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Nadia Aubinhorth - One of the best experts on this subject based on the ideXlab platform.
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testing the parasite mass burden effect on alteration of host behaviour in the schistocephalus stickleback system
The Journal of Experimental Biology, 2018Co-Authors: Lucie Grecias, Julie Valentin, Nadia AubinhorthAbstract:ABSTRACT Many parasites with complex life cycles modify the behaviour of their intermediate host, which has been proposed to increase transmission to their definitive host. This behavioural change could result from the parasite actively manipulating its host, but could also be explained by a mechanical effect, where the physical presence of the parasite affects host behaviour. We created an artificial internal parasite using silicone injections in the body cavity to test this mechanical effect hypothesis. We used the Schistocephalus solidus and threespine stickleback ( Gasterosteus aculeatus ) system, as this cestode can reach up to 92% of its fish host mass. Our results suggest that the mass burden brought by this macroparasite alone is not sufficient to cause behavioural changes in its host. Furthermore, our results show that wall-hugging (Thigmotaxis), a measure of anxiety in vertebrates, is significantly reduced in Schistocephalus -infected sticklebacks, unveiling a new altered component of behaviour that may result from manipulation by this macroparasite.
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testing the parasite mass burden effect on host behaviour alteration in the schistocephalus stickleback system
bioRxiv, 2017Co-Authors: Lucie Grecias, Julie Valentin, Nadia AubinhorthAbstract:Many parasites with complex life cycles modify their intermediate host9s behaviour, which has been proposed to increase transmission to their definitive host. This behavioural change could result from the parasite actively manipulating its host, but could also be explained by a mechanical effect, where the parasite9s physical presence affects host behaviour. We created an artificial internal parasite using silicone injections in the body cavity to test this mechanical effect hypothesis. We used the Schistocephalus solidus - threespine stickleback (Gasterosteus aculeatus) system, as this cestode can reach up to 92% of its fish host mass. Our results suggest that the mass burden brought by this macroparasite alone is not sufficient to cause behavioural changes in its host. Furthermore, our results show that wall-hugging (Thigmotaxis), a measure of anxiety in vertebrates, is significantly reduced in Schistocephalus-infected sticklebacks, unveiling a new altered component of behaviour that may result from manipulation by this macroparasite.
Caio Maximino De ,oliveira - One of the best experts on this subject based on the ideXlab platform.
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Papel da serotonina no comportamento defensivo do paulistinha (Danio rerio Hamilton 1822) adulto: Diferenças entre modelos comportamentais, linhagens, e efeitos do estresse predatório agudo
2014Co-Authors: Caio Maximino De ,oliveiraAbstract:Os transtornos de ansiedade apresentam a maior incidência na população mundial dentre os transtornos psiquiátricos, e a eficácia clínica das drogas ansiolíticas é baixa, em parte devido ao desconhecimento acerca das bases neuroquímicas desses transtornos. Para uma compreensão mais ampla e evolutivamente substanciada desses fenômenos, a utilização de espécies filogeneticamente mais antigas pode ser uma aproximação interessante no campo da modelagem comportamental; assim, sugerimos o uso do paulistinha (Danio rerio Hamilton 1822) na tentativa de compreender a modulação de comportamentos tipo-ansiedade pelo sistema serotonérgico. Demonstramos que os níveis extracelulares de serotonina no encéfalo de paulistinhas adultos expostos ao teste de preferência claro/escuro [PCE] (mas não ao teste de distribuição vertical eliciada pela novidade [DVN]) apresentam-se elevados em relação a animais manipulados mas não expostos aos aparatos. Além disso, os níveis