Tesis sobre el tema "Rat"
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Madhoo, Jitesh. "Continuous low dose rate irradiation of the rat brain". Doctoral thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26785.
Texto completoAmorim, João Paulo de Arruda 1981. "Caracterização do comportamento materno e suas implicações no desenvovimento fisico,na função reprodutiva e no perfil hormonal da prole feminina de ratas UChA e UChB (consumidoras voluntárias de etanol a 10%)". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317536.
Texto completoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Estudos realizados com mães dependentes de etanol demonstraram que elas apresentam maior dificuldade em cuidar de suas crianças, quando comparadas às mães não dependentes, evidenciando um distúrbio no comportamento materno durante o período pós-natal, que corresponde ao período onde as primeiras ligações sociais do animal são formadas e o organismo está muito sensível aos efeitos de estímulos ambientais. Vários estudos têm documentado as conseqüências do uso de etanol durante a gestação para a saúde do infante, porém pouca atenção tem sido dada à relação materno-infantil em mulheres alcoólicas durante o período pós-natal e as consequências dessa relação para prole feminina na vida adulta. O presente trabalho teve o objetivo de caracterizar o comportamento materno das ratas da variedade consumidora de etanol (UChA e UChB) e verificar as influências da variação do comportamento materno no desenvolvimento físico, na função reprodutiva e no status hormonal da prole feminina. O comportamento foi avaliado observando os seguintes parâmetros: carregar, lamber, amamentar com o dorso arcado e lamber, amamentar com o dorso arcado, amamentar passivamente e não contato com a prole. A avaliação do desenvolvimento físico da prole feminina considerou o dia do nascimento dos pêlos, da abertura dos olhos e do descolamento de orelhas. Para avaliar o desenvolvimento sexual inicial foram analisados os dias da abertura vaginal e idade do primeiro e segundo estro. A função reprodutiva foi avaliada pela regularidade de ciclo estral, pela expressão dos receptores AR, ER-? e ER-? no ovário e pelo perfil hormonal da prole feminina (níveis plasmáticos de FSH, LH, 17?-estradiol, progesterona e corticosterona). As fêmeas UChA apresentaram maiores frequências dos comportamentos de carregar, de lamber/limpar e de amamentar os filhotes. Mães muito cuidadosas apresentaram concentrações elevadas de corticosterona e 17?-estradiol. A prole UChA apresentou maior ganho de peso corporal, aceleração da abertura dos olhos, da abertura vaginal, da instalação da puberdade e sincronização do ciclo estral. A prole feminina que recebeu baixo cuidado materno (UChB) revelou maior duração do ciclo estral, aumento das concentrações de corticosterona e 17?-estradiol e de seus receptores ovarianos (ER-? e ER-?), maior peso dos ovários, maior número de folículos primordiais, antrais e maduros e mais imunomarcações positivas do Ki67 nos folículos ovarianos. Concluímos que a variedade de ratas UChB, apresenta acentuada variação do comportamento materno, sendo classificada como mãe pouco cuidadosa e essa variação do cuidado materno afeta diretamente o desenvolvimento físico, a instalação da puberdade, os níveis hormonais, desregula o ciclo estral e a foliculogênese e regula diferencialmente a expressão dos receptores ER-? e ER-? nos ovários de ratas adultas
Abstract: Studies focused on drug-dependent mothers (mainly ethanol-dependent mothers) have demonstrated that there is an enormous difference in the care of their children compared to non-dependent mothers, showing an disorder in maternal behavior during the postnatal period, which corresponds to the period where the first social bonds are formed and the animal's organism is very sensible to the effects of environmental stimuli. Various studies have documented the consequences of ethanol use during pregnancy for the health of the infant, but little attention has been given to the mother-child relationship in alcoholic female during the postnatal period and the consequences of this relationship to female offspring in adulthood. The aim of the present work is to evaluate maternal care in ethanol-preferring rats (UChA and UChB) and its effects on physical development, in sexual function and in status hormones in female offspring. The behavior was evaluated by observing the following parameters: carry, licking/grooming, arched-back nursing and licking/grooming, arched-back nursing, passive nursing, contact and not with the pups. The evaluation of the physical development of the female offspring considered the day of birth of hair, eye opening and detached ears. To evaluate the early sexual development were analyzed days of vaginal opening and age of first and second estrous. The reproductive function was evaluated by the regularity of the estrous cycle, the expression of receptors AR, ER-? and ER-? in the ovary and the hormonal status of female offspring (plasma levels of FSH, LH, 17?-estradiol, progesterone and corticosterone). UChA mothers showed higher frequencies of carrying, licking/grooming and nursing the pups. Mothers high care evidencing the highest plasma corticosterone levels and 17?-estradiol. The UChA offspring showed greater body weight gain, accelerated eye opening, vaginal opening, the installation and synchronization of estrous cycle. The female offspring who received low maternal care (UChB) showed an increase of the estrous cycle, concentrations of corticosterone and 17?-estradiol and ovarian receptors (ER-? and ER-?, higher ovarian weight and increased number of primordial, antral and mature follicles and higher Immunoreactivity for Ki-67 in the ovarian follicles. We conclude that UChB rats show marked variations in maternal care, being classified as low maternal care and the variation of maternal care directly affects the physical, the installation of puberty, hormone levels, deregulate the estrous cycle and folliculogenesis and differentially regulates the expression of receptors ER-? and ER-? in the ovaries of adult rats
Doutorado
Anatomia
Doutor em Biologia Celular e Estrutural
Lewis, S. J. "Studies in catch-up growth in the rat skeleton". Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382473.
