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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Trends in evolutionary morphology : a case study in the relationships of angel sharks and batoid fishes

Claeson, Kerin Michele 20 October 2010 (has links)
Chondrichthyans are cartilaginous fishes that include the extant chimaeras, sharks, and batoids, and their extinct relatives. In this dissertation, I examined the growth, development, and relationships of extinct and extant chondrichthyans. I reexamined the skeleton of fossil and fetal specimens of the angel sharks (Squatiniformes) and reanalyzed the current morphologically based hypothesis of chondrichthyan evolution, which conflicts with the current molecular based hypothesis. I did this by including extinct taxa and new characters based on dentition, and the ethmoid, occipital, pectoral, and vertebral skeleton. My results supported the pre-existing morphological hypothesis that angel sharks, saw sharks, and batoids form a clade. However, some of my new characters, particularly those based on the vertebral morphology, indicate that fetal and juvenile angel sharks do not share as many apomorphies with batoids as previously hypothesized from the examination of adults. I also examine the relationships of major groups within batoids, beginning with the construction of a hypothesis of the evolutionary history of electric rays (Torpediniformes). My results are consistent with previous rank-based classifications. However, they deviate from previous classifications depending on the criteria used to generate the hypothesis and on which taxon, or combination of taxa, were used to root the ingroup phylogeny. Because pectoral and vertebral morphology are so critical to morphological hypotheses, I also examined the growth and development of the synarcual cartilage in batoid fishes, with particular emphasis on the synarcual of skates (Rajiformes). My results demonstrate that calcification and chondrification do not proceed in the same order, temporally and spatially. Finally, I redescribe the extinct batoid †Cyclobatis, known only from the Cretaceous, and evaluate its phylogenetic position. My results indicate that †Cyclobatis, the oldest known rajid, is also the sister taxon to a clade of all known extant members of Rajidae. Furthermore, the inclusion of new characters, mainly derived from the synarcual, help to resolve the interrelationships of Rajidae. / text
212

Topographie de l’activité EEG en fuseaux au cours du sommeil chez des enfants et adultes autistes

Chicoine, Marjolaine 07 1900 (has links)
Les fuseaux de sommeil sont des ondes électroencéphalographiques reflétant les mécanismes électrophysiologiques de protection du sommeil. Les adultes autistes ont un sommeil léger et moins de fuseaux de sommeil que des adultes neurotypiques. L’étude vérifie si les enfants autistes montrent également moins de fuseaux de sommeil que les enfants neurotypiques et documente leur évolution avec l’âge. Nous avons enregistré le sommeil de 34 adultes (16 autistes) et 26 enfants (13 autistes) et comparé la quantité de fuseaux de sommeil enregistrés aux électrodes préfrontales (Fp1, Fp2) et centrales (C3, C4). Les deux groupes montrent une diminution similaire des fuseaux en vieillissant. Le groupe d’enfants autistes montre moins de fuseaux que le groupe témoin aux électrodes Fp2 et C4; les adultes autistes montrent significativement moins de fuseaux que les adultes contrôles aux deux électrodes centrales. Le mauvais sommeil des autistes pourrait être causé par une faible protection du sommeil déjà présente en bas âge. / Autism is characterized by poor sleep maintenance. Sleep spindles are electroencephalographic markers representing a sleep protective mechanism. Autistic adults display less spindles than matched controls. This study investigates sleep spindle activity in children and adults with and without autism. The sleep of 34 adults (16 autistics) and 26 children (13 autistics) was recorded. Sleep spindles were counted and compared between groups at prefrontal (Fp1, Fp2) and central (C3, C4) electrodes. Both diagnostic groups showed a similar decrease in sleep spindle with age. Autistic children had significantly less spindles than controls at Fp2 and C4; adults with autism had significantly less spindles than controls at the two central electrodes. Poor sleep in children and adults with autism may be due to impaired protective mechanisms. The developmental pattern of sleep spindle topography suggests an atypical maturational course of the thalamo-cortical loop in autism.
213

Desenvolvimento e morfologia da flor em espécies da tribo Dipterygeae (Leguminosae, Papilionoideae) / Floral development and morphology in species of Dipterygeae (Papilionoideae - Leguminosae)

Leite, Viviane Gonçalves 26 July 2012 (has links)
Espécies da tribo Dipterygeae apresentam morfologia floral interessante, em especial o cálice, bem diferente dos demais membros de Papilionoideae. Representantes desta tribo exibem cálice assimétrico, constituído por duas sépalas adaxiais muito grandes e livres, e três sépalas unidas na base, com lobos abaxiais em forma de pequenos dentes. Assim, este trabalho visa a elucidar a origem deste tipo de cálice, por meio do estudo do desenvolvimento floral dos três gêneros da tribo, representados pelas espécies Dipteryx alata Vogel, Pterodon pubescens (Benth.) Benth. e Taralea oppositifolia Aubl.. Pretende-se também fornecer dados de desenvolvimento floral com valores taxonômico e evolutivo potenciais para o grupo. Botões florais e flores foram dissecados e preparados para análises de superfície em microscopia eletrônica de varredura e anatômica em microscopia de luz. As flores das espécies estão organizadas em inflorescências racemosas indeterminadas, são perfeitas e zigomorfas. A sequencia de surgimento dos verticilos florais é semelhante nas três espécies: bractéolas, sépalas, pétalas, carpelo + primeiros primórdios de estames antessépalos, e estames antepétalos. Dois primórdios de bractéolas são iniciados assincronicamente em D. alata e simultaneamente em P. pubescens e T. oppositifolia; estas bractéolas recobrem o meristema floral; a iniciação dos cinco primórdios de sépalas é unidirecional modificada em D. alata, helicoidal em P. pubescens e sequencial/sequencial modificada em T. oppositifolia; a iniciação dos cinco primórdios de pétalas é simultânea; o primórdio carpelar surge concomitante à iniciação dos primeiros primórdios de estames antessépalos; a iniciação dos estames antessépalos é em ordem unidirecional tendendo para verticilada; os cinco estames antepétalos surgem por último. A fenda carpelar surge do lado adaxial, sendo orientada para a direita ou para a esquerda, no lado oposto ao de iniciação do estame antepétalo adaxial. O androceu é assimétrico. Os filetes fundem-se devido ao meristema intercalar, mas não completamente, formando uma bainha aberta ao redor do carpelo. O carpelo é central com estigma truncado em D. alata, capitado em P. pubescens e puntiforme em T. oppositifolia. O tipo de cálice é elucidado nos estádios intermediários do desenvolvimento floral: a sépala abaxial e as laterais não se alongam, fundem-se, resultando em três lobos diminutos; já as adaxiais se alargam muito e alongam, permanecendo livres. O crescimento avantajado das sépalas adaxiais decorre do aumento do número de camadas e volume das células epidérmicas e subepidérmicas marginais. As flores possuem um apêndice em suas bractéolas, sépalas abaxiais e laterais, pétalas e anteras, onde se localiza um canal secretor. Em T. oppositifolia estes apêndices não ocorrem nas bractéolas e anteras. Além de canais, cavidades secretoras estão presentes no mesofilo das bractéolas, nas margens das sépalas e no apêndice das anteras. As alas exibem esculturas do tipo lamelado em D. alata e T. oppositifolia e lunado em P. pubescens. A presença de um canal secretor no apêndice dos órgãos florais constitui uma provável sinapomorfia para Dipterygeae. Caracteres com valor diagnóstico para as espécies são: (1) iniciação dos primórdios de bractéolas, (2) iniciação dos primórdios de sépalas, (3) proeminência do apêndice da antera, (4) tipo de escultura presente nas alas, (5) formato do estigma, (6) comprimento do estipe, (7) pilosidade do ovário, (8) curvatura do estilete, (9) posição da nervura central e (10) tipo de fruto. / Representatives of the tribe Dipterygeae exhibit interesting floral features, in special considering the calyx, which is quite different from that exhibited by other papilionoids. The calyx is asymmetric, constituted by two adaxial very large free sepals, and three abaxial unite sepals with teeth-like lobes. Thus, this work aims to to elucidate the developmental vias of this type of calyx, by studying the floral development and morphology of three genera of the tribe, represented by Dipteryx alata Vogel, Pterodon pubescens (Benth.) Benth. and Taralea oppositifolia Aubl. Also, we intend to provide other data on floral development with taxonomic and evolutionary values. Buds and flowers were dissected and prepared for surface and anatomical analyses, under scanning electron and light microscopy, respectively. The flowers of all species are arranged in indeterminate racemes, are zygomorphic and perfect. The initiation of floral whorls is similar in the three species: bracteoles, sepals, petals, carpel + antesepalous stamens, and antepetalous stamens. The floral apex initiates two bracteoles asynchronously in D. alata and simultaneously in P. pubescens and T. oppositifolia; these bracteoles cover the floral apex; the order of initiation of five sepal is modified unidirectional in D. alata, helical in P. pubescens and sequential or modified sequential in T. oppositifolia; the five petals initiate in a simultaneous order; the initiation of the carpel is concomitant to that of the antesepalous abaxial stamens; antesepalous stamens initiates in tendencies towards whorled order, and the five antepetalous stamens arise later. A central carpel with truncate stigma occurs in D. alata, capitate stigma in P. pubescens and punctiform stigma in T. oppositifolia. The carpel cleft of all species arises in the adaxial side and is positioned to the right or the left opposite to the antepetalous adaxial stamen primordium. The androecium is asymmetric. The filaments fuse due to intercalary meristematic activity, but not completely, forming an open sheath around the carpel. The different type of calyx is elucidate by observing the intermediary stages of floral development: the abaxial and lateral sepals do not elongate, fuse, resulting in a united structure with three lower lobes, while the adaxial sepals enlarge and elongate, remaining free. The great growth of adaxial sepals results of the increasing in the number of layers and volume of marginal epidermal and subepidermal cells. Bracteoles, abaxial and lateral sepals, petals and anthers are appendiculate. In T. oppositifolia these appendices do not occur in bracteoles and anthers. One secretory canal is observed within each appendix. Besides secretory canals, secretory cavities are found in the mesophyll of bracteoles, in the sepal margins and in the anther appendices. The wings show sculptures of lamellate type in D. alata and T. oppositifolia and of lunate type in P. pubescens. The presence of secretory canal in the floral appendices can be considered a synapomorphy for the tribe Dipterygeae. Diagnostic characters for the species are: (1) order of bracteole initiation, (2) order of sepal initiation, (3) anther appendix salience, (4) pattern of wing sculpture, (5) stigma shape, (6) stipe length, (7) ovary hairiness, (8) style bend, (6) position of the central rib, and (7) type of fruit.
214