teciduais de serotonina no rombencéfalo e no prosencéfalo são elevados pela exposição ao PCE, enquanto no mesencéfalo são elevados pela exposição ao DVN. Os níveis extracelulares de serotonina estão correlacionados negativamente com a geotaxia no DVN, e positivamente com a escototaxia, tigmotaxia e a avaliação de risco no PCE. O tratamento agudo com uma dose baixa de fluoxetina (2,5 mg/kg) aumenta a escototaxia, a tigmotaxia e a avaliação de risco no PCE, diminui a geotaxia e o congelamento e facilita a habituação no DVN. O tratamento com buspirona diminui a escototaxia, a tigmotaxia e o congelamento nas doses de 25 e 50 mg/kg no PCE, e diminui a avaliação de risco na dose de 50 mg/kg; no DVN, ambas as doses diminuem a geotaxia, enquanto somente a maior dose diminui o congelamento e facilita a habituação. O tratamento com WAY 100635 diminui a escototaxia nas doses de 0,003 e 0,03 mg/kg, enquanto somente a dose de 0,03 mg/kg diminui a tigmotaxia e a avaliação de risco no PCE. No DVN, ambas as doses diminuem a geotaxia, enquanto somente a menor dose facilita a habituação e aumenta o tempo em uma “base” (“homebase”). O tratamento com SB 224289 não produziu efeitos sobre a escototaxia, mas aumentou a avaliação de risco na dose de 2,5 mg/kg; no DVN, essa droga diminuiu a geotaxia e o nado errático nas doses de 2,5 e 5 mg/kg, enquanto a dose de 2,5 mg/kg aumentou a formação de “bases”. O tratamento com DL-para-clorofenilalanina (2 injeções de 300 mg/kg, separadas por 24 horas) diminuiu a escototaxia, a tigmotaxia e a avaliação de risco no PCE, aumentou a geotaxia e a formação de bases e diminuiu a habituação no DVN. Quando os animais são pré-expostos a uma “substância de alarme” co-específica, observa-se um aumento nos níveis extracelulares de serotonina associados a um aumento na escototaxia, congelamento e nado errático no PCE; os efeitos comportamentais e neuroquímicos foram bloqueados pelo pré tratamento com fluoxetina (2,5 mg/kg), mas não pelo pré-tratamento com WAY 100,635 (0,003 mg/kg). Animais da linhagem leopard apresentam maior escototaxia e avaliação de risco no PCE, assim como níveis teciduais elevados de serotonina no encéfalo; o fenótipo comportamental é resgatado pelo tratamento com fluoxetina (5 mg/kg). Esses dados sugerem que o sistema serotonérgico dessa espécie modula o comportamento no DVN e no PCE de forma oposta; que a resposta de medo produzida pela substância de alarme também parece aumentar a atividade do sistema serotonérgico, um efeito possivelmente mediado pelos transportadores de serotonina, e ao menos um fenótipo mutante de alta ansiedade também está associado a esses transportadores. Sugere-se que, de um ponto de vista funcional, a serotonina aumenta a ansiedade e diminui o medo em paulistinhas.ABSTRACT: Anxiety disorders present the highest incidence in the world population among psychiatric disorders, and the clinical efficacy of anxiolytic drugs is low, partially due to lack of knowledge on the neurochemical bases of these disorders. To reach a more ample and evolutionarily grounded comprehension of these phenomena, the use of phylogenetically older species can be an interesting approach in the field of behavioral modeling; thus, we suggest the use of zebrafish (Danio rerio Hamilton 1822) in the attempt to understand the modulation of these behaviors by the serotonergic system. We demonstrate that extracellular serotonin levels in the brains of adult zebrafish exposed to the light/dark preference test [LDT] (but not to the novel tank test [NTT]) are increased in relation to animals which are handled, but not exposed to the apparatuses. Moreover, serotonin tissue levels levels in the hindbrain and forebrain are elevated by the exposure to the LDT, while tissue levels in the midbrain are elevated by exposure to the NTT. Extracellular serotonin levels correlate positively with scototaxis, Thigmotaxis and risk assessment in the LDT and negatively with geotaxis in the NTT. Acute treatment with a low dose of fluoxetine (2.5 mg/kg) increases scototaxis, Thigmotaxis, and risk assessment in the LDT, and decreases geotaxis and freezing and facilitates habituation