Texto completoSadi, Gokhan. "Antioxidant Enzyme Activities In Rat Liver Tissues Of Diabetic Rats". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605254/index.pdf.
Texto completoEdlund, G. L. "Lactate and pyruvate transport in rat erythrocytes and rat hepatocytes". Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375019.
Texto completoCosta, Rafaela 1984. "Efeitos da estimulação tatil em ratos adultos jovens, submetidos ou não ao modelo de estresse cronico". [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288840.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Problemas emocionais como ansiedade e depressão, relacionados ao estresse, estão cada vez mais presentes na sociedade moderna, e o suporte social, mais especificadamente suporte familiar, pode exercer um importante papel em atenuar os efeitos de diversos estressores. Em modelos animais o enriquecimento ambiental tem sido utilizado para melhora do bem estar animal. O objetivo deste estudo foi avaliar os efeitos do enriquecimento ambiental por meio da estimulação tátil em ratos submetidos ou não a estresse crônico. No Capítulo I, foi evidenciado que a estimulação tátil diminuiu a ansiedade e aumentou as respostas indicadoras de aprendizado e memória em ratos jovem-adultos. No Capítulo II, foram avaliados os efeitos do estresse crônico moderado e imprevisível e da estimulação tátil sobre respostas comportamentais (ansiedade, anedonia, aprendizado e memória) e sobre o perfil lipídico. O estresse aumentou a secreção de corticosterona avaliada quinze dias após o fim do estresse; induziu anedonia evidenciada pela diminuição da preferência pela sacarose 1%; aumentou a atividade locomotora; teve efeito negativo sobre o aprendizado e memória; e aumentou a concentração sérica de triglicerídeos, colesterol total e lipoproteína de baixa densidade (LDL). A manipulação diminuiu a ansiedade em animais submetidos ou não ao estresse crônico; diminuiu a secreção de corticosterona induzida pelo estresse e cancelou a redução do aprendizado e retenção de memória induzida pelo estresse crônico. Os resultados obtidos mostram que a estimulação tátil de ratos adultos jovens produziu efeitos comportamentais positivos que podem melhorar o bem-estar animal e diminuir efeitos deletérios induzidos pelo estresse crônico.
Abstract: Emotional problems such as stress related anxiety and depression, are becoming increasingly present in modern society, and social support, more specifically familiar support, can play an important role in attenuating the effects of various stressors. In animal models environmental enrichment has been used to improve animal welfare. The aim of this study was to evaluate the effects of environmental enrichment by handling, in rats submitted and those not submitted to chronic stress. In chapter 1 it was shown that handling diminished anxiety, and enhanced learning abilities and memory indicating response in young-adult rats. In chapter 2 the effects of handling on behavioral (anxiety, ahnedonia, learning and memory) and metabolic responses induced by chronic mild unpredictable stress. Whereas stress raised the corticosterone secretion evaluated fifteen days after the end of stress; induced ahnedonia evidenced by a 1% decrease in sucrose preference; increased locomotor activity; had negative effects on learning and memory; and raised the serum concentration of triglycerides, total cholesterol and low density lipoprotein (LDL). Handling reduced the anxiety in animals both when they were and were not submitted to chronic stress; diminished the corticosterone secretion induced by the stress and cancelled the reduction of learning and memory retention induced by the chronic stress. The results obtained showed that the handling of young-adult rats produced positive behavioral effects capable of improving the animal's welfare and diminishing the deleterious effects induced by chronic stress.
Mestrado
Fisiologia Oral
Mestre em Odontologia
Bobrov, Evgeny. "Rat social touch". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/17036.
