Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
1.
Br Poult Sci ; 58(4): 366-372, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28463011

RESUMO

1. The aim of the study was to estimate the heritability of the laying performance in the cumulative and partial production of eggs and predict the breeding values of native Zatorska geese in a conservation programme using Best Linear Unbiased Prediction (BLUP) methodology. Second, the trajectory of the egg production curve was examined. 2. The data contain information about the laying performance of 1831 individuals in the first year of laying. To describe the trajectory of the laying performance, 10 mathematical models were tested. For the genetic parameter estimation of egg production, data from 1038 birds were used with a production higher than 20 eggs during the first season of laying. 3. The analysis of egg production was based on single and multi-trait models. Heritability, genetic and phenotypic correlations between phases of the laying performance as well as breeding values were estimated. 4. The best adaptation to the goose egg laying curve was the Ali and Schaeffer model. The estimates of heritability were 0.20 (0.06 SE) using the single-trait model and ranged from 0.12 to 0.24 using the multi-trait model. 5. The results suggest that the BLUP method can support the conservation programme.


Assuntos
Gansos/genética , Hereditariedade , Comportamento de Nidação , Animais , Cruzamento , Feminino , Gansos/fisiologia , Polônia
2.
Animal ; 17(10): 100960, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37690335

RESUMO

The skeletal system of young animals undergoes a series of intensive and rapid changes. In this study, we aimed to verify the hypothesis that geese exhibit a distinct pattern of bone growth compared to gallinaceous species. Specifically, we hypothesised that geese would experience an accelerated growth rate in the humerus bone, which can be attributed to the increased wing mobility facilitated by their rearing in free-range systems. This need for access to both ground and water environments contributes to the unique demands placed on their skeletal development. We focused on evaluating the mechanical properties and geometry of the humerus as the forelimb bone, and the tibia as the hindlimb bone. The 320 geese used in this study were divided into 12 groups according to sex (females and males) and age (0-,1-,3-,6-,8-,12-,14-week-old). To assess bone mechanical properties, a three-point bending test was performed, along with densitometry and morphological measurements. The tibiae of the geese showed the most intensive growth until 6 weeks of age and then stabilised. The wing bones (humerus) showed only slight changes in the first weeks after hatching, and then a rapid growth between the third and sixth week, both in terms of mechanical and morphological properties. This is most likely due to a change in the geese's living environment during this period, i.e., allowing them to leave their enclosures and enter open space, which gives them the opportunity to use their wings, resulting in the rapid growth of the wing bones to support increasing muscle mass in this area. This study increases our understanding of bone growth and development in domesticated birds, specifically waterfowl species, and highlights the importance of rearing methods on the proper bone development and functionality of the entire skeletal system, and thus, on their welfare.

3.
J Endourol ; 37(8): 935-939, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37337653

RESUMO

Purpose: On February 6, 2018, the European Atomic Energy Community reduced the annual equivalent dose limit for the lens from 150 to 20 mSv/year, because of its association with cataracts at low radiation doses. Our aim was to estimate the radiation doses received by the lens during endourologic procedures that require fluoroscopy. Materials and Methods: Multicenter study including prospective data of annual eye dosimeters between 2017 and 2020. Four endourologists used an eye dosimeter in endourologic procedures that require fluoroscopy (ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy). Surgeons 1 and 2 wore leaded glasses; surgeon 1 also used the as low as reasonably achievable (ALARA) protocol. Descriptive statistical analysis using SPSS 25.0 was conducted. Results: Surgeons 1, 2, 3, and 4 performed a median of 159, 586, 102, and 129 endourologic procedures per year, respectively, for a total of 641, 2340, 413, and 350 procedures between 2017 and 2020. The median annual dose of lens radiation exposure was 0.16, 1.18, 3.79, and 1.42 mSv per year, respectively, which corresponds to 0.001, 0.009, 0.024, and 0.012 mSv per procedure. The two surgeons who used leaded glasses registered a lower radiation dose per procedure (0.001 vs 0.027). Similarly, the urologist who used the ALARA protocol registered the lowest lens radiation dose compared with the three surgeons who did not use it (0.001 vs 0.023). Conclusions: The endourologists who participated in this study effectively comply with current guidelines on radiation exposure to the lens. Registered eye lens radiation does not seem to be related to the number of procedures but rather to the use of leaded glasses and the ALARA protocol.


