The introduction of parental behaviour in naive animals has been studied in several species. Male and female adult Mongolian gerbils, Meriones unguiculatus were singly exposed to protected pups (PP exposures). Exposures lasted for ten minutes, and were carried out each day. Behaviour patterns shown by the adults were recorded, and their frequencies measured. After several PP exposures (3-18), adults were exposed to unprotected pups (UP exposures) in order to detect whether or not the normal aggressive response to pups was still present, or had been overcome and replaced by parental responsiveness. Preliminary experiments showed the aggressive response could be overcome in as little as five ten minute exposures. A variety of parental behaviour patterns were shown by some individuals, suggesting that stages may exist in the process under investigation. Following on from preliminary experiments, the effect of increasing the number of both PP and UP exposures was investigated. Increasing PP and UP exposures increased the percentage of animals responding non-aggressively towards pups. However no increase was seen in the range of parental responses shown. Again, results suggested the development of the parental response was a non-unitary process occurring in stages: first the overcoming of fear of pups or aggression towards pups; second, investigation of the pup; third, the development of parental responsiveness. The role of olfactory and auditory cues from the pups were next investigated. If a pup bore the scent gland sebum of the experimental adult, aggression was overcome more quickly than before. Also, more parental behaviour patterns were shown. If the pup bore the experimental adult's urine, aggression was overcome more quickly than in preliminary experiments, but not as quickly as when the pups bore the adult's sebum. No correlation was found between the rate of ultrasonic calling and the rate of the induction of parental responsiveness. This was thought to be an artefact of the recording procedure, since the source of individual calls was not identified, and the frequency of calls could therefore have been increased due to adults calling. Parental responsiveness appeared to be maintained 2 weeks after its induction, but not 10 weeks after induction. An exception to this was the animals exposed to pups smeared with the experimental adults sebum, who did not appear to maintain responsiveness even up to 2 weeks after induction. Overall twice as many males as females were able to be induced to show parental responsiveness. Males overcame their aggression to pups, and showed parental responsiveness more quickly than females did. Further work arising from the present studies would include a more detailed study of both the influence of ultrasonic calling by pups on the development of parental responsiveness and the quicker development of parental responsiveness found when pups bore an odour familiar to the adults.

No description available.

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / There are two types of extracellular fluid in the cochlea: the endolymph of the scala media and the perilymph of the scala vestibuli and scala tympani. Cochlear endolymph and perilymph have different compositions, and the concentration gradient of solutes across the cochlear partition is actively maintained in vivo. In experiments involving fresh cochleas that have been dissected to allow access to the cochlear partition, the cochlea is generally placed in a single medium that aims to nourish the cochlear cells. However, the dissection usually disrupts the separation of endolymph and perilymph across the organ of Corti, the organ in the cochlear partition that contains the auditory sensory cells. Separating the fluids across the cochlear partition during experiments involving dissected cochleas would allow for more physiologically relevant observations to be made. This work was aimed at creating a two-chambered device for holding excised Mongolian gerbil (Meriones unguiculatus) cochlear preparations during in vitro electrical stimulation experiments. Primarily, this device creates experimental conditions that more closely mimic the in vivo physiologic conditions found within the gerbil cochlea by isolating the endolymph medium and perilymph medium bathing the opposing surfaces of the organ of Corti. The device also provides a means to electrically stimulate the organ of Corti and allows for imaging of the response to stimulation. The ability of the device to seal endolymph medium from perilymph medium is shown via electrical resistance measurements between the chambers. The imaging of hair cell motion during electrical stimulation is also demonstrated. / 2031-01-02

Este trabalho visa avançar o conhecimento sobre a interferência da nicotina no protocolo de treino forçado em gerbilos isquêmicos. Utilizamos 110 Gerbilos, distribuídos em 11 grupos. Grupo controle com animais ingênuos (C), falso operado (S) e isquêmicos (I). Grupos nicotina (CN, SN, SNE, IN e INE) e salina (CS, SS, IS) com ou sem treinamento. Os animais receberam uma injeção de 2mg/kg de nicotina ou salina durante 9 dias. Utilizamos uma esteira motorizada (treino contínuo, 5 dias, 5m/min por 15 minutos), um monitor de atividades e o Rota Rod. Os resultados foram analisados por uma ANOVA e pós teste de Holm-Sidak, p<0,05. Observamos aumento de apresentação de todos comportamentos no monitor de atividades, o CN maior do que os C, S, SS, SNE e INE, o SN maior do que o SNE, o I maior do que os C, S, SS, SNE, IS, INE e ainda, o IN maior do que os C, S, SS, SNE, IS e INE (cruzamento, F10,93 = 2,97), (distância, F10,93 = 2,79), (velocidade, F10,93 = 2,79) e (atividade, F10,93 = 2,81). No Rota Rod o CN apresentou maior tempo de permanência com relação aos outros grupos exceto SNE, já o SNE, em relação aos CS, S, SN, I, IN e o I menor tempo de permanência do que o C e INE (F10,93 = 3,35). Nos grupos I e IS observamos menor densidade de neurônios no hipocampo (F6,42 = 31,02), córtex motor M1 (F6,42 = 4,01) e estriado (F6,42 = 23,33). A nicotina não interferiu com a melhora do comportamento dos animais isquêmicos. / This work aims to advance the knowledge about the interference of nicotine in the forced training protocol in ischemic gerbils. We use 110 gerbils, distributed in 11 groups. Control (C), false operated (S) and ischemic (I). Nicotine groups (CN, SN