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Sample records for rhombencephalon

  1. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

    International Nuclear Information System (INIS)

    Nightingale, S.; Schofield, I.S.; Dawes, P.J.D.K.

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings. (author)

  2. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

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    Nightingale, S. (Royal Victoria Infirmary, Newcastle upon Tyne (UK)); Schofield, I.S.; Dawes, P.J.D.K. (Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings.

  3. Experiment list: ERX402274 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other struc...tures in the BRAIN STEM. 30676338,97.5,14.1,1336 Illumina Genome Analyzer IIx seque

  4. Experiment list: SRX680478 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available CEREBELLUM; and other structures in the BRAIN STEM. 21281853,90.1,46.2,1952 GSM1479201: AUTS2 mBrain ChIPse...); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM;

  5. Experiment list: SRX150258 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available CEREBELLUM; and other structures in the BRAIN STEM. 10945554,97.9,14.2,523 GSM939572: ChIP of sonicated who...); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM;

  6. Experiment list: SRX116258 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available uctures in the BRAIN STEM. 59051475,60.4,7.7,25795 GSM862560: CTCF BxC; Mus musculu...; and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other str

  7. Experiment list: ERX402281 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other struc...tures in the BRAIN STEM. 38099443,98.2,8.3,553 Illumina Genome Analyzer IIx sequenc

  8. Computer ranking of the sequence of appearance of 100 features of the brain and related structures in staged human embryos during the first 5 weeks of development.

    Science.gov (United States)

    O'Rahilly, R; Müller, F; Hutchins, G M; Moore, G W

    1984-11-01

    The sequence of events in the development of the brain in staged human embryos was investigated in much greater detail than in previous studies by listing 100 features in 165 embryos of the first 5 weeks. Using a computerized bubble-sort algorithm, individual embryos were ranked in ascending order of the features present. This procedure made feasible an appreciation of the slight variation found in the developmental features. The vast majority of features appeared during either one or two stages (about 2 or 3 days). In general, the soundness of the Carnegie system of embryonic staging was amply confirmed. The rhombencephalon was found to show increasing complexity around stage 13, and the postoptic portion of the diencephalon underwent considerable differentiation by stage 15. The need for similar investigations of other systems of the body is emphasized, and the importance of such studies in assessing the timing of congenital malformations and in clarifying syndromic clusters is suggested.

  9. Three-dimensional morphology of the human embryonic brain

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    N. Shiraishi

    2015-09-01

    Full Text Available The morphogenesis of the cerebral vesicles and ventricles was visualized in 3D movies using images derived from human embryo specimens between Carnegie stage 13 and 23 from the Kyoto Collection. These images were acquired with a magnetic resonance microscope equipped with a 2.35-T superconducting magnet. Three-dimensional images using the same scale demonstrated brain development and growth effectively. The non-uniform thickness of the brain tissue, which may indicate brain differentiation, was visualized with thickness-based surface color mapping. A closer view was obtained of the unique and complicated differentiation of the rhombencephalon, especially with regard to the internal view and thickening of the brain tissue. The present data contribute to a better understanding of brain and cerebral ventricle development.

  10. Effect of 12-Day Spaceflight on Brain of Thick-Toed Geckos

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    Proshchina, A. E.; Karlamova, A. S.; Barabanovet, V. M.; Godovalova, O. S.; Guilimova, V. I.; Krivova, Y. S.; Makarov, A. N.; Nikitin, V. B.; Savelieva, E. S.; Saveliev, S. V.

    2008-06-01

    In the frames of Russian-American joint space experiment onboard Foton-M3 satellite there was undertaken a study of spaceflight influence on brain of the thick-toed gecko (Pachydactylus turneri Gray, 1864). Serial brain sections were stained according to Nissl and also the immunohistochemical method with antibodies to NGF-receptor (p75NGFR), CD95 (also known as Fas and APO-1), glial fibrillary acidic protein (GFAP) and transferrin-receptor (CD71). Detailed examination of the sections of rhombencephalon revealed cytological changes in the neuron bodies of vestibular nuclei inside the flight group. Immunohistochemicaly we found the increase density of CD95 and p75NGFR and decrease of GFAP expression in medial cortex and epithalamus in flight group compared both control.