Texto completoRats use their stiff facial hairs (whiskers) for somatosensation, and the pathway from the whiskers to the primary somatosensory cortex (barrel cortex, BC) is well known. Rats also show diverse social behaviors, including touch of conspecifics with their whiskers. The representation of these social touch signals in the brain is however unknown. Thus, the present study aimed at characterizing the neuronal representation of social touch signals in BC and comparing them with non-social somatosensory stimulation. Using extracellular single-cell recordings in freely-moving rats, I could show that the activity of a large fraction of BC neurons is modulated by social touch. Responses were typically excitatory and the pattern of firing rates during interactions differed between cortical layers. Rats preferred interactions with alive conspecifics over inanimate stimuli. Whisking strategies also differed in that inanimate stimuli were whisked at with more regular movements from more protracted set angles. Neuronal responses were also different, such that objects elicited slightly but consistently weaker responses than alive rats. Interestingly, I observed sex-specific differences in neuronal responses. Prominently, there was stronger modulation by social touch in regular-spikers (RS) recorded from males. This could not be explained by behavioral measures, possibly indicating a neural origin of this difference. Further, RS from females fired much more weakly when females were in estrus. In summary, this is the first study that investigated social signals in a primary sensory area of freely-moving animals at the cellular level. It suggests that representations in sensory cortices might be less stimulus-driven and more top-down modulated than previously thought.
HASSANI, OUM KALTOUM. "Controle dopaminergique du noyau sybthalamique chez le rat normal et chez le rat modele de la maladie de parkinson (rats 6-ohda)". Paris 11, 1997. http://www.theses.fr/1997PA112037.
Texto completoOsypiw, Jacqueline Connett. "Heterogeneity of rat hepatocytes". Thesis, Liverpool John Moores University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261422.
Texto completoSullivan, Lawrence. "Roof Rat Control around Homes and Other Structures". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2002. http://hdl.handle.net/10150/146716.
Texto completoMahdouani, Kacem. "Stéroïdes libres urinaires chez le rat normal et le rat génétiquement hypertendu : souche lyonnaise". Lyon 1, 1994. http://www.theses.fr/1994LYO1W331.
Texto completoPascotto, Viviane Mattos [UNESP]. "Influência da mistura de cinco praguicidas em baixas doses sobre o sistema reprodutor de ratas Aprague-Dawley, Wistar e Lewis". Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/95894.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O presente projeto objetivou investigar os efeitos da combinação, em baixas doses, de cinco praguicidas (dieldrin, dicofol, endosulfan, diclorvos e permetrina) sobre o sistema reprodutor de ratas Sprague-Dawley, Wistar e Lewis. Ratas de cada linhagem, com seis semanas de idade, foram randomizadas em três grupos: GI: controle negativo; GII: praguicidas adicionados à ração em doses de NOEL (mg/Kg/dia) - diclorvos (0,23), dicofol (0,5), dieldrin (0,025); endosulfan (0,7), permetrina (5); GIII: praguicidas adicionados à ração em doses de LOEL (mg/Kg/dia) - diclorvos (2,3), dicofol (2,1), dieldrin (0,05), endosulfan (3,8), permetrina (25). A eutanásia foi realizada entre a 10ª e a 12ª semana experimental, na fase de estro. Os parâmetros de avaliação foram: peso de fígado, útero e ovários; análise histológica qualitativa de fígado, útero e ovários; morfometria do endométrio; avaliação do ciclo estral; dosagem de LH, FSH e progesterona; e contagem de folículos ovarianos. Animais das três linhagens tratados com a LOEL apresentaram toxicidade sistêmica, evidenciada pela diminuição de peso corpóreo e aumento de peso de fígado. A análise qualitativa de útero e ovários, assim como a avaliação do ciclo estral e níveis hormonais não indicaram sinais de toxicidade reprodutiva exercida pelas misturas. A contagem de folículos ovarianos indicou ausência de resposta dose dependente e alta variabilidade entre os animais de mesmo grupo experimental. Desta forma concluímos que, embora os resultados tenham mostrado diminuição de algumas populações foliculares nas doses de NOEL e LOEL, este parâmetro não pode ser utilizado isoladamente como indicativo de toxicidade reprodutiva. Estes achados remetem à necessidade de maiores estudos para o esclarecimento dos efeitos destes compostos nas populações foliculares
