Biomedical subjects

Z Halata

Publications and source records attributed to Z Halata.

At least 37 records · Page 2Linked to original sources

PubMed1996

The sensory innervation of the shoulder joint of the mouse.

The ultrastructure and location of sensory nerve endings in the shoulder-joint capsule, its tendinous reinforcements and in the periarticular connective and muscle tissue have been studied by means of light and electron microscopy in adult female white NMRI-F2 laboratory mice, aged 2.5-13 months. Most of the sensory nerve endings were detected in the fibrous layer of the joint capsule or in the inserting tendons. The identified lamellated corpuscles of the Pacini type are small and sometimes associated with Golgi tendon-organs. Large Vater-Pacini corpuscles were not detected. Ruffini corpuscles are found in small numbers only in the moderately dense connective tissue of the joint capsule. Golgi tendon organs were found mainly at the muscle-tendon junction of the muscles surrounding the joint. Muscle spindles have been identified mainly in periarticular muscles close to the muscle-tendon junctions. The number and distribution of the different types of mechanoreceptors investigated in the present study suggest that periarticular corpuscular sensory nerve endings play an important role in shoulder-joint control and mobility. The occurrence of small uniformly shaped lamellated corpuscles of the Pacini type in qualitatively different areas of surrounding tissue implies that they are susceptible to different kinds of mechanical stimuli.

Afferent Pathways↗

PubMed1996

The structure of sensory nerve endings in the knee joint capsule of the dog.

The ultrastructure and distribution patterns of sensory nerve endings in the dorsal knee joint capsules of the beagle dog (Canis familiaris) have been investigated using light and electron microscopy. Each dorsal knee joint capsule was divided into four quadrants, cut into small pieces and then processed for electron microscopy. Free nerve endings and corpuscular nerve endings (Ruffini and lamellated corpuscles) were found. They were most frequently observed in the medial-proximal quadrant of the dorsal joint capsule. All nerve endings were found to be situated within or adjacent to the fibrous layer of the capsule. No nerve endings were found within the synovial layer. Free nerve endings were usually situated at the border between the fibrous layer and the synovial layer near blood vessels. Their associated afferent axon was myelinated (1.5-2.5 microns in diameter) or non-myelinated (0.3-1.5 microns in diameter). Ruffini corpuscles were found in the fibrous layer and within the dorsal ligamentous apparatus. Each Ruffini corpuscle was surrounded by a multilayered perineural capsule which was usually incompletely developed. The perineural capsule is the continuation of the perineurium of the afferent axon and gives a cylindrical form to the corpuscles. Ruffini corpuscles were present as single, cylindrical structures (small corpuscles) or as aggregates of these cylinders (large corpuscles). Both varieties consist of terminal nerve endings surrounded by collagen fibres which pass through the opened ends of the cylinders. The diameter and length of the small Ruffini corpuscles were 80 microns and 400 microns, as compared to 200 microns and 800 microns for the large aggregated forms. The supplying afferent axons of both types were 4-5 microns in diameter. Two types of small lamellated corpuscles could be observed in the fibrous layer: very small corpuscles, 55 microns long, 25 microns wide and medium corpuscles, 100 microns long, 40 microns wide. Each consists of an inner core of terminal Schwann cells, a nerve terminal and a perineural capsule. Some lamellated corpuscles had two inner cores and two nerve terminals. The diameter of the afferent axon was approximately 6 microns. Vater-Pacini corpuscles were not found in the dorsal knee joint capsule of the dog.

Animals↗

PubMed1994

A comparative physiological and morphological study of periodontal ligament mechanoreceptors represented in the trigeminal ganglion and the mesencephalic nucleus of the cat.