Assuntos
Cristalino , Exposição Ocupacional , Exposição à Radiação , Humanos , Estudos Prospectivos , Doses de Radiação , Fluoroscopia/efeitos adversos , Estudos Multicêntricos como Assunto
4.
J Clin Med ; 11(11)2022 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35683595

RESUMO

(1) Background: New pulse modulation (PM) technologies in Holmium:YAG lasers are available for urinary stone treatment, but little is known about them. We aim to systematically evaluate the published evidence in terms of their lithotripsy performance. (2) Methods: A systematic electronic search was performed (MEDLINE, Scopus, and Cochrane databases). We included all relevant publications, including randomized controlled trials, non-randomized comparative and non-comparative studies, and in-vitro studies investigating Holmium:YAG lithotripsy performance employing any new PM. (3) Results: Initial search yielded 203 studies; 24 studies were included after selection: 15 in-vitro, 9 in-vivo. 10 In-vitro compared Moses with regular PM, 1 compared Quanta's, 1 Dornier MedTech's, 2 Moses with super Thulium Fiber Laser, and 1 compared Moses with Quanta PMs. Six out of seven comparative studies found a statistically significant difference in favor of new-generation PM technologies in terms of operative time and five out of six in fragmentation time; two studies evaluated retropulsion, both in favor of new-generation PM. There were no statistically significant differences regarding stone-free rate, lasing and operative time, and complications between Moses and regular PM when data were meta-analyzed. (4) Conclusions: Moses PM seems to have better lithotripsy performance than regular modes in in-vitro studies, but there are still some doubts about its in-vivo results. Little is known about the other PMs. Although some results favor Quanta PMs, further studies are needed.

5.
Science ; 152(3723): 755-7, 1966 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-17797442

RESUMO

A much sharper and lower superconducting transition has been found for alpha-uranium than any reported previously. A model that explains the unusual volume dependence of alpha-uranium below 43 degrees K and the unusual pressure dependence of its superconducting transition temperature is presented.

6.
Science ; 159(3814): 530, 1968 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-17792467

RESUMO

Ferromagnetism, antiferromagnetism, or superconductivity has been discovered in most hexa- and dodecaborides.

7.
Science ; 160(3835): 1443-4, 1968 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-17817351

RESUMO

Magnetic ordering in the rare-earth hexaborides has been studied by a variety of methods, and a clear correlation with the presence of conduction electrons has been found.

8.
Poult Sci ; 98(10): 5152-5156, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31073603

RESUMO

Embryo development and chick quality are influenced by parental genotype, age, nutrition, environment, and flock management. The aim of study was to determine if genotype, age of goose or eggs laid near the onset of egg production vs. eggs laid near the end of reproduction influence the stage of embryo at oviposition. Three experiments were undertaken. To compare genotypes (Experiment 1) 150 eggs were collected from 3-year-old commercial line White Koluda (WK) geese and from two breeds involved in a genetic resources conservation program, Zatorska (Za) and Bilgoraj (Bi). Age comparison (Experiment 2) was conducted with 200 eggs collected from 1-, 2-, 3-, and 4-year-old WK geese. To compare laying periods (Experiment 3), 150 WK eggs were collected at the first week of March and 100 at the second half of June. Eggs were stored for 72 h at 16°C, staged using Eyal-Giladi and Kochav (EGK, Roman numerals) and Hamburger and Hamilton (HH, Arabic numerals) procedures. Experiment 1: Individual breed differences were evident with Stage X EGK embryos comprising 42.4, 33.3, and 38.7% in the eggs examined from the WK, Bi, and Za, respectively. For all breeds combined, 38.8% of the embryos were in Stage X, but in the next order in WK there was stage XI (18.2%), while in geese from the genetic reserve it was stage XIII (Bi - 33.3; Za - 29.0%). Experiment 2: In eggs of 1-, 2-, and 3-year-old WK geese, the majority of embryos (38.7, 32.4 and 42.2%, respectively) were in Stage X. In contrast, in 4-year-old geese the embryos were in Stage XI (36.1%). Experiment 3: In eggs collected in March and in June most of embryos were in Stage X (33.7% and 43.6%, respectively). In addition, more developmentally advanced stages (XI-XIII) were similar in both periods. However, embryos in Stage 2 HH were only observed in eggs collected at the end of laying season. Interestingly, earlier stages (VI-IX) were observed exclusively in the eggs collected in March.


Assuntos
Embrião não Mamífero/embriologia , Desenvolvimento Embrionário , Gansos/embriologia , Genótipo , Reprodução/fisiologia , Fatores Etários , Animais , Gansos/genética , Gansos/fisiologia , Oviposição , Fatores de Tempo
9.
J Comp Neurol ; 407(1): 130-50, 1999 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-10213193

RESUMO

The habenular complexes represent phylogenetically constant structures in the diencephalon of all vertebrates. Available evidence suggests that this area is engaged in a variety of important biological functions, such as reproductive behaviors, central pain processing, nutrition, sleep-wake cycles, stress responses, and learning. Based on Nissl-stained sections, one medial nucleus and two lateral nuclei (divisions) have been widely accepted in the rat. Cytochemical, hodologic, and functional studies suggest a considerably more complex subnuclear structure. To improve our knowledge of the precise structural composition of the habenular complexes, we have systematically investigated their fine ultrastructure in the rat. Based on the detailed analysis of complete series of large, semithin sections supplemented with electron photomicrographs of selected fields, clear criteria for the delineation of five distinct subnuclei of the medial and ten subnuclei of the lateral habenular complexes were elaborated for the first time. All 15 subnuclei were reconstructed, and their dimensions were determined. A medial and lateral stria medullaris were described. Different roots of the fasciculus retroflexus were differentiated within the medial and lateral habenular complexes. The topographical relationships with respect to the adjacent habenular areas as well as to the neighboring thalamic nuclei were identified and demonstrated. The new understanding of the subnuclear organization of the habenular complexes certainly will facilitate further functional investigations. Whether the newly identified subnuclei finally will be recognized as functionally distinct awaits ongoing immunocytochemical, hodologic, and functional studies.


Assuntos
Diencéfalo/ultraestrutura , Habenula/ultraestrutura , Ratos/anatomia & histologia , Animais , Diencéfalo/anatomia & histologia , Feminino , Habenula/anatomia & histologia , Masculino
10.
Microsc Res Tech ; 53(2): 96-105, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11301485

RESUMO

Pachymeninx and leptomeninx of cranial cavity and spine are considerably different in their collagenous fiber texture, cellular composition, vascularization, and innervation. The majority of meningeal nerve fibers terminate as free nerve endings whereas encapsulated and lamellated nerve terminals additionally occur in higher vertebrates including man. With respect to nerve fiber classification, arborization pattern, topography, and organization of the microenvironment at the termination site afferent and efferent nerve terminals are differentiated. Only the dura mater and the pial subcompartment of the leptomeninx possess the morphological prerequisites for neurogenic inflammation. In the current review, the results of morphological studies regarding the meningeal innervation including the sites of CSF (cerebrospinal fluid) production and absorption are discussed with emphasis on their structure-function relationships.


Assuntos
Meninges/ultraestrutura , Terminações Nervosas/ultraestrutura , Fibras Nervosas/ultraestrutura , Crânio/inervação , Coluna Vertebral/inervação , Aracnoide-Máter/ultraestrutura , Líquido Cefalorraquidiano/metabolismo , Dura-Máter/ultraestrutura , Humanos , Meninges/anatomia & histologia , Meninges/metabolismo , Pia-Máter/ultraestrutura , Crânio/anatomia & histologia , Crânio/ultraestrutura , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/ultraestrutura
11.
Science ; 151(3713): 985-6, 1966 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-17796778
12.
Neurosci Lett ; 151(1): 74-6, 1993 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-8469440

RESUMO

The adult hagfish, Myxine glutinosa, does not exhibit a lateral line system. The hypodermal layer of the dorsal head and body skin contains a prominent receptor system--lamellated corpuscles--arranged in a segmental pattern close to the body fascia. The topography and the structural organization of the lamellated receptors are described at the light- and electronmicroscopical levels. Spinal nerves supply the lamellated receptor organs. A mechanoreceptive function and evolutionary aspects are discussed.


Assuntos
Feiticeiras (Peixe)/fisiologia , Mecanorreceptores/fisiologia , Fenômenos Fisiológicos da Pele , Animais , Histocitoquímica , Microscopia Eletrônica , Pele/citologia , Pele/inervação , Fixação de Tecidos
13.
Neurosci Lett ; 127(1): 121-4, 1991 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-1881608

RESUMO

Myelinated and unmyelinated axons terminate within the arachnoid granulations. Serial section analysis by light and transmission electron microscopy reveals that the nerve fibers terminate at different locations or tissue compartments of the arachnoid granulation. 1. Myelinated axons ramify and terminate as free axon terminals like slowly adapting type II mechanoreceptors in the leptomeningeal connective tissue core of the granulation. 2. Myelinated and unmyelinated axons terminate in the transitional spongy zone which represents a tissue compartment for the diffusion of the cerebrospinal fluid from the subarachnoidal space to the venous sinus. This zone is composed of arachnoidal cells, dural neurothelial cells and fibrocytes. 3. Myelinated and unmyelinated axons terminate within lymphoid cell aggregation associated to the arachnoid granulation.


Assuntos
Aracnoide-Máter/ultraestrutura , Terminações Nervosas/ultraestrutura , Fibras Nervosas/ultraestrutura , Neurônios Aferentes/ultraestrutura , Animais , Macaca mulatta , Microvilosidades/ultraestrutura , Fibras Nervosas Mielinizadas/ultraestrutura , Primatas
14.
Anat Embryol (Berl) ; 177(6): 523-35, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3377193

RESUMO

Two types of electroreceptors, the ampullary and the tuberous electroreceptor (silurid knollenorgan) in the epidermis of the catfish, Pseudocetopsis spec., were investigated with semithin and ultrathin serial sections. The ampullary organ contains one or two sensory cells which are embedded in supporting cells at the base of open epithelial canals. They bear some slender microvilli on their apical surface and form several synaptic bars. The afferent myelinated nerve fiber arborizes in the connective tissue papilla and looses its myelin sheath about 30 micron below the supporting cell layer. A second thin myelinated axon occur up to the supporting cell layer. The tuberous electroreceptor organ contains one large receptor cell. Most of the cell body is exposed to the lumen of a specialized proximal canal segment and is closely covered with microvilli. A single myelinated axon looses its myelin sheath within the supporting cell layer about 1 micron before terminating as a flat calyx at the base of the sensory cell. A functional significance of the two types of receptors will be discussed.


Assuntos
Peixes-Gato/anatomia & histologia , Células Receptoras Sensoriais/ultraestrutura , Animais , Epitélio/ultraestrutura , Resposta Galvânica da Pele , Órgãos dos Sentidos/ultraestrutura , Pele/ultraestrutura
15.
Anat Embryol (Berl) ; 184(4): 371-93, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1952110

RESUMO

The gross anatomy and nerve supply of the bill of echidna (Tachyglossus aculeatus) is described in relation to its function as an outstanding sensory organ. The sensory innervation of the skin of the echidna snout was investigated by means of frontal serial sections, after decalcification of the specimens. A comprehensive light and electron microscopic description of the location and fine structure of cutaneous sensory receptors of the trigeminal system was made by this means. The encapsulated and non-encapsulated Ruffini receptors, the types of other free receptors in the connective tissue and the Merkel cell receptor do not differ morphologically from those of higher mammals, whereas the pacinian-like corpuscle shows a unique organization of its outer core. This is composed of large perineural cells containing a unique reticulum of parallel-orientated endoplasmic membranes. Lamellated corpuscles, seen in isolation or in association with push rods, are numerous in the snout and in the tip of the tongue of echidna. Push rod receptor organs occur in the hairless skin of the bill with a very dense array at its rostral end and in the pseudopalatal ridges. Gland duct receptors are restricted to the skin adjacent to the nostrils and the mouth opening, including the pseudopalatal plates. Only about one quarter of the total number of 400 seromucous glands receive a sensory innervation of their intraepidermal duct segment. Within each innervated gland two types of receptor terminals are identified. The distributions of the different receptor types are mapped for different regions of the skin, the mucous membrane of the nasal and oral vestibule and the tip of the tongue. The fine structure of nerve terminals is discussed from a comparative anatomical point of view, and some speculations are made about possible transduction processes that underlie the known electrophysiological properties. The sensory organs such as the "push rod" and "gland duct receptor", and most of their sensory terminals, are less differentiated in echidna snout than in the platypus (Ornithorhynchus anatinus) bill.


Assuntos
Células Receptoras Sensoriais/anatomia & histologia , Tachyglossidae/anatomia & histologia , Animais , Tecido Conjuntivo/inervação , Glândulas Écrinas/inervação , Microscopia Eletrônica , Terminações Nervosas/anatomia & histologia , Nariz/anatomia & histologia , Nariz/inervação , Pele/inervação , Nervo Trigêmeo/anatomia & histologia
16.
Anat Embryol (Berl) ; 175(3): 289-301, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3826655

RESUMO

The dura mater encephali of the rat is richly supplied by myelinated (A-axons) and unmyelinated (C-axons) nerve fibres. For the supratentorial part the main nerve supply stems from all three branches of the trigeminal nerve. Finally, 250 myelinated and 800 unmyelinated nerve fibres innervate one side of the supratentorial part. The vascular bed of the dura mater exhibits long postcapillary venules up to 200 micron in length with segments of endothelial fenestration. Lymphatic vessels occur within the dura mater. They leave the cranial cavity through the openings of the cribriform plate, rostral to the bulla tympani together with the transverse sinus, and the middle meningeal artery. The perineural sheath builds up a tube-like net containing the A- and C-axons. It is spacious in the parietal dura mater and dense at the sagittal sinus along its extension from rostral to caudal and at the confluence of sinuses. Terminals of both the A- and C-axons are of the unencapsulated type. Unencapsulated Ruffini-like receptors stemming from A-axons are found in the dural connective tissue at sites where superficial cerebral veins enter the sagittal sinus and at the confluence of sinuses. The terminations of single A-axons together with C-fibre bundles mix up in their final course in one Schwann cell to build up multiaxonal units or terminations (up to 15 axonal profiles). A morphological differentiation is made due to the topography of these terminations; firstly, in different segments of the vascular bed: postcapillary venule, venule, the sinus wall, lymphatic vessel wall, and secondly, within the dura mater: inner periosteal layer, collagenous fibre bundles of the meningeal layer and at the mesothelial cell layer of the subdural space.


Assuntos
Dura-Máter/anatomia & histologia , Terminações Nervosas/ultraestrutura , Fibras Nervosas/anatomia & histologia , Animais , Axônios/ultraestrutura , Vasos Sanguíneos/ultraestrutura , Encéfalo , Tecido Conjuntivo/anatomia & histologia , Dura-Máter/irrigação sanguínea , Dura-Máter/ultraestrutura , Sistema Linfático/inervação , Fibras Nervosas Mielinizadas/ultraestrutura , Ratos , Ratos Endogâmicos , Vênulas/inervação
17.
Anat Embryol (Berl) ; 172(2): 133-43, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4051190

RESUMO

In cats the time course of degeneration following lumbal sympathectomy was studied in the ramus communicans griseus (rcg) and in the nerves to the triceps surae muscle using light and electron microscopic methods. The left lumbar sympathetic trunk including its rami communicantes was removed from L2 to S1 using a lateral approach. The animals were sacrificed between 2 and 48 days after the sympathectomy. Tissue samples were taken (a) one cm proximal to the entrance of the rcg into the spinal nerve, and (b) one cm proximal to the entrance of the nerve into the muscle belly. In the rcg signs of degeneration can already be recognized in the myelinated as well as in the unmyelinated axons 48 h after sympathectomy. The degenerative processes in the axons reach their peak activity at about 4 days p.o. They end a week later. Signs of the reactions of the Schwann cells and of the endoneural cells can first be seen 2 days p.o. They are most pronounced around the 8th day p.o., and last at least up to the third week. Thereafter the cicatrization processes settled to a rather steady state (total observation period 7 weeks). In the muscle nerves the first signs of an axonal degeneration of the sympathetic fibers can be recognized 4 days after surgery. The signs of axonal degeneration are most striking about 8 days p.o. They have more or less disappeared another week later. The reactions of the Schwann cells also start on the fourth day but outlast the degenerative processes by some 8 days. Thus the degenerative and reactive processes in the rcg precede those in the muscle nerves by 2 days early after surgery and by 6 days 3 weeks later. Seven weeks after surgery, fragments of folded basement lamella and Remak bundles with condensed cytoplasm and numerous flat processes are persisting signs of the degeneration. In addition to the differences in time course between the proximal and the distal site of observation, it was also noted that both the axonal degeneration and the reactions of the Schwann cells are more pronounced in the rcg than in the muscle nerve. For example there was abundant mitotic activity in the central endoneural and Schwann cells whereas we could not detect such activity in the periphery.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Gânglios Simpáticos/patologia , Degeneração Neural , Fibras Nervosas/patologia , Simpatectomia , Animais , Axônios/ultraestrutura , Gatos , Músculos/inervação , Fibras Nervosas/ultraestrutura , Fatores de Tempo
18.
Anat Embryol (Berl) ; 172(2): 145-56, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4051191

RESUMO

In sympathectomized cats the innervation of the Achilles tendon by fine afferent nerve fibers was studied with semithin and ultrathin sections. Several different types of sensory endings of group III and group IV nerve fibers were identified. Of the five different types of endings in the group III range (T III endings), two are located within vessel walls. One of them ends in the circumference of the venous vessels (T III/VV). Its lanceolate terminals have characteristic receptor areas at their edges. The second type ends in the adventitia of lymphatic vessels (T III/LV). Its receptive areas are scattered along their terminal course. Two further group III endings ramify within the connective tissue compartments of the vessel-nerve-fascicles of the peritenonium externum and internum. One type is tightly surrounded by collagen fibrils (T III/PTic); the other terminates between the collagen fiber bundles (T III/PTgc). The latter arrangement recalls the ultrastructural relation between nerve terminals and collagen tissue in Golgi tendon organs. The fifth type innervates the endoneural connective tissue of small nerve fiber bundles (T III/EN). At least some of them come into close contact with bundles of collagen fibers which penetrate the perineural sheath to terminate within the endoneurium. The endings of group IV afferents (T IV endings) show a striking topographic relationship to the blood and lymphatic vessels of all connective tissue compartments of the Achilles tendon. They form penicillate endings which may contain granulated vesicles. In any event, they can easily be discriminated from the T III endings in the vessel walls. In close neighborhood to Remak bundles, a cell has been regularly found which fulfilled all ultrastructural criteria for mast cells. But this cell is not a mast cell proper because it is surrounded by a basal lamina (pseudo mast cell).