This project aimed to investigate the effects of the combination, in low doses, of five pesticides (dieldrin, dicofol, endosulfan, dichlorvos and permethrin) on the reproductive system of Sprague- Dawley, Wistar and Lewis rats. Six-weeks-old rats from each strain were randomized into three groups: GI: negative control; GII: pesticides added to the feed at NOEL doses (mg/kg/day) - dichlorvos (0.23), dicofol (0.5), dieldrin (0.025), endosulfan (0.7), permethrin (5), GIII: pesticides added to the feed at LOEL doses (mg / kg / day) – dichlorvos (2.3), dicofol (2.1), dieldrin (0.05), endosulfan (3.8), permethrin (25). Euthanasia was performed between the 10th and 12th experimental week, in the estrous stage. The evaluation parameters were: weight of liver, uterus and ovaries; qualitative histological analysis of liver, uterus and ovaries; endometrium morphometry; estrous cycle assessment; dosage of LH, FSH and progesterone; and counting of ovarian follicles. Animals from all three strains showed systemic LOEL toxicity, as evidenced by decreased body weight and increased liver weight. Qualitative analysis of the uterus and ovaries, as well as estrous cycle and hormone levels evaluations indicated no signs of reproductive toxicity exerted by the mixtures. Counting of ovarian follicles indicated lack of dose-dependent response and high variability among animals from the same experimental group. Hence, we concluded that, although our results have shown a decrease of some follicular populations at the NOEL and LOEL doses, this parameter can not be used alone as an indicator of reproductive toxicity. These findings underscore the need for more studies to clarify the effects of these compounds on follicular populations
Arena, Arielle Cristina. "Parametros reprodutivos masculinos e fertilidade de ratos adultos expostos ao inseticida fenvalerato". [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/318043.
Texto completoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O fenvalerato é um inseticida piretróide sintético amplamente utilizado na agricultura para o controle de pragas. Embora seja considerado de baixa toxicidade para os mamíferos, trabalhos têm demonstrado que certos piretróides podem apresentar atividade estrogênica e atuar como desreguladores endócrinos, acarretando disfunções reprodutivas importantes no sexo masculino. Está documentado na literatura que a exposição de ratas prenhes ao fenvalerato reduziu os níveis plasmáticos de testosterona e os pesos da vesícula seminal e do ducto deferente dos filhotes machos na idade adulta, além de alterações no comportamento sexual desses animais. Também foi observado que ratos adultos expostos à formulação de fenvalerato, por inalação, exibiram uma redução significativa no peso dos testículos e na contagem espermática no epidídimo. Até o momento pouco se sabe sobre os mecanismos pelos quais o fenvalerato exerce sua ação na reprodução, assim, o objetivo do presente trabalho foi investigar a atividade estrogênica e os efeitos do inseticida piretróide fenvalerato sobre o sistema reprodutor masculino e fertilidade de ratos machos adultos. Para tanto, ratos machos adultos (90 dias de idade) receberam durante 30 dias consecutivos, por gavage (via oral), 40 mg/kg/dia de fenvalerato (grau técnico; 96,8% de pureza). O grupo controle recebeu apenas o veículo (óleo de milho), segundo o mesmo protocolo experimental. No final do tratamento, foram avaliados os seguintes parâmetros: peso corporal; peso absoluto de órgãos da reprodução, fígado e rins; níveis plasmáticos de testosterona; contagem de células germinativas no testículo e no epidídimo; morfologia espermática; estudo da fertilidade através de cruzamentos naturais e inseminação artificial in utero; contagem de espermatozóides ejaculados no útero; avaliação do comportamento sexual; análises do testículo e epidídimo em nível de microscopia óptica e eletrônica e avaliação da possível atividade estrogênica de diferentes doses do fenvalerato (0,4; 1,0; 4,0; 8,0 e 40 mg/kg) através do teste uterotrófico. A quantificação de resíduos de fenvalerato por Cromatografia Líquida de Alta Precisão (HPLC) em órgãos reprodutores e vitais e análises de proteínas espermáticas e epididimárias também foram realizadas. Os resultados foram comparados pelos testes ¿t¿ de Student e Mann-Whitney, dependendo da natureza da distribuição dos dados, enquanto os resultados do teste uterotrófico comparados pela ANOVA seguida pelo teste de Tukey. Os resultados da quantificação de fenvalerato revelaram que o piretróide foi retido em órgãos reprodutores (testículo e epidídimo) e vitais (cérebro e fígado). O tratamento com fenvalerato reduziu os pesos absolutos do testículo e do epidídimo. Além disso, o tratamento não provocou diminuição nos níveis plasmáticos de testosterona. Verificou-se também que os ratos tratados apresentaram redução na produção espermática no testículo e no número de espermatozóides no epidídimo. No entanto, não foi observado comprometimento na fertilidade desses machos quando acasalados com fêmeas controles. As análises morfológicas do testículo e epidídimo assim como as análises de proteínas espermáticas e epididimárias não mostraram alterações. Além disso, o fenvalerato, nas doses testadas, não apresentou atividade estrogênica in vivo. Concluiu-se que o fenvalerato, nestas condições experimentais, foi retido em órgãos reprodutores e vitais. O fenvalerato foi espermatotóxico, visto que reduziu tanto a produção quanto as reservas espermáticas dos animais tratados. No entanto, apesar dessa alteração, a fertilidade dos animais tratados não foi comprometida, uma vez que o rato tem uma grande eficiência reprodutiva, diferentemente do que acontece com o ser humano
Abstract: Fenvalerate is a synthetic pyrethroid insecticide widely used in agriculture to control a variety of insects. Although it is considered to be of low acute toxicity to mammals, studies have showed that pyrethroids can have estrogenic activity and can act as endocrine disruptors, causing important reproductive impairment in males. It is documented in the literature that the exposure of pregnant rats to fenvalerate decreased plasma testosterone levels and weights of seminal vesicle and vas deferens in male pups during adult life, besides alterations in their sexual behavior. It was also observed that adult rats exposed to formulated fenvalerate,by inhalation, exhibited a significant reduction in the testis weight and epididymal sperm count. Little is known about the mechanisms by which fenvalerate exerts its action on reproduction; thus, the objective of the present study was to investigate the estrogenic activity and the effects of fenvalerate on the reproductive system and fertility of adult male rats. For this, adult male rats (aged 90 days) received, for 30 consecutive days, by oral gavage, 40 mg/kg/day of fenvalerate (technical grade; 96.8% purity). The control group received only the vehicle (corn oil), in the same experimental conditions. At the end of the treatment, the following parameters were analyzed: body weight; absolute weight of reproductive organs, liver and kidneys; plasma testosterone levels; germ cell count in the testis and epididymis; sperm morphology; fertility tests by natural matings and artificial insemination in utero; ejaculated sperm counts in uterus; sexual behavior; analysis of testis and epididymis at the optical and electron microscopic levels, and evaluation of possible estrogenic activity of different doses (0.4; 1.0; 4.0; 8.0 and 40 mg/kg) of fenvalerate by the uterotrophic test. Fenvalerate residues were quantified using High Performance Liquid Chromatography (HPLC) in reproductive and vital organs; sperm and epididymal protein were also realized. The results were compared by Student-t and Mann-Whitney tests, according to the characteristics of each variable, while the results of the uterotrophic test were compared by ANOVA followed by the Tukey test. The results of fenvalerate quantification revealed that the pyrethroid was retained in reproductive (testis and epididymis) and vital organs (brain and liver). The treatment with fenvalerate decreased the absolute weights of testis and epididymis. Furthermore, the treatment did not provoke reduction of plasma testosterone levels. It was also verified that the treated rats presented a reduction in daily sperm production and in epididymal sperm number. The fertility tests did not reveal differences related to the treatment. The results of the fenvalerate quantification revealed high concentrations of insecticide residues in the epididymis, testis, brain and liver. The histopathology of the testis and epididymis as well as analysis of sperm and epididymal proteins did not show alterations. Moreover, fenvalerate, at the tested doses, did not present estrogenic activity in vivo. It was concluded that fenvalerate, in these experimental conditions, was retained in reproductive organs and was spermatotoxic, since it reduced sperm production and storage, but this alteration was not sufficient to compromise fertility by virtue of the high reproductive efficiency of rodents in contrast with humans
Doutorado
Biologia Celular
Doutor em Biologia Celular e Estrutural
Sokolic, Ljiljana. "Olfactory discrimination in the rat". University of Sydney, 2009. http://hdl.handle.net/2123/4986.
Texto completoAbstract Olfactory tasks are used very often with laboratory animals in studies of the neurobiology of learning and memory. Rats and mice are extremely sensitive in their detection and discrimination of odours, learn olfactory tasks rapidly, and can display higher order cognitive functions in olfactory tasks. This cognitive capacity may rival the ability of primates to learn analogous tasks with visual cues and most likely reflects strong anatomical connections between the olfactory bulbs and higher brain regions such as the piriform cortex, orbitofrontal cortex and hippocampus. The current thesis explored olfactory discrimination learning and performance in rats and had two principal aims. The first part of the thesis was oriented around odour masking phenomena in rats: the ability of one odour in a mixture to suppress detection of a second odour in that mixture. A specialized behavioural paradigm was developed to allow the study of odour masking in the rat. The second part of the thesis was pharmacological and determined whether the acquisition, reversal and performance of olfactory discriminations, and analogous auditory discriminations, are affected by two commonly used classes of drugs (benzodiazepines and cannabinoids). Together, these studies attempt to gain a better understanding of the nature of olfactory discrimination learning in rats, by using both psychophysical and pharmacological approaches, and to develop behavioural paradigms which may be used in future psychophysical and pharmacological studies. Following an introduction and review of olfactory and auditory studies in rat (Chapter 1), odour masking phenomena were studied in Chapter 2. The aliphatic aldehydes butanal (C4) and heptanal (C7) were used in the study. Aldehydes were of interest as this class of odorants abound in nature and may be important for rodents’ species-specific communication. Thirsty rats were initially trained to discriminate C4 and C7 in the olfactometer, using a go/no-go olfactory discrimination task. This involved rats learning to nose poke in an odour port and to lick a tube for a water reward on presentation of the rewarded component S+, while withholding licking at the tube when the other, unrewarded, aldehyde (S-) was presented. Odour mixtures (C4C7 or C7C4) were then introduced into the task as an additional non-rewarded condition (mixture S-). The concentration of the non-rewarded aldehyde in the mixture was then systematically decreased, while the concentration of the rewarded aldehyde was kept constant. When the non-rewarded aldehyde reached a critical low level in the mixture, rats started to make responses to the non-rewarded mixture (false alarms) showing that the S+ odour was suppressing the S- odour in the mixture, so the mixture was being responded to in the same manner as the S+ odour presented alone. Results also showed asymmetric suppression in the mixture condition, such that butanal suppressed detection of heptanal at a much lower concentration than vice versa. A second experiment demonstrated that when both butanal and heptanal were present in a binary mixture at the same concentration (10-6 volume %), rats responded to the mixture as if only butanal was present. Our findings are in agreement with human studies showing component interactions in binary mixtures of aldehydes. The molecular feature of carbon chain length appears to be a critical factor in determining the outcome of interactions between aldehydes at peripheral olfactory receptors, with smaller chain aldehydes better able to compete for receptor occupancy. Subsequent chapters explored the effects of two classes of commonly used drugs - benzodiazepines and cannabinoids - on olfactory and auditory discrimination in rats. Animal models such as the radial arm maze, Morris water maze and object recognition test are routinely used to test adverse and facilitatory effects of drugs on cognition in rodents. However, comparatively few pharmacological studies employ olfactory or auditory go/no-go paradigms. Thus, an important part of the present thesis was to assess the viability of using such paradigms in detecting pharmacological effects, and to identify whether such effects may be modality specific (i.e. whether a drug has a greater effect on olfactory or auditory tasks). In Chapter 3, the effects of benzodiazepines on olfactory discrimination tasks were explored. Rats were injected with the benzodiazepine drugs midazolam or diazepam and tested on discrimination tasks involving either the auditory and olfactory modality. Results showed that midazolam (0.5–2 mg/kg sc) did not affect the performance of a well-learned two-odour olfactory discrimination task, and moderately facilitated the performance of a go/no-go auditory discrimination task. On the contrary, midazolam (1 mg/kg) impaired the acquisition of a novel go/no-go olfactory discrimination task, as well as the reversal of a previously well-learned olfactory discrimination. However, midazolam did not affect the acquisition or reversal of an equivalent auditory discrimination task. The olfactory bulb and the piriform cortex are intimately involved in associative learning and behavioural aspects of olfactory performance, and have high concentrations of benzodiazepine receptors. These may therefore be possible neural substrates for the disruptive effects of benzodiazepines on olfactory learning. Findings from Chapter 4 indicated that the prototypical cannabinoid agonist delta-9-tetrahydrocanabinol (Δ9 THC) (0.3, 1 and 3 mg/kg) impairs auditory discrimination performance, but had no effect on equivalent olfactory discriminations. This is in marked contrast to the effects of benzodiazepines. Residual effects were observed, such that auditory discrimination performance was still impaired on the day following Δ9 THC administration. Delta-9-tetrahydrocanabinol effects were prevented by co-administration of the cannabinoid antagonist rimonabant (3 mg/kg). In addition, the anandamide hydrolysis inhibitor URB597 (0.1 and 0.3 mg/kg), which boosts levels of endogenous cannabinoids in the synapse, also impaired auditory discrimination performance, and this effect was also reversed by rimonabant. This study also assessed the effects of Δ9 THC (0.3, 1 and 3 mg/kg) and URB597 (0.1 and 0.3 mg/kg) on acquisition and reversal of novel olfactory discriminations. Results showed that Δ9 THC impairs olfactory reversal learning without affecting acquisition of the original discrimination. It is argued that this reversal deficit may be part of a wider capacity for cannabinoids to impair cognitive flexibility. The final Chapter (General Discussion) discusses the relevance and implications of the combined findings. The results add significantly to our current understanding of perceptual, learning and memory processes involving the olfactory modality in rats. With respect to olfactory perception, this thesis introduced a new behavioural paradigm, which can be used to assess component suppression in mixtures, and may be of use in future psychophysical studies involving rodents or other species. With respect to learning and memory, the thesis provides novel information on the disruptive effects of benzodiazepines and cannabinoids on olfactory and auditory tasks. It is concluded that go/no-go olfactory and auditory discrimination tasks in rats can provide a useful platform for assessing the disruptive and modality-specific effects of drugs on learning, performance and cognitive flexibility. Future studies might expand the range of drugs tested on these paradigms and might consider chronic as well as acute drug effects.
Irvine, Rodney James. "Nociception in the hypertensive rat". Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phi7185.pdf.
Texto completoBirzniece, Vita. "Neuroactive steroids and rat CNS". Doctoral thesis, Umeå : Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-296.
Texto completoOliet, Stéphane H. R. "Osmoreception in rat supraoptic neurons". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28874.
Texto completoParker, Ruth E. "The rat interleukin-4 receptor". Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318893.
Texto completoWalter, D. J. "Fibre metabolism in the rat". Thesis, University of Edinburgh, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370595.
Texto completoBenjamin, Irving Stuart. "Portacaval transposition in the rat". Thesis, University of Glasgow, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293482.
Texto completoOdom, N. J. "Lung preservation in the rat". Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234476.
Texto completoBenns, L. M. "Meningeal innervation in the rat". Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376821.
Texto completoСулим, Григорій Анатолійович, Григорий Анатольевич Сулим, Hryhorii Anatoliiovych Sulym, Микола Сергійович Линдін, Николай Сергеевич Лындин, Mykola Serhiiovych Lyndin, Владислав Володимирович Сікора et al. "Ultraviolet impact on rat skin". Thesis, Springer, 2020. https://essuir.sumdu.edu.ua/handle/123456789/81258.
Texto completoKwok, Hon Hung. "Immunolesioning in the rat brain". HKBU Institutional Repository, 1999. http://repository.hkbu.edu.hk/etd_ra/234.
Texto completoSokolic, Ljiljana. "Olfactory discrimination in the rat". Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/4986.
Texto completoLewis, Beverley Anne. "Cell biology of rat spermatozoa". Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/23087.
Texto completoWallace, Timothy J. "Characterization of rat pulmonary carboxylesterase". VCU Scholars Compass, 1999. https://scholarscompass.vcu.edu/etd/5616.
Texto completoHo, Peter D. "Regulation of morphology and intracellular calcium by Ras in rat neonatal cardiac myocytes /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9984293.
Texto completoLee, Gabriel Y. F. "Origin of macrophages in rat syringomyelia : an investigative study using rat radiation bone marrow chimeras /". Title page, table of contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09MS/09msl478.pdf.
Texto completoPahre, Hauke. "Das Recht des Europäischen Rates : eine Untersuchung im Lichte aktueller Entwicklungen der Europäischen Union /". Frankfurt, M. ; Berlin Bern Bruxelles New York, NY Oxford Wien : Lang, 2008. http://d-nb.info/989695905/04.
Texto completoRolfe, David F. S. "The contribution of mitochondrial proton leak to the standard metabolic rate of a rat". Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339591.
Texto completoNicolescu-Catargi, Bogdan. "Resténose après angioplastie dans trois modèles de rats diabétiques et chez le rat normoglycémique". Bordeaux 2, 2001. http://www.theses.fr/2001BOR28918.
Texto completoAtheosclerotic stenosis and its ischemic complications lead to the need for arterial reconstruction. However, restenosis after baloon angioplasty that results from both intimal hyperplasia and arterial remodeling lead to restenosis, especially in the setting of diabetes mellitus. Therefore the study of restenosis in diabetes (a major cardiovascular risk factor) is of importance. However the ideal animal model to study restenosis on one hand and the animal model that mimics type 2 diabetes in humans on the other hand are still lacking. Furthermore, many of the potential mechanisms promoting restenosis in diabetic patients are related to elevated glucose or insulin levels, or both, but most of them are hypothetical. We have studied the rat carotid artery subjected to balloon injury in three models of diabetic rats (streptozotocin, streptozotocin treated with insulin and Goto-Kakizaki (GK), a genetic model of type 2 diabetes) in comparison of normal, normoglycemic rats. Arterial restenosis after balloon angioplasty was the highest in the GK rats. Intimal hyperplasia played the main role in the lumen loss after angioplasty together with the enhanced expression of TGF and fibronectin, whereas arterial remodeling was the main mechanism in the other models and in the normal rat. We further confirmed the implication of the adventitial layer in neointimal formation. Finally, we have shown that cell proliferation in the adventitial layer was the highest in the GK rat and that adventitial proliferation is supplied by an adventitial angiogenesis. We further found a close correlation between the intimal hyperplasia area and angiogenesis indexes in the adventitia layer. Accordingly, we have found enhanced expressions of HIF-1α (Hypoxia Inducible Factor) and VEGF (Vascular Endothelial growth Factor) suggesting a majpr role of hypoxia in arterial healing and restenosis after restenosis in the GK rat. In conclusion we have shown that intimal hyperplasia is the main mechanism of restenosis in a genetic model of type 2 diabetes, in accordance with most of clinical studies. We suggest a direct implication of the adventitial layer supplied by angiogenesis in restenosis. Even if causality is not established by our study, we suggest the use of recombinant VEGF with caution for revascularisation in the setting of diabetes, since the intimal hyperplasia may be enhanced
Dethy, Sophie. "Investigation "in vivo" du système dopaminergique présynaptique chez le rat sain et le rat rendu hémiparkinsonien". Doctoral thesis, Universite Libre de Bruxelles, 1998. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211976.
Texto completoMokhtar, Najat. "Etude de la réponse métabolique du coeur in vivo à un traitement chronique à l'isoprénaline et à l'hypoxie aiguë chez le rat et chez le cobaye". Dijon, 1985. http://www.theses.fr/1985DIJOS050.
Texto completoOiso, Yutaka, Hiroshi Nagasaki y Hisashi Yokoi. "Transgenic rat models of vasopressin overexpression". Nagoya University School of Medicine, 2003. http://hdl.handle.net/2237/5393.
Texto completoEjdesjö, Andreas. "Teratogenic Predisposition in Diabetic Rat Pregnancy". Doctoral thesis, Uppsala universitet, Institutionen för medicinsk cellbiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-178175.
Texto completoTumelty, James Martin. "Calcium imaging in rat retinal arterioles". Thesis, Queen's University Belfast, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486231.
Texto completoHultin, Magnus. "Turnover of chylomicrons in the rat". Doctoral thesis, Umeå universitet, Institutionen för medicinsk kemi och biofysik, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-102338.
Texto completoDiss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 5 uppsatser.
digitalisering@umu.se
Dadgar, Anoushiravan. "Studies on rat gastrointestinal neuropeptide Y". Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27410.
Texto completoMedicine, Faculty of
Cellular and Physiological Sciences, Department of
Graduate
Rooney, Thomas A. "Inositol phospholipid metabolism in rat brain". Thesis, University of Leicester, 1987. http://hdl.handle.net/2381/33609.
Texto completoAshley, George Russell. "EphB signalling in rat prostate development". Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/26151.
Texto completoHu, Ying. "Optic nerve regeneration in adult rat". University of Western Australia. School of Anatomy and Human Biology, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0080.
Texto completoDavidoff, Allen Warren. "Congestive heart failure in the rat". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0022/MQ31340.pdf.
Texto completoNoble, Jos Leonard Martin Louis le. "Microcirculation in the spontaneously hypertensive rat". Maastricht : Maastricht : Rijksuniversiteit Limburg ; University Library, Maastricht University [Host], 1987. http://arno.unimaas.nl/show.cgi?fid=5892.
Texto completoJans, Sylvia Wilhelmina Sophia. "Annexin V in the rat heart". [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 1997. http://arno.unimaas.nl/show.cgi?fid=5915.
Texto completoRayner, Jennifer Leigh Ball Louise M. "Atrazine and rat mammary gland development". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,516.
Texto completoTitle from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment for the requirements for the degree of Doctor of Philosophy in the Department of Environmental Sciences and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.
Brons, I. G. M. "Tissue culture of rat insulinoma cells". Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303711.
Texto completoAkhtar, Sobia. "Properties of rat recombinant K+ channels". Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314344.
Texto completoCumming, D. V. E. "Nuclear protein phosphorylation in rat liver". Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375227.
Texto completoHardingham, Neil Robert. "Synaptic connections in rat visual cortex". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325298.
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