Navegando por CNPq "CNPQ::CIENCIAS BIOLOGICAS::MORFOLOGIA::ANATOMIA"

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Alterações da formação hipocampal do Calidris pusilla associadas à migração outonal de longa distância
(Universidade Federal do Pará, 2017-08-31) MAGALHÃES, Nara Gyzely de Morais; DINIZ, Cristovam Guerreiro; http://lattes.cnpq.br/1025250990755299; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286
After breeding in the upper Arctic tundra, shorebirds affected by migratory restlessness trace an inherited preliminary route and use compasses, maps and visual landmarks, until they reach, in the northern hemisphere, stopover sites that have the necessary nutritional resources for fast and high gain of energy reserves for migratory journey, as in the Bay of Fundy-Canada. Following this stopover site that is used by 75% of the population of Calidris pusilla, the long-distance autumn migratory experience continues with uninterrupted 6-day non-stop flights over the Atlantic until these birds reach South America and then the island of Canela-Brazil. To test the hypothesis that the long-distance migratory process would influence neurogenesis, astrogenesis and activation of earlier-expression genes, we captured 12 individuals in full migratory activity in the Bay of Fundy and 9 individuals in the Island of Canela in Brazil. After selective immunostaining for mature neurons (NeuN), immature neurons (Dcx), astrocytes (GFAP), and neuronal activation by early genes (c-Fos), we quantified these markers in the hippocampal formation and compared the results of this quantification of the individuals in migration (Bay of Fundy) with those of wintering birds (Canela Island). We used quantitative stereological analyzes to estimate the total number of cells of hippocampal formation, number of active cells, total number of astrocytes and young and mature neurons. To verify if the differences found were statistically significant, we used the Student t test. Our results confirmed that autumnal migration alone, caused hippocampal changes in Calidris pusilla. After migration, we detected that the hippocampal formation has fewer activated cells and fewer astrocytes, more new neurons and greater relative volume in the quantified hemisphere (left hemisphere). However, this process did not influence the number of total cells and mature neurons. We suggest that the difference found between the volume and number of new neurons, of the full migration and wintering individuals, possibly occurred due to the migratory process in combination with local conditions found during the beginning of the wintering period. Taken together our findings demonstrate long-distance migratory shorebirds offer a unique opportunity to investigate many issues related to the cellular neurobiology of migration in general, and, on the neural plasticity associated with hippocampal neuronal and neurogenesis in adult birds.
Acesso aberto (Open Access)
Encefalite viral induzida pelo vírus da dengue em camundongos suíços albinos: a resposta inflamatória do sistema nervoso central do hospedeiro neonato
(Universidade Federal do Pará, 2011-10-14) TURIEL, Maíra Catherine Pereira; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286
To study the innate immune response produced specifically within the developing CNS, avoiding the influence of the immune system, employ viral infection model induced by intracerebral inoculation of dengue virus in neonatal mice. Eight newborn mice two days old of the species Mus musculus and Swiss albino variety were inoculated intracerebrally with brain homogenate infected with Flavivirus species (DENV3 genotype III). Another group of animals was used as control (uninfected) and inoculated with an equal volume of non-infectious brain homogenate and maintained under the same conditions of those infected. After 7 days after infection the mice were sacrificed and patients have had their brains processed for immunostaining of astrocytes and microglia. We quantified the glial and astrocitic immune response in the stratum lacunosum molecular (Lac Mol), radiatum (Rad) and pyramidale (Pir) of hippocampus and in the stratum molecular of dentate gyrus (DGMol) using the optical ractionator to estimate the number of microglias and astrocytes in the hippocampus of infected and control animals. Intense reactive astrocytosis and microglial activation were associated with clinical signs of meningoencephalitis in neonate subjects. Although the number of activated microglia to be higher in infected than in control subjects in the GDMol (Inf:738,95 } 83,07 vs Cont: 232,73 } 70,38; p = 0,0035), Rad (Inf: 392,49 } 44,13 vs Cont: 62,76 } 15,86; p = 0,0004) the number of total microglias (activated or not) was different only in the stratum radiatum (Inf: 6.187,49 } 291,62; Cont: 4.011,89 } 509,73;p = 0,01). On the other hand the total number of astrocytes was higher in control than in infected subjects only in the DGMol (Inf: 8.720,17 } 903,11; Cont: 13.023,13 }1.192,14; p = 0,02). Taken together the results suggest that the immune innate response in neonate mice after encephalitis induced by DENV3 genotype III is associated with a higher increase in the activated microglias than astrocytes in a regional and laminardependent fashion. The patophysiology implications of these events remain to be investigated.
Acesso aberto (Open Access)
Sistema reprodutor feminino de três espécies do gênero Saimiri Voigt, 1831 (Primates: Cebidae): observações macroscópicas e histológicas
(Universidade Federal do Pará, 2014-08-18) LOPES, Gerson Paulino; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225; DOMINGUES, Sheyla Farhayldes Souza; http://lattes.cnpq.br/2794753357251149
The platyrrhine primates show variation in their reproductive aspects, their strategies, behaviors, physiology and morphoanatomy. Some of these variations may be consequences of the coevolution of the constituent elements of the genitalia of both sexes through sexual selection. Morphological differences may represent a high degree of specialization of the intraspecific genital organs, which entails a "lock-key" mechanism, which may constitute one of the mechanisms of copulatory and reproductive isolation, with implications in the speciation processes. In females, anatomical and physiological barriers within the vagina, cervix, uterus, uterus-tubal junction, and uterine tubes may be obstacles to male gametes towards fertilization and may influence the outcome of potential sperm competition. In neotropical primates, some morphological descriptions pointed out several similarities and differences between the components of the female reproductive system. Saimiri sciureus, Saimiri oerstedii and Saimiri collinsi were described in primates of the Saimiri genus. Recently, previously identified forms as S. sciureus and considered as subspecies of this, were elevated to the level of species. Among them are Saimiri macrodon and Saimiri cassiquiarensis. These species are widely distributed in the Amazon and occur in peripatria with Saimiri vanzolinii in the Mamirauá Reserve, Central Amazonia. The limits of the geographical distribution of the three species are well delineated, but the mechanisms that promote the reproductive isolation are still not clear. The possibility of hybrids and the progressive invasion of S. cassiquiarensis in the area of S. vanzolinii occurrence are of concern. Some mixed groups were observed in the contact zone between S. vanzolinii and S. cassiquiarensis. The absence of geographical barriers requires that segregation between these species be elucidated by other parameters, such as reproductive isolation due to morphological incompatibility. In this context, we describe the female reproductive system of these species in order to evaluate the possibility that genital morphology constitutes a mechanism of reproductive isolation between them, through the anatomical, topographic and histological description of the external genitalia and internal organs of the female reproductive system. We found that these species share many similarities in most of the organs analyzed. Although some important differences have been identified that may play a relevant role in the evolution of the components of the reproductive system of these species, these differences are not enough to compose a mechanism of reproductive isolation for these three species of Saimiri. Our descriptions provide important information that can assist in the construction of conservation strategies for these and other species of the Saimiri genus. As well as subsidizing the development of reproductive biotechnologies, especially endangered species such as S. vanzolinii, and elucidating questions about evolutionary aspects of the components of the reproductive system of these species and other primates.