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Kinds of Of Species Selected AbstractsExpressional changes of ganglioside GM3 during ovarian maturation and early embryonic development in db/db miceDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2003Dong Hoon Kwak Diabetes and obesity cause abnormal development of reproductive processes in a variety of species, but the mechanisms that underlie this effect have not been fully elucidated. This study examined the expressional changes of ganglioside GM3 during ovarian maturation, in vitro fertilization (IVF) and early embryonic development in diabetic/obese db/db mice. In high-performance thin-layer chromatography studies, GM3 expression was conspicuously low in the ovaries of db/db mice compared to non-diabetic db/+ mice. Signal detected by anti-GM3 monoclonal antibody was greatly reduced in the primary, secondary and graffian follicles of db/db mice compared to control mice. Results from IVF with ova and sperm from db/db mice showed that GM3 expression during early embryonic development was obviously decreased compared to db/+ mice. This study also elucidated the effects of high glucose (20 and 30 mm) on early embryonic development in ICR strain mice. High glucose caused a decrease in GM3 expression during early embryonic development. Taken together, the results of this study indicate decreased GM3 expression during ovarian maturation and embryonic development of db/db mice, suggesting that alteration of ganglioside expression induced by the diabetic condition may be implicated in the abnormal follicular embryonic development. [source] Optimized green fluorescent protein variants provide improved single cell resolution of transgene expression in ascidian embryosDEVELOPMENTAL DYNAMICS, Issue 2 2006Robert W. Zeller Abstract The green fluorescent protein (GFP) is used extensively to monitor gene expression and protein localization in living cells, particularly in developing embryos from a variety of species. Several GFP mutations have been characterized that improve protein expression and alter the emission spectra to produce proteins that emit green, blue, cyan, and yellow wavelengths. DsRed and its variants encode proteins that emit in the orange to red wavelengths. Many of these commercially available fluorescent proteins have been "codon optimized" for maximal levels of expression in mammalian cells. We have generated several fluorescent protein color variants that have been codon optimized for maximal expression in the ascidian Ciona intestinalis. By analyzing quantitative time-lapse recordings of transgenic embryos, we demonstrate that, in general, our Ciona optimized variants are detected and expressed at higher levels than commercially available fluorescent proteins. We show that three of these proteins, expressed simultaneously in different spatial domains within the same transgenic embryo are easily detectable using optimized fluorescent filter sets for epifluorescent microscopy. Coupled with recently developed quantitative imaging techniques, our GFP variants should provide useful reagents for monitoring the simultaneous expression of multiple genes in transgenic ascidian embryos. Developmental Dynamics 235:456,467, 2006. © 2005 Wiley-Liss, Inc. [source] Liposome-mediated uptake of exogenous DNA by equine spermatozoa and applications in sperm-mediated gene transferEQUINE VETERINARY JOURNAL, Issue 1 2008B. A. BALL Summary Reasons for performing study: Sperm-mediated gene transfer has been reported as a method for production of transgenic animals in a variety of species, and this technique represents a possible method for production of transgenic equids. Objectives: To evaluate the uptake of exogenous DNA (enhanced green fluorescent protein; pEGFP) by equine spermatozoa and to assess the ability of transfected spermatozoa to introduce this transgene into early equine embryos. Methods: To evaluate incorporation of pEGFP into equine spermatozoa, washed spermatozoa were incubated with 32P-pEGFP, with or without lipofection. Spermatozoa were also transfected with fluorescently-labelled DNA (Alexa647 -pEGFP) and changes in sperm viability and DNA uptake were assessed. Mares were inseminated with pEGFP-transfected spermatozoa and embryos recovered. Expression of pEGFP was assessed by epifluorescence microscopy of embryos, and the presence of pEGFP DNA and mRNA was assessed by PCR and RT-PCR, respectively. Results: Liposome-mediated transfection increased the incorporation of 32P-pEGFP into spermatozoa compared to controls. Flow cytometric evaluation of spermatozoa after transfection with Alexa647 -pEGFP revealed a linear increase in the proportion of live, Alexa647+ spermatozoa with increasing DNA concentrations. After insemination with transfected spermatozoa, 8 embryos were recovered. There was no evidence of EGFP