in the NTT. Treatment with buspirone decreases scototaxis, Thigmotaxis and freezing at 25 and 50 mg/kg in the LDT and decreases risk assessment at 50 mg/kg; in the NTT, both doses decrease geotaxis, while the highest dose decreases freezing and facilitates habituation. Treatment with WAY 100635 decreases scototaxis at 0.003 and 0.03 mg/kg, while only the highest dose decreases Thigmotaxis and risk assessment in the LDT. In the NTT, both doses decrease geotaxis, while only the lower dose facilitates habituation and increases homebase time. Treatment with SB 224289 did not alter scototaxis, but increased risk assessment at 2.5 mg/kg; in the NTT, this drug decreased geotaxis and decreased erratic swimming at 2.5 and 5 mg/kg, while at 2.5 mg/kg it increased homebase time. Treatment with DL-para-clorophenylalanine (2 x 300 mg/kg injections, separated by 24 h) decreased scototaxis, Thigmotaxis and risk assessment in the LDT, and increased geotaxis and homebase time and decreased habituation in the NTT. When animals were pre-exposed to a conspecific “alarm substance”, extracellular serotonin levels were raised in association with an increase in scototaxis, freezing and erratic swimming in the LDT; both behavioral and neurochemical effects were blocked by pre-treatment with fluoxetine (2,5 mg/kg), but not with WAY 100,635 (0,003 mg/kg). Animals from the leopard strain show increased scototaxis and risk assessment in the LDT, as well as increased 5-HT tissue levels in the encephalon; the behavioral phenotype is rescued by treatment with fluoxetine (5 mg/kg). These data suggest that the serotonergic system of zebrafish modulates behavior in the LDT and NTT in opposite ways; that the fright response produced by alarm substance seems to increase serotonergic activity, an effect which is possibly mediated by serotonin transporters; and that at least one high-anxiety mutant phenotype is associated with serotonin uptake. It is thus suggested that from a functional point of view serotonin increases anxiety and decreases fear in zebrafish
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Papel da serotonina no comportamento defensivo do paulistinha (Danio rerio Hamilton 1822) adulto: Diferenças entre modelos comportamentais, linhagens, e efeitos do estresse predatório agudo
Programa de Pós-Graduação em Neurociências e Biologia Celular, 2014Co-Authors: Caio Maximino De ,oliveiraAbstract:Anxiety disorders present the highest incidence in the world population among psychiatric disorders, and the clinical efficacy of anxiolytic drugs is low, partially due to lack of knowledge on the neurochemical bases of these disorders. To reach a more ample and evolutionarily grounded comprehension of these phenomena, the use of phylogenetically older species can be an interesting approach in the field of behavioral modeling; thus, we suggest the use of zebrafish (Danio rerio Hamilton 1822) in the attempt to understand the modulation of these behaviors by the serotonergic system. We demonstrate that extracellular serotonin levels in the brains of adult zebrafish exposed to the light/dark preference test [LDT] (but not to the novel tank test [NTT]) are increased in relation to animals which are handled, but not exposed to the apparatuses. Moreover, serotonin tissue levels levels in the hindbrain and forebrain are elevated by the exposure to the LDT, while tissue levels in the midbrain are elevated by exposure to the NTT. Extracellular serotonin levels correlate positively with scototaxis, Thigmotaxis and risk assessment in the LDT and negatively with geotaxis in the NTT. Acute treatment with a low dose of fluoxetine (2.5 mg/kg) increases scototaxis, Thigmotaxis, and risk assessment in the LDT, and decreases geotaxis and freezing and facilitates habituation in the NTT. Treatment with buspirone decreases scototaxis, Thigmotaxis and freezing at 25 and 50 mg/kg in the LDT and decreases risk assessment at 50 mg/kg; in the NTT, both doses decrease geotaxis, while the highest dose decreases freezing and facilitates habituation. Treatment with WAY 100635 decreases scototaxis at 0.003 and 0.03 mg/kg, while only the highest dose decreases Thigmotaxis and risk assessment in the LDT. In the NTT, both doses decrease geotaxis, while only the lower dose facilitates habituation and increases homebase time. Treatment with SB 224289 did not alter scototaxis, but increased risk assessment at 2.5 mg/kg; in the NTT, this drug decreased geotaxis and decreased erratic swimming at 2.5 and 5 mg/kg, while at 2.5 mg/kg it increased homebase time. Treatment with DL-para-clorophenylalanine (2 x 300 mg/kg injections, separated by 24 h) decreased scototaxis, Thigmotaxis and risk assessment in the LDT, and increased geotaxis and homebase time and decreased habituation in the NTT. When animals were pre-exposed to a conspecific “alarm substance”, extracellular serotonin levels were raised in association with an increase in scototaxis, freezing and erratic swimming in the LDT; both behavioral and neurochemical effects were blocked by pre-treatment with fluoxetine (2,5 mg/kg), but not with WAY 100,635 (0,003 mg/kg). Animals from the leopard strain show increased scototaxis and risk assessment in the LDT, as well as increased 5-HT tissue levels in the encephalon; the behavioral phenotype is rescued by treatment with fluoxetine (5 mg/kg). These data suggest that the serotonergic system of zebrafish modulates behavior in the LDT and NTT in opposite ways; that the fright response produced by alarm substance seems to increase serotonergic activity, an effect which is possibly mediated by serotonin transporters; and that at least one high-anxiety mutant phenotype is associated with serotonin uptake. It is thus suggested that from a functional point of view serotonin increases anxiety and decreases fear in zebrafish.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoOs transtornos de ansiedade apresentam a maior incidência na população mundial dentre os transtornos psiquiátricos, e a eficácia clínica das drogas ansiolíticas é baixa, em parte devido ao desconhecimento acerca das bases neuroquímicas desses transtornos. Para uma compreensão mais ampla e evolutivamente substanciada desses fenômenos, a utilização de espécies filogeneticamente mais antigas pode ser uma aproximação interessante no campo da modelagem comportamental; assim, sugerimos o uso do paulistinha (Danio rerio Hamilton 1822) na tentativa de compreender a modulação de comportamentos tipo-ansiedade pelo sistema serotonérgico. Demonstramos que os níveis extracelulares de serotonina no encéfalo de paulistinhas adultos expostos ao teste de preferência claro/escuro [PCE] (mas não ao teste de distribuição vertical eliciada pela novidade [DVN]) apresentam-se elevados em relação a animais manipulados mas não expostos aos aparatos. Além disso, os níveis teciduais de serotonina no rombencéfalo e no prosencéfalo são elevados pela exposição ao PCE, enquanto no mesencéfalo são elevados pela exposição ao DVN. Os níveis extracelulares de serotonina estão correlacionados negativamente com a geotaxia no DVN, e positivamente com a escototaxia, tigmotaxia e a avaliação de risco no PCE. O tratamento agudo com uma dose baixa de fluoxetina (2,5 mg/kg) aumenta a escototaxia, a tigmotaxia e a avaliação de risco no PCE, diminui a geotaxia e o congelamento e facilita a habituação no DVN. O tratamento com buspirona diminui a escototaxia, a tigmotaxia e o congelamento nas doses de 25 e 50 mg/kg no PCE, e diminui a avaliação de risco na dose de 50 mg/kg; no DVN, ambas as doses diminuem a geotaxia, enquanto somente a maior dose diminui o congelamento e facilita a habituação. O tratamento com WAY 100635 diminui a escototaxia nas doses de 0,003 e 0,03 mg/kg, enquanto somente a dose de 0,03 mg/kg diminui a tigmotaxia e a avaliação de risco no PCE. No DVN, ambas as doses diminuem a geotaxia, enquanto somente a menor dose facilita a habituação e aumenta o tempo em uma “base” (“homebase”). O tratamento com SB 224289 não produziu efeitos sobre a escototaxia, mas aumentou a avaliação de risco na dose de 2,5 mg/kg; no DVN, essa droga diminuiu a geotaxia e o nado errático nas doses de 2,5 e 5 mg/kg, enquanto a dose de 2,5 mg/kg aumentou a formação de “bases”. O tratamento com DL-para-clorofenilalanina (2 injeções de 300 mg/kg, separadas por 24 horas) diminuiu a escototaxia, a tigmotaxia e a avaliação de risco no PCE, aumentou a geotaxia e a formação de bases e diminuiu a habituação no DVN. Quando os animais são pré-expostos a uma “substância de alarme” co-específica, observa-se um aumento nos níveis extracelulares de serotonina associados a um aumento na escototaxia, congelamento e nado errático no PCE; os efeitos comportamentais e neuroquímicos foram bloqueados pelo pré tratamento com fluoxetina (2,5 mg/kg), mas não pelo pré-tratamento com WAY 100,635 (0,003 mg/kg). Animais da linhagem leopard apresentam maior escototaxia e avaliação de risco no PCE, assim como níveis teciduais elevados de serotonina no encéfalo; o fenótipo comportamental é resgatado pelo tratamento com fluoxetina (5 mg/kg). Esses dados sugerem que o sistema serotonérgico dessa espécie modula o comportamento no DVN e no PCE de forma oposta; que a resposta de medo produzida pela substância de alarme também parece aumentar a atividade do sistema serotonérgico, um efeito possivelmente mediado pelos transportadores de serotonina, e ao menos um fenótipo mutante de alta ansiedade também está associado a esses transportadores. Sugere-se que, de um ponto de vista funcional, a serotonina aumenta a ansiedade e diminui o medo em paulistinhas
Lucie Grecias - One of the best experts on this subject based on the ideXlab platform.
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testing the parasite mass burden effect on alteration of host behaviour in the schistocephalus stickleback system
The Journal of Experimental Biology, 2018Co-Authors: Lucie Grecias, Julie Valentin, Nadia AubinhorthAbstract:ABSTRACT Many parasites with complex life cycles modify the behaviour of their intermediate host, which has been proposed to increase transmission to their definitive host. This behavioural change could result from the parasite actively manipulating its host, but could also be explained by a mechanical effect, where the physical presence of the parasite affects host behaviour. We created an artificial internal parasite using silicone injections in the body cavity to test this mechanical effect hypothesis. We used the Schistocephalus solidus and threespine stickleback ( Gasterosteus aculeatus ) system, as this cestode can reach up to 92% of its fish host mass. Our results suggest that the mass burden brought by this macroparasite alone is not sufficient to cause behavioural changes in its host. Furthermore, our results show that wall-hugging (Thigmotaxis), a measure of anxiety in vertebrates, is significantly reduced in Schistocephalus -infected sticklebacks, unveiling a new altered component of behaviour that may result from manipulation by this macroparasite.
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testing the parasite mass burden effect on host behaviour alteration in the schistocephalus stickleback system
bioRxiv, 2017Co-Authors: Lucie Grecias, Julie Valentin, Nadia AubinhorthAbstract:Many parasites with complex life cycles modify their intermediate host9s behaviour, which has been proposed to increase transmission to their definitive host. This behavioural change could result from the parasite actively manipulating its host, but could also be explained by a mechanical effect, where the parasite9s physical presence affects host behaviour. We created an artificial internal parasite using silicone injections in the body cavity to test this mechanical effect hypothesis. We used the Schistocephalus solidus - threespine stickleback (Gasterosteus aculeatus) system, as this cestode can reach up to 92% of its fish host mass. Our results suggest that the mass burden brought by this macroparasite alone is not sufficient to cause behavioural changes in its host. Furthermore, our results show that wall-hugging (Thigmotaxis), a measure of anxiety in vertebrates, is significantly reduced in Schistocephalus-infected sticklebacks, unveiling a new altered component of behaviour that may result from manipulation by this macroparasite.
Rachel E Blaser - One of the best experts on this subject based on the ideXlab platform.
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measures of anxiety in zebrafish danio rerio dissociation of black white preference and novel tank test
PLOS ONE, 2012Co-Authors: Rachel E Blaser, Denis B RosembergAbstract:The effects of wall color stimuli on diving, and the effects of depth stimuli on scototaxis, were assessed in zebrafish. Three groups of fish were confined to a black, a white, or a transparent tank, and tested for depth preference. Two groups of fish were confined to a deep or a shallow tank, and tested for black-white preference. As predicted, fish preferred the deep half of a split-tank over the shallow half, and preferred the black half of a black/white tank over the white half. Results indicated that the tank wall color significantly affected depth preference, with the transparent tank producing the strongest depth preference and the black tank producing the weakest preference. Tank depth, however, did not significantly affect color preference. Additionally, wall color significantly affected shuttling and immobility, while depth significantly affected shuttling and Thigmotaxis. These results are consistent with previous indications that the diving response and scototaxis may reflect dissociable mechanisms of behavior. We conclude that the two tests are complementary rather than interchangeable, and that further research on the motivational systems underlying behavior in each of the two tests is needed.
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behavioral measures of anxiety in zebrafish danio rerio
Behavioural Brain Research, 2010Co-Authors: Rachel E Blaser, L Chadwick, G C McginnisAbstract:While zebrafish may be a useful behavioral model of human anxiety, it is not obvious which behaviors are accurate measures of anxiety in zebrafish. Beginning with the premise that the most fundamental indicator of fear is avoidance, the goal of the current study was to determine which behaviors are systematically observed in the presence of an avoided stimulus. In a dark/bright preference task, adult zebrafish preferred a black chamber and avoided a white chamber. Then, subjects were confined to each chamber, and their behaviors recorded. A principal component analysis was used to determine which behaviors clustered with the tendency to avoid white. Additionally, the behaviors of High-avoidant and Low-avoidant animals were compared using analysis of variance. Results indicate that confinement to white systematically elicited freezing in animals with a strong dark preference, but not in animals with little preference. Turn rate (erratic movement) was weakly related to avoidance, while Thigmotaxis and locomotor activity were poor predictors. Freezing is therefore suggested to be a viable measure of white-induced anxiety, while interpretation of the other behaviors is more ambiguous and will require further investigation.
Michael K Richardson - One of the best experts on this subject based on the ideXlab platform.
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translating rodent behavioral repertoire to zebrafish danio rerio relevance for stress research
Behavioural Brain Research, 2010Co-Authors: Danielle L Champagne, Carlijn C M Hoefnagels, Ronald De Kloet, Michael K RichardsonAbstract:Abstract The current study provides a detailed description of the pattern of exploratory behaviors encountered in adult zebrafish when exposed to a novel/unfamiliar environment using the light/dark box and open field tests. We also document the impact of an acute stressor ( restraint stress ) given just prior the onset of behavioral testing. We report the following main findings: (1) zebrafish display anxiety-like behaviors including dark-avoidance (in light / dark box test) and Thigmotaxis (in open field test), (2) upon exposure to a novel environment (first 2 min), zebrafish display place preference for the outer zone of the testing apparatus where they seek escape via the transparent wall, and exhibit high locomotor activity accompanied by high swimming speed, (3) Thigmotaxis , behavioral hyperactivity, and swimming speed habituate (decrease) over time, (4) prior history of stress attenuates the natural tendency to engage in dark-avoidance behavior and Thigmotaxis , reduces attempts to escape via the transparent wall, and greatly increased behavioral hyperactivity and swimming speed. Stress-induced patterns of behavior normalize to levels comparable to that of non-stressed controls by the end of the 5-min test session. Taken together, these findings suggest that novel environment can elicit anxiety-like behaviors in zebrafish such as dark-avoidance and Thigmotaxis and the prior history of stress greatly affects patterns of exploration, defensive behaviors, and coping strategies in the light / dark box and open field tests. These findings are consistent with previous findings in rodents and support the usefulness of such behavioral paradigms in zebrafish.
