ISSN:1422-6405    

DOI:10.1159/000147412

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000147413

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The distribution of fibronectin (FN), laminin (LM), hyaluronic acid (HA) and chondroitin sulfate (CS) were examined by peroxidase immunocytochemistry in long-tailed monkey embryos during the period of neural tube and notochord formation (stages 8-11). Reactivity for each component in the neuroepithelial basement membrane (BM) increased with advancing development. Discontinuous staining was observed in areas of epithelial-to-mesenchymal transformation, i.e. in dorsolateral sites of neural crest emigration and in the axial region of the primitive streak. The BM forming around the developing notochord also showed increased reactivity for FN, LM, HA and CS between stages 8 and 11. No staining occurred within the notochord. Stage-related increases in reactivity in the mesenchymal matrix was particularly notable for FN and HA which were ubiquitous throughout the mesoderm by stage 11. The results of this study are consistent with the proposed role of these components in maintaining epithelial integrity and providing a permissive substrate for cell migration during development. The observed temporal and regional staining patterns suggest that these glycoproteins and glycosaminoglycans are important morphogenetic factors in the macaque.

ISSN:1422-6405    

DOI:10.1159/000147414

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

An intimate association of nerve fibers with the central lacteal endothelium was demonstrated in the duodenum and ileum of the monkey by immunohistochemistry and transmission electron microscopy. In the basal portion of the central lacteal, nerve fibers containing large cored vesicles and small clear vesicles were located closely beneath the lacteal endothelium. Identification of nerves was performed by immunohistochemistry using antisera against substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide, gastrin-releasing peptide and neuropeptide Y. These nerves contained immuno-reactivities for SP and CGRP only. Some of the nerves, either singly or in a dense bundle, indented the endothelial cells to form a conspicuous cushion protruding into the lumen. The attenuated endothelium covering the cushion occasionally was failing, and the nerves were exposed to the lumen. Tight of occasionally subendothelial nerve terminals bundles formed a synapse-like association between themselves: a swollen axonal profile was invaginated by a fingerlike projection of another axon, the latter being filled with synaptic vesicles. These results suggest that the central lacteal lymphatics might be afferently monitored, presumably with regard to the luminal pressure, and, at the same time, efferently modulated by these nerves.

ISSN:1422-6405    

DOI:10.1159/000147415

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The region above, below and in front of the ileocecal valve opening has been studied in man using both light and electron microscopy. A cecocolonic junction, comprising the colonic basal portion of the ileocecal valve, could be demonstrated in man, due to the specific anatomy of the inner portion of the circular muscle. This muscle was arranged in anastomosing cords, richly innervated and enveloped by elastic fibers. Its smooth muscle cells were characterized by extremely wide sarcoplasmic cisternae and cell-to-cell junctions, numerous caveolae and large amounts of glycogen. Interstitial cells were rarely found. This junction might be considered responsible for (1) ileal flow accommodation, (2) colonic active movements and (3) ileocecal valve closing and opening.

ISSN:1422-6405    

DOI:10.1159/000147416

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The inter-relationship between putative cholinergic and noradrenergic innervation of the human adrenal cortex was investigated using a technique which combined acetylcholinesterase histochemistry, choline acetyltransferase radio-chemistry and dopamine β-hydroxylase immunohistochemistry. Cholinergic and noradrenergic nerve fibres had a near-identical distribution, with varicose noradrenergic fibres located immediately alongside non-varicose cholinergic nerve bundles in all cortical zones. Choline acetyltransferase activity was consistently detected in the adrenal cortex, confirming the presence of cholinergic neurons. It is postulated that noradrenergic innervation has a role in the modulation of cortical endocrine secretion, while cholinergic nerves are mainly concerned with the control of medullary secretion

ISSN:1422-6405    

DOI:10.1159/000147417

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

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. The density of receptors in the oral mucous membrane of the lower jaw of M. domestica implies that this richly innervated mechanoreceptive area acts as an antagonist of the tongue and provides important information during mastication.

ISSN:1422-6405    

DOI:10.1159/000147418

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

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.

ISSN:1422-6405    

DOI:10.1159/000147419

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Pacinian corpuscles in the cat urinary bladder were studied using the hematoxylin and eosin staining, formaldehyde-induced fluorescence histochemistry, immunohistochemistry for tyrosine hydroxylase (TH) and immunoelectron microscopy. The existence of catecholaminergic nerve fibers penetrating into the corpuscles was clarified. (1) About 10 Pacinian corpuscles which were mainly located in the subserosa were found in the lower one-third portion of each urinary bladder. (2) One or two corpuscles containing blue-green fluorescent fibers were detected in each bladder. These fibers were equivalent to TH-immunopositive varicose fibers using the avidin-biotin-peroxidase complex method. (3) Thin nerve fibers containing dense-cored vesicles were found in the corpuscle by immunoelectron microscopy. These fibers spirally encompassed a swollen sensory terminal at a distance in the inner core. According to the above findings, we discuss a modulatory function of the catecholaminergic fibers in this mechanoreceptor.

ISSN:1422-6405    

DOI:10.1159/000147420

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A morphoquantitative study was carried out to clarify the cytoarchitecture of the human nuclear complex of the posterior commissure (NPC), a collection of cell groups which is thought to be involved in the pupillary light reflex and eye movements. On the basis of the topographical features, 5 different parts (rostral, principal, magnocellular, subcommissural and infracommissural) were identified in NPC. In these 5 parts, the neuronal population consisted of small and medium-sized neurons with a structural pattern similar to that of the central reticular formation. The only exception was the magnocellular part in which the neurons, mainly medium-sized and large, did not show the reticular-like features. In the Golgi material, two types of NPC neurons were identified: multipolar and fusiform cells. In the multipolar cells, 2-3 dendrites emerged from the soma and gave off a wide dendritic arborization. Many of the dendrites and axons of the multipolar cells were seen spreading outside NPC. The fusiform cells had 2 dendrites emerging from the opposite poles of their elongated perikaryon. Dendrites and axons of the fusiform cells always lay inside NPC. These observations suggest that the multipolar cells are mainly projective neurons and that the fusiform cells are neurons which mainly perform a local integrative function. Since the present study concludes our investigation of the human accessory oculomotor nuclei, a comparison of their structure was carried out. All the nuclei showed a common reticular-like structure, although each nucleus had its own structural particularities. These results are in agreement with and give an anatomical support to the functional findings.

ISSN:1422-6405    

DOI:10.1159/000147421

出版商:S. Karger AG    

年代:1993

数据来源: Karger