  11. X-ray microanalysis of Zn in the taste organ of the teleost Ameiurus nebulosus

    International Nuclear Information System (INIS)

    Reutter, K.

    1983-01-01

    The trace metal Zn seems to be essential for the normal functioning of the gustatory sense. It was tried to localize Zn within the peripheral and central parts of the bullhead's gustatory system by the use of scanning electron microscopy and X-ray microanalysis. In freeze dried preparations of the bullhead's barbel taste buds (and the taste buds of rabbits) Zn is found in randomly distributed granules, which cannot be related to distinct taste bud regions. Furthermore, Zn occurs in subunits of the central gustatory nuclei, the vagal and facial lobe of the rhombencephalon. Therefore Zn appears to be essential for intact peripheral as well as central gustatory processes, at least in lower vertebrates. (author)

  12. The distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the medulla oblongata, spinal cord, cranial and spinal nerves of frog, Microhyla ornata.

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    Jadhao, Arun G; Biswas, Saikat P; Bhoyar, Rahul C; Pinelli, Claudia

    2017-04-01

    Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) enzymatic activity has been reported in few amphibian species. In this study, we report its unusual localization in the medulla oblongata, spinal cord, cranial nerves, spinal nerves, and ganglions of the frog, Microhyla ornata. In the rhombencephalon, at the level of facial and vagus nerves, the NADPH-d labeling was noted in the nucleus of the abducent and facial nerves, dorsal nucleus of the vestibulocochlear nerve, the nucleus of hypoglossus nerve, dorsal and lateral column nucleus, the nucleus of the solitary tract, the dorsal field of spinal grey, the lateral and medial motor fields of spinal grey and radix ventralis and dorsalis (2-10). Many ependymal cells around the lining of the fourth ventricle, both facial and vagus nerves and dorsal root ganglion, were intensely labeled with NADPH-d. Most strikingly the NADPH-d activity was seen in small and large sized motoneurons in both medial and lateral motor neuron columns on the right and left sides of the brain. This is the largest stained group observed from the caudal rhombencephalon up to the level of radix dorsalis 10 in the spinal cord. The neurons were either oval or elongated in shape with long processes and showed significant variation in the nuclear and cellular diameter. A massive NADPH-d activity in the medulla oblongata, spinal cord, and spinal nerves implied an important role of this enzyme in the neuronal signaling as well as in the modulation of motor functions in the peripheral nervous systems of the amphibians. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Timing of neurodegeneration and beta-amyloid (Abeta) peptide deposition in the brain of aging kokanee salmon.

    Science.gov (United States)

    Maldonado, Tammy A; Jones, Richard E; Norris, David O

    2002-10-01

    Brains of kokanee salmon (Oncorhynchus nerka kennerlyi) in one of four reproductive stages (sexually immature, maturing, sexually mature, and spawning) were stained with cresyl violet and silver stain to visualize neurodegeneration. These reproductive stages correlate with increasing somatic aging of kokanee salmon, which die after spawning. Twenty-four regions of each brain were examined. Brains of sexually immature fish exhibited low levels of neurodegeneration, whereas neurodegeneration was more marked in maturing fish and greatest in spawning fish. Neurodegeneration was present in specific regions of the telencephalon, diencephalon, mesencephalon, and rhombencephalon. Pyknotic neurons were observed in all regions previously reported to be immunopositive for A beta. Regions that did not exhibit neurodegeneration during aging included the magnocellular vestibular nucleus, the nucleus lateralis tuberis of the hypothalamus, and Purkinje cells of the cerebellum, all of which also lack A beta; perhaps these regions are neuroprotected. In 14 of 16 brain areas for which data were available on both the increase in A beta deposition and pyknosis, neurodegeneration preceded or appeared more or less simultaneously with A beta production, whereas in only two regions did A beta deposition precede neurodegeneration. This information supports the hypothesis that A beta deposition is a downstream product of neurodegeneration in most brain regions. Other conclusions are that the degree of neurodegeneration varies among brain regions, neurodegeneration begins in maturing fish and peaks in spawning fish, the timing of neurodegeneration varies among brain regions, and some regions do not exhibit accelerated neurodegeneration during aging. Copyright 2002 Wiley Periodicals, Inc.

  14. Extrabulbar olfactory system and nervus terminalis FMRFamide immunoreactive components in Xenopus laevis ontogenesis.

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    Pinelli, Claudia; D'Aniello, Biagio; Polese, Gianluca; Rastogi, Rakesh K

    2004-09-01

    The extrabulbar olfactory system (EBOS) is a collection of nerve fibers which originate from primary olfactory receptor-like neurons and penetrate into the brain bypassing the olfactory bulbs. Our description is based upon the application of two neuronal tracers (biocytin, carbocyanine DiI) in the olfactory sac, at the cut end of the olfactory nerve and in the telencephalon of the developing clawed frog. The extrabulbar olfactory system was observed already at stage 45, which is the first developmental stage compatible with our techniques; at this stage, the extrabulbar olfactory system fibers terminated diffusely in the preoptic area. A little later in development, i.e. at stage 50, the extrabulbar olfactory system was maximally developed, extending as far caudally as the rhombencephalon. In the metamorphosing specimens, the extrabulbar olfactory system appeared reduced in extension; caudally, the fiber terminals did not extend beyond the diencephalon. While a substantial overlapping of biocytin/FMRFamide immunoreactivity was observed along the olfactory pathways as well as in the telencephalon, FMRFamide immunoreactivity was never observed to be colocalized in the same cellular or fiber components visualized by tracer molecules. The question whether the extrabulbar olfactory system and the nervus terminalis (NT) are separate anatomical entities or represent an integrated system is discussed.

  15. Brain size regulations by cbp haploinsufficiency evaluated by in-vivo MRI based volumetry

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    Ateca-Cabarga, Juan C.; Cosa, Alejandro; Pallarés, Vicente; López-Atalaya, José P.; Barco, Ángel; Canals, Santiago; Moratal, David

    2015-11-01

    The Rubinstein-Taybi Syndrome (RSTS) is a congenital disease that affects brain development causing severe cognitive deficits. In most cases the disease is associated with dominant mutations in the gene encoding the CREB binding protein (CBP). In this work, we present the first quantitative analysis of brain abnormalities in a mouse model of RSTS using magnetic resonance imaging (MRI) and two novel self-developed automated algorithms for image volumetric analysis. Our results quantitatively confirm key syndromic features observed in RSTS patients, such as reductions in brain size (-16.31%, p < 0.05), white matter volume (-16.00%, p < 0.05), and corpus callosum (-12.40%, p < 0.05). Furthermore, they provide new insight into the developmental origin of the disease. By comparing brain tissues in a region by region basis between cbp+/- and cbp+/+ littermates, we found that cbp haploinsufficiency is specifically associated with significant reductions in prosencephalic tissue, such us in the olfactory bulb and neocortex, whereas regions evolved from the embryonic rhombencephalon were spared. Despite the large volume reductions, the proportion between gray-, white-matter and cerebrospinal fluid were conserved, suggesting a role of CBP in brain size regulation. The commonalities with holoprosencephaly and arhinencephaly conditions suggest the inclusion of RSTS in the family of neuronal migration disorders.

  16. Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh).

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    Mazengenya, Pedzisai; Bhagwandin, Adhil; Manger, Paul R; Ihunwo, Amadi O

    2018-01-01

    In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey parrot ( Psittacus erithacus ) and Timneh grey parrot ( Psittacus timneh ) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey parrots, but minor differences were also observed. In both species of parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations.

  17. Developmental disturbances of the fetal brain in guinea-pigs caused by methylmercury

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    Inouye, Minoru; Kajiwara, Yuji

    1988-08-01

    Pregnant guinea-pigs of Hartley strain were orally administered methylmercuric chloride once at a dose of 7.5 mg Hg/animal (weighing 500-800 g) on one of days 21, 28, 35, 42 or 49 (3-7 weeks) of gestation. They were killed on day 63 (9 weeks) and their fetuses were removed. Both maternal and fetal blood, brain, liver and kidney, and fetal hair, urine, gastric content and amniotic fluid as well, were sampled for mercury analysis. The fetal brains were also examined pathologically. The maternal kidney contained mercury at a high concentration but the fetal kidney did not. The mercury concentration was strikingly high in the fetal hair, but fairly low in the urine, gastric contents and amniotic fluid. Mercury distributed unevenly in various brain regions of both dams and fetuses after treatment at 6 and 7 weeks of pregnancy (3 and 2 weeks before sampling). The concentration was high in the neopallium and archipallium, followed by the paleopallium, diencephalon and mesencephalon, but low in the rhombencephalon, including cerebellum. Mercury contents were relatively low and distributed almost evenly in various brain regions of both the dams and fetuses following treatment at 3, 4 and 5 weeks of pregnancy. Morphologically, the fetal brains were disturbed in the development following treatment at 3, 4 and 5 weeks of pregnancy. The cerebral cortex was thinned, the nucleus caudatus putamen and the hippocampal formation were reduced in size, and the lateral ventricles were dilated. However, the histological architecture of the cerebral cortex was not strikingly maldeveloped; only a slight disarrangement of the cellular alignment was noted. Following treatment at 6 and 7 weeks of pregnancy, focal degeneration of the neuronal cells was observed in the fetal neocortex; the severe cases showed spongy degeneration and dysgenetic hydrocephalus.

  18. Expression pattern of the thrombopoietin receptor (Mpl) in the murine central nervous system.

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    Ivanova, Anna; Wuerfel, Jens; Zhang, Juan; Hoffmann, Olaf; Ballmaier, Matthias; Dame, Christof

    2010-07-28

    Thrombopoietin (Thpo) and its receptor (Mpl), which regulate megakaryopoiesis, are expressed in the central nervous system (CNS), where Thpo is thought to exert pro-apoptotic effects on newly generated neurons. Mpl expression has been analysed in brain tissue on transcript level and in cultured primary rat neurons and astrocytes on protein level. Herein, we analysed Mpl expression in the developing and adult murine CNS by immunohistochemistry and investigated the brain of mice with homozygous Mpl deficiency (Mpl-/-) by MRI. Mpl was not detectable at developmental stages E12 to E15 in any resident cells of the CNS. From E18 onwards, robust Mpl expression was found in various brain areas, including cerebral cortex, olfactory bulb, thalamus, hypothalamus, medulla, pons, and the grey matter of spinal cord. However, major developmental changes became obvious: In the subventricular zone of the cerebral cortex Mpl expression occurred only during late gestation, while in the hippocampus Mpl expression was detectable for first time at stage P4. In the white matter of the cerebellum Mpl expression was restricted to the perinatal period. In the adult cerebellum, Mpl expression switched to Purkinje cell. The majority of other Mpl-positive cells were NeuN-positive neurons. None of the cells could be double-labelled with astrocyte marker GFAP. Mpl-/- mice showed no gross abnormalities of the brain. Our data locate Mpl expression to neurons at different subdivisions of the spinal cord, rhombencephalon, midbrain and prosencephalon. Besides neuronal cells Mpl protein is also expressed in Purkinje cells of the adult cerebellum.

  19. LPXRFa peptide system in the European sea bass: A molecular and immunohistochemical approach.

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    Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Gómez, Ana; Zanuy, Silvia; Mañanos, Evaristo; Muñoz-Cueto, José A

    2016-01-01

    Gonadotropin-inhibitory hormone (GnIH) is a neuropeptide that suppresses reproduction in birds and mammals by inhibiting GnRH and gonadotropin secretion. GnIH orthologs with a C-terminal LPXRFamide (LPXRFa) motif have been identified in teleost fish. Although recent work also suggests its role in fish reproduction, studies are scarce and controversial, and have mainly focused on cyprinids. In this work we cloned a full-length cDNA encoding an LPXRFa precursor in the European sea bass, Dicentrarchus labrax. In contrast to other teleosts, the sea bass LPXRFa precursor contains only two putative RFamide peptides, termed sbLPXRFa1 and sbLPXRFa2. sblpxrfa transcripts were expressed predominantly in the olfactory bulbs/telencephalon, diencephalon, midbrain tegmentum, retina, and gonads. We also developed a specific antiserum against sbLPXRFa2, which revealed sbLPXRFa-immunoreactive (ir) perikarya in the olfactory bulbs-terminal nerve, ventral telencephalon, caudal preoptic area, dorsal mesencephalic tegmentum, and rostral rhombencephalon. These sbLPXRFa-ir cells profusely innervated the preoptic area, hypothalamus, optic tectum, semicircular torus, and caudal midbrain tegmentum, but conspicuous projections also reached the olfactory bulbs, ventral/dorsal telencephalon, habenula, ventral thalamus, pretectum, rostral midbrain tegmentum, posterior tuberculum, reticular formation, and viscerosensory lobe. The retina, pineal, vascular sac, and pituitary were also targets of sbLPXRFa-ir cells. In the pituitary, this innervation was observed close to follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH) cells. Tract-tracing retrograde labeling suggests that telencephalic and preoptic sbLPXRFa cells might represent the source of pituitary innervation. The immunohistochemical distribution of sbLPXRFa cells and fibers suggest that LPXRFa peptides might be involved in some functions as well as reproduction, such as feeding, growth, and behavior.

  20. Involvement of 5-HT(2) serotonergic receptors of the nucleus raphe magnus and nucleus reticularis gigantocellularis/paragigantocellularis complex neural networks in the antinociceptive phenomenon that follows the post-ictal immobility syndrome.

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    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Ferreira, Célio Marcos Dos Reis; Coimbra, Norberto Cysne

    2006-09-01

    The post-ictal immobility syndrome is followed by a significant increase in the nociceptive thresholds in animals and men. In this interesting post-ictal behavioral response, endogenous opioid peptides-mediated mechanisms, as well as cholinergic-mediated antinociceptive processes, have been suggested. However, considering that many serotonergic descending pathways have been implicated in antinociceptive reactions, the aim of the present work is to investigate the involvement of 5-HT(2)-serotonergic receptor subfamily in the post-ictal antinociception. The analgesia was measured by the tail-flick test in seven or eight Wistar rats per group. Convulsions were followed by statistically significant increase in the tail-flick latencies (TFL), at least for 120 min of the post-ictal period. Male Wistar rats were submitted to stereotaxic surgery for introduction of a guide-cannula in the rhombencephalon, aiming either the nucleus raphe magnus (NRM) or the gigantocellularis complex. In independent groups of animals, these nuclei were neurochemically lesioned with a unilateral microinjection of ibotenic acid (1.0 microg/0.2 microL). The neuronal damage of either the NRM or nucleus reticularis gigantocellularis/paragigantocellularis complex decreased the post-ictal analgesia. Also, in other independent groups, central administration of ritanserin (5.0 microg/0.2 microL) or physiological saline into each of the reticular formation nuclei studied caused a statistically significant decrease in the TFL of seizing animals, as compared to controls, in all post-ictal periods studied. These results indicate that serotonin input-connected neurons of the pontine and medullarly reticular nuclei may be involved in the post-ictal analgesia.

  1. Proliferation zones in the axolotl brain and regeneration of the telencephalon

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    Maden Malcolm

    2013-01-01

    Full Text Available Abstract Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells

  2. Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus and Timneh Grey Parrot (Psittacus timneh

    Directory of Open Access Journals (Sweden)

    Pedzisai Mazengenya

    2018-02-01

    Full Text Available In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey parrot (Psittacus erithacus and Timneh grey parrot (Psittacus timneh using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA, which labels proliferating cells, and doublecortin (DCX, which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey parrots, but minor differences were also observed. In both species of parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL. The widespread distribution of PCNA and DCX in the brains of both parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations.

  3. Regional distribution of calretinin and calbindin-D28k expression in the brain of the urodele amphibian Pleurodeles waltl during embryonic and larval development.

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    Joven, Alberto; Morona, Ruth; Moreno, Nerea; González, Agustín

    2013-07-01

    The sequence of appearance of calretinin and calbindin-D28k immunoreactive (CRir and CBir, respectively) cells and fibers has been studied in the brain of the urodele amphibian Pleurodeles waltl. Embryonic, larval and juvenile stages were studied. The early expression and the dynamics of the distribution of CBir and CRir structures have been used as markers for developmental aspects of distinct neuronal populations, highlighting the accurate extent of many regions in the developing brain, not observed on the basis of cytoarchitecture alone. CR and, to a lesser extent, CB are expressed early in the central nervous system and show a progressively increasing expression from the embryonic stages throughout the larval life and, in general, the labeled structures in the developing brain retain their ability to express these proteins in the adult brain. The onset of CRir cells primarily served to follow the development of the olfactory bulbs, subpallium, thalamus, alar hypothalamus, mesencephalic tegmentum, and distinct cell populations in the rhombencephalic reticular formation. CBir cells highlighted the development of, among others, the pallidum, hypothalamus, dorsal habenula, midbrain tegmentum, cerebellum, and central gray of the rostral rhombencephalon. However, it was the relative and mostly segregated distribution of both proteins in distinct cell populations which evidenced the developing regionalization of the brain. The results have shown the usefulness in neuroanatomy of the analysis during development of the onset of CBir and CRir structures, but the comparison with previous data has shown extensive variability across vertebrate classes. Therefore, one should be cautious when comparing possible homologue structures across species only on the basis of the expression of these proteins, due to the variation of the content of calcium-binding proteins observed in well-established homologous regions in the brain of different vertebrates.

  4. Neuropathogenesis of a highly pathogenic avian influenza virus (H7N1 in experimentally infected chickens

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    Chaves Aida J

    2011-10-01

    Full Text Available Abstract In order to understand the mechanism of neuroinvasion of a highly pathogenic avian influenza virus (HPAIV into the central nervous system (CNS of chickens, specific pathogen free chickens were inoculated with a H7N1 HPAIV. Blood, cerebrospinal fluid (CSF, nasal cavity and brain tissue samples were obtained from 1 to 4 days post-inoculation (dpi of infected and control chickens. Viral antigen topographical distribution, presence of influenza A virus receptors in the brain, as well as, the role of the olfactory route in virus CNS invasion were studied using different immunohistochemistry techniques. Besides, viral RNA load in CSF and blood was quantified by means of a quantitative real-time reverse transcription-polymerase chain reaction. Viral antigen was observed widely distributed in the CNS, showing bilateral and symmetrical distribution in the nuclei of the diencephalon, mesencephalon and rhombencephalon. Viral RNA was detected in blood and CSF at one dpi, indicating that the virus crosses the blood-CSF-barrier early during infection. This early dissemination is possibly favoured by the presence of Siaα2,3 Gal and Siaα2,6 Gal receptors in brain vascular endothelial cells, and Siaα2,3 Gal receptors in ependymal and choroid plexus cells. No viral antigen was observed in olfactory sensory neurons, while the olfactory bulb showed only weak staining, suggesting that the virus did not use this pathway to enter into the brain. The sequence of virus appearance and the topographical distribution of this H7N1 HPAIV indicate that the viral entry occurs via the haematogenous route, with early and generalized spreading through the CSF.

  5. Neuropathogenesis of a highly pathogenic avian influenza virus (H7N1) in experimentally infected chickens.

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    Chaves, Aida J; Busquets, Núria; Valle, Rosa; Rivas, Raquel; Vergara-Alert, Júlia; Dolz, Roser; Ramis, Antonio; Darji, Ayub; Majó, Natàlia

    2011-10-07

    In order to understand the mechanism of neuroinvasion of a highly pathogenic avian influenza virus (HPAIV) into the central nervous system (CNS) of chickens, specific pathogen free chickens were inoculated with a H7N1 HPAIV. Blood, cerebrospinal fluid (CSF), nasal cavity and brain tissue samples were obtained from 1 to 4 days post-inoculation (dpi) of infected and control chickens. Viral antigen topographical distribution, presence of influenza A virus receptors in the brain, as well as, the role of the olfactory route in virus CNS invasion were studied using different immunohistochemistry techniques. Besides, viral RNA load in CSF and blood was quantified by means of a quantitative real-time reverse transcription-polymerase chain reaction. Viral antigen was observed widely distributed in the CNS, showing bilateral and symmetrical distribution in the nuclei of the diencephalon, mesencephalon and rhombencephalon. Viral RNA was detected in blood and CSF at one dpi, indicating that the virus crosses the blood-CSF-barrier early during infection. This early dissemination is possibly favoured by the presence of Siaα2,3 Gal and Siaα2,6 Gal receptors in brain vascular endothelial cells, and Siaα2,3 Gal receptors in ependymal and choroid plexus cells. No viral antigen was observed in olfactory sensory neurons, while the olfactory bulb showed only weak staining, suggesting that the virus did not use this pathway to enter into the brain. The sequence of virus appearance and the topographical distribution of this H7N1 HPAIV indicate that the viral entry occurs via the haematogenous route, with early and generalized spreading through the CSF.

  6. The long adventurous journey of rhombic lip cells in jawed vertebrates: a comparative developmental analysis

    Directory of Open Access Journals (Sweden)

    Mario F Wullimann

    2011-04-01

    Full Text Available This review summarizes vertebrate rhombic lip and early cerebellar development covering classic approaches up to modern developmental genetics which identifies the relevant differential gene expression domains and their progeny. Most of this information is derived from amniotes. However, progress in anamniotes, particularly in the zebrafish, has recently been made. The current picture suggests that rhombic lip and cerebellar development in jawed vertebrates (gnathostomes share many characteristics. Regarding cerebellar development, these include a ptf1a expressing ventral cerebellar proliferation (VCP giving rise to Purkinje cells and other inhibitory cerebellar cell types, and an atoh1 expressing upper rhombic lip giving rise to an external granular layer (EGL, i.e., excitatory granule cells and an early ventral migration into the anterior rhombencephalon (cholinergic nuclei. As for the lower rhombic lip (LRL, gnathostome commonalities likely include the formation of precerebellar nuclei (mossy fiber origins and partially primary auditory nuclei (likely convergently evolved from the atoh1 expressing dorsal zone. The fate of the ptf1a expressing ventral LRL zone which gives rise to (excitatory cells of the inferior olive (climbing fiber origin and (inhibitory cells of cochlear nuclei in amniotes, has not been determined in anamniotes. Special for the zebrafish in comparison to amniotes is the predominant origin of anamniote excitatory deep cerebellar nuclei homologues (i.e., eurydendroid cells from ptf1a expressing VCP cells, the sequential activity of various atoh1 paralogues and the incomplete coverage of the subpial cerebellar plate with proliferative EGL cells. Nevertheless, the conclusion that a rhombic lip and its major derivatives evolved with gnathostome vertebrates only and are thus not an ancestral craniate character complex is supported by the absence of a cerebellum (and likely absence of its afferent and efferent nuclei in jawless

  7. The Histamine H1 Receptor Participates in the Increased Dorsal Telencephalic Neurogenesis in Embryos from Diabetic Rats

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    Karina H. Solís

    2017-12-01

    Full Text Available Increased neuron telencephalic differentiation during deep cortical layer formation has been reported in embryos from diabetic mice. Transitory histaminergic neurons within the mesencephalon/rhombencephalon are responsible for fetal histamine synthesis during development, fibers from this system arrives to the frontal and parietal cortex at embryo day (E 15. Histamine is a neurogenic factor for cortical neural stem cells in vitro through H1 receptor (H1R which is highly expressed during corticogenesis in rats and mice. Furthermore, in utero administration of an H1R antagonist, chlorpheniramine, decreases the neuron markers microtubuline associated protein 2 (MAP2 and forkhead box protein 2. Interestingly, in the diabetic mouse model of diabetes induced with streptozotocin, an increase in fetal neurogenesis in terms of MAP2 expression in the telencephalon is reported at E11.5. Because of the reported effects on cortical neuron differentiation of maternal diabetes in one hand and of histamine in the other, here the participation of histamine and H1R on the increased dorsal telencephalic neurogenesis was explored. First, the increased neurogenesis in the dorsal telencephalon at E14 in diabetic rats was corroborated by immunohistochemistry and Western blot. Then, changes during corticogenesis in the level of histamine was analyzed by ELISA and in H1R expression by qRT-PCR and Western blot and, finally, we tested H1R participation in the increased dorsal telencephalic neurogenesis by the systemic administration of chlorpheniramine. Our results showed a significant increase of histamine at E14 and in the expression of the receptor at E12. The administration of chlorpheniramine to diabetic rats at E12 prevented the increased expression of βIII-tubulin and MAP2 mRNAs (neuron markers and partially reverted the increased level of MAP2 protein at E14, concluding that H1R have an important role in the increased neurogenesis within the dorsal telencephalon