Phosphorylated microtubule associated protein (MAP1B-Phos) in the retina during regeneration of the fish optic nerve.
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Animals↗
Biomedical subjects
E Vecino
Publications and source records attributed to E Vecino.
Spatial-temporal expression of calbindin D-28K during embryonic and postnatal development of the fish retina.
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Animals↗
Microglia in normal and regenerating visual pathways of the tench (Tinca tinca L., 1758; Teleost): a study with tomato lectin.
We have studied the microglial cells in the normal and regenerating visual pathways of Tinca tinca (Cyprinid, Teleost) by using the lectin from Lycopersicum esculentum (tomato), which, in our case, has been demonstrated as a specific marker for teleost microglia. In the normal fish, there are tomato lectin positive microglial cells in the retina, optic nerve, and optic tectum. Following optic nerve crush, we observed a more extensive labeling of the microglia in the crushed optic nerve and in the contralateral optic tectum affecting the stratum opticum and stratum fibrosum et griseum superficiale. In both cases, there was an increase of rounded and less ramified microglial cells, and granular cells. This response of a more extensive labeling of microglial cells increases to a maximum at 2-3 weeks after the crush; the density of labeled microglial cells decreases after 3 months after crushing. However, in the retina no changes were observed after optic nerve crush. These results suggest that the microglial cells could play an important role in regeneration of fish optic pathway, as other neuroglial cells do.
Animals↗
Localization of enkephalinergic neurons in the central nervous system of the salmon (Salmo salar L.) by in situ hybridization and immunocytochemistry.
The distribution of neurons expressing preproenkephalin (PPE) mRNA in the brain of the salmon was investigated by means of non-radioactive in situ hybridization, and directly compared with the distribution of enkephalin-immunoreactive (ENKir) neurons. This approach, utilized here for the first time in a non-mammalian vertebrate for the identification of neurons containing opioid peptides, permitted a detailed analysis of the distribution of putative enkephalinergic neurons in the salmon brain. Several cell groups containing neurons that express PPE mRNA also contain ENKir neurons. Such cell groups are located in the ventral telencephalic area, the nucleus of the rostral mesencephalic tegmentum and another nucleus immediately dorsal to it, the torus semicircularis, the valvula cerebelli and the corpus cerebelli. These cell groups consistently contain larger numbers of PPE mRNA expressing cells than ENKir ones. Some cell groups express PPE mRNA, but do not contain ENKir neurons. These cell groups are located in the dorsal telencephalic area, the inferior lobes of the hypothalamus, the pretectal area, the magnocellular superficial pretectal nucleus, the optic tectum, the oculomotor nucleus, the trochlear nucleus, the magnocellular vestibular nucleus, the secondary gustatory nucleus, the superior and medial reticular nuclei, the motor nucleus of the vagus and the ventral horn of the spinal cord. Moreover, some cell groups contain ENKir neurons, but no PPE mRNA expressing neurons. These cell groups are located in the ventromedial thalamic nucleus, the lateral tuberal nucleus, the nucleus of the lateral recess and the nucleus of the posterior recess. The majority of these periventricular ENKir neurons were of the cerebrospinal fluid-contacting type. ENKir neurons were also located in the dorsal lateral tegmental nucleus and in area B9. The results also permitted a tentative identification of enkephalinergic neurons afferent to the optic tectum, that have previously not been identified with immunocytochemistry, located in the dorsal telencephalic area, as well as enkephalinergic neurons intrinsic to the tectum that may contribute to the laminar arrangement of ENKir fibers in the optic tectum.
Animals↗
In situ hybridization of neuropeptide Y (NPY) mRNA in the goldfish brain.
The distribution of neurones expressing neuropeptide Y (NPY) mRNA in the brain of the goldfish was investigated using a non-radioactive in situ hybridization technique. Neurones expressing NPY mRNA were located in cell groups previously shown to exhibit NPY immunoreactivity in the ventral telencephalon, thalamus, optic tectum and a region adjacent to the locus coeruleus. In addition, neurones expressing NPY mRNA were observed in the diffuse nucleus of the torus lateralis and in the mesencephalic tegmentum. Our results suggest that in the two latter groups of neurones the rate of transport of NPY from the perikarya is higher, or that NPY is not synthesized at levels detectable by immunocytochemistry.
Animals↗
Calbindin D-28K distribution in the retina of the developing trout (Salmo fario L.).
The appearance of calbindin D-28K, a calcium-binding protein, during development of the trout retina was studied by immunohistochemistry. The first calbindin immunoreactive cells appear in the inner nuclear layer at the equator of the embryonic retina at the stage 227 degrees C (around embryonic day 15). Just before hatching, stage 440 degrees C (around embryonic day 30) cells located in the ganglion cell layer and inner nuclear layer, expressed calbindin. This pattern of immunoreactivity was conserved in post-embryonic retinae (alevins 15 days old). In adult retinae the ganglion cells showed a faint immunoreaction; the amacrine cells are markedly fewer and their immunoreaction declined; and the bipolar cells expressed calbindin for the first time. The results obtained in the present work attending to the expression of calbindin, generally conforms with the vitreal to scleral progression of differentiation of the teleost retina. Ganglion, amacrine and bipolar cells undergo further maturation after beginning calbindin expression.
