Staining with Ziehl's fuchsin of semithin sections mounted on slides.
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Animals↗
Biomedical subjects
J Lara
Publications and source records attributed to J Lara.
Ruffed cells in the olfactory bulb of freshwater teleosts. II. A Golgi/EM study of the ruff.
The morphological characteristics of the synaptic contacts in the ruff of the cichlid fish Hemichromis bimaculatus were studies using the combined Golgi-electron microscope technique. Ruffed cells were located in the glomerular and plexiform layers and exhibited a pyriform or round cell body and numerous thin dendritic branches that were highly ramified. Four different segments could be distinguished on the initial portion of the axon (IP) according to the number and density of protrusions. These protrusions or lateral appendages are highly interdigitated, forming a characteristic synaptic field: the ruff. The ruff displayed a very high number of synapses with terminals showing a varied morphology. Protrusions of the ruff were both presynaptic and postsynaptic, taking also part in reciprocal pairs of synapses. Synapses from the ruff to the adjacent prolongation are asymmetrical, the prolongation to protrusion synapses being symmetrical. The axonal shaft participates in fewer synaptic contacts. Boutons contacting with one protrusion can synapt with other one, and can also receive an asymmetric synapse from another terminal, forming a serial synapse. This constitutes the most complex synaptic system observed in the glomerular layer of the olfactory bulb in any vertebrate. The synaptology of the ruffed cell IP is compared with previous reports on other species, with the teleostean mitral cells and with the IP of higher vertebrates neurons, the ruffed cells showing a completely different synaptic pattern.
Animals↗
Distribution of parvalbumin-immunoreactivity in the rat thalamus using a monoclonal antibody.
1. The distribution of parvalbumin cell bodies and fibers in the thalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei ventralis posterior, reticularis, ventralis anterior and zona incerta, whereas the nuclei habenularis lateralis, lateralis posterior, lateralis, centralis lateralis and ventralis lateralis had the lowest density. In the nucleus geniculatum laterale ventralis, the density of parvalbumin cell bodies was intermediate. In all these thalamic nuclei, small, round or fusiform immunoreactive cells with short immunolabeled dendritic processes were observed. 2. The densest network of immunoreactive fibers was observed in the nuclei geniculatum laterale ventralis, reticularis and zona incerta. The nuclei geniculatum laterale dorsalis, ventralis posterior, medialis ventralis, ventralis anterior, anterior ventralis, anterior dorsalis and rhomboidens contained a moderate number of parvalbumin fibers, whereas the nuclei lateralis posterior, habenularis lateralis, parataenialis, centrum medianum, lateralis, centralis lateralis, ventralis lateralis, medialis dorsalis, anterior medialis, ventralis medialis and lateralis anterior had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the lemniscus medialis and a scarce number in the stria medullaris. 3. No immunoreactive structure was observed in the nuclei habenularis medialis, paraventricularis, reuniens and geniculatum mediale. 4. Thus, perikarya and fibers containing parvalbumin are widely distributed throughout the thalamus of the rat, suggesting that parvalbumin might play a role, directly or indirectly, in limbic, visual and somatosensory mechanisms.
Animals↗
Interspecies differences in the substance P- and vasoactive intestinal polypeptide-like immunoreactivities in the olfactory bulb of Salmo gairdneri and Barbus meridionalis.
The distribution of substance P-like (SP) and vasoactive intestinal polypeptide-like (VIP) structures was studied using an indirect immunoperoxidase technique in the mediterranean barbel Barbus meridionalis and in the rainbow trout Salmo gairdneri. SP-like positive fibers were observed in the inner strata of the mediterranean barbel olfactory bulb, mainly the granule cell and the plexiform layers. Ganglion cells and fibers of the terminal nerve were also labeled. No SP-positive structure was found in the olfactory bulb of the rainbow trout. On the contrary, the VIP antiserum used displayed very strong immunostaining in the olfactory nerve fiber layer of Salmo gairdneri, whereas those fibers in Barbus meridionalis showed no immunoreactivity. After a complete transection of the olfactory tract and a survival time of 20 days, SP-immunostained fibers were not observed. Thus, they can presumably be identified as centrifugal fibers, coursing from the telencephalic hemispheres through the olfactory tracts, into the olfactory bulb. The VIP immunoreactivity was confined to the olfactory fibers, both in the olfactory nerve and the olfactory bulb. The positive immunostaining disappeared after chemical lesion of the olfactory mucosa. These observations demonstrate that the olfactory bulb of freshwater teleosts exhibits a high degree of heterogeneity in its immunocytochemical distribution pattern, this pattern also differing from previous reports on higher vertebrates.
Animals↗
Distribution of parvalbumin immunoreactivity in the rat septal area.
The distribution of parvalbumin (PV)-containing neurons and processes in the septal area of the rat brain was studied using a monoclonal antibody and the avidin-biotin immunoperoxidase method. PV-immunoreactive neurons were mainly located in the medial septum/diagonal band complex and in the horizontal limb of the diagonal band of Broca, showing a high density of heavily immunostained neurons and fibers. Nonimmunoreactive cells surrounded by PV-positive cells and processes were observed in the same region, but no pericellular basket-like arrangements were found. On the contrary, the dorsal, intermediate, and ventral nuclei of the lateral septum were practically devoid of PV-positive neurons and processes. Thus, in these nuclei only a very low density of isolated neurons was labeled; these were specially scattered in the ventrolateral septal nucleus and in the dorsolateral septal nucleus just below the corpus callosum. Delicate PV-positive axonal plexuses were also observed in the dorsal and intermediate nuclei of the lateral septum. The immunopositive neurons displayed very different sizes and morphologies among the various septal nuclei and inside each of them, indicating that they do not belong to a single morphological class of neurons. Finally, the distribution of PV in the rat septal area is not directly related to cholinergic and GABAergic septal neurons.
Animals↗
Substance P-like immunoreactivity in the ganglion cells of the tench terminal nerve.
The distribution of substance P (SP) in the olfactory bulb of the tench Tinca tinca was studied by using an indirect immunoperoxidase technique. Many perikarya and processes of the ganglion cells of the nervus terminalis (NT) were strongly labeled. In addition, SP-like immunopositive fibers were observed in the proximity of these neurons and extending along the olfactory nerves and the olfactory tracts. The ganglion cells of the NT were not immunoreactive for methionine- and leucine-enkephalin, motilin, vasoactive intestinal polypeptide, neuropeptide Y, cholecystokinin-8, and tyrosine hydroxylase.
Animals↗
Distribution of vasoactive intestinal polypeptide-like immunoreactivity in the olfactory bulb of the rainbow trout (Salmo gairdneri).
The distribution of vasoactive intestinal polypeptide-like structures in the olfactory bulb of the rainbow trout was studied using an indirect-immunoperoxidase technique. Olfactory fibres were very strongly labelled, whereas the fibres or cell bodies in the remaining strata of the olfactory bulb showed no immunoreactivity. In addition, the olfactory nerve fibres were not immunoreactive for methionine- and leucine-enkephalins, motilin, neuropeptide Y, substance P, cholecystokinin-8 and tyrosine-hydroxylase.
Animals↗
Nontranslated cellular mRNAs are associated with the cytoskeletal framework in influenza virus or adenovirus infected cells.
In an effort to understand the molecular mechanisms underlying the selective shutoff of host protein synthesis in influenza virus and adenovirus infected cells, we analyzed the subcellular location of representative cellular and viral mRNAs. Earlier work has shown that the majority of cellular mRNAs remain polysome associated after infection by either virus and that both the initiation and elongation steps of host protein synthesis were blocked in infected cells (M. G. Katze, D. DeCorato, and R. M. Krug, J. Virol., 60, 1027-1039, 1986). The present study was undertaken to test whether these cellular mRNAs were rendered nontranslatable during infection as a result of their dissociation from the cytoskeleton framework. HeLa cells were fractionated into subcellular components by first gently disrupting the cells with Triton X-100 yielding the soluble fraction (SOL); the cytoskeleton (CSK) fraction was obtained from the Triton insoluble material by the double detergent treatment of Tween-40 and sodium deoxycholate. In uninfected cells the majority of host mRNAs were associated with polysomes which were exclusively bound to the CSK as would be expected of actively translated mRNAs. The cellular mRNAs also remained almost totally associated with the cytoskeleton in adenovirus and influenza virus infected cells despite the fact that these mRNAs are not translated during infection. Indeed, the host mRNAs and the efficiently translated viral mRNAs were CSK associated to the same extent. In contrast to the adenovirus and influenza systems, significant amounts of cellular mRNAs were dissociated from the CSK and found in the SOL fraction of poliovirus infected cells as others have reported. In accordance with the biochemical analysis, morphological studies utilizing electron microscopy revealed that the cytoskeleton remained relatively intact during adenovirus and influenza infection but was substantially reorganized in poliovirus infected cells. We conclude that translational regulatory events are likely different in the poliovirus system and that cytoskeletal association of mRNAs may be required but is not sufficient for efficient mRNA translation during adenovirus or influenza virus infection.
Adenoviridae↗
Tyrosine hydroxylase immunoreactivity in a subpopulation of granule cells in the olfactory bulb of teleost fish.
The distribution of tyrosine hydroxylase (TH)-like immunoreactivity in the olfactory bulb was studied in three species of teleosts, the tench Tinca tinca, the Mediterranean barbel Barbus meridionalis and the rainbow trout Salmo gairdneri, by using an indirect immunoperoxidase method. The antiserum used displayed a characteristic pattern of immunostaining in the three species, and four main conclusions can be drawn: (1) there is a large population of TH-like positive cell bodies and fibers in the olfactory bulb in fish, mainly in the granule cell and plexiform layers; (2) the immunolabeled cells are identified as granule cells, but only one group of granule cells is positive; (3) specific quantitative variations exist in the pattern of TH immunoreactivity, with use of the same fixative, antibody and localization method, among the three species studied, and (4) the pattern of TH immunoreactivity in the olfactory bulb in teleosts is completely different from that described previously in amniotes.
Animals↗
The cavum septi pellucidi: a fifth ventricle?
The morphological characteristics of the cavum septi pellucidi (CSP) in the rat are described. This structure is formed by a set of cavities generally located in the midline area of the septal region. Into the lumen of the cavities free cells rooted out from the CSP walls were observed. Several layers could be delimitated from the surface of the CSP to the most inner region consisting of connective cells and fibers, and astrocytes. However, no ependymal cells were visualized. According to the morphological data, the CSP wall could have a function of resistance against mechanical tensions that are produced in this brain region. The term 'fifth ventricle' for the CSP seems to be inappropriate.
Animals↗
Immunocytochemical study of substance P-like cell bodies and fibres in the brain of the rainbow trout, Salmo gairdneri.
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Journal Article↗
Immunocytochemical study of parvalbumin fibers and cell bodies in the rat hipothalamus.
The distribution of parvalbumin (PA) cell bodies and fibers in the hypothalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei mamillare medialis, arcuatus and dorsomedialis hypothalami, whereas the corpus mamillare lateralis had the lowest density. The densest network of immunoreactive fibers was observed in the corpus mamillare lateralis and nucleus arcuatus. The corpus mamillare medialis contained a moderate number of PA fibers, whereas the nucleus dorsomedialis hypothalami had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the tractus opticus and the tractus mamillo-thalamicus. Essentially, the distribution of PA in the rat hypothalamus after using a monoclonal antibody seems to be broader in comparison with previous studies carried out in the same diencephalic region of the rat. The presence of PA in several nuclei of the rat hypothalamus suggests that this protein could be directly or indirectly involved in neuroendocrine, limbic and visual functions.
Animals↗
Cell proliferation in the olfactory bulb of adult freshwater teleosts.
The olfactory bulb of adult specimens of Carassius auratus was subjected to an autoradiographic study using [3H]thymidine. Adult specimens of Carassius auratus, Barbus meridionalis, Cyprinus carpio and Salmo gairdneri were also studied using light and electron microscopy. Cells were found undergoing mitotic division with two characteristic locations: a group can be seen near to the ventricle or ventricular recess; these cells can be identified as granule cells or precursors of granule cells. Other cells undergoing division are seen on the outer limiting glial membrane and in the olfactory nerve fibre layer; these cells are identified as astrocytes. Different hypotheses about the destination and meaning of these proliferating cells and the similarities and differences with the cell proliferation in adult higher vertebrates are discussed.
Animals↗
[Aortic stenosis with left ventricular systolic dysfunction: a severe disease but with good surgical prognosis].
From our series of 72 patients with severe valvular aortic stenosis, we identified 19 showing features of left ventricular systolic disfunction (ventriculographic ejection fraction less than 55% and/or fractional shortening less than 30% at M-mode echocardiography). In these patients, we found a significant inverse correlation between the fractional shortening and the systolic wall stress (r = 0.79, p less than 0.001). Clinically, 18 of the 19 patients were in NYHA class III (n = 11) or IV (n = 5), and two died before they could be operated upon. The remaining 17 had their aortic valve replaced (coronary artery bypass surgery was simultaneously performed in 2 patients). After a mean follow-up of 18 months, all patients are alive and show substantial symptomatic improvement (15 patients in class I and 2 patients in class II). Cardiothoracic index was reduced (61 +/- 5% preoperatively versus 52 +/- 5% postoperatively), and fractional shortening changed from 21 +/- 5% to 30 +/- 5%. The latter remains under normal limits in two thirds of the patients. Our results lend support to the idea that the systolic left ventricular dysfunction in aortic stenosis is due to the increased afterload, rather than to an intrinsic contractility defect. This explains the great functional improvement after the reduction of the systolic wall stress achieved by surgery.
Adult↗
Comparative study of the anatomy and laminar organization in the olfactory bulb of three orders of freshwater teleosts.
The anatomy and lamination of the olfactory bulb in Cyprinus carpio, Tinca tinca, Barbus bocagei (Fam. Cyprinidae, Or. Cypriniformes); Salmo gairdneri (Fam. Salmonidae, Or. Salmoniformes); and Gambusia affinis (Fam. Poeciliidae, Or. Cyprinodontiformes), all of them freshwater teleosts, are studied. These species show significative differences on the location, size, morphology, and lamination of their olfactory bulbs. The presence of a new stratum in the olfactory bulb of Salmo gairdneri and a completely different laminar organization in the olfactory bulb of Gambusia affinis are described for the first time. The anatomical and histological peculiarities of this structure in the orders studied could be the basis for different experimental approaches.
Animals↗
Does Valsalva's maneuver precipitate paradoxical brain embolism in healthy individuals?
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Adult↗
Dense osmiophilic material in the surface of the olfactory bulb in the teleost Cyprinus carpio L.
A dense osmiophilic structure was found associated to the basal lamina of the outer limiting glial membrane of the carp olfactory bulb. In certain sections this material appears as "beads" composed of small strand-like structures, and in others it seems to form a palisade-like structure. The possible origin and function of this structure is discussed.
Animals↗
Ruffed cells in the olfactory bulb of freshwater teleosts. I. Golgi impregnation.
The olfactory bulbs of Barbus meridionalis, Carassius carassius, Chondrostoma polylepis, Cyprinus carpio, Tinca tinca and Salmo gairdneri were examined by two variants of the Golgi technique. We report, for the first time, the existence of ruffed cells in these species. This neuronal type shows a characteristic morphology and location. Overall, these cells exhibit a generalised pattern, although there are qualitative and quantitative variations between the various species studied.
Animals↗