bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of chondroitin sulfate and keratan sulfate proteoglycans in the path of growing retinal axons in the developing chick
Authors: McAdams Brian D. , McLoon Steven C. 
Published: January 2005

AbstractPrevious investigations have identified proteoglycans in the central nervous system during development and have implicated some proteoglycans as axon guidance molecules that act by inhibiting axon extension. The present study investigated the pattern of immunoreactivity for several glycosaminoglycans common to certain proteoglycans relative to growing retinal axons in the developing chick visual system and in retinal explant cultures. Immunostaining for chondroitin‐6‐sulfate, chondroitin‐4‐sulfate, and keratan sulfate was observed to colocalize with retinal axons throughout the retinofugal pathway during the entire period of retinal axon growth. The proteoglycan form of collagen IX, however, was only observed in the retina, primarily peripheral to the areas with actively growing axons, The pattern of immunostaining for chondroitin sulfate in tissue sections suggested that the retinal axons might be a source for some of the chondroitin sulfate immunostaining in the developing visual pathway. This was confirmed in that chondroitin sulfate immunostaining was also observed on neurites emanating from cultured retinal explants. These findings indicate that retinal axons grow in the presence of chondroitin sulfate and keratan sulfate proteoglycans and that these proteoglycans in the developing chick visual pathway have functions other than to inhibit axon growth. © 1995 Wiley‐Liss, Inc.
Localization of the heptapeptide GFSKLYFamide in the sea cucumber holothuria glaberrima (echinodermata): A light and electron microscopic study
Authors: Díaz‐Miranda Lucy , Blanco Rosa E. , García‐Arrarás José E. 
Published: January 2005

AbstractTwo peptides, Gly‐Phe‐Ser‐Lys‐Leu‐Tyr‐Phe‐ NH2 (GFSKLYFamide) and Ser‐Gly‐Tyr‐Ser‐Val‐Leu‐Tyr‐Phe‐ NH2 (SGYSVLYFamide), recently isolated from the sea cucumber Holothuria glaberrima [Díaz‐Miranda et al. (1992) Biol. Bull. 182:241–247] represent the first neuropeptides isolated from holothurians. Using an antibody against GFSKLYFa, we describe here the localization and distribution pattern of GFSKLYFa‐like immunoreactivity in H. glaberrima, where immunoreactive fibers form a prominent and extensive peptidergic nervous system component. Neuron‐like cells and nerve fibers expressing GFSKLYFa‐like immunoreactivity are found in the ectoneural and hyponeural divisions of the radial nerve cords as well as in the digestive, haemal, respiratory, and reproductive systems; in the tentacles; and in tube feet. Neuroendocrine‐like cells are found in the mucosal layer of the intestine. Ultrastructure immunocytochemical analysis revealed that, in nerve cells and fibers in the serosal layer of the intestine, the immunoreactivity is concentrated in vesicles. The immunoreactive nerve fibers are found mainly within a dense nerve plexus overlying and in close contact with smooth muscle cells of the intestine.The exclusive expression of GFSKLYFa‐like immunoreactivity in neuronal or neuroendocrine tissue together with the close apposition of some fibers to muscle cells suggests that GFSKLYFa acts as a neuromuscular transmitter or neuromodulator in H. glaberrima. The wide occurrence of GFSKLYFa‐like immunoreactivity throughout the nervous system of the sea cucumber suggests that GFSKLYFa plays an important role in the control of multiple action systems, including digestion, respiration, circulation, reproduction, and locomotion. © 1995 Wiley‐Liss, Inc.
Early cytoskeletal changes following injury of giant spinal axons in the lamprey
Authors: mcHale Mary K. , Hall Garth F. , Cohen Melvin J. 
Published: January 2005

AbstractThe spinal cord of the larval sea lamprey contains identified giant axons that readily regenerate following spinal transection. In this study, we used serial light and electron microscopy to analyze the early ultrastructural consequences of axotomy in the proximal stumps of these axons near the lesion site. Axotomy results in two types of striking ultrastructural changes: (1) changes associated with the degeneration of axoplasm and subsequent retraction of the cut axon from the lesion and (2) changes associated with the early stages of axonal regeneration. Degenerative changes include the disruption of mitochondria to form large vacuoles, the collapse of neurofilaments into closely packed masses (condensed filamentous cores; CFCs), and the appearance of amorphous electron‐dense bodies (dense granular masses; DGMs). Events associated with regeneration include the disappearance of vacuoles, DGMs, and CFCs and the appearance of small, sprout‐like projections from the axon stump. Thus, we show that degenerative and regenerative events can be clearly separated from one another in identified axons, unlike the situation in the central nervous systems of amniote vertebrates such as mammals. © 1995 Wiley‐Liss, Inc.
Ultrastructural and immunocytochemical characterization of terminals of postsynaptic ascending dorsal column fibers in the rat cuneate nucleus
Authors: De Biasi S. , Vitellaro‐Zuccarello L. , Bernardi P. , Valtschanoff J. G. , Weinberg R. J. 
Published: January 2005

AbstractThe morphology, synaptic contacts, and neurotransmitter enrichment of postsynaptic dorsal column terminals in the cuneate nucleus of rats were investigated and compared with those of identified primary afferents. For this purpose, anterograde transport of horseradish peroxidase–based tracers injected in the spinal cord was combined with postembedding immunogold labeling for glutamate and gamma‐aminobutyric acid (GABA).Anterogradely labeled postsynaptic dorsal column terminals were morphologically homogeneous: they were small (mean area = 1. 37 μM2) and dome‐shaped, contacted single dendritic shafts or cell bodies, and were not involved in axoaxonic synapses. The majority of them were not enriched in glutamate or GABA immunoreactivity compared with other tissue components. Their morphology, size, and neurotransmitter content thus differed from that of primary afferents. These differences are consistent with distinct functional roles for the two main afferent systems ascending to the cuneate nucleus. © 1995 Wiley‐Liss, Inc.
Neurochemical coding of enteric neurons in the guinea pig stomach
Authors: Schemann Michael , Schaaf Cornelia , Mäder Michael 
Published: January 2005

AbstractThe aim of this study was to investigate the neurochemical coding of myenteric neurons in the guinea pig gastric corpus by using immunohistochemical methods. Antibodies and antisera against calbindin (CALB), calretinin (CALRET), choline acetyltransferase (ChAT), calcitonin gene‐related peptide (CGRP), dopamine β‐hydroxylase (DBH), β‐endorphin (ENK), neuropeptide Y (NPY), neuron‐specific enolase (NSE), nitric oxide synthase (NOS), protein gene product 9.5 (PGP), parvalbumin (PARV), serotonin (5‐HT), somatostatin (SOM), substance P (SP), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP) were used. Double‐ and triple‐labeling studies revealed colocalization of certain transmitters and enabled the identification of distinct subpopulations of gastric enteric neurons. NPY/VIP/NOS/ENK were present in 28% of all neurons, whereas 11% had NPY/VIP / DBH / ChAT; NOS‐only neurons made up 2% of the population. The combination SP/ChAT/ENK occurred in 21% of the population, whereas SP/ChAT/ENK/CALRET and SP/CHAT/SOM/ ± CALRET was identified in 5% and 6% of all cells, respectively. 5‐HT‐containing neurons comprised 2% of all cells and could be further classified by the presence of additional antigens as 5‐HT/SP/(ChAT) or 5‐HT/VIP/(ChAT). Approximately 21% of all neurons contained only ChAT with no additional antigen present and are referred to as ChAT/–. Gastric myenteric ganglion cells were not immunoreactive for CALB, PARV, CGRP, or TH. The results of this study indicate that gastric myenteric neurons can be characterized on the basis of different chemical coding. Neurochemical coding of corpus myenteric neurons revealed some similarities and significant differences in comparison with other regions of the gut. These differences might reflect adaptation of enteric nerves according to regional specialization and the distinct functions of the proximal stomach as a gastric reservoir. © 1995 Wiley‐Liss, Inc.
Preservation of topography in the connections between the subiculum, field CA1, and the entorhinal cortex in rats
Authors: Tamamaki Nobuaki , Nojyo Yoshiaki 
Published: January 2005

AbstractIn order to examine whether the entorhinal‐hippocampal‐entorhinal circuit is reciprocal and topographic, the connections between the subiculum, the CA1 field, and the entorhinal cortex were studied with the carbocyanine dye (Dil), which moves in both retrograde and anterograde directions. We investigated the organization of reciprocal connections revealed by injections of Dil in the entorhinal cortex along the rhinal sulcus. Anterograde fluorescent labeling showed the same pattern reported in previous studies of the dorsal hippocampus. When the injection site of DiI extended into the deep layers (IV–VI) of the same cortical column, the anterograde labeling of the perforant path was accompanied by retrograde labeling of the subicular neurons and the CA1 neurons. The distribution of labeled cells overlapped the distribution of labeled fibers, and the distribution of labeled cells paralleled that of the labeled fibers in the CA1 field. DiI injection into the medial entorhinal cortex revealed fewer retrogradely labeled subicular neurons than injection into the lateral entorhinal cortex, whereas the number of labeled CA1 neurons was not dependent on the injection site. The number of labeled CA1 neurons was always several times greater than the number of subicular neurons. Thus, the amount of information conveyed by the CA1 projection might be higher than that conveyed by the subicular projection. These results indicate that the entorhinal cortex, CA1, and the subiculum are connected reciprocally and topographically. We believe that the framework of the major hippocampal circuit proposed in previous studies should be reconsidered. We propose that the CA1 projection, rather than the subicular projection, is the main projection that feeds back information from the hippocampus to the entorhinal cortex. © 1995 Wiley‐Liss, Inc.
Distribution of myomodulin‐like immunoreactivity in the brain and retrocerebral complex of the locust, schistocerca gregaria
Authors: Swales Lesley S. , Evans Peter D. 
Published: January 2005

AbstractThe distribution of myomodulin‐like immunoreactivity is described for the brain and retrocerebral complex of an insect, the locust, Schistocerca gregaria. The locust brain contains 70–100 neuronal cell bodies and numerous neuropilar processes exhibiting myomodulin‐like immunoreactivity. The most marked feature of the staining is a group of lateral tritocerebral neurones that form a highly immunoreactive tract that gives rise to a complex neuropile of stained processes in the dorsal tritocerebrum. This tract continues dorsally and bifurcates into a major branch that exits the brain via nervi corpora cardiaca 1 (NCC1) to innervate the corpora cardiaca and the corpora allata. A minor branch, consisting of several individual axons, combines with immunoreactive processes from the ventral nerve cord and generates a complex immunoreactive neuropile in the anterior and posterior regions of the protocerebrum. Immunoreactive processes are also found in the structured neuropile of the central body complex. Immunoreactive cell bodies are also found in the antennal lobes, in the lateral margins of the protocerebrum, in the optic lobes, and in a few cells in the pars intercerebralis.The results suggest that myomodulin‐like neuropeptides may play roles as central neurotransmitters or neuromodulators in insects as well as being released into the circulation as neurohormones or acting as releasing agents for neurohormones in neurohaemal areas. They also further strengthen the idea that myomodulins, which were first identified in molluscs, may represent another interphyletic family of neuropeptides. © 1995 Wiley‐Liss, Inc.
Distribution and developmental expression of octopamine‐immunoreactive neurons in the central nervous system of the leech
Authors: Gilchrist Laura S. , Klukas Kathleen A. , Jellies John , Rapus Jürgen , Eckert Manfred , Mesce Karen A. 
Published: January 2005

AbstractOctopamine, a biogenic amine analogous to norepinephrine, plays an important role in the orchestration and modulation of invertebrate behavior. In the leech, the behavioral actions of octopamine have been demonstrated; however, identification of octopaminergic neurons had not been determined by using immunohistochemical techniques. Thus, we used an antibody highly specific to octopamine to examine the distribution of octopamine‐immunoreactive neurons in the segmental ganglia of American and European medicinal leeches (Macrobdella decora and Hirudo medicinalis). One pair of octopamine‐immunoreactive neurons was located in the dorsolateral ganglionic region of anterior ganglia 1–6 and posterior ganglia 15–21. No corresponding octopamine‐immunoreactive neurons were found in midbody ganglia 7–14. Using Neutral Red staining in combination with intracellular Neurobiotin injections and octopamine immunostaining, we determined the identity of the dorsolateral octopamineimmunoreactive cells. The dorsolateral octopamine‐immunoreactive neuron (the DLO) was not cell 21, the only previously reported Neutral Red staining neuron in the dorsolateral position. We also determined that the Leydig neuron was not octopamine immunoreactive in either of the two medicinal leech species. Octopamine immunostaining in the sex ganglia revealed hundreds of immunoreactive neurons in sexually mature leeches. Such neurons were not observed in juvenile leeches. The developmental time course of octopamine immunoreactivity in the dorsolateral octopamine‐immunoreactive neurons was also investigated by staining embryonic Hirudo medicinalis, Octopamine expression occurred relatively late as compared with the detectable onset of serotonin expression. Octopamine expression in the dorsolateral octopamine‐immunoreactive cells was not detectable at early to mid‐embryonic stages, and must commence during late embryonic to early juvenile stages. The identification of octopamineimmunoreactive cells now sets the stage for further investigations into the functional role of octopamine in leech behavior and the development of behavior. © 1995 Wiley‐Liss, Inc.
Organization of the efferent projections from the spinal cervical enlargement to the parabrachial area and periaqueductal graye. A PHA‐L study in the rat
Authors: Bernard Jean‐Franiçois , Dallel Radhouane , Raboisson Patrick , Villanueva Luis , Bars Daniel Le 
Published: January 2005

AbstractThe organization of efferent projections from the spinal cervical enlargement to the parabrachial (PB) area and the periaqueductal gray (PAG) was studied in the rat by using microinjections of Phaseolus vulgaris–leucoagglutinin (PHA‐L) into different laminae around the C7 level. The results demonstrated two areas of cervical enlargement which project in different ways to the PB area and PAG.First, the superficial laminae (I, II) showed a very dense projection, with a clear contralateral dominance at the coronal level where the inferior colliculus merges with the pons, to a restricted “superficial” portion of the PB area, namely the lateral crescent area, the dorsal lateral, the superior lateral (PBsl), and the outer portion of the external lateral PB subnuclei. Less dense projections were observed in the Kölliker‐Fuse nucleus (KF) and in the ventrolateral/ lateral quadrant of the caudal and mid PAG. By contrast, the labeling was weak or absent in the other PB subnuclei and the outer adjacent regions; in particular, no, or very little, labeling was found in the cuneiform nucleus. The PB area appeared to be the supraspinal target that received the densest projection from laminae I and II. Projections were less dense in the PAG and the thalamus and markedly less in other sites such as the ventrolateral medulla, the subnucleus reticularis dorsalis, and the nucleus of the solitary tract.Second, the reticular portion of lamina V, the medial portion of laminae IV–VI up to X and lamina VIII, showed bilateral projections with a weak ipsilateral dominance and a high to medium density on a very restricted portion of the PB area, namely the internal lateral PB subnucleus. A lesser projection was also observed in the adjacent portion of the PBsl, the KF, and the lateral quadrant of the PAG.These results suggest that signals carried by neurons from lamina I–II converge on a restricted superficial portion of the PB area and the ventral part of the lateral quadrant of the PAG. These results are discussed in the context of the role of the spino‐PB and spino‐PAG pathways in nociception. © 1995 Wiley‐Liss, Inc.
Two channels in the cerebellothalamocortical system
Authors: Steriade M. 
Published: January 2005

AbstractTwo channels of the cerebellothalamocortical system were investigated in cats by using cerebellar‐evoked synaptic responses and cortical‐evoked antidromic invasion of single thalamic cells. One channel arises in interpositus and dentate cerebellar nuclei and mainly projects through ventroanterior‐ventrolateral (VA‐VL) thalamic nuclei to cortical motor areas 4 and 6; the other channel arises in cerebellar fastigial nuclei and projects through ventromedial (VM) thalamic nuclei to more widespread cortical areas. The antidromic response latencies of VM neurons to stimuli applied to cortical areas 4 and 6 were longer (medians 2.8 and 3.0 msec, respectively) than the antidromic response latencies of VA‐VL neurons to stimulation of the same cortical areas (1.8 and 2.3 msec). This was a statistically significant difference, and it matched the longer latencies of fastigial‐evoked synaptic responses of VM cells (2.9 msec) compared to the response latencies of VA‐VL cells elicited by stimulation of interpositus or dentate nuclei (1.7 and 2.4 msec).These differences among thalamic nuclei relaying cerebellocortical impulses were corroborated by dissimilar effects exerted on the electroencephalogram (EEG) during high‐frequency (300 Hz) pulse trains applied to different deep cerebellar nuclei. The distribution of activated EEG patterns over the cortex depended on the stimulated site. Fastigial stimulation elicited the blockage of slow EEG rhythms and the appearance of fast oscillations (20–40 Hz) over widespread cortical areas in the proreus, pericruciate, and suprasylvian gyri. At variance, the activating influence of interpositus or dentate nuclei was restricted to the motor cortex. It is proposed that, besides their role in controlling the postural axial and proximal musculature, fastigial nuclei are part of diffusely activating systems. © 1995 Wiley‐Liss, Inc.
A comparison of the Eimer's organs of three north american moles: The hairy‐tailed mole (Parascalops breweri), the star‐nosed mole (Condylura cristata), and the eastern mole (Scalopus aquaticus)
Authors: Catania Kenneth C. 
Published: January 2005

AbstractEimer's organ is a tactile sensory structure found predominantly on the snouts of moles. It consists of a raised papilla of epidermis containing a column of cells associated with sensory receptors. This study compares the Eimer's organs of the hairy‐tailed mole, Parascalops breweri, the star‐nosed mole, Condylura cristata, and the eastern mole, Scalopus aquaticus, by using scanning electron microscopy and light microscopy. Eimer's organs are visible on the snout of the hairy‐tailed and the star‐nosed moles, but not the eastern mole. The Eimer's organs of the hairy‐tailed mole are similar in external appearance, distribution, and internal structure to those found in most species examined. The Eimer's organs of the star‐nosed mole and the eastern mole diverge from this basic form in seemingly opposite directions. The Eim&'s organs of the star‐nosed mole are more numerous, smaller, and highly organized units with a consistent pattern of neuronal terminal swellings within a cell column, below a thin keratinized epidermis. By contrast, the Eimer's organs ofthe eastern mole lie below a thick keratinized epidermis, are less organized in structure, and have no central cell column. The extreme differences between the Eimer's organs of the star‐nosed mole and those of the eastern mole may be the result of the habitat of each species, saturated mud allowing a more elaborate and delicate sensory apparatus in the star‐nosed mole and drier soil requiring a thick keratinized epidermis over the organ in the eastern mole. © 1995 Wiley‐Liss, Inc.
Metabolic mapping of visual areas in the behaving cat: A[14C]2‐deoxyglucose study
Authors: Vanduffel W. , Vandenbussche E. , Singer W. , Orban G. A. 
Published: January 2005

AbstractVisually responsive cortical areas and subcortical nuclei were studied in the awake cat using the 2‐deoxyglucose technique. Visual input was confined to one hemisphere by unilaterally sectioning the optic tract, the corpus callosum and the commissura anterior. Within the intact hemisphere, numerous cortical regions were distinguishable in the autoradiographs due to differential labelling. Comparison of the intact with the visually deafferented hemisphere confirmed the visual character of eighteen cortical areas (areas 17, 18, 19, 20a, 20b, 21a, 21b, the posteromedial lateral, posterolateral lateral, anteromedial lateral, anterolateral lateral, dorsal lateral, ventral lateral, and posterior suprasylvian areas, the splenial and anterior ectosylvian sylvian areas, insular visual area and posterior area 7) and revealed the visual nature of an area in the posterior cingulate gyrus which had not been described previously. We refer to this area as cingulate visual area (CVA). This area exhibits a gradient in interhemispheric differences along a caudorostral axis similar to that observed in posterior area 7 which is in keeping with the strong and topographic connections between CVA and posterior area 7. These results support the validity of metabolic mapping for the characterisation of cortical areas. © 1995 Wiley‐Liss, Inc.
Abnormal ipsilateral visual field representation in areas 17 and 18 of hypopigmented cats
Authors: Ault Steven J. , Leventhal Audie G. , Vitek Dagmar J. , Creel Donnell J. 
Published: January 2005

AbstractWe compared the central projections of retinal ganglion cells in temporal retina and the cortical representation of visual fields in areas 17 and 18 in cats with various hypopigmentation phenotypes (albino, heterozygous albino, Siamese, and heterozygous Siamese). In all cats studied, we found that the extent of abnormal ipsilateral visual field representation varied widely, and more of the ipsilateral visual field was represented in area 18 than in area 17. The greatest degree of ipsilateral visual field representation was found in albino cats, followed by Siamese, heterozygous albino and heterozygote Siamese cats, respectively. Additionally, in the different groups there was wide variation in the numbers of contralaterally projecting alpha and beta ganglion cells in temporal retina. In all cases, however, contralaterally projecting alpha cells were found to extend further into temporal retina than beta cells. We found that in each cat studied, the maximum extent of the abnormal ipsilateral visual field representation in areas 18 and 17 corresponded to the location of the 50% decussation line (i. e., the point where 50% of the ganglion cells in temporal retina project to the contralateral hemisphere) for alpha and beta cells, respectively, for that cat. Our results suggest that the extent of the abnormal visual field representations in visual cortex of hypopigmented cats reflects the extent of contralaterally projecting retinal ganglion cells in temporal retina. © 1995 Wiley‐Liss, Inc.