expression in the recovered embryos; however, PCR analysis revealed evidence of the pEGFP transgene in 2 of 5 embryos analysed. Conclusions: The incorporation of exogenous DNA by equine spermatozoa was enhanced by liposome-mediated transfection and this did not adversely affect sperm viability, acrosomal integrity or fertility. Although the EGFP transgene was detected in a proportion of Day 7,10 embryos, there was no evidence of expression of EGFP in these embryos. Potential relevance: Sperm-mediated gene transfer offers a potential technique for the generation of transgenic equids. [source] Microscopic configurations on the bare-bone surfaces of mammalian synovial jointsINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2001A.E.W. MilesArticle first published online: 30 NOV 200 Abstract The smoothness characteristic of synovial joint surfaces of bare bones is shown to be an illusion; low-power microscopy of young adult human bones from interments revealed, on the surfaces of a variety of synovial joints, a system of basically hemispherical elevations, often united as short chains or groups. This system was also found on joints of a variety of species of six mammalian orders. Under the higher magnification of scanning electron microscopy (SEM), many elevations had a pit at their summits. The bare-bone surfaces of synovial joints have a thin covering of mineralized cartilage, including its mineralizing-front, which survives taphonomic processes, as well as the preparative procedures used in the study of articular surfaces. In its formative phase, the front has the chondrocyte,columnar structure of cartilage. It is postulated here that the newly-discovered elevations arise when cartilage formation is ceasing, or becoming dormant, and that each column-unit produces a globular mineralized mass, often with a pit which had accommodated a chondrocyte. These masses may incorporate the fibre systems of the unmineralized cartilage and aid in its attachment to the bony surface. Copyright © 2001 John Wiley & Sons, Ltd. [source] Molecular mechanisms of calorie restriction's protection against age-related sclerosisIUBMB LIFE, Issue 12 2006Elena Chiarpotto Abstract The current knowledge on the molecular mechanisms of the protective effect of calorie restriction (CR) against age-related fibrosclerosis is tentatively reviewed with specific reference to the role of oxidative stress in aging. The effects of oxidative stress are often mediated by its own final products. Of these, 4-hydroxy-2,3-nonenal (HNE) induces the expression and synthesis of transforming growth factor ,1 (TGF,1) and activates nuclear binding of transcription factor activator protein 1 (AP-1) thus stimulating fibrogenesis. Several studies have shown that, as well as extending mean and maximum life span in a variety of species, CR delays the onset and slows the progression of a variety of age-associated diseases, including diabetes, cardiovascular diseases and neoplasia. However, the anti-aging mechanisms of CR are still not clearly understood. Of the numerous hypotheses put forward, one that still remains popular is protection against the age-associated increase of oxidative stress and consequent cell damage. CR protects the rat aorta from the age-related increase of both oxidative damage and fibrosis; as regards the possible mechanism/s of CR's protection against fibrosclerosis, it is conceivable that, by decreasing oxidative stress, CR reduces HNE levels and consequently TGF,1 expression and collagen deposition, likely by down-regulating the activation of Jun-N terminal kinase and of AP-1. Through the modulation of reactive oxygen species and oxidative stress CR may also attenuate the age-associated increase in the inflammatory milieu, thus preserving vascular functional integrity by suppressing the age-associated increase in inflammatory enzyme activities and prostanoids. iubmb Life, 58: 695-702, 2006 [source] Developmental plasticity in a passerine bird: an experiment with collared flycatchers Ficedula albicollisJOURNAL OF AVIAN BIOLOGY, Issue 3 2007Gergely Hegyi Young birds often face poor food supply, which reduces their growth and development. However, if the shortage of resources is only temporary, there is a possibility to adjust the growth trajectory of morphological traits after the end of the short-term limitation period. The two main ways of compensatory growth are delayed development (parallel growth) and growth acceleration (catch-up growth). Parallel growth has been widely demonstrated in birds, but the presence of catch-up growth in altricial species has been questioned. However, most experiments have been conducted in laboratory conditions. We manipulated the food supply of nestling collared flycatchers Ficedula albicollis in the wild by removing the male parent for three days at 4,7 days of chick age. We performed early partial swapping to control for origin effects on growth, and total swapping after the period of food limitation to ensure similar late growth environment for deprived and control chicks. Both body mass and tarsus length of deprived chicks was negatively affected by the food scarcity. Body mass showed efficient catch-up growth, but this compensation was absent in skeletal size. Body mass is an important determinant of postfledging survival in this long-distance migrant. Further studies are needed in a variety of species to examine developmental plasticity in relation to age at food scarcity and the allocation hierarchy of various morphological traits. [source] Dietary restriction and aging, 2009AGING CELL, Issue 2 2010Subhash D. Katewa Summary Dietary restriction (DR) is a robust nongenetic, nonpharmacological intervention that is known to increase active and healthy lifespan in a variety of species. Despite a variety of differences in the protocols and the way DR is carried out in different species, conserved relationships are emerging among multiple species. 2009 saw the field of DR mature with important mechanistic insights from multiple species. A report of lifespan extension in rapamycin-treated mice suggested that the TOR pathway, a conserved mediator of DR in invertebrates, may also be critical to DR effects in mammals. 2009 also saw exciting discoveries related to DR in various organisms including yeast, worms, flies, mice, monkeys and humans. These studies complement each other and together aim to deliver the promise of postponing aging and age-related diseases by revealing the underlying mechanisms of the protective effects of DR. Here, we summarize a few of the reports published in 2009 that we believe provide novel directions and an improved understanding of dietary restriction. [source] Spatial and temporal scales of adaptive divergence in marine fishes and the implications for conservationJOURNAL OF FISH BIOLOGY, Issue 2006D. O. Conover Knowledge of geographic and temporal scales of adaptive genetic variation is crucial to species conservation, yet understanding of these phenomena, particularly in marine systems, is scant. Until recently, the belief has been that because most marine species have highly dispersive or mobile life stages, local adaptation could occur only on broad geographic scales. This view is supported by comparatively low levels of genetic variation among populations as detected by neutral markers. Similarly, the time scale of adaptive divergence has also been assumed to be very long, requiring thousands of generations. Recent studies of a variety of species have challenged these beliefs. First, there is strong evidence of geographically structured local adaptation in physiological and morphological traits. Second, the proportion of quantitative trait variation at the among-population level (QST) is much higher than it is for neutral markers (FST) and these two metrics of genetic variation are poorly correlated. Third, evidence that selection is a potent evolutionary force capable of sustaining adaptive divergence on contemporary time scales is summarized. The differing spatial and temporal scales of adaptive v. neutral genetic divergence call for a new paradigm in thinking about the relationship between phenogeography (the geography of phenotypic variation) and phylogeography (the geography of lineages) in marine species. The idea that contemporary selective processes can cause fine-scale spatial and temporal divergence underscores the need for a new emphasis on Darwinian fishery science. [source] Ammonia in estuaries and effects on fishJOURNAL OF FISH BIOLOGY, Issue 6 2005F. B. Eddy This review aims to explore the biological responses of fish in estuaries to increased levels of environmental ammonia. Results from laboratory and field studies on responses of fish to varying salinity and their responses increased ammonia will be evaluated, although studies which examine responses to ammonia, in relation to varying salinity, pH and temperature together are rare. In a survey of British estuaries the continuous measurement of total ammonia showed values that ranged from background levels increasing up to c. 10 mg N l,1 although higher values have been noted sporadically. In outer estuaries pH values tended to stabilize towards sea water values (e.g. c. pH 8). Upper reaches of estuaries are influenced by the quality of their fresh waters sources which can show a wide range of pH and water quality values depending on geological, climatic and pollution conditions. In general the ammonia toxicity (96 h LC50) to marine species (e.g. 0·09,3·35 mg l,1 NH3) appears to be roughly similar to freshwater species (e.g. 0·068,2·0 mg l,1 NH3). Ammonia toxicity is related to differences between species and pH rather than to the comparatively minor influences of salinity and temperature. In the marine environment the toxicity of ionized ammonia should be considered. The water quality standard for freshwater salmonids of 21 ,g l,1 NH3,N was considered to be protective for most marine fish and estuarine fish although the influence of cyclical changes in pH, salinity and temperature were not considered. During ammonia exposures, whether chronic or episodic, estuarine fish may be most at risk as larvae or juveniles, at elevated temperatures, if salinity is near the seawater value and if the pH value of the water is decreased. They are also likely to be at risk from ammonia intoxication in waters of low salinity, high pH and high ammonia levels. These conditions are likely to promote ammonia transfer from the environment into the fish, both as ionized and unionized ammonia, as well as promoting ammonia retention by the fish. Fish are more likely to be prone to ammonia toxicity if they are not feeding, are stressed and if they are active and swimming. Episodic or cycling exposures should also be considered in relation to the rate at which the animal is able to accumulate and excrete ammonia and the physiological processes involved in the transfer of ammonia. In the complex environment of an estuary, evaluation of ammonia as a pollutant will involve field and laboratory experiments to determine the responses of fish to ammonia as salinity and temperature vary over a period of time. It will also be necessary to evaluate the responses of a variety of species including estuarine residents and migrants. [source] Ultradian Corticosterone Rhythm and the Propensity to Behave Aggressively in Male RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2000J. Haller Abstract Ultradian fluctuations in plasma glucocorticoids have been demonstrated in a variety of species including humans. The significance of such rhythms is poorly known, although disorganized ultradian glucocorticoid rhythms have been associated with behavioural disorders. Here we report that ultradian glucocorticoid rhythms may establish the propensity to behave aggressively in male rats. Male rats were significantly more aggressive in the increasing phase of their corticosterone fluctuation when confronting a male intruder than counterparts in the decreasing phase of their corticosterone fluctuations facing such opponents. Corticosterone fluctuations were mimicked by a combination of treatments with the corticosterone synthesis inhibitor metyrapone and corticosterone. Again, males with increased plasma corticosterone levels were more aggressive than counterparts with a decreased plasma corticosterone concentration. These data suggest that the behavioural response to an aggressive challenge may vary in the same animal across the day due to the pulsating nature of corticosterone secretion. Aggressive behaviour is also episodic in humans; moreover, intermittent explosive behaviour is recognized as a psychological disorder. It can be hypothesized that a temporal coincidence between the occurrence of a challenge and a surge in plasma corticosterone concentration may be one of the factors that promote episodic aggressive outbursts. [source] Morphine, opioids, and the feline pulmonary vascular bedACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2008A. D. KAYE Background: Opioid-induced vasodepressor responses have been reported in a variety of species and laboratory models. The aim of this study was to ascertain the relative potencies of different clinically relevant opioids compared with traditional vasodepressor agents in the feline pulmonary vascular bed. A second aim was to study the effects of morphine and to identify the receptors involved in the mediation or the modulation of these effects. Methods: This was a prospective vehicle-controlled study involving an intact chest preparation of adult mongrel cats. The effects of various opioids, morphine, fentanyl, remifentanil, sufentanil, and meperidine were compared with other vasodepressor agents. Additionally, the effects of l - N5 -(1-iminoethyl) ornithine hydrochloride (l -NIO) (nitric oxide synthase inhibitor), nimesulide [selective cyclooxygenase (COX)-2 inhibitor], glibenclamide (ATP-sensitive K+ channel blocker), naloxone (non-selective opioid receptor antagonist), and diphenhydramine (histamine H1 -receptor antagonist) were investigated on pulmonary arterial responses to morphine and other selected agonists in the feline pulmonary vascular bed. The systemic pressure and lobar arterial perfusion pressure were continuously monitored, electronically averaged, and recorded. Results: In the cat pulmonary vascular bed of the isolated left lower lobe, morphine, remifentanil, fentanyl, sufentanil, and meperidine induced a dose-dependent moderate vasodepressor response and it appeared that sufentanil was the most potent on a nanomolar basis. The effects of morphine were not significantly altered after administration of l -NIO, nimesulide, and glibenclamide. However, the vascular responses to morphine were significantly attenuated following administration of naloxone and diphenhydramine. Conclusion: The results of the present study suggest that sufentanil appears to have slightly more potency and morphine the least of the five opioid agonists studied on a nanomolar basis. Morphine-induced vasodilatory responses appeared to be mediated or modulated by both opioid receptor and histamine-receptor-sensitive pathways. [source] DIET OF HARBOR PORPOISES IN THE KATTEGAT AND SKAGERRAK SEAS: ACCOUNTING FOR INDIVIDUAL VARIATION AND SAMPLE SIZEMARINE MAMMAL SCIENCE, Issue 1 2003Patrik Börjesson Abstract Stomach contents of 112 bycaught harbor porpoises (Phocoena phocoena) collected between 1989 and 1996 in the Kattegat and Skagerrak seas were analyzed to describe diet composition and estimate prey size, to examine sample size requirements, and to compare juvenile and adult diets. Although porpoises preyed on a variety of species, only a few contributed substantially to the diet. Atlantic herring (Clupea harengus) was the dominating prey species for both juveniles and adults. Our results, in combination with those from previous studies, suggest that where herring is a dominant food source, porpoises prey primarily on size classes containing mature or maturing individuals. Further, we also show that Atlantic hagfish (Myxine glutinosa) may be an important food resource, at least for adult porpoises. Examination of sample size requirement showed that, depending on the taxonomic level used to describe the diet, a minimum of 35,71 stomachs are needed to be confident that all common prey species will be found. [source] Heterogeneous chemical processes as a source of persistent meteor trainsMETEORITICS & PLANETARY SCIENCE, Issue 9 2001Edmond MURAD The latter occurs on the surfaces of dust left by the explosive fragmentation of larger meteoroids. A strong role is attributed to reactions of troilite (FeS), a meteorite component, with the atmosphere at elevated temperatures. The suggestions made in this paper complement previous work that suggested that long-lived emissions results from a variety of species made in the shock of larger meteoroids. [source] An ecological risk assessment for spinosad use on cottonPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2002Cheryl B Cleveland Abstract Spinosad is a reduced-risk insecticide with a novel mode of action that provides an alternative to older classes of insecticides such as organophosphates, carbamates and pyrethroids. A comprehensive ecological risk assessment for spinosad use in US cotton crops is presented within a framework of tiered levels of refinement following the guidelines of the US EPA for ecological risk assessments. Toxicity information for a variety of species is documented and utilized, environmental concentrations estimated, and risk characterizations in the form of risk quotients are quantified. Results indicate that spinosad use in cotton does not exceed the most conservative Tier I levels of concern (LOC) values for groundwater, mammals and birds or acute risk to aquatic organisms. Use of very conservative Tier I screening methods resulted in exceeding LOC values for chronic exposure for some aquatic organisms, thus prompting further refinement. When the exposure prediction was refined using less conservative, Tier II mechanistic environmental fate transport models to predict off-site transport and environmental concentrations, chronic risk was not predicted for these species. Spinosad is acutely toxic to bees under laboratory conditions, but toxicity of residue studies and field studies indicate that under actual use conditions the impact on bees is minimal. © 2001 Society of Chemical Industry [source] Language out of Music: The Four Dimensions of Vocal LearningTHE AUSTRALIAN JOURNAL OF ANTHROPOLOGY, Issue 3 2008Nicholas Bannan A growing consensus drawing on research in a wide variety of disciplines has, over the last fifteen years or so, argued the need to revisit Darwin's conjecture of 1871 that language may be descended from an existing, musical medium of communication that developed from animal calls. This paper seeks to examine, in an extension of Hockett's analysis of the design features required for linguistic communication, the nature of the acoustic information produced and perceived in human vocalisation, and to consider the anatomical and neural mechanisms on which these depend. An attempt is made to sketch an evolutionary chronology for key prerequisites of human orality. Cross-species comparisons are employed to illuminate the role of four acoustic variables (pitch, duration, amplitude and timbre), viewing the potential for human vocal productivity from the perspective of animal communication. Although humans are the only species to combine entrainment to pulse with attunement to precisely-tracked pitches, we also depend both for musical interaction and the production and perception of vowel sounds on precise and conscious control of the property of timbre. Drawing on, amongst others, Scherer's analyses of emotionally triggered sounds in a variety of species, and Fernald's presentation of the similarities of infant cries and adult production of infant-directed speech in a variety of cultures and languages, a case is made for the instinctive components of human communication being more music-like than language-like. In conclusion, historical and comparative data are employed to outline the adaptive and exaptive sequence by which human vocal communication evolved. The roles of selective pressures that conform to different adaptive models are compared,natural selection, sexual selection, group selection,leading to the proposal that all of these must have played their part at different stages in the process in a ,mosaic' model consistent with the development of other human traits. [source] ,-Aminobutyric acid is present in a spatially discrete subpopulation of hair cells in the crista ampullaris of the toadfish Opsanus tauTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2004Gay R. Holstein Abstract Although ,-aminobutyric acid (GABA) and glutamate are known to be present in the vestibular sensory epithelia of a variety of species, the functional relationship between these two transmitters is not clear. The present study addresses the three-dimensional spatial distribution of GABA and glutamate immunoreactivity in the vestibular labyrinth of the oyster toadfish by using whole end organs labeled by immunofluorescence with monoclonal anti-GABA and/or antiglutamate antibodies and visualized as whole mounts by multiphoton confocal microscopy. We find glutamate-immunoreactive hair cells present throughout the sensory epithelium. In contrast, prominent GABA immunoreactivity is restricted to a small population of hair cells located in the central region of the crista. Double immunofluorescence reveals two distinct staining patterns in GABA-labeled hair cells. Most (,80%) GABA-labeled cells show trace levels of glutamate, appropriate for the metabolic/synthetic role of cytoplasmic glutamate. The remainder of the GABA-stained cells contain substantial levels of both GABA and glutamate, suggesting transmitter colocalization. In the toadfish utricle, glutamatergic hair cells are present throughout the macula. GABA-immunoreactive hair cells follow the arc of the striola, and most GABA-labeled receptor cells coexpress glutamate. The localization of GABA was explored in other species as well. In the pigeon, GABAergic hair cells are present throughout the crista ampullaris. Our findings demonstrate that multiple, neurochemically distinct types of hair cells are present in vestibular sensory epithelia. These observations, together with the excitatory activity generally associated with 8th nerve afferent fibers, strongly suggest that GABA serves an important, specific, and complex role in determining primary afferent response dynamics. J. Comp. Neurol. 471:1,10, 2004. © 2004 Wiley-Liss, Inc. [source] Comparison of chorionic gonadotropin expression in human and macaque (Macaca fascicularis) trophoblastsAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2002Jason A. Wilken Abstract We have designed novel DNA primers that allow us to detect the expression of the subunits of chorionic gonadotropin (CG) from a variety of species of the order Primates. Using these primers, reverse transcriptase-polymerase chain reaction (RT-PCR), and standard cloning techniques, we detected the expression of a single gene for the common glycoprotein hormone (GPH) ,-subunit and at least two genes for the CG ,-subunit in trophoblasts of Macaca fascicularis (cynomolgous macaque (cm)) at gestational day (GD) = 26 (± 2d). No cmCG expression was detected at GD = 35,40. When sequences of cmGPH-, and cmCG-, genes were compared to the corresponding genes of other primates, we found that the ,-subunit of M. fascicularis was highly conserved compared to other primate species. However, cmCG ,-subunits appeared to be less conserved, residing between those of human CG-, and baboon CG-, when analyzed phylogenetically. Of particular interest was a three amino acid stretch in one of the expressed cmCG-, genes that is distinct from all other primates studied. Our findings imply that not only does the expression of multiple CG ,-subunit genes appear to be common to Old World monkeys, but that the presented methodology will greatly facilitate our ability to understand primate evolution. Am. J. Primatol. 56:89,97, 2002. © 2002 Wiley-Liss, Inc. [source] Endogenous extracellular serotonin modulates the spinal locomotor network of the neonatal mouseTHE JOURNAL OF PHYSIOLOGY, Issue 1 2010Mary J. Dunbar Serotonin (5-HT) can potently activate and modulate spinal locomotor circuits in a variety of species. Many of these findings have been obtained by applying serotonin exogenously to the isolated spinal cord of in vitro preparations, which has the drawback of indiscriminately activating extrasynaptic receptors and neurons. To investigate the role of endogenously released serotonin in modulating locomotor networks, the selective serotonin reuptake inhibitor citalopram was used. Fictive locomotion was elicited by either electrical stimulation of the brainstem or the sacral 4 (S4) dorsal root. The addition of 20 ,m of citalopram caudal to thoracic segment 5 (T5) had an overall inhibitory effect on the lumbar central pattern generator (CPG). Left,right and flexor,extensor coupling were significantly decreased, and there was also a phase shift in the flexor,extensor relationship. In addition, there was a significant decrease in burst amplitude. These effects were observed during both afferent and brainstem evoked fictive locomotion. When citalopram was added in the presence of 5-HT1A and 5-HT1B antagonists, the inhibitory effects were largely reversed. The remaining excitatory effects were mediated by 5-HT7 and 5-HT2 receptors. These results suggest that endogenous 5-HT release can modulate locomotor-like activity early in neonatal development. [source] Birds as tourism flagship species: a case study of tropical islandsANIMAL CONSERVATION, Issue 6 2009D. Veríssimo Abstract Species selected as flagships to promote conservation activities around the world are typically well known and charismatic mega-fauna. Unfortunately this limits the scope for applying the concept as some critical areas for biodiversity conservation, such as tropical islands, lack such species. In this study, we explore the potential to apply the concept of ,tourism flagship species' to tropical island birds of the Seychelles, an archipelago of considerable importance for conservation that is highly dependent on international tourism. In particular we wish to identify which species attributes are most influential with regard to their potential for fundraising among international tourists. Using a choice experiment approach and using state-of-the-art econometric methods, we found that conservation attributes and physical appearance of the bird species are both important in terms of raising funds for conservation. Nevertheless, conservation attributes ranked higher in the respondents preferences. Our results suggest that there is considerable potential for a variety of species to effectively act as flagships in developing nations that are dependent on international tourism and rich in biodiversity but lack charismatic fauna. [source] Neural Regulation Of Renal Blood Flow: A Re-ExaminationCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2000Simon C Malpas SUMMARY 1. The importance of renal sympathetic nerve activity (RSNA) in the regulation of renal function is well established. However, it is less clear how the renal vasculature responds to the different mean levels and patterns of RSNA. While many studies have indicated that small to moderate changes in RSNA preferentially regulate renin secretion or sodium excretion and only large changes in RSNA regulate renal blood flow (RBF), other experimental evidence suggests that small changes in RSNA can influence RBF 2. When RSNA has been directly measured in conjunction with RBF, it appears that a range of afferent stimuli can induce reflex changes in RBF. However, many studies in a variety of species have measured RBF only during stimuli designed to reflexly increase or decrease sympathetic activity, but have not recorded RSNA. While this approach can be informative, it is not definitive because the ability of the vasculature to respond to RSNA may, in part, reflect the resting level of RSNA and, therefore, the vasoconstrictive state of the vasculature under the control conditions. 3. Further understanding of the control of RBF by RSNA has come from studies that have analysed the underlying rhythms in sympathetic nerve activity and their effect on the cardiovascular system. These studies show that the frequency,response characteristic of the renal vasculature is such that higher frequency oscillations in RSNA (above 0.6 Hz) contribute to setting the mean level of RBF. In comparison, lower frequency oscillations in RSNA can induce cyclic vasoconstriction and dilation in the renal vasculature, thus inducing oscillations in RBF. 4. In summary, the present review discusses the neural control of RBF, summarizing evidence in support of the hypothesis that RBF is under the influence of RSNA across the full range of RSNA. [source] | |||||||||||||||||||