Animals↗
Colocalization of neuropeptide Y (NPY)-like and FMRFamide-like immunoreactivities in the brain of the Atlantic salmon (Salmo salar).
The colocalization of the peptides neuropeptide Y (NPY) and Phe-Met-Arg-Phe-NH2 (FMRFamide) in the brain of the Atlantic salmon was investigated with double immunofluorescence labeling and peroxidase-antiperoxidase immunocytochemical techniques. Colocalization of NPY-like and FMRF amide-like immunoreactivities was observed in neuronal cell bodies and fibers in four brain regions: in the lateral and commissural nuclei of the area ventralis telencephali, in the nucleus ventromedialis thalami, in the laminar nucleus of the mesencephalic tegmentum, and in a group of small neurons situated among the large catecholaminergic neurons in the isthmal region of the brainstem. All cell bodies in these nuclei were immunoreactive to both NPY and FMRF. We consistently observed larger numbers of FMRF-immunoreactive than NPY-immunoreactive fibers. In the nucleus ventromedialis thalami NPY- and FMRFamide-like immunoreactivities were colocalized in cerebrospinal fluid (CSF)-contacting neurons. NPY-immunoreactive, but not FMRF-immunoreactive, neurons were found in the stratum periventriculare of the optic tectum, and at the ventral border of the nucleus habenularis (adjacent to the nucleus dorsolateralis thalami). Neurons belonging to the nucleus of the nervus terminalis were FMRF-immunoreactive but not NPY-immunoreactive. The differential labeling indicates, as do our cross-absorption experiments, that the NPY and FMRFamide antisera recognize different epitopes. Thus, it is probable that NPY-like and FMRF amide-like substances occur in the same neurons in some brain regions.
Animals↗
The development of substance P-like immunoreactivity in the goldfish brain.
The development of substance P-like immunoreactivity (SPLI) in the goldfish brain was studied by means of the indirect peroxidase-antiperoxidase technique and an antibody to substance P. By 80 h after fertilization, the first SPLI-cell bodies appear in the ventricular zone of the future diencephalon and the first SPLI-fibers appear in the olfactory bulbs. Two days after hatching (which occurs at 100 h after fertilization), SPLI fibers connecting the olfactory bulbs and hypothalamus are seen. In the optic tectum SPLI-fibers appear for the first time 5 days after hatching. In the brain stem, SPLI-cell bodies appear in juvenile animals 40 days after hatching. The highest number and intensity of SPLI-cell bodies and fibers are found in the area postrema. SPLI-cell bodies are also seen in the gustatory nucleus, nucleus ambiguous, reticular formation of the medulla, dorsal motor nucleus of the vagus and commissural nucleus of Cajal. The significant information gained from the present study is: 1. The rostro-caudal sequence in which the SPLI appears in the developing nuclei of the goldfish brain 2. The reduction of SPLI-cell bodies in some nuclei with age Thus, in the brain stem, SPLI-cell bodies that were labeled in juvenile goldfish were not seen in adults. This might be due to changes in the rate of axonal transport, changes of the SP phenotype during development or cell death. The developmental sequence and relative timing in which SPLI-cell bodies appear in the goldfish, rat and mice are similar.
Aging↗
Distribution of enkephalin-like immunoreactivity in the central nervous system of the rainbow trout: an immunocytochemical study.
The distribution of enkephalin-like immunoreactive (ELI) cell bodies and fibres in the brain of the teleost Salmo gairdneri L. was demonstrated with the indirect peroxidase-antiperoxidase immunocytochemical technique using a highly specific antiserum. In the telencephalon, ELI cell bodies were located in the area ventralis. In the diencephalon, they were found in the nucleus ventromedialis of the thalamus, nucleus lateralis tuberis, nucleus recessus lateralis, and nucleus recessus posterioris. In the mesencephalic tegmentum, ELI cell bodies were found in the nucleus of the rostral mesencephalic tegmentum, and in a group of neurons which was located dorsal to the nucleus of the rostral mesencephalic tegmentum. In the medial torus semicircularis, small numbers of immunoreactive cell bodies were found. In the cerebellum, numerous cell bodies were observed in the granule cell layer and at the border between the granular and molecular layer. ELI cell bodies were also seen in the nucleus tegmenti dorsalis lateralis and nucleus fasciculi solitarii. ELI fibres were widely distributed in the rainbow trout brain. The highest density of immunoreactive fibres was found in the area ventralis telencephali, the mesencephalic tegmentum, the stratum opticum of the optic tectum, the central gray of the brainstem, the caudal part of the fasciculi solitarii and the dorsal horn of the spinal cord. In the stratum fibrosum et griseum superficiale, stratum griseum centrale and stratum album centrale of the optic tectum, a moderate number of immunoreactive fibres was observed. In the olfactory bulb only a few immunoreactive fibres were present. No effect in the labelling was found after colchicine injections. These results provide the first complete mapping of the ELI in a fish brain. It is clear that enkephalins show a similar distribution pattern in Salmo gairdneri to that in other vertebrates; however, the number of ELI cell bodies in the fish brain is smaller than in land vertebrates. The distribution of enkephalins in specific hypothalamic nuclei, visual areas, and in the brainstem of the rainbow trout brain, suggests that these peptides are involved in the modulation of neuroendocrine and as well in visual and somatosensory functions.
Animals↗
Expression of the homeobox engrailed gene during the embryonic development of the nervous system of the trout (Salmo fario L.).
The expression of the engrailed homeobox gene during trout embryogenesis has been examined using immunohistochemistry and the monoclonal antibody 'Mab 4D9'. Engrailed has been suggested to play an important role during development by controlling position-specific characteristics in the CNS of the early embryo. In the present study we have analyzed the expression of engrailed at 5 stages of embryonic development of the trout (Salmo fario L.). The earliest stage analyzed was when the optic vesicles appear. Engrailed was then expressed in the posterior mesencephalon and anterior metencephalon, in a caudorostrally decreasing gradient. As the embryo develops, the pattern of the engrailed expression increases in spatial complexity. Thus, in the later stages of development, just before hatching, engrailed was found in hypothalamic areas, the germinative matrix layer of the cerebellum, the mesencephalic tegmentum, the caudal optic tectum and in the area of the trigeminal motor nucleus. This is similar to the distribution of engrailed in embryos of amphibians, birds and mammals.
Animals↗
Enkephalin-immunoreactive cells in the mesencephalic tegmentum project to the optic tectum of the teleosts Salmo gairdneri and Salmo salar.
Immunocytochemistry using antibodies against Met-enkephalin and Leu-enkephalin has demonstrated a group of large enkephalin-immunoreactive neurons in the nucleus of the rostral mesencephalic tegmentum (mRMT) of two teleost fish. Salmo gairdneri and Salmo salar. Injections of cobalt-lysine in the medial optic tectum retrogradely labeled the above group of tegmental neurons. Tegmental neurons were labeled only ipsilaterally to the injection site. This indicates that enkephalinergic neurons in the nRMT project to the optic tectum, and that at least some of the enkephalinergic axons observed in the optic tectum belong to a tegmen-to-tectal pathway. Comparable enkephalinergic pathways have been described in reptiles and birds, where pretectal-mesencephalic nuclei contribute to the enkephalin-containing fibers that project to the optic tectum.
Animals↗
Distribution of Met-enkephalin, Leu-enkephalin, substance P, neuropeptide Y, FMRFamide, and serotonin immunoreactivities in the optic tectum of the Atlantic salmon (Salmo salar L.).
The distribution of the neuropeptides methionine- and leucine-enkephalins, substance P, FMRFamide, neuropeptide Y, and vasoactive intestinal peptide, as well as the biogenic amine serotonin was studied in the optic tectum of the Atlantic salmon by means of immunocytochemistry. Peroxidase-antiperoxidase and indirect immunofluorescence methods were used to compare the differential laminar distribution of each of these substances. Nine parts of the optic tectum were selected for analysis on frontal sections: median, dorsolateral, and ventrolateral areas at rostral, medial, and caudal levels. Methionine- and leucine-enkephalin immunoreactive fibers were found in discrete sublayers in the following strata: stratum opticum, stratum fibrosum et griseum superficiale, stratum griseum centrale, stratum, and album centrale. Most of the substance P-, serotonin-, and vasoactive intestinal peptide-immunoreactive fibers were found in the stratum album centrale, whereas the FMRFamide- and neuropeptide Y-immunoreactive fibers were more or less randomly distributed within most of the strata of the optic tectum. Neuropeptide Y-immunoreactive cell bodies were located in the stratum periventriculare. We suggest an extrinsic origin for most of the immunoreactive fibers observed in the optic tectum, except for the neuropeptide Y-immunoreactive fibers that probably originate in the periventricular neurons. Although retinal peptidergic input to the optic tectum has been proposed in other vertebrates, there is no evidence that any of the neuropeptidelike or serotonin immunoreactive fibers in the optic tectum of the salmon should be of retinal origin. Differences and similarities with the distribution of neuropeptides in the optic tectum in representatives of other vertebrate classes are discussed.
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↗
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↗
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↗
Neuroglia in the optic tectum of teleosts.
The morphology of the neuroglial cells of the optic tectum of Cyprinid teleosts (Cyprinus carpio and Barbus bocagei) was analyzed using two variants of the Golgi method (Colonnier and Meyer) and electron microscopy. Although the description of the results is based on the three classical neuroglial types (ependymocytes, astrocytes and oligodendrocytes), their analysis shows that the differentiation between astrocytes and oligodendrocytes is complex. Owing to the occurrence of numerous elements with intermediate characteristics, it is suggested that in Teleosts both glial types (astrocytes and oligodendrocytes) correspond to functional variants of a single cell type.
Animals↗