摘要:

AbstractThe extrinsic innervation of the guinea pig pylorus was studied by the use of the horseradish peroxidase (HRP) tracing technique. Forty‐eight hours after injection of HRP into the pyloric sphincter labeled neurons of varying sizes were found throughout the rostrocaudal extent of the dorsal motor nuclei of the vagus. No HRP positive cells were seen in the medial solitary nuclei or the ambiguus nuclei. Many HRP‐positive cells were observed in the celiac‐superior mesenteric ganglion complex. Occasional cells in the superior cervical and stellate ganglia were also labeled. When the vagal ganglia were analyzed many enzyme‐containing cells were found in the nodose ganglia and some cells in the jugular ganglia. Furthermore, about 15–20% of the labeled afferent neurons were located in dorsal root ganglia on both sides, with the majority of cells at the T5–T10 levels. The results are discussed in relation to recent transmitter histochemical findings as well as to possible functional roles of

ISSN:0092-7317    

DOI:10.1002/cne.902080402

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe peripheral branching of the identified motor neurons Dfand Dswhich innervate the coxal depressor muscles in the legs of cockroaches was examined using the anterograde transport of a cobaltic ‐lysine complex and the retrograde transport of cobaltous ion or horseradish peroxidase. In all animals the axons of these motor neurons leave the ganglion in the dorsal portion of nerve root 5 and undergo a 180° spiral that brings them directly to the first branch. They leave the nerve root at this branch to innervate the muscles. The pattern of branching of Dfwithin muscles 178 and 179 was highly stereotyped with little variability being observed among identical and homologous muscles within the same and different individuals. The great extent of the neuronal branching within the muscles suggests that a relatively large percentage of the surface area of the muscle fibers is involved in intercellular interactions with the motor neurons. The two motor neurons could also be distinguished by the structure of their axon terminals. Those of Dfwere beaded and extended either parallel or perpendicular to the muscle fiber. Those of Dswere thinner, wavy, less regular, and appeared with a greater frequency. Identified neurons may therefore be further characterized by their stereotypical peripheral branching and axon terminal structu

ISSN:0092-7317    

DOI:10.1002/cne.902080403

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe localization of a new low molecular weight glycoprotein subunit in cerebellum was studied with the aid of the indirect immunohistochemical method at the electron microscope level. The specificity of this molecule for Purkinje cells in the rat cerebellum suggested by earlier light microscope studies was confirmed. Immunoperoxidase reaction product indicative of the presence of this glycoprotein was exclusively limited to Purkinje cells, attached to the plasma membrane, membranes of the rough endoplasmic reticulum, the cytoplasmic surface of the nuclear membrane, and on polyribosomes. The antigen was found throughout the whole cell, except for the nucleus, and enabled Purkinje cell processes to be traced in the molecular layer, in the granule cell layer (including the nerve terminals in this layer), and to their axon terminals in the deep nuclei. The fine structural localization is discussed with reference to the known properties of this antigen.

ISSN:0092-7317    

DOI:10.1002/cne.902080404

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractParaphyseal epithelial cells ofNatrix maurahave been studied with light and electron microscopy. They showed a clear polarity apically related to the third ventricle and, basally, to a connective tissue layer which surrounded the whole organ. The apical surface of the cells, attached by junctional complexes, showed many microvilli, scarce cilia, and some pinocytotic coated vesicles. In their apical cytoplasm many mitochondria and a well developed Golgi apparatus and endoplasmic reticulum were observed. Whereas lamellar bodies were abundant and closely related with mitochondria, glycogen particles were absent. Basal cell membrane showed infoldings where pinocytotic coated vesicles were detected. In the connective tissue layer, fenestrated sinusoids and fibrocytes, as well as rare unmyelinated nerve fibers engulfed by Schwann cells, were present. The possible active role of paraphyseal cells in exchanging substances between cerebrospinal fluid and blood is discussed.

ISSN:0092-7317    

DOI:10.1002/cne.902080405

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe technique of intracellular recording and staining of the same neuron with horseradish peroxidase (HRP) was used to study the soma‐dendritic and axonal morphology of nigrothalamic and nigrotectal cells in the rats.The nigrothalamic and nigrotectal cells were spread throughout the dorsoventral extent of the pars reticulata (SNR) and exhibited the same soma‐dendritic and axonal features. Both populations consisted of medium‐sized and large cells with extensive dendritic fields overlapping in all three directions. Their axons collateralized within the substantia nigra (SN) and in the mesencephalic tegmentum. The intrinsic collaterals were thin and branched partly within the dendritic field of a parent cell partly in remote regions of the SNR, and even in the pars compacta (SNC). The extrinsic branches involved thin arborizations in the rostroventral mesencephalic reticular substance and thicker descending and ascending collaterals.This material was supplemented by physiologically nonidentified HRP stained medium‐sized and large neurons located in the SNR. The two kinds displayed the same extent and orientation of their dendrites but the branching patterns differed slightly. Proximal dendrites of all cells were coarse and smooth; thinner distal dendrites had varicosities and spinelike appendages. Some dendrites, especially those near the crus cerebri, terminated in dendritic thickets bearing many pleomorphic appendages.The orientation of dendritic fields varied with dorsoventral position of cells within the SNR. The most ventral region of the SNR contained neurons with dendrites oriented parallel to the crus cerebri and thus remained confined to the deepest stratum. The dendrites of cells in the central region of SNR were oriented mainly anteroposteriorly and ventrally, the ventral dendrites terminating in the ventralmost layer. Cells in the dorsolateral part of the SNR were characterized by the large dorsoventral extent of their dendrites which penetrated the entire thickness of SN. This variation in the arrangement of dendritic fields indicates that the SN is organized in three dorsoventral

ISSN:0092-7317    

DOI:10.1002/cne.902080406

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractAbducens motoneurons and internuclear neurons were identified electrophysiologically in anesthesized, paralyzed cats and stained by intracellular injection of horseradish peroxidase. Neurons were reconstructed and surface area of selected cells measured by light microscopy. Surface area of motoneurons and internuclear neurons with similar soma size and shape were roughly comparable. Dendrites of motoneurons were highly tapered and highly branched. By contrast, dendrites of internuclear neurons were less tapered and less branched. Axons of motoneurons had no collaterals within the brainstem. Internucler axons crossed the midline at the level of their parent somata and ascended in the medial longitudinal fasciculus toward the oculomotor nucleus. Approximately 30% of the internuclear axons branched in the contralateral medial longitudinal fasciculus sending a fine collateral caudal toward the prepositus hypoglossi nucleus. The results suggest that, on the average, structural correlates of injected neurons (i.e., soma‐dendritic morphology) can account at least in part for the earlier firing and higher intraburst frequencies of internuclear neurons versus motoneurons during on‐direction rapid eye movements in alert c

ISSN:0092-7317    

DOI:10.1002/cne.902080407

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractWe used the intraocular transplantation technique to test the developmental potential of isolated, fetal area dentata, and to help define the determinants of such critical aspects of brain development as cell arrangements, dendritic arborization, axon growth, synaptogenesis, and connectional specificity. Fetal hippocampal formations were removed from embryos of 19 to 20 days of embryonic age. A region, termedarea dentata, was dissected from the hippocampal formation. This region included the anlage of the dentate gyrus, the hilus, and the medial regio inferior. Areae dentatae were transplanted into the anterior eye chamber of isogenic, adult rats. The growth and vascularization of area dentata transplants were monitored over the first 2 months in oculo. From 2 to 7 months after transplantation host animals were killed and the area dentata transplants were examined with a variety of histological techniques. The cytoarchitectonics of a great majority of the transplants were highly reminiscent of area dentata in situ. A typical morphogenetic outcome included tightly packed, continuous, C‐shaped sheets of granule cells with mossy fibers which made contact with the proximal dendrites of a segregated group of dispersed hilar cells and a loosely packed layer of pyramidal cells. The axons of pyramidal and hilar cells, in turn, provided the major innervation of the granule cell dendrites. The granule cell dendritic spine density was nearly normal, and synapses were common in the granule cell neuropil. Very little innervation of the transplant was found to originate from the axons of the ciliary or trigeminal ganglia which innervate the host iris and enter the transplant. Sympathetic fibers from the host iris innervate the transplant in a reproducible and organotypic fashion although the degree of innervation is less than the in situ noradrenergic innervation of area dentata. Few Timm‐positive fibers of the transplant were found to leave the transplant and enter the host iris. Area dentata transplants had several features which were different from their in situ counterparts. These differences included less expansive granule cell dendrites, extensive presence of fibrous astrocytes, pyramidal cells with reduced kainic acid sensitivity, hypervascularized neuropil, and transformation of peripheral adrenergic fiber morphology to one of central characteristics.Thus, pieces of isolated area dentata display a great self‐developing capacity, in terms of cellular and afferent organization, both of which follow “rules” present in situ. A powerful capacity for intrinsic and appropriate innervation of area dentata is apparent in the face of a total lack of normal extrinsic afferents and an availability of extrinsic but inappropriate sources of innervation. This initial description of isolated area dentata organization in oculo is meant to lay the groundwork for experimental investigations into the regulatory mechanisms governing morphogenesis and afferent org

ISSN:0092-7317    

DOI:10.1002/cne.902080408

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractSince recent studies indicate that distinct neuropeptides and projections are associated with discrete portions of the central amygdaloid nucleus (CN), a detailed investigation of the cytoarchitecture of CN should contribute to an understanding of its organization. Qualitative and quantitative analyses of the rat CN using Nissl, Klüver‐Barrera, and Golgi techniques suggests that it consists of four subdivisions. The medial subdivision (CM), which is closely associated with the stria terminalis, is narrow caudally but enlarges near the rostral pole of CN. Most neurons in CM have long dendrites that branch sparingly and have a moderate number of dendritic spines. A smaller number of CM neurons have thick dendrites with virtually no spines. Lateral to CM is the lateral subdivision (CL) which appears round in coronal sections. Neurons of CL have a very dense covering of dendritic spines and resemble medium‐size spiny neurons of the striatum. Area X of Hall contains spiny neurons similar to those of CL and spine‐sparse neurons that resemble medium‐size spine‐sparse cells of the striatum. Since area X encapsulates the lateral aspect of CL, it is termed the lateral capsular subdivision (CLC) of CN. The lateral capsular subdivision enlarges rostrally and is divided into dorsal and ventral portions by a laminar extension of the putamen. Near the rostral pole of CN a small region of tightly packed, intensely stained neurons is interposed between CL and CM. Golgi preparations reveal that this intermediate subdivision (CI) of CN contains neurons similar to those of CM. The lateral subdivision, CLC, and CM correspond, in part, to subdivisions recognized in previous Nissl studies. The intermediate subdivision has not been recognized as a distinct subdivision in previous investigations. This is the first Golgi study to recognize differences in neuronal morphology in particular subdivisions of the rat CN. The correlation of Nissl and Golgi preparations has permitted a more accurate determination of the boundaries and total extent of each subdivision than the use of Nissl techni

ISSN:0092-7317    

DOI:10.1002/cne.902080409

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractMorphometric analyses of Golgi‐impregnated mitral and tufted cells in the main olfactory bulb of the hamster indicate that these second‐order neurons cannot be considered a homogeneous population. They are comprised of several categories based on differences in the sizes and spatial organizations of their dendritic fields and in their likely patterns of lateral and recurrent interactions with granule cells and/or periglomerular cells. External tufted cells have their somata in the periglomerular region or at the superficial border of the external plexiform layer (EPL) and can be subdivided into three morphological categories. Many external tufted cells lack secondary dendrites, i.e., all of their dendrites arborize within glomeruli. Most of these neurons are not in positions where they could receive synaptic contacts from granule cells and thus are likely to receive interneuronal input predominantly from periglomerular cells. Another category of external tufted cells is characterized by secondary dendrites which are highly branched and form dense but spatially restricted fields in the EPL. In contrast, external tufted cells in the third category have sparsely branched secondary dendrites which extend tangentially in the EPL and tend to be asymmetrically distributed with respect to the soma. Most of the deeperlying tufted cells, and the mitral cells, have sparsely branched secondary dendrites whose lengths and laminar distributions within the EPL are correlated with the depths of their parent somata. Internal tufted cells, which have their somata in the deep one‐third of the EPL, and mitral cells exhibit the largest secondary dendritic fields. These fields extend tangentially within the EPL in relatively symmetric radial patterns from their parent somata and envelop substantial proportions of the EPL. Middle tufted cells have their somata in the superficial two‐thirds of the EPL and exhibit secondary dendritic morphologies which are intermediate between those of internal and external tufted cells. These differences in the size and spatial organization of secondary dendritic fields are likely to be associated with differences in the amount and spatial distribution of lateral and recurrent inhibition mediated through synaptic contacts with granule cells. External tufted cells which lack secondary dendrites have large glomerular arbors that are comparable in size to those of mitral and internal tufted cells, whereas external tufted cells with secondary dendrites and middle tufted cells tend to have relatively small glomerular arbors. The morphological differences among mitral and tufted cells and the likely differences in their synaptic interactions within the olfactory bulb, together with recent evidence that these neurons differ in their pharmacology and in their patterns of interconnections with more central regions of the forebrain, suggest that the mitral and tufted cells and the central olfactory circuits may be organized as functionally defined parallel p

ISSN:0092-7317    

DOI:10.1002/cne.902080410

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902080401

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY