552 resultados para Rostral ventrolateral medulla


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Quantitative data on early mother-infant relationships in the Tibetan macaque was collected during the first 23 weeks of infant life in spring, 1987, at Mt. Emei, China. During the first week of life, infants spent 98.3% of their time in ventroventral contact with their mothers. This contact rapidly decreased to 33.8% by the 4th week and thereafter to 0.85% by the 23rd week. Nipple contact decreased relatively slowly from 89.7% to 62.9% within the first 4 weeks of infant life and to 19.8% by the 23rd week. Ventrolateral and ventrodorsal contact appeared by the 2nd week, mean-while, maternal restraining behavior appeared, and reached a peak by the 3rd week. The mother neither encouraged nor discouraged her infant's independence during 4-8th weeks. Maternal rejection of the infant was first observed when the infant was 11 weeks old and continued thereafter.

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Generally it has not been recognized that salamanders of two distinctive color morphs currently are assigned to Tylototriton verrucosus Anderson. One form is uniformly dark brown dorsally, with bright orange coloration confined to the ventral edge of the tail; the other has a dark brown to black dorsal ground color with orange dorsolateral warts, an orange vertebral crest, and orange lateral and medial crests on the head. In addition, the limbs and ventrolateral surfaces of the second form have a variable pattern of orange coloration. The brown form occurs in northeastern India, Nepal, northern Burma, Bhutan, northern Thailand, the type locality in extreme western Yunnan, and perhaps in northern Vietnam. The orange-patterned form occurs only in western Yunnan Province, People's Republic of China. The two forms appear to be allopatric but occur close together in the area of the type locality near the Burma border in western Yunnan. There is no evidence of color intergradation in specimens from this region. Analyses of morphometric and meristic characters, however, suggest the possibility of limited genetic exchange between adjacent populations of brown and orange-patterned forms in western Yunnan. The genetic and taxonomic relationships between the two forms is not fully resolved. However, these two highly distinctive forms obviously have evolved along independent trajectories and merit taxonomic recognition. We therefore propose to restrict the concept of Tylototriton verrucosus to the brown form and designate a neotype for that purpose, and we describe a new species to receive the orange-patterned form.

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Pituitary adenylate cyclase-activating polypeptide (PACAP) which belongs to the secretin/glucagon/ VIP family has been originally isolated from the sheep hypothalamus on the basis of its ability to stimulate cAMP formation in culture rat anterior pituitary cells. Post-translational processing of the PACAP precursor generates two biologically active molecular forms, PACAP-38 and PACAP-27. The primary structure of PACAP has been remarkably conserved during evolution. The sequence of PACAP-27 exhibits substantial similarities with those of vasoactive intestinal polypeptide (VIP), glucagon and secretin. The gene encoding the PACAP precursor is widely expressed in brain and various peripheral organs, notably in endocrine glands, gastro-intestinal, urogenital tracts and respiratory system. In vivo, and in vitro studies have shown that PACAP exhibits multiple activities especially a trophic activity during ontogenesis, notably in the adrenal medulla and the central nervous system. The biological effects of PACAP are mediated through three distinct receptor subtypes which exhibit differential affinities for PACAP and VIP. The PAC1 receptor, which shows high selectivity for PACAP, is coupled to several transduction systems. In contrast, VPAC1 and VPAC2, which bind with the same affinity for PACAP and VIP, are mainly coupled to the adenylyl cyclase pathway. In conclusion, PACAP is neuropeptide, and it functions as a hypothalamic hormone, neurohormone, neuromodulator, vasodilator, neurotransmitter or trophic factor in the brain and the various organs.

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Humans have the arguably unique ability to understand the mental representations of others. For success in both competitive and cooperative interactions, however, this ability must be extended to include representations of others' belief about our intentions, their model about our belief about their intentions, and so on. We developed a "stag hunt" game in which human subjects interacted with a computerized agent using different degrees of sophistication (recursive inferences) and applied an ecologically valid computational model of dynamic belief inference. We show that rostral medial prefrontal (paracingulate) cortex, a brain region consistently identified in psychological tasks requiring mentalizing, has a specific role in encoding the uncertainty of inference about the other's strategy. In contrast, dorsolateral prefrontal cortex encodes the depth of recursion of the strategy being used, an index of executive sophistication. These findings reveal putative computational representations within prefrontal cortex regions, supporting the maintenance of cooperation in complex social decision making.

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Reward processing is linked to specific neuromodulatory systems with a dopaminergic contribution to reward learning and motivational drive being well established. Neuromodulatory influences on hedonic responses to actual receipt of reward, or punishment, referred to as experienced utility are less well characterized, although a link to the endogenous opioid system is suggested. Here, in a combined functional magnetic resonance imaging-psychopharmacological investigation, we used naloxone to block central opioid function while subjects performed a gambling task associated with rewards and losses of different magnitudes, in which the mean expected value was always zero. A graded influence of naloxone on reward outcome was evident in an attenuation of pleasure ratings for larger reward outcomes, an effect mirrored in attenuation of brain activity to increasing reward magnitude in rostral anterior cingulate cortex. A more striking effect was seen for losses such that under naloxone all levels of negative outcome were rated as more unpleasant. This hedonic effect was associated with enhanced activity in anterior insula and caudal anterior cingulate cortex, areas implicated in aversive processing. Our data indicate that a central opioid system contributes to both reward and loss processing in humans and directly modulates the hedonic experience of outcomes.

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Our ability to have an experience of another's pain is characteristic of empathy. Using functional imaging, we assessed brain activity while volunteers experienced a painful stimulus and compared it to that elicited when they observed a signal indicating that their loved one--present in the same room--was receiving a similar pain stimulus. Bilateral anterior insula (AI), rostral anterior cingulate cortex (ACC), brainstem, and cerebellum were activated when subjects received pain and also by a signal that a loved one experienced pain. AI and ACC activation correlated with individual empathy scores. Activity in the posterior insula/secondary somatosensory cortex, the sensorimotor cortex (SI/MI), and the caudal ACC was specific to receiving pain. Thus, a neural response in AI and rostral ACC, activated in common for "self" and "other" conditions, suggests that the neural substrate for empathic experience does not involve the entire "pain matrix." We conclude that only that part of the pain network associated with its affective qualities, but not its sensory qualities, mediates empathy.

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A new genus and two new species are described from the Pearl River drainage in Guangxi Province, South China. Hongshuia, new genus, can be distinguished from all other Asian genera of the Labeonini by having a lower lip with its median lobe modified into a round, fleshy plate peripherally greatly protruded so as to form a ring-like fold that is posteromedially continuous with the mental region, and centrally sunken so as to form a round, flat, fleshy pad. This genus is distinct from all other Asian labeonine genera of the Garrina except for one newly described species of Parasinilabeo ( P. longibarbus), Pseudocrossocheilus, and Sinocrossocheilus, in the presence of well-developed maxillary barbels. Hongshuia differs from the above three genera in the lower lip morphology, and further from both Pseudocrossocheilus and Qianlabeo in the number of pharyngeal tooth rows and from Sinocrossocheilus in the colour pattern. Two new species, H. banmo and H. paoli, differ in the distribution density and degree of development of papillae on the rostral fold, depth of indentations on the distal edge of the rostral fold, presence or absence of papillae on the lower lip, size and shape of tubercles on the tip of the snout and anterior portion of the lachrymal, length, position and colour pattern of the dorsal fin, and snout length.

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A new genus of Cobitinae, Bibarba gen. n., and a new species, B. bibarba sp. n., were discovered and are described for the Chengjiang River, a tributary of the Hongshuihe River in Guangxi Province of southern China. This river region is characterized by a Karst landscape, and the river that is inhabited by the new genus is a slowly moving stream with arenaceous and cobblestone beds. The new genus resembles Cobitis Linnaeus, 1758 (subfamily Cobitinae) in the shape and pigmentation pattern of their body, the absence of scales on their head, and the presence of a suborbital spine, but differs from it by a single Lamina circularis on the third pectoral fin ray instead of on the base of the second pectoral fin ray; two pairs of barbels (one rostral pair and one maxillo-mandibular pair) instead of three pairs of barbels (one rostral pair, one maxillary pair, and one maxillo-mandibular pair); a relatively thick and short suborbital spine with a strong medio-lateral process instead of a suborbital spine without or with a weakly formed medio-lateral process as in Cobitis; and the lack of a black stripe extending from the occiput through the eye to the insertion of the rostral barbel. The first two characters have not been reported in any other genus of the subfamily Cobitinae. A morphometric character analysis based on PCA reveals differences between B. bibarba and C. sinensis in body size, barbel length, interorbital width, pectoral fin length in males, and the position of the dorsal and ventral fins. Type specimens of the new species are kept in the Freshwater Fishes Museum of the Institute of Hydrobiology at the Chinese Academy of Sciences in Wuhan, Hubei Province. (c) 2007 Elsevier GmbH. All rights reserved.

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The cDNA encoding grass carp intelectin was isolated from a head kidney cDNA library, and termed gcIntL. The deduced amino acid sequence of gcIntL consists of 318 amino acids, and about 55% identical and 74% similar to human intelectin, which is a new type of lectin recognizing galactofuranose, and plays a role in the recognition of bacteria-specific components in animal hosts. The gcIntL gene consists of seven exons and six introns, spacing over approximately 3 kb of genomic sequence. Phylogenetic analysis clearly demonstrated that the gcIntL formed a clade with Danio rerio intelectin and 35 kDa serum lectin. By real-time quantitative RT-PCR analysis, gcIntL transcripts were significantly induced in head kidney, trunk kidney, spleen, and intestine from LPS-stimulated fish. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcIntL gene have the same expression pattern, and both were detected in brain, gill, intestine, head kidney, trunk kidney, spleen, and heart. Furthermore, gcIntL protein could be detected in gill, intestine, trunk kidney, head kidney, spleen, heart, and brain including medulla oblongata and optic lobe, as determined by immunohistochemistry. This is the first report of intelectin expression pattern in fish, and of recombinant gcIntL and polyclonal antibody against gcIntL. (c) 2006 Elsevier Ltd. All rights reserved.

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A novel fish chemokine receptor gene, chemokine (C-X-C motif) receptor 3 (CXCR3)-like was isolated from the grass carp Ctenopharyngodon idella , with its full-length genomic sequence. The cDNA of grass carp CXCR3-like (gcCXCR3-like) consists of 1261 bp with a 49bp 5'-UTR and a 189 bp 3'-UTR. An open reading frame of 1023 bp encodes a 341-amino acid peptide, with seven transmembrane helices. The deduced amino acid sequence showed the same sequence identities (37.8%) with its counterparts in goat and human. The gcCXCR3-like gene consists of two exons, with one intervening intron, spaced over approximately 2 kb of genomic sequence. Phylogenetic analyses clearly demonstrated that the gcCXCR3-like resembles the CXCR3s of other vertebrates. Real-time PCR analysis showed that gcCXCR3-like was expressed in all tested organs except heart and the expression level of gcCXCR3-like was highest in brain. Flow cytometric analyses showed the positive rate of labelled leukocytes from the healthy grass carp was 17.3%, and the labelled leukocytes were divided into three types by cell sorting. Immunohistochemical localization revealed that gcCXCR3-like expressed in whole brain regions including cerebel, diencephalon, medulla oblongata, optic lobe, and rhinencephalon, and that the labelled leukocytes are actually populations of monocyte and/or phagocyte, lymphocyte and the granulocyte. It is considered that fish CXCR expression and their function may need to be investigated in both nervous and immune systems. (c) 2006 Elsevier Ltd. All rights reserved.

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The orange-spotted grouper, Epinephelus coioides, is an important marine aquaculture fish, but its large-scale aquaculture has been hindered by the rarity of natural males because it is a protogynous hermaphroditic fish. Hypothalamus-pituitary-gonad is an important endocrine axis in regulating reproduction and sex differentiation. To reveal the molecular mechanism of hypothalamic physiological functions, we performed he studies on identification of genes expressed in the hypothalamus of male orange-spotted grouper using EST and RT-PCR strategy. A total of 1006 ESTs were sequenced, and 402 (39.96%) clones were identified as known genes and 604 (60.04%) as unknown genes. The 402 clones of known gene products represent transcripts of 18 1 genes. Moreover, the expression patterns of 26 unknown genes were analyzed in various tissues, such as liver, kidney, spleen, fat, heart, muscle, pituitary, hypothalamus, telencephalon, cerebellum, midbrain, medulla oblongata, ovary and testes. Five different categories of expression patterns were observed from them. Several unknown ESTs, such as DN551996, DN551998, DN552082, and DN552070, were detected to be hypothalamus-specific, brains-specific, or hypothalamus and gonad-specific genes. Interestingly, DN551996, not only exhibiting expression differences between ovary and testis, but also showing sex-dependent differences in hypothalamus of grouper, might play significant role in grouper reproduction or sex inversion. Further functional studies on these genes will provide more information on molecule regulation mechanism of sex inversion in groupers. (c) 2006 Elsevier B.V All fights reserved.

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Akrokolioplax, new genus, is erected for the reception of Epalzeorhynchos bicornis Wu, 1977. It shares with the remaining species of Epalzeorhynchos what have usually been called "rostral lateral lobes" on the snout, which are non-homologous structures used to distinguish the two genera from all other Labeoninae genera. Akrokolioplax and Epalzeorhynchos differ in the position and structure of these lobes, and also in the morphology of the oromandibular structures. A detailed redescription is also provided for the type species of this monotypic genus, A. bicornis. It is presently known from the upper Salween River (=Nu Jiang in Chinese) basin in Yunnan (South China), Myanmar and Thailand.

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The type species of the cyprinid genus Sinilabeo was misidentified as Varicorhinus tungting, and the species under the generic name belong to Bangana and Linichthys. In order to make Sinilabeo available, its type species is fixed under Article 70.3.2 of the 1999 edition of the International Code of Zoological Nomenclature as S. hummeli, a new species herein described from the upper Yangtze River basin in Chongqing City and Sichuan Province, South China. A re-definition is provided for Sinilabeo. It resembles Qianlabeo in having an upper lip only present in the side of the upper jaw and uncovered by the rostral fold, but missing in the median part of the upper jaw that, instead, bears a thin, flexible, and cornified sheath, covered by the rostral fold, a character that can separate both from all other existing genera of Asian labeonins. However, Sinilabeo is distinguished from Qianlabeo in the presence of a rostral fold disconnected from the lower lip; a broadly interrupted postlabial groove only restricted to the side of the lower jaw; an upper lip, which is only present in the side of the upper separated from it by a groove; 9-10 branched dorsal-fin rays; two pairs of tiny maxillary barbels.

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Qianlabeo striatus gen. et sp. nov. is described from a stream tributary to the Beipan Jiang of the upper Zhu Jiang (Pearl River) drainage in Matou, Anshun County, Guizhou Province, China. This monotypic genus is mainly characterized by its oromadibular morphology, namely an upper lip only present in and fully adnate to the side of the upper jaw, not covered by the pendulous rostral fold; the median portion of the upper jaw lacking an upper lip but bearing a thin, flexible and cornified cutting edge that is fully covered by the pendulous rostral fold; a postlabial groove prolonged, extended anteromedially close to the anteromost point of the midline of the lower lip but not to meet with its counterpart. The type species of this genus, Q. striatus has a longitudinal dark stripe along the side of the body.

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Placocheilus is re-diagnosed on the basis of oromandibular structures compared to those of closely related groups. It is represented in China by three species restricted to Yunnan, namely P. caudofasciatus from the Tengtiaohe River (Nam Na), P. cryptonemus from the Nujiang Rive ( upper Salween River basin), and P. robustus, herein described as a new species from the Yuanjiang River ( Red River basin). P. robustus n. sp. is differentiated from its congeners in having a stout caudal peduncle ( depth 72.4-82.5% of its length) and the medium-sized scaleless midventral region of belly extended slightly beyond halfway from the pectoral- to pelvic-fin origin. It is further distinguished from P. caudofasciatus in having a coarsely crenulated rostral fold with 18-23 indentations on its distal margin and a smaller mental adhesive disc ( length 66.7-71.4% of its width and 37.0-43.1% of the head length).