Assuntos
Tendão do Calcâneo/inervação , Fibras Nervosas/anatomia & histologia , Sensação/fisiologia , Vias Aferentes/anatomia & histologia , Vias Aferentes/ultraestrutura , Animais , Axônios/classificação , Axônios/ultraestrutura , Gatos , Terminações Nervosas/ultraestrutura , Fibras Nervosas/ultraestrutura
19.
Anat Embryol (Berl) ; 182(4): 363-73, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-1701289

RESUMO

Density and pattern of nerve fibers with neuropeptide Y-like immunoreactivity (NPY-LI) and substance P-like immunoreactivity (SP-LI) in the rat dura mater encephali were investigated by light and electron microscopy using whole-mount preparations. NPY-LI fibers are observed throughout the encephalic dura mater. A remarkable net of NPY-LI nerve fibers is located in the walls of the sagittal and transverse sinuses. Beyond that NPY-LI network, distinct NPY-LI nerve fibers or plexus occur in the rostral falx, parietal dura mater of the olfactory bulb, supratentorial dura mater, parietal dura mater of the cerebellum, tentorium cerebelli and the ventral dura mater. Electron microscopic studies reveal that NPY-LI is exclusively located in unmyelinated axons of small and large nerve fiber bundles, with or without a perineural sheath. Immunopositive C-fibers are predominantly associated with the vascular bed. SP-LI nerve fibers have a moderate and more uniform distribution in the encephalic dura mater. A distinct plexus of SP-LI fibers follows the branches of the middle meningeal artery and the adjacent dura mater. SP-LI fibers are most prominent in the parietal dura mater of the cerebellum. Fine beaded SP-LI fibers, arising from larger SP-LI fiber bundles, are observed in close association to the capillary bed. SP-LI axons are all unmyelinated. They are found in larger nerve fiber bundles with a perineural sheath or in Schwann cells lacking any perineural sheath. The function of NPY-LI and SP-LI nerve fibers in the rat dura mater is discussed in relation to their topography, density and termination.


Assuntos
Dura-Máter/ultraestrutura , Fibras Nervosas/ultraestrutura , Neuropeptídeo Y/análise , Substância P/análise , Animais , Axônios/química , Axônios/ultraestrutura , Cerebelo/ultraestrutura , Masculino , Microscopia Eletrônica , Bulbo Olfatório/ultraestrutura , Ratos , Ratos Endogâmicos , Células de Schwann/ultraestrutura
20.
Eur J Morphol ; 32(2-4): 248-56, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7803174

RESUMO

Topography and ultrastructural organization of proprioceptors in the striated parietal muscle of the hagfish, Myxine glutinosa, are described. Due to the topographical location of the afferent nerve terminals four subtypes of proprioceptors are distinguished. Type 1-receptor and type 2-receptor are localized in an encapsulated and lamellated corpuscular organ located along and above the myosepta of the parietal muscle. Type 3-receptor is composed of a complex of free en plaque nerve endings within the dense collagen fibre texture at the site where myoseptum, muscle fascia and body fascia fuse to a raphe. Type 4-receptor resembles type 3 but it is localized in the straight collagen fibre bundles of the myoseptum and the body fascia. A proprioceptive function of the nerve terminals is discussed.


Assuntos
Feiticeiras (Peixe)/anatomia & histologia , Propriocepção , Células Receptoras Sensoriais/ultraestrutura , Animais , Microscopia Eletrônica , Músculo Esquelético/inervação
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa