Nerve, bundles containing CGRP-immunoreactive fibres were found at dermal and hypodermal level, and blood vessels were often surrounded by CGRP nerve fibres. In pig snout skin some nerve fibres containing CGRP penetrated the epidermis and terminated as free endings, and in the human fingertip a small number of CGRP-immunoreactive nerve fibres were seen in Meissner's corpuscles.     

Development of sensory innervation in chick skin: comparison of nerve fibre and chondroitin sulphate distributions in vivo and in vitro

In bird skin, nerve fibres develop in the dermis but do not enter the epidermis. In co-cultures of 7-day-old chick embryo dorsal root ganglia and epidermis, the neurites also avoid the epidermis. Previous studies have shown that chondroitin sulphate proteoglycans may be involved. Chondroitin sulphate has therefore been visualized by immunocytochemistry, using themonoclonal antibody CS-56, both in vivo and in vitro using light and electron microscopy. Its distribution was compared to those of 2 other chondroitin sulphate epitopes and to that of the growing nerve fibres. In cultures of epidermis from 7-day-old embryonic chicks, immunoreactivity is found uniformly around the epidermal cells while at 7.5 days the distribution in dermis is heterogeneous, and particularly marked in feather buds. In vivo, chondroitin sulphate immunoreactivity is detected in the epidermis, on the basal lamina, on the surfaces of fibroblasts and along collagen fibrils. This localization is complementary to the distribution of cutaneous nerves. Chondroitin sulphate in the basal lamina could prevent innervation of the epidermis and the dermal heterogeneities could partly explain the nerve fibres surrounding the base of the feathers. Chondroitin sulphate could therefore be important for neural guidance in developing chick skin.     

Calcitonin gene-related peptide (CGRP) immunoreactivity in the neuroendocrine Merkel cells and nerve fibres of pig and human skin

The presence of calcitonin gene-related peptide (CGRP) in the skin of pig snout and human fingertip was investigated using immunohistochemical techniques. CGRP immunoreactivity was found in Merkel cells and nerve fibres of both species. In pig snout skin, Merkel cells containing CGRP were seen forming clusters at the tips of rete ridge epidermis and in the external root sheath of sinus hair follicles (vibrissae). Human Merkel cells immunostained for CGRP were found isolated or forming small groups in the basal layer of glandular epidermal ridges. In all cases, immunoreactivity was more intense on the side of the Merkel cell facing the associated nerve terminal (which was never positive for CGRP). This part of the Merkel cell has the greatest density of dense-cored granules, suggesting that CGRP must be stored in these granules. Nerve bundles containing CGRP-immunoreactive fibres were found at dermal and hypodermal level, and blood vessels were often surrounded by CGRP nerve fibres. In pig snout skin some nerve fibres containing CGRP penetrated the epidermis and terminated as free endings, and in the human fingertip a small number of CGRP-immunoreactive nerve fibres were seen in Meissner's corpuscles.     

Distribution of neurofilament-immunoreactive nerve fibers in human skin

Summary Neurofilament immunoreactive nerve fibers were demonstrated in human skin using indirect immunohistochemical technique with antibodies to neurofilament polypeptides. Neurofilament-positive fibers were seen as free nerve endings in the epidermis and in dermal papilla, in Meissner's corpuscles and as fibers crousing in the dermis. Strongly fluorescent nerve fibers were also seen around hair follicles, sweat gland ducts and sometimes in relation to blood vessels. From the distribution pattern it was concluded that predominantly sensory nerve fibers were labelled and that this technique may be used to study reinnervation of cutaneous sensory nerved following tramatic injuries and surgical procedures.     

江豚背部小齿的超微结构与功能

长江江豚背部皮肤表面有一长条小齿,由1—3排组成。它是由表皮向体表突起而成。小齿区皮肤中的乳头深深伸入表皮,几达表面,它的高度在成体约占整个表皮厚度的70—80%,新生幼儿为84.6%。经研究,我们发现在小齿区皮肤中存在着大量类似于人类皮肤中的环层小体那样的被囊神经末梢和几种有鞘神经纤维束。根据这些结构,我们认为小齿是一种感觉器官,它并不能起到防止幼儿从母体背部滑落的作用。       

Innervation of the synovial membrane of the cats joint capsule

Summary 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.