A correlative morphological study was carried out on two electrophysiologically identified and located periodontal ligament mechanoreceptors in anaesthetised cats. One mechanoreceptor had its cell body in the mesencephalic nucleus and the other had its cell body in the trigeminal ganglion. Physiological recordings were made from each of their cell bodies. The two receptors were located by punctate and electrical stimuli in the labial aspect of the periodontal ligament of the left mandibular canine tooth. Both receptors had similar positions relative to the tooth apex and fulcrum and were situated in the labial part of the ligament in each tooth. The receptor loci were marked, and these regions were studied in a series of semi-thin and ultra-thin sections. Only Ruffini nerve endings were observed under each ink mark. Both Ruffini nerve endings branched, were unencapsulated and were incompletely surrounded by terminal Schwann cells with extensions projecting towards collagen bundles. The results indicate that periodontal ligament mechanoreceptors with cell bodies in the mesencephalic nucleus and those with their cell bodies in the trigeminal ganglion can both be Ruffini nerve endings. Furthermore, there was no apparent morphological difference between the two periodontal ligament mechanoreceptors.

Animals↗

PubMed1994

A possible explanation for the response characteristics of multi-tooth periodontal ligament mechanoreceptors in the cat.

During the course of a study on the morphology of periodontal ligament mechanoreceptors it was observed that a direct relation, without intervening bone, existed between the mandibular canine and first premolar tooth roots in the cat. An area, representing a window in the alveolar septal bone, extended 2-3 mm from the apex towards the tooth crown. Ruffini nerve terminals were observed amongst the collagen bundles in the ligament between the roots of the two teeth. Light and electron microscopy were used to identify the receptors. It is proposed that a periodontal ligament mechanoreceptor can respond to forces applied to adjacent teeth; movement of both teeth need not occur. This may explain the observation made in the past that single periodontal ligament mechanoreceptors respond to forces applied to more than one tooth.

Alveolar Process↗

PubMed1993

Sensory nerve endings in the beak skin of Japanese quail.

This study is concerned with the distribution and ultrastructure of sensory nerve endings in the beak skin of adult Japanese quail (Coturnix coturnix japonica). The following nerve endings were found: free nerve endings, clusters of dermal Merkel nerve endings, Herbst corpuscles and Ruffini corpuscles. The latter were found only in the dermis of the tip of the upper beak. The remaining endings were present in the skin of all areas of upper and lower beak. Free nerve endings were supplied by either thin myelinated axons or unmyelinated C-fibers and were localized in the dermis close to the basal layer of the epidermis. Merkel cells formed clusters (up to 50) localized below and between the epidermal cones of the beak skin. Disc-shaped thickenings of nerve endings were squeezed between individual Merkel cells. Small Herbst corpuscles were found in the dermis close to the epidermal cones of the beak skin. Large Herbst corpuscles occurred in deep layers of the dermis. The Ruffini corpuscles were cylindrical in shape (80 microns x 400 microns) and arranged in groups of up to ten corpuscles. Each corpuscle was surrounded by an incomplete fibrous capsule.

Animals↗

PubMed1993

The Splotch mutation interferes with muscle development in the limbs.

Homozygosity for the Splotch mutation causes neural tube and neural crest defects in mice. It has been demonstrated that Splotch mutant mice carry mutations in the homeodomain of the Pax-3 gene. Pax-3 is expressed in the neural tube, some neural crest derivatives, the mesenchyme of the limb bud and the somites. We have examined the development of the somite-derived skeletal muscles in homozygotes carrying the Splotch (Sp1H) mutation. Our results suggest that the Splotch mutation affects the development of skeletal muscles in a region-specific way: 1. The expression of the CMZ transgene in homozygotes reveals a disorganisation of the dermomyotome in whole stained embryos. 2. The axial musculature is reduced in size along a rostro-caudal gradient. 3. The muscle anlagen in the limbs develop much more slowly. Muscles of the head and the ventral body wall are normally developed in the mutant on day 13.5 of gestation. Recently, it has been shown that the myogenic precursors of the limbs are derived from the lateral half of the somite. The specific disturbance of muscle development in the limbs of Splotch mutants thus suggests a role for Pax-3 in the organisation of the somite, the production of trophic factors in the limb mesenchyme or an alteration of myogenic and mesenchymal cells.

Animals↗

PubMed1993

Sensory innervation of the hairy skin (light- and electronmicroscopic study.

The sense of touch develops early in phylogeny and is one of the most important senses for the survival of the animal. Touch organs of hairy skin in mammals include the so-called "Haarscheiben" (also Pinkus corpuscles) and all types of hair follicles with their nerve endings. The touch organs of the skin consist of a mechanical transducing component and the sensory component. The epithelium and its derivatives like hair follicles and sebaceous glands are the mechanical transducing component transmitting the mechanical forces like pressure or touch to the second component--the sensory nerve endings. In mammalian hairy skin all sinus and guard hairs and many vellus hairs are touch organs. The sinus hair is a typical example of a touch organ. All mammals except humans are equipped with these highly differentiated touch organs. The hair follicle is almost completely embedded in a blood sinus and equipped with more than 2,000 sensory nerve endings. All sinus and guard hairs are equipped with free nerve endings (nociceptors), Merkel nerve endings (slowly adapting [SA I] mechanoreceptor units-pressure detectors), palisades of lanceolate nerve endings (velocity detectors), and pilo-Ruffini corpuscles (tension receptors). In most of the sinus hairs lamellated corpuscles of Pacini type could be found (rapidly adapting receptors-acceleration detectors). Most vellus hairs are equipped with free and lanceolate nerve endings. Some of the vellus hairs of the upper portion of the body (head, upper extremity) are innervated by Merkel nerve endings. The presence of pilo-Ruffini nerve endings in vellus hairs is very unusual.

Animals↗

PubMed1993

The sensory innervation of the gingiva and mucosa in Monodelphis domestica: an ultrastructural study.

The location and structure of sensory nerve endings was examined in the mucosa and in the gingiva propria adjacent to the third premolar of Monodelphis domestica by light and electron microscopy. The mucous membrane of the gingiva propria is covered with a stratified keratinized squamous epithelium. The mucous membrane of the adjacent inner aspect of the lip and of the vestibulum oris were covered with a nonkeratinized squamous epithelium. Free nerve endings, Merkel nerve endings and lamellated corpuscles were found in all the examined areas. Free nerve endings were located in the connective tissue papillae between the epithelial cones, in the basal layer of the epithelium and directly under the epithelium of the cones. They were innervated by myelinated A-delta- and nonmyelinated C-fibers. The basal layer of the first three to four epithelial cones of the gingiva propria contained single or groups of Merkel nerve endings. The epithelial cones of the oral mucous membrane contained five times more Merkel nerve endings than those of the vestibular mucous membrane. Lamellated corpuscles were mainly found in the plica sublingualis. In the connective tissue below the epithelial cones of the mucous membranes they usually occur with a perineural capsule, in the connective tissue papillae between the cones they occur without a perineural capsule. In the latter position they resemble the Meissner corpuscles of glabrous skin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

The sensory innervation of the periodontium of the third premolar in Monodelphis domestica.

Location and structure of sensory nerve endings in the periodontium of the third premolar in Monodelphis domestica have been investigated by means of light and electron microscopy. The periodontal cleft of the tooth is apically enlarged. The number of nerve endings increases towards apex. Three types of sensory nerve endings have been observed: free nerve endings, Ruffini nerve endings and lamellated corpuscles. Free nerve endings could only be identified by electron microscopy. Ruffini nerve endings are only incompletely surrounded by lamellae of the terminal Schwann cell. Protrusions of nerve terminals of the Ruffini corpuscles are anchored between bundles of collagen fibers. Small lamellated corpuscles occur exclusively in the apical portion of the periodontium. Ruffini and lamellated corpuscles are considered as part of a masticatory reflex feedback control system. Ruffini corpuscles detect tension, rapidly adapting lamellated corpuscles detect pressure and vibration in the periodontium. Free nerve endings may function as thermoreceptor or nociceptor.

Animals↗

PubMed1992

Schwann cells are not required for guidance of motor nerves in the hindlimb in Splotch mutant mouse embryos.

The topogenesis of the hindlimb nerves of Splotch homozygous mutant mouse embryos was studied using light and electron microscopy. Homozygous mutants show multiple defects of neural crest-derived tissues. The defects increase along a rostro-caudal gradient. The cervical and upper thoracic segments have small spinal ganglia, and Schwann cells are associated with the spinal nerves. In the lumbo-sacral region neurulation is not complete, and the derivatives of the neural crest are missing. The lumbo-sacral nerve trunks are formed by ventral roots only. They are occasionally associated with presumptive glial cells that have migrated from the spinal cord for a short distance. Beyond the vertebral primordia, the spinal nerves are not accompanied by Schwann cells. No compartmentalization of the axons within the lumbo-sacral nerves was visible, whereas Schwann cells did segment the nerve into the fascicles in brachial nerves. The lumbo-sacral plexus develops, and its branches grow into the hindlimb despite the absence of Schwann cells. On day 13.5 of gestation, the lumbo-sacral nerve trunks extend well into the distal calf. They are topographically correctly positioned. Their branches enter the muscle primordia and form contacts with their mesenchymal cells though the cutaneous branches are missing. Generally, the outgrowth of lumbo-sacral nerves is slower than in phenotypically normal littermates, whose nerves reach the foot plate at corresponding stages of development. These results demonstrate that the lumbo-sacral plexus and the topographically correct position of lumbo-sacral nerve trunks develop despite the absence of Schwann cells. Therefore Schwann cells are not necessary for the outgrowth and guidance of axons within the limb.

Animals↗

PubMed1991

Topography and ultrastructure of sensory nerve endings in the glans penis of the rat.

The aim of the present study was to describe the types and location of sensory nerve endings in the glans penis of the rat on the basis of light and electron microscopy. Free nerve endings are abundant throughout the glans and are derived from either thinly myelinated A delta or unmyelinated C fibers. The free nerve endings derived from A delta fibers often extend into the epidermis as far as the granular layer and exhibit buttonlike terminal thickenings. The distal urethra contains many free nerve endings from C fibers. Numerous lamellated corpuscles are present. Each corpuscle, innervated by one or two medium diameter myelinated nerve fibers, consists of 4-10 spiralling and intertwined inner cores enveloped by Schwann cell lamellae. The corpuscles are usually enclosed by a perineural capsule, although some located near the epidermis lack a capsule. Lamellated corpuscles in the superficial dermis are located adjacent to but not directly under a penile spine and change their orientation when the glans is erect. The dermal papillae of the penile spines are devoid of any neural structure. Lamellated corpuscles are also located within the trabeculae of the corpus spongiosum glands and in the lamina propria of the urethra. Occasionally, unmyelinated nerve bundles are seen inside these corpuscles. Ruffini corpuscles are few in number and are located in the deep connective tissue near the os penis. They have an incomplete connective tissue capsule and the nerve terminals are anchored between collagen fiber bundles. No Merkel nerve endings, Meissner, or Vater-Pacini corpuscles were found in any of the sections. We conclude that the glans penis of the rat contains a sensory receptor complement that is generally similar to the human glans penis but is unlike the glabrous and hairy skin.

Animals↗

PubMed1991

Innervation of hairs in the facial skin of marsupial mammals.

The innervation of pelage, guard hairs and vibrissae hairs was studied in five species of marsupial mammals by means of electron microscopy for the first time. This study showed that members of different superfamilies in marsupial mammals displayed the same pattern of hair innervation. This also resembled the pattern seen in the placental mammals. All types of hairs had both longitudinal and transverse lanceolate nerve terminals. Pelage hairs did not have any Merkel cells. Guard hairs were very richly innervated and had free nerve endings, lanceolate nerve endings, many Merkel cells with their associated nerve endings and pilo-Ruffini nerve endings. Vibrissae hairs had free nerve endings, Merkel nerve endings and lamellated corpuscles, but pilo-Ruffini nerve endings were not seen in this investigation. Because of the profusion and variety of innervation in guard hairs of the marsupial mammals, these hairs may have a similar function to vibrissae hairs in placental mammals.

Animals↗

PubMed1991

[Antetorsion of the femur neck. A variable of the trochanter minor?].

The antetorsion angle (beta) of the femoral neck and the "retrotorsion" angle (alpha) of the lesser trochanter were measured in 52 female and 34 male femora taken from 46 human cadavers (age at death 80.3 +/- 8.67 years). In addition, the diameter of the femoral head (d) and the length of the femur (l) were measured. As expected, the antetorsion angle varied over a wide range (beta = 10.5 degrees +/- 9.22 degrees). Measurements on right and left demonstrated an asymmetry: beta right = 8.2 degrees +/- 9.14 degrees; beta left = 12.6 degrees +/- 8.99 degrees. The measurements for retrotorsion of the lesser trochanter also varied in a similar way: alpha total = 31.5 degrees +/- 11.8 degrees; alpha right = 35 degrees +/- 10.7 degrees; alpha left = -28 degrees +/- 11.9 degrees. If alpha and beta are combined to couples, a strong regression is visible (r = 0.7657): beta = 29.5 degrees +/- 0.6 . alpha. Thus, the antetorsion angle depends on the retrotorsion angle or vice versa. The measurements of d and l show marked symmetry: d total = 47.4 +/- 3.6 mm; d right = 47.6 +/- 3.6 mm; d left = 47.2 +/- 3.5 mm; l total = 442.7 +/- 24.6 mm; l right = 441.3 +/- 24.4 mm; l left = 444.0 +/- 24.8 mm. Thus, d and l also vary in dependence on each other (r = 0.578). As the length of the femur is determined by body height, there must be a correlation between the diameter of the femoral head and height; that is to say, a short patient will have a small femoral head.

Aged↗

PubMed1990

Innervation of the anterior cruciate ligament.

The innervation of 21 human anterior cruciate ligaments (ACL) obtained at autopsy or during operation was studied by light microscopy. Nerves and nerve endings were found in the synovium and interfascicular connective tissue. The nerves were myelinated and/or unmyelinated and had terminal nerve structures with free nerve endings which provide nociception and supply the blood vessels, Ruffini corpuscles and Pacini corpuscles, which are mechanoreceptors in the ligaments.

Anterior Cruciate Ligament↗

PubMed1990

Origin of spinal cord meninges, sheaths of peripheral nerves, and cutaneous receptors including Merkel cells. An experimental and ultrastructural study with avian chimeras.

The origin of cells covering the nervous system and the cutaneous receptors was studied using the quail-chick marking technique and light and electron microscopy. In the first experimental series the brachial neural tube of the quail was grafted in place of a corresponding neural tube segment of the chick embryo at HH-stages 10 to 14. In the second series the leg bud of quail embryos at HH-stages 18-20 was grafted in place of the leg bud of the chick embryos of the same stages and vice versa. It was found that all meningeal layers of the spinal cord, the perineurium and the endoneurium of peripheral nerves, as well as the capsular and inner space cells of Herbst sensory corpuscles, develop from the local mesenchymal cells. Schwann cells and cells of the inner core of sensory corpuscles are of neural crest origin. The precursors of Merkel cells migrate similarly to the Schwann cells into the limb bud where they later differentiate. This means that in addition to the Schwann cells and the melanocytes a further neural crest-derived subpopulation of cells enters the limb.

Animals↗

PubMed1990

Structure of the sensory innervation of the anal canal in the pig. A light- and electron-microscopical study.

The sensory innervation of the anal canal of the pig was investigated by light and electron microscopy. The distribution of the different types of sensory nerve endings correlates with the histology of different zones: (1) After the rectal mucosa there was a zone lined with nonkeratinized stratified squamous epithelium. (2) A middle zone was lined with keratinized stratified squamous epithelium. Here the dermis already showed a papillary and reticular layer. (3) The last zone showed hairy skin with a high hair density. The following nerve endings were found: Free nerve endings reached the stratum superficiale in nonkeratinized squamous epithelium and the stratum granulosum in the keratinized squamous epithelium. Dermal free nerve endings were found in all zones near the epithelium and two different types were identified as those derived from C-fibers and those from A-delta-fibers. Merkel nerve endings showed different features depending on their location. Few Merkel-like cells were found in the epithelium of the anal crypts. Typical Merkel Tastscheiben were located at the base of epithelial ridges or pegs in zones 2 and 3. The number of Merkel cells varied up to 200. The myelinated afferent fiber supplied 10-15 Merkel cells. Merkel cells were also found regularly in the outermost layer of the external rooth sheath of hair follicles at about the same level as perifollicular nerve endings. Lamellated corpuscles were found in the dermis of all zones except the cranial part of zone 1, where the anal crypts are located. Generally they consisted of a central nerve terminal which may be branched. Each terminal was surrounded by an inner core of concentrically arranged lamellae of the terminal Schwann cell and one or several inner cores were included in a capsule of perineural cells. The size of the corpuscle, the regularity of the inner core and the number of capsular layers depended on the location of the corpuscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Canal↗

PubMed1990

CGRP-like immunoreactivity in sensory nerve endings of the Golgi tendon organ. A light- and electron-microscopic study in the grey short-tailed opossum (Monodelphis domestica).

Using light- and electron-microscopic immunohistochemistry, it was shown that primary sensory nerve endings in Golgi tendon organs of the grey short-tailed opossum (Monodelphis domestica) contain immunoreactivities to a polyclonal antibody directed against calcitonin gene-related peptide (CGRP). Myelinated afferent axons (6-9 microns in diameter) of the Golgi tendon organs stained moderately for CGRP. Sensory nerve endings within the sensory compartment of the Golgi tendon organs displayed electron-dense accumulations corresponding to dark-brown staining in adjacent semithin sections. On the outer surface of tendon organs C fibre bundles were observed showing CGRP-like immunoreactivity.

Animals↗

PubMed1990

Functional topography and ultrastructure of periarticular mechanoreceptors in the lateral elbow region of the rat.

The distribution and ultrastructure of sensory nerve endings were investigated in the deep lateral elbow region of the rat. Three zones of distribution of mechanoreceptors were distinguished, each in relation to the functional architecture of the connective and muscular tissue in that area: (1) a zone with muscle spindles, Golgi tendon organs, free nerve endings and single small lamellated corpuscles ('muscle-tendon spectrum'), situated in the middle third of the supinator muscle and its superficial aponeurosis; (2) a zone with small lamellated corpuscles and free nerve endings, situated pericapsularly to the humeroradial joint capsule ('shearing spectrum'): this moderately dense, irregular connective tissue is covered by the proximal continuation of the supinator's aponeurosis, and muscle fibers insert from beneath this aponeurosis, which displays, as a part of the joint capsule, a strong collagenous tissue plate; (3) a zone with only free nerve endings within the tendon-like, most proximal part of the supinator's aponeurosis, inserting into the periosteal layer of the lateral humeral epicondyle ('endotenonial spectrum'): it is part of the joint capsule. The ultrastructure of these sensory endings is described and the distribution pattern of the mechanoreceptors observed is discussed in relation to the classification into 'muscle receptors' and 'joint receptors'.

Animals↗