Desenvolvimento estrutural da hipófise e ontogenia das células adeno-hipofisárias do dourado Salminus brasiliensis (Cuvier, 1816) Teleostei, Characiformes. / Structural development of the pituitary gland and ontogeny of adenohypophyseal cells from dourado Salminus brasiliensis (Cuvier, 1816) Teleostei, Characiformes.

Jesus, Lázaro Wender Oliveira de 19 August 2011 (has links)
Neste estudo foi verificado que a hipófise de S. brasiliensis era composta por dois tecidos, a neuro hipófise (NH) e a adeno-hipófise (AH). Nesta última, foram distinguidos sete tipos celulares. Na RPD foram detectadas as células adrenocorticotrópicas e prolactínicas, na PPD as células gonadotrópicas, somatotrópicas e tireotrópicas, e na PI, as células melanotrópicas e somatolactínicas. Foi evidenciada única célula gonadotrópica, produtora de LH e FSH. O primórdio da hipófise foi detectado 12 horas após a eclosão (hpe), a NH com 72 hpe e o início da formação do pedúnculo com 300 hpe. Nos juvenis (600 hpe), a hipófise apresentou uma morfologia semelhante àquela observada nos adultos. As células prolactínicas foram detectadas com 12 hpe, juntamente com as células adrenocorticotrópicas e melanotrópicas, seguidas das somatotrópicas e somatolactínicas, com 36 hpe. Por outro lado, nas larvas e juvenis foram detectadas duas populações distintas de células gonadotrópicas, as células produtoras de FSH foram detectadas com 600 hpe, enquanto as produtoras de LH com 120 hpe. / This study showed that the pituitary gland of S. brasiliensis was formed by two tissues, neurohypophysis and adenohypophysis. In the latter, seven cell types were distinguished. In RPD, prolactin and adrenocorticotropic cells were present. In PPD, gonadotropic, somatotrope and thyrotropic cells were detected, and in PI, somatolactin and melanotropic cells were found. Interestingly, was detected a single gonadotropic cell responsible for producing both gonadotropins. The primordium of the pituitary gland was detected 12 hours after hatching (hah), the neurohypophysis was detected 72 hah and formation of the stalk 300 hah. In juveniles, 600 hah, the pituitary showed a similar morphology to that observed in adults of this species. Prolactin cells were detected 12 hah together with adrenocorticotropic and melanotropic cells, followed by somatotropic and somatolactin cells 36 hah. Unlike adults, larvae and juveniles have shown two distinct populations of gonadotropic cells. FSH-producing cells were detected 600 hah, while LH-producing cells were detected 120 hah.
215

Functional architecture of the medial entorhinal cortex

Ray, Saikat 05 September 2016 (has links)
Schicht 2 des mediale entorhinale Kortex (MEK) beinhaltet die größte Anzahl von Gitterzellen, welche durch ein hexagonales Aktivitätsmuster während räumlicher Exploration gekennzeichnet sind. In dieser Arbeit wurde gezeigt, dass spezielle Pyramidenzellen, die das Protein Calbindin exprimieren, in einem hexagonalen Gitter im Gehirn der Ratte angeordnet sind und cholinerg innerviert werden. Es ist bekannt, dass die cholinerge Innervation wichtig für die Aktivität von Gitterzellen ist. Weiterhin ergaben neuronale Ableitungen und Methoden zur Identifikaktion einzelner Neurone in frei verhaltenden Ratten, dass Calbindin-positive Pyramidenzellen (Calbindin+) eine große Anzahl von Gitterzellen beinhalten. Reelin-positive Sternzellen (Reelin+) im MEK, zeigten keine anatomische Periodizität und ihre Aktivität orientierte sich an den Begrenzungen der Umgebung. Eine weitere Studie untersucht die Architektur des MEK in verschiedenen Säugetieren, die von der Etrusker Spitzmaus, bis hin zum Menschen ~100 Millionen Jahre evolutionäre Vielfalt und ~20,000 fache Variation der Gehirngröße umfassen. Alle Arten zeigten jeweils eine periodische Anhäufung der Calbindin+ Zellen, was deren evolutive Bedeutung unterstreicht. Eine Studie zur Ontogenese der Calbindin Anhäufungen ergab, dass die periodische Struktur der Calbindin+ Zellen, sowie die verstreute Anordnung der Reelin+ Sternzellen schon zum Zeitpunkt der Geburt erkennbar war. Weitere Ergebnisse zeigen, dass Calbindin+ Zellen strukturell später ausreifen als Reelin+ Sternzellen - passend zu der Erkenntnis, dass Gitterzellen funktionell später reifen als Grenzzellen. Eine Untersuchung des Parasubiculums ergab, dass Verbindungen zum MEK präferiert in die Calbindin Anhäufungen in Schicht 2 projizieren. Zusammenfassend beschreibt diese Doktorarbeit eine Dichotomie von Struktur und Funktion in Schicht 2 des MEK, welche fundamental für das Verständnis von Gedächtnisbildung und deren zugrundeliegenden Mikroschaltkreisen ist. / The medial entorhinal cortex (MEC) is an important hub in the memory circuit in the brain. This thesis comprises of a group of studies which explores the architecture and microcircuits of the MEC. Layer 2 of MEC is home to grid cells, neurons which exhibit a hexagonal firing pattern during exploration of an open environment. The first study found that a group of pyramidal cells in layer 2 of the MEC, expressing the protein calbindin, were clustered in the rat brain. These patches were physically arranged in a hexagonal grid in the MEC and received preferential cholinergic-inputs which are known to be important for grid-cell activity. A combination of identified single-cell and extracellular recordings in freely behaving rats revealed that grid cells were mostly calbindin-positive pyramidal cells. Reelin-positive stellate cells in MEC were scattered throughout layer 2 and contributed mainly to the border cell population– neurons which fire at the borders of an environment. The next study explored the architecture of the MEC across evolution. Five mammalian species, spanning ~100 million years of evolutionary diversity and ~20,000 fold variation in brain size exhibited a conserved periodic layout of calbindin-patches in the MEC, underscoring their importance. An investigation of the ontogeny of the MEC in rats revealed that the periodic structure of the calbindin-patches and scattered layout of reelin-positive stellate cells was present around birth. Further, calbindin-positive pyramidal cells matured later in comparison to reelin-positive stellate cells mirroring the difference in functional maturation profiles of grid and border cells respectively. Inputs from the parasubiculum, selectively targeted calbindin-patches in the MEC indicating its role in shaping grid-cell function. In summary, the thesis uncovered a structure-function dichotomy of neurons in layer 2 of the MEC which is a fundamental aspect of understanding the microcircuits involved in memory formation.
216

ONTOGENIA INICIAL E CONSUMO DE VITELO EM EMBRIÕES DE BETTA SPLENDENS

Duarte, Shaytner Campos 13 February 2009 (has links)
Made available in DSpace on 2016-08-10T10:31:05Z (GMT). No. of bitstreams: 1 SHAYTNER CAMPOS DUARTE.pdf: 11135197 bytes, checksum: 3ee26fdd9a567634d92906a8c356a0a6 (MD5) Previous issue date: 2009-02-13 / Among the ornamental species, the Betta splendens deserve highlights, because of its great commercial interest. The process of ontogeny can be described as the development of the embryo at the time of fertilization, trough embryonic development stage to the hatching or later stages. The study of the embryogenesis of a species is of great importance and is a useful tool in study of the growth of species in their natural environment. This work aimed to describe the initial ontogeny in embryos of specimen B. splendens. It was possible to observe that as time marches on embryogenesis, there was a decrease in the height of the yolk and in its length, mainly in the final third of the embryonic period. The volume of yolk available to the embryo decreased during embryonic development, from 0.19912 mm3 average value of the HPF 12.5 to 0.10262 mm3 moments after the eruption that began with 34.0 HPF. It was possible to observe that the newly-hatched larvae had a residual volume of yolk of 0.01935 mm3 ± 0005, where was still possible to observe drops of oil. The newly hatching larvae observed in this study did not use exogenous food source. The embryo of B. splendens has stages of embryo development comparable to that observed in other species of teleosts. Consumption of yolk is more prominent in the final third of embryonic development, after 15.0 hours post-fertilization, in the period near the hatch and the period immediately after hatching. Through this work we observed and recorded the main stages of the development of the Siamese fighting fish B. splendens, and also verify the rate of consumption of yolk during the stages of embryogenesis until the larvae hatch and the newly-hatched, contributing thus to a better understanding of the biology of the species. / Dentre as espécies ornamentais o Betta splendens é uma das que merece destaque, devido ao grande interesse comercial. O processo de ontogenia pode ser descrito como o desenvolvimento do embrião do momento da fecundação, passando pela fase de desenvolvimento embrionário, até a eclosão ou fases posteriores. O estudo da embriogênese de uma espécie é de grande importância, sendo uma ferramenta útil no estudo do crescimento de espécies em seu ambiente natural. O presente trabalho teve por objetivo descrever a ontogenia inicial em embriões da espécie B. splendens. Foi possível observar que com o passar do tempo embrionário, houve uma diminuição na altura do vitelo e posteriormente no comprimento do vitelo principalmente no terço final do período embrionário. Os volumes de vitelo disponíveis para o embrião diminuíram durante o desenvolvimento embrionário, passando de 0,19912 mm3 média do valor às 12,5 HPF, para 0,10262 mm3 momentos após a eclosão que se iniciou com 34,0 HPF. Foi possível observar que as larvas recém-eclodidas continham um volume residual de vitelo de 0,01935mm3 ± 0,005 e nesse resíduo ainda foi possível observar gotas de óleo. As larvas recém eclodidas observadas no presente estudo não utilizaram alimentos de fonte exógena. O embrião de B. splendens tem fases de desenvolvimento embrionário comparáveis ao observado em outras espécies de teleósteos. O consumo de vitelo é mais acentuado no terço final do desenvolvimento embrionário, após as 15,0 horas-pós-fecundação, no período próximo à eclosão e no período logo pós-eclosão. Através do presente trabalho foi possível observar e registrar os estágios principais do desenvolvimento do peixe de briga siamês B. splendens, e também verificar a taxa de consumo de vitelo durante as fases da embriogênese até o momento da eclosão e das larvas recém-eclodidas, contribuindo dessa forma para um melhor conhecimento da biologia da espécie.
217

Caracterização da diferenciação celular durante a morfogênese da hipófise em Astyanax altiparanae (Garutti & Britski, 2000). / Characterization of cell differentiation during morphogenesis in the pituitary gland Astyanax altiparanae (GARUTTI & BRITSKI, 2000).

Branco, Giovana Souza 02 February 2016 (has links)
Após a reprodução de Astyanax altiparanae, foram obtidas larvas e juvenis da espécie, os quais foram coletados desde a eclosão até 120 dias após a eclosão (dpe). Por meio de métodos histoquímicos e imuno-histoquímica foram detectadas a neuro (NH) e adeno-hipófise (AH). Nas 3 regiões da AH, rostral (RPD) e proximal (PPD) pars distalis, e pars intermedia (PI), foram encontrados 8 tipos celulares produtores de hormônios, sendo, na RPD, as células produtoras de ACTH e PRL; na PPD, GTH (FSH e LH), GH e TSH; e na PI, MSH e SL. As prolactínicas foram as primeiras células identificadas com 1 dpe no início da formação da glândula. A NH foi diferenciada com 3 dpe junto com as células produtoras de ACTH, MSH, TSH e FSH. A identificação das células produtoras de LH, SL e GH ocorreu com 5 dpe. Com 20 dpe houve um grande aumento da hipófise e o aparecimento do pedúnculo. Com 60 dpe a hipófise apresentou-se semelhante à observada nos adultos. Os resultados desta pesquisa colaboram para o conhecimento do eixo hipotálamo-hipófise-gônada em teleósteos sul-americanos. / After reproduction of A. altiparanae, was made larvae and juveniles of this specie, were collected from zero to 120 days post hatching (dph). By histochemical and immunohistochemical techniques were detected neuro (NH) and adenohypophysis (AH). In 3 regions of AH, rostral (RPD), proximal (PPD) pars distalis and in pars intermedia (PI), eight producing hormones cell types are distinguished, being, in the RPD, ACTH and PRL producing cells; in PPD, GTH (FSH and LH), GH and TSH; and in the PI, MSH and SL. The first cells identified were prolactins at 1dph, in the beginning of the formation of the gland. NH differentiated at 3dph along with identification of ACTH, MSH, TSH and FSH producing cells. The identification of LH, SL and GH producing cells was possible at 5dph. At 20dph, there was a large increase in the pituitary, and it was observed the presence of the pituitary stalk. At 60 dph the pituitary showed a similar morphology to that observed in adults. The results of this research collaborate to knowledge of the hypothalamic-pituitary-gonadal axis in South American teleosts.
218

Abundância, distribuição e caraterização morfológica de larvas de Atherinella brasiliensis (Atherinopsidae,Atheriniformes) no estuário do rio Jaguaribe,Pernambuco, Brasil

FRANÇA, Elton José de 28 February 2005 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-02-10T12:49:41Z No. of bitstreams: 1 Elton Jose de Franca.pdf: 570351 bytes, checksum: 22c2a56d2a6e533728edd19f56fbb5ef (MD5) / Made available in DSpace on 2017-02-10T12:49:41Z (GMT). No. of bitstreams: 1 Elton Jose de Franca.pdf: 570351 bytes, checksum: 22c2a56d2a6e533728edd19f56fbb5ef (MD5) Previous issue date: 2005-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study presents information about Atherinella brasiliensis larvae from the Jaguaribe river estuary, located in the northern coast of the state of Pernambuco, northeastern Brazil. Its objective was to characterize the abundance and distribution of larvae, along with a description of their external morphology and morphometric data. Ichthyoplankton samples were taken monthly, from April 2001 to April 2002, through surface towing of a 500μm conical-cylindrical plankton net, at six different sampling stations. Temperature and salinity average values ranged, respectively, from a minimum of 17.44 and 27.26ºC in January and June, to a maximum of 37.73 and 29.90oC in December and April. A total density of 258.04 larvae.10m-3 was recorded throughout the study period, 94.23% of which were in the preflexion stage. Higher larvae densities were recorded in October, January and March, and lower in September. Among stations, higher densities were recorded in the upper reaches of the estuary, which presented low and quiet waters. A. brasiliensis larvae hatch with an average standard length (SL) of 1.4mm. In the preflexion stage, the body is envolved by a finfold, beginning just behind the head, and four dendritic chromatophores are present on top of the head. The flexion stage begins with a SL of 3.8mm, dorsal and anal fins present pterigyophores and the mouth is terminal, but somewhat upward orientated. With 4.7mm SL, the larva is at the end of the flexion stage and beginning of postflexion. In the postflexion stage, an ossification of dorsal and anal fin rays is evident, as well as the pelvic buds and darkening of lateral pigmentation. With approximately 12.0mm SL, all fins are formed, and the second dorsal one is the last to be formed, being located posterior to the anal. The juvenile stage begins at approximately 15mmSL. In this stage, A. brasiliensis present the anal fin located at the body midpoint, and the posterior end of pectorals surpasses the pelvic fin origin, which is located at an equal distance from the pectoral and anal fins’ origins. Scales are clearly visible at the dorso-lateral region, behind the head. The results indicate most of the species life cycle takes place in the estuary, it presents multiple spawning, and initial recruitment occurs in January and March. The morphological features herein described allow the identification of its larvae, together with an adequate differentiation from hemiramphids and other atheriniform species. / O presente trabalho apresenta informações sobre larvas de Atherinella brasiliensis, no estuário do rio Jaguaribe, localizado no litoral norte do estado de Pernambuco. O mesmo teve como objetivo, caracterizar a abundância e distribuição de larvas desta espécie, bem como, caracterizar o seu desenvolvimento inicial, através da descrição de sua morfologia externa e aspectos morfométricos. Foram realizadas coletas mensais de ictioplâncton, no período de abril de 2001 a abril de 2002, através de arrastos horizontais na superfície, com rede de plâncton cônico-cilíndrica, de malha de 500 μm, em seis diferentes estações de amostragem. Os valores médios de salinidade e temperatura registrados foram menores nos meses de janeiro e junho, com 17,44 e 27,26 ºC, e os maiores nos meses de dezembro e abril, com 37,73 e 29,90ºC, respectivamente. Uma densidade total de 258,04 larvas.10m-3 foi registrada para todo o período, sendo 94,23% delas representadas pelo estágio de pré-flexão. As maiores ocorrências de larvas foram registradas nos meses de outubro, janeiro e março, e a menor em setembro. Dentre as estações, as maiores densidades foram registradas na porção superior do estuário, a qual apresentou águas calmas e rasas. Larvas de A. brasiliensis eclodem com comprimento padrão (CP) médio de 1,4mm. No estágio de pré-flexão, a larva apresenta o corpo revestido por membrana embrionária, que se inicia logo atrás da cabeça e a larva apresenta quatro cromatóforos dendríticos sobre a cabeça. O estágio de flexão inicia-se com CP de aproximadamente 3,8mm, as nadadeiras dorsal e anal já evidenciam a presença de pterigióforos e a bocaassume uma posição terminal, sendo esta ligeiramente inclinada para cima. Com CP médio de 4,7mm, a larva encontra-se no estágio final da flexão e início da pós-flexão. No estágio de pós-flexão, apresenta uma maior ossificação dos raios das nadadeiras dorsal e anal, já apresentando também o botão da nadadeira pélvica e um adensamento da pigmentação lateral. Com aproximadamente 12,0mm de CP, a larva apresenta todas as nadadeiras formadas, sendo a primeira nadadeira dorsal a última a passar pelo processo de ossificação, estando localizada em posição posterior à anal. O estágio juvenil tem inicio com CP de aproximadamente 15mm. Nesta fase, A. brasiliensis apresenta a nadadeira anal localizada na porção mediana do corpo e a margem posterior das peitorais ultrapassa a origem das pélvicas, sendo estas últimas localizadas no ponto médio entre as origens das nadadeiras peitoral e anal. Na região dorso-lateral, próximo à cabeça, é possível visualizar escamas. Os resultados indicam que a espécie tem boa parte do seu ciclo de vida ocorrendo no estuário e que a mesma apresenta desova do tipo parcelada. O seu principal período de recrutamento ocorre nos meses de janeiro a março e as características morfológicas aqui descritas permitem uma adequada identificação de suas larvas, bem como sua diferenciação daquelas da família Hemiramphidae e de outras espécies de Atheriniformes.
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Deple??o cerebral de serotonina durante o per?odo neonatal programa a homeostase metab?lica energ?tica e a express?o comportamental de ratos adultos. / Brain serotonin depletion during neonatal period programme energetic metabolic homeostasis and behavioral expression of adulthood rats

Moreira, Rodrigo Mencalha 28 August 2008 (has links)
Made available in DSpace on 2016-04-28T20:18:30Z (GMT). No. of bitstreams: 1 2008 - Rodrigo Mencalha Moreira.pdf: 2348355 bytes, checksum: 249dc9822a474bb30086d8952df6f1f2 (MD5) Previous issue date: 2008-08-28 / Brain serotonin (5-HT) depletion during the neonatal period lead a plastic cytoarchitecture change of the serotonergic system influencing directly several brain systems ontogeny development. This dissertation was aimed to elucidate the influence of brain 5-HT depletion during the neonatal period on the metabolic programming and the behavioral expression of adulthood rats. Brain 5-HT depletion was raised with the subcutaneous (s.c) administration of 100 mg. Kg-1 para-chlorophenylalanine (pCPA), a competitive inhibitor of the tryptophan hydroxylase enzyme, from the eighth at sixteenth post-natal days. In order to investigate the influence of pCPA on the subject metabolic programming, during and after treatment, the milk intake and body weight gain from the neonatal period to adulthood were evaluated. Furthermore, evaluating indirectly this influence on the energetic metabolism, the repercussions on the glycemic homeostasis through of the glycemia baseline measurements and under fasting in the adult rat were investigated. Around the ingestive behavior, baseline conditions paradigm and under fasting were made. In these experimental trials, water intake, ration, 2% sucrose and 0.3M NaCl were evaluated. Also, the 0.3 M NaCl intake after sodium depletion (furosemide 20mg. Kg-1, s.c) and water intake after hypertonic stimulus (1.0 M NaCl, s.c) were measured. The behavioral expression was evaluated through models involved with emotional-behavioral signals. In this analysis, the rat s anxiety status was investigated through of open field test, elevated plus-maze (EPM), social interaction and forced swimming. The results showed that treatment with pCPA reduces milk intake (P˂0.001) and therefore the body weight gain in the neonatal period (P˂0.001), claiming to be smaller until adulthood (P˂0.01). The glycemic homeostasis was also affected reflected in lower pCPA-male (P˂0.01) and pCPA-female (P˂0.001) levels after 24 hours of fasting. About to baseline intake, a higher pCPA-female sodium appetite (P˂0.05), related to a greater demand for 2% sucrose solution in both females (P˂0,001) were observed. Under fasting, a lower male-pCPA cumulative ration intake at 60 min (P˂0.05) and a higher female pCPA at 60 (P˂0.05) and 120 min (P˂0.01) were observed. Furthermore, after water deprivation, a higher pCPA-female cumulative water intake at 120 min (P˂0.05) compared with pCPA-male was rated. Was also observed a greater pCPA-male water intake at 120 and 180 min (P˂0.001) after hypertonic stimulus, however, it was not observed significant difference in the natriorexigenic responses in sodium depleted rats. In addition, pCPA male showed a evident anxiolytic activity in EPM test expressed by the higher time spent in the open arm (O.A) (P˂0.05), higher head-dipping in the O.A episodes (P˂0.001), less S.A.P. (P˂0.001) and grooming episodes (P˂0.01). Therefore, these results showed that 5-HT depletion during the neonatal period programme the energetic metabolic homeostasis and the behavioral expression of adulthood rats. / A deple??o cerebral de serotonina (5-HT) durante o per?odo neonatal acarreta uma altera??o pl?stica na citoarquitetura do sistema seroton?rgico influenciando diretamente o desenvolvimento ontog?nico de diversos sistemas cerebrais. Nesta disserta??o objetivou-se elucidar a influ?ncia da deple??o cerebral de 5-HT durante o per?odo neonatal sobre a programa??o metab?lica energ?tica e express?o comportamental de ratos adultos. A deple??o cerebral de 5-HT foi evocada com a administra??o subcut?nea (s.c) de 100 mg. Kg-1, de para-clorofenilalanina (pCPA), um inibidor competitivo da enzima triptofano hidroxilase, do oitavo ao d?cimo sexto dias p?s-natais. A fim de investigar a influ?ncia da pCPA, durante e ap?s o tratamento, sobre a programa??o metab?lica do indiv?duo, foram avaliadas a ingest?o de leite e o ganho de peso corporal do per?odo neonatal ? vida adulta. Ademais, avaliando indiretamente esta influ?ncia sobre o metabolismo energ?tico, foram investigadas as repercuss?es sobre a homeostase glic?mica atrav?s da mensura??o basal e sob jejum da glicemia do rato adulto. Em rela??o ao comportamento ingestivo foram realizados protocolos em condi??es basais e sob jejum. Nestes ensaios experimentais foram avaliadas as ingest?es de ?gua, ra??o, sacarose 2% e NaCl 0,3 M. Outrossim, foram mensuradas as ingest?es de NaCl 0,3 M ap?s deple??o de s?dio (furosemida 20mg. Kg-1, s.c) e de ?gua ap?s est?mulo hipert?nico (NaCl 1,0 M, s.c). A express?o comportamental foi avaliada atrav?s de modelos envolvidos com aspectos afetivo-comportamentais. Nesta an?lise, foi investigado o status de ansiedade dos ratos atrav?s dos testes de campo aberto, labirinto em cruz elevado (LCE), intera??o social e nata??o for?ada. Os resultados demonstraram que o tratamento com pCPA diminui a ingest?o de leite (P˂0,001) e conseq?entemente o ganho de peso corporal no per?odo neonatal (P˂0,001), sustentando-se menor at? a vida adulta (P˂0,01). A homeostase glic?mica tamb?m foi afetada refletida nos menores n?veis glic?micos em machos-pCPA (P˂0,01) e f?meas pCPA (P˂0,001) ap?s jejum alimentar de 24 horas. Em rela??o ?s ingest?es basais, foi observado um maior apetite por s?dio em f?meas-pCPA (P˂0,05), al?m de uma maior procura pela solu??o de sacarose 2% em ambas as f?meas (P˂0,001). Sob jejum alimentar, foi observada uma menor ingest?o cumulativa de ra??o em machos-pCPA aos 120 min (P˂0,05) e maior ingest?o em f?meas-pCPA aos 60 (P˂0,05) e 120 min (P˂0,01). Ademais, ap?s jejum h?drico, foi notada uma maior ingest?o cumulativa de ?gua em f?meas-pCPA aos 120 min (P˂0,05) em rela??o aos machos-pCPA. Observou-se ainda uma maior ingest?o de ?gua nos machos-pCPA aos 120 e 180 min (P˂0,001) ap?s est?mulo hipert?nico, por?m, n?o foi observada diferen?a significativa na resposta natriorexig?nica em ratos s?dio-depletados. Al?m disso, foi observada uma evidente atividade ansiol?tica no LCE expressa pelo maior tempo gasto no bra?o aberto (B.A) (P˂0,05), maior n?mero de epis?dios de head-dipping no B.A (P˂0,001), menos epis?dios de S.AP. (P˂0,001) e grooming (P˂0,01). Em resumo, estes resultados demonstram que a deple??o de 5-HT durante o per?odo neonatal programa a homeostase metab?lica energ?tica e a express?o comportamental de ratos adultos.
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Impact of environmental factors on the development of corticotroph subpopulations in the fetal sheep pituitary.

Farrand, Kirsten January 2008 (has links)
The prepartum surge in fetal plasma cortisol, essential for the maturation of organs in mammals and the normal timing of parturition in some species, including sheep, may result from an increase in the molar ratio of adrenocorticotropin (ACTH) to pro-opiomelanocortin (POMC) in the fetal circulation. Related to this, the cleavage of POMC to ACTH by the enzyme, prohormone convertase 1 (PC1), may be influenced by corticotrophin releasing hormone (CRH) stimulation. Accumulating evidence suggests that the capacity of individual corticotrophs to process POMC to ACTH may vary and individual corticotrophs are differentially responsive to CRH. It is not known, however, if there are separate corticotroph subpopulations in the fetal sheep pituitary which can be identified by differential colocalisation of POMC, ACTH and the CRH receptor 1, CRHR₁, nor if changes in the relative proportions of such subpopulations play a role in the molecular mechanisms underlying the overall changes in pituitary function described previously during gestation and in response to suboptimal uterine environments. To investigate these hypotheses, it was first necessary to develop novel methods for the simultaneous immunohistochemical labelling of POMC, ACTH and CRHR₁ in individual cells on sections of fetal sheep pituitary. In addition, I developed and validated an automated method to categorise and count individual cells to increase the quantitative power of this study. Pituitary tissue was collected from control fetuses at 53-55 (n=6), 63-85 (n=6), 110 (n=4), 139-141 (n=4) and 144-145 (n=6) days gestation. Two animal models, known to alter pituitary function in the fetal sheep, were used to investigate corticotrophic adaptations to suboptimal uterine environments. For the maternal periconceptional undernutrition (PCUN) model, maternal feed was reduced to 70% of maintenance requirements from at least 45 days before to 7 days after mating and fetal tissues were collected at 53-55 days gestation (n=7). For the placental restriction (PR) model, the majority of the placental attachment sites were removed in five ewes before mating and fetal tissues were collected at 140 (n=4) and 144 (n=4) days gestation. Pituitary sections were simultaneously labelled with antisera raised against full length POMC, ACTH and CRHR₁ and the proportions of pituitary cells with combinations of antisera were quantified. Four subpopulations of corticotrophs were identified, which expressed either: POMC+ACTH+CRHR₁, ACTH+CRHR₁, POMC+ CRHR₁ or POMConly. There was a significant decrease in the proportion of pituitary cells expressing POMC+ACTH+CRHR₁ between 53-55 and 65-85 days gestation, before an increase at 110 days gestation and a further marked decrease between 139-141 and 144-145 days gestation. In fetuses from the PCUN group, the proportion of pituitary cells expressing POMC+ACTH+CRHR₁ in early gestation was reduced. PR resulted in a significantly higher proportion of corticotrophs expressing POMC+ACTH+CRHR₁ during the prepartum period. This work represents the discovery of the differential expression of POMC, ACTH and CRHR₁ in individual corticotrophs of the fetal sheep pituitary and the first insights into the pituitary adaptations to periconceptional nutrient restriction and placental restriction at the level of individual corticotrophs. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337370 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

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