摘要:

AbstractWe investigated the localization of alkaline phosphatase (AP) in the peripheral and central nervous systems of the frog (Rana pipiens) and rat. In the frog sciatic nerve, AP reaction product was seen as a precipitate within caveolae and vesicular profiles of perineurial cells, and frequently filled the extracellular space. In the rat peripheral nerve, AP reaction product appeared as small tufts on the cell surfaces and within vesicular profiles of endoneurial blood vessels. AP reaction product was not detected in the rat perineurium or in endoneurial blood vessels of the frog. In the frog central nervous system, AP reaction product was detected in the arachnoid membrane adjacent to the subarachnoid space, but not in the cerebral or pial vessels, whereas in the rat it was detected in the outer arachnoid membrane and in the cerebral and pial blood vessels. Biochemical analysis indicated a sevenfold higher AP activity in the frog perineurium over the endoneurium, whereas in the rat, threefold more activity was measured in the endoneurium over the perineurium. Levamisole, an AP inhibitor, decreased the enzyme activity by 95% in rat tissues, and by 70% in frog tissues and in plasma from both animals. Similar decrements were observed cytochemically.This study suggests that: (1) the distribution of AP varies between species, but that it is always present in at least one component of the blood‐brain and blood‐nerve barriers, (2) because barrier tissues of the nervous system have enzymatic activity, they may biochemically modify the adjacent environment, (3) vesicular profiles and caveolae in the blood vessels and perineurium may function as microenvironments for enzymatic activity, and (4) in the rat and frog, different isozymes of AP may be pres

ISSN:0092-7317    

DOI:10.1002/cne.902640302

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe hagfish lateral line system was studied by horseradish peroxidase transganglionic transport. The anterior lateral line nerve innervates the group of lateral line canals situated anteriorly to the eye, and the posterior lateral line nerve innervates the group of canals situated posteriorly to the eye. Although both nerves pass through the muscle fascia at the same point, each runs a different course to the brain. The anterior lateral line nerve runs near the trigeminal nerve and its ganglion is closely attached to the trigeminal ganglion, but both systems are completely independent. The posterior lateral line nerve runs independently of any other cranial nerve and makes a peculiar U‐turn at the point of entry to the brain capsule. The anterior lateral line ganglion contains both cutaneous sensory cells (small to large cells) and lateral line sensory cells (small cells); from this ganglion projections run to both the trigeminal sensory nucleus (fine and thick fibers) and medial nucleus of the area acousticolateralis (fine fibers). The posterior lateral line ganglion contains only small lateral line cells that project fine fibers to the medial nucleus of the area acousticolateralis. There are no efferent components in this lateral line system, and its only afferent terminal field is the medial nucleus of the area acousticolaterali

ISSN:0092-7317    

DOI:10.1002/cne.902640303

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe cellular and synaptic morphology of a component of the feeding motor circuit inAplysia californicawas examined with light and electron microscopic techniques. The circuit consists of a pair of inhibitory premotor interneurons, B4 and B5, as well as two motoneurons, B15 and B16, which innervate the accessory radula closer muscle. The neurons have wide, varicose arborizations in the buccal ganglion neuropil. All four of these neurons are cholinergic, and in addition, B15 contains immunoreactivity to sera raised against small cardioactive peptide B. Varicose processes in the accessory radula closer muscle are immunoreactive with antisera against several neuropeptides. We identified specific neuromuscular junctions by visualizing horseradish peroxidase uptake in recycled synaptic vesicles. Direct innervation of the accessory radula closer muscle by B15 and B16 is demonstrated by experiments in which horseradish peroxidase is transported from motoneuronal soma to the terminals on muscle fibers. In addition, specific synaptic contacts between B4 and B5 and each of the motoneurons are observed in the buccal ganglion neuropil. Finally, multiple contacts consistent with peptidergic, serotoninergic, and cholinergic synapses are made onto the neurons, suggesting that a variety of transmitters modulate motor output at each level of the hierarchical circuit. These results support the physiological evidence suggesting the involvement of neuropeptides as well as “classical” transmitters in the modulation of circuitry governing feeding behavior inAply

ISSN:0092-7317    

DOI:10.1002/cne.902640304

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractAs an essential preliminary to a series of experimental studies of the afferent and efferent connections of the monkey entorhinal cortex, we have carried out a detailed analysis of its cytoarchitectonic organization. Primarily on the basis of features observed in Nissl‐ and fiber‐stained preparations, supplemented with Golgi‐stained material and preparations stained for heavy metals by Timm's method and histochemically for acetylcholinesterase, the entorhinal cortex has been divided into seven fields that are named according to their rostrocaudal and mediolateral positions except for one rostrally located field that is named for the prominent input that it receives from the olfactory bulb. At rostral levels, the entorhinal cortex is marked by a number of morphological inhomogeneities. The neurons tend to be organized in patches that are surrounded by large, thick, radially oriented bundles of fibers. At caudal levels, the entorhinal cortex has a more distinctly laminated appearance, reminiscent of that in the neocortex, and most of the neurons and fiber fascicles are arranged in discrete radial columns. The cortical region adjoining the entorhinal cortex laterally, which is commonly known as the “perirhinal cortex,” is in fact composed of two separate fields corresponding to areas 35 and 36 of Brodmann. Area 35 occupies the fundus and part of the lateral aspect of the rhinal sulcus. Area 36 extends from the lateral bank of the rhinal sulcus into the inferior temporal gyrus, where it borders fields TA and TE rostrally, and field TF of the parahippocampal gyrus caudally. The surface extents of each of the entorhinal fields have been determined by making “unfolded” two‐dimensional maps of the region and measuring the areas with a computerized di

ISSN:0092-7317    

DOI:10.1002/cne.902640305

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe entorhinal cortex of the monkey is commonly viewed as the major link between the cerebral cortex and the other fields of the hippocampal formation. Until recently, however, little was known about the origins of the cortical projections to the entorhinal cortex, and most of the available information is still based on degeneration studios. We have carried out a systematic analysis of these connections by placing small injections of the retrograde tracer wheat germ agglutinin conjugated to horseradish peroxidase into each of the fields of the entorhinal cortex of the Macaca fascicularis monkey, Retrograde labeled cells were observed in several areas of the frontal and temporal lobes, the insula, and the cingulate cortex. In the frontal lobe, the greatest number of labeled cells were observed in the orbital region and specifically in areas 13 and 13a: labeled cells were also seen in areas 14, 11, and 12. In the dorsolateral frontal cortex, labeled cells were observed mainly in the rostral half of area 46; occasionally cells were also seen in areas 9, 8, and 6. In the cingulate cortex, labeled cells were observed in area 25, area 32, and rostral levels of area 24; fewer cells were observed at caudal levels of area 24 or in area 23. The retrosplenial region (areas 30 and 29), including its caudal extension along the rostral calcarine sulcus and its ventral extension into the temporal lobe, contained numerous labeled cells. In the temporal lobe, retrogradely labeled cells were arranged in two rostrocaudally oriented bands. Rostral to the hippocampal formation, the first band encompassed the priform and periamygdaloid cortices and areas 35 and 36; the labeling in area 36 was continuous to the temporal pole. At more caudal levels this band was located immediately lateral to the hippocampal formation and included areas 35 and 36 rostrally and areas TH and TF caudally. The second band was situated in the superior temporal gyrus where labeled cells were observed in several distinct cytoarchitectonic fields, including the parainsular cortex in the fundus of the inferior limiting sulcus. In the insula proper, retrogradely labeled cells were seen mainly in the rostral or agranular division; far fewer were observed in the dysgranular and granular insula. Whereas there is little available physiological information concerning many of the cortical regions that project to the entorhinal cortex, on anatomical grounds they may be generally characterized as poly sensory associational regions.

ISSN:0092-7317    

DOI:10.1002/cne.902640306

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe subcortical afferent connections of the entorhinal cortex of theMacaca fascicularismonkey were investigated by the placement of small injections of the retrograde tracer wheat germ agglutinin conjugated to horseradish peroxidase into each of its subdivisions. Retrogradely labeled cells were observed in several subcortical regions including the amygdaloid complex, claustrum, basal forebrain, thalamus, hypothalamus, and brainstem. In the amygdala, labeled cells were observed principally in the lateral nucleus, the accessory basal nucleus, the deep or paralaminar portion of the basal nucleus, and the periamygdaloid cortex. Additional retrogradely labeled cells were found in the endopiriform nucleus, the anterior amygdaloid area, and the cortical nuclei. Retrogradely labeled cells were observed throughout much of the rostrocaudal extent of the claustrum and tended to be located in its ventral half. In the basal forebrain, retrogradely labeled cells were observed in the medial septal nucleus, the nucleus of the diagonal band, and to a lesser extent within the substantia innominata. Several of the cells in the latter region were large and located within the densely packed neuronal clusters of the basal nucleus of Meynert. Most of the labeled cells in the thalamus were located in the midline nuclei. Many were found in nucleus reuniens, but even greater numbers were located in the centralis complex. Additional labeled cells were located in the paraventricular and parataenial nuclei. In all cases, numerous retrogradely labeled cells were observed in the medial pulvinar. In the hypothalamus, most of the retrogradely labeled cells were located in the supramamillary area, though scattered cells were also observed in the perifornical region and in the lateral hypothalamic area. Caudal to the mamillary nuclei there were labeled cells in the ventral tegmental area. There were relatively few labeled cells in the brainstem and these were invariably located either in the raphe nuclei or locus coeruleus.

ISSN:0092-7317    

DOI:10.1002/cne.902640307

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractWe describe the architecture of the dorsal lateral geniculate nucleus and primary visual cortex (striate cortex; area 17) of the New World capuchin monkey (Cebus apella) on the basis of the distribution of cell bodies and cytochrome oxidase histochemistry. Changes in staining for cytochrome oxidase following unilateral enucleation served to indicate the organization of the representation of the two eyes in the retinogeniculocortical pathway.The number and disposition of eye‐specific layers within the lateral geniculate nucleus ofCebusare consistent with the common plan of geniculate organization in anthropoid primates, and the radial organization of area 17 fits the pattern common to New World squirrel and Old World macaque monkeys, including the presence of cytochrome‐oxidase‐rich zones in supragranular and deeper cortical layers (Horton:Philos. Trans. R. Soc. Lond. [Biol.]304: 199–253, '84).Our principal finding is that cytochrome oxidase histochemistry following unilateral eye removal unequivocally reveals ocular dominance columns in the striate cortex ofCebus.As in the macaque (Hubel:Nature 292: 762–764, '82), ocular dominance columns extend through the thickness of cortex and blobs are centered on columns, but the array of columns viewed tangentially is less orderly or more mosaic than in the macaque, and there is apparently significant overlap between columns.The presence of well‐defined ocular dominance columns inCebus, as inAteles(Florence, Conley, and Casagrande:J. Comp. Neurol. 243: 234–248, '86) but not in other New World monkeys examined previously, emphasizes the phylogenetic lability of binocular segregation in the primate visual cortex. In addition, the present results indicate significant differences with respect to the tangential organization of the ocular dominance domain between primate species in which ocular dominance column

ISSN:0092-7317    

DOI:10.1002/cne.902640308

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractIn the present study we employed quantitative morphometric techniques to assay the response of septal cholinergic neurons following unilateral transection of the fimbria/fornix and supracallosal stria. Analysis of 50‐μm‐thick tissue sections with a Quantimet 920 image analysis system demonstrated a reduction in ChAT immunoreactivity as early as 1 day following denervation. This decrease was associated with a drop in the number of labeled cells ipsilateral to the lesion and a decrease in the area of cholinergic perikarya on the lesioned and nonlesioned side of the septum. The response at 1 day, however, was transient, and at 4 days the number of labeled neurons was not significantly different from controls. By 8 days we observed a dramatic reduction in the number and size of ChAT‐positive cells ipsilateral to the lesion and a reduction in the size of cholinergic perikarya on the contralateral (i.e., nonlesioned) side. These values persisted throughout the remainder of the study.To assess more completely the morphologic response of neurons to axotomy than can be determined in 50‐μm‐thick tissue sections, we embedded the adjacent immunolabeled tissue section in Epon and then serially sectioned it to a thickness of 0.75–1.0 μm. By using this method, we wore able to measure the area, length, and width of the cell, the area of the nucleus and nucleolus, and the position of the nucleus (i.e., eccentricity). Measurements were performed on ChAT‐labeled and nonlabeled cells. The results of our studies demonstrate that cholinergic and noncholinergic cells responded to axotomy in a characteristic yet different fashion from each other and that this response could be quantitatively assayed. In general, labeled and non‐labeled cells on the lesioned side of the septum shrink in response to denervation. This shrunken state was reflected in measurements of cellular area, length, width, and nuclear area. Moreover, other measurements of cellular morphology (i.e., area of the nucleolus, position of the nucleus) indicate that none of the neuronal populations examined in the present study displayed morphologic evidence of regeneration.Our results indicate a dramatic loss of cholinergic perikarya ipsilateral to the lesion. Moreover, although a few neurons do persist they do so in a shrunken state. These data provide an essential baseline for the second study in this series, which will evaluate the effect of nerve growth factor on the survival of denerva

ISSN:0092-7317    

DOI:10.1002/cne.902640309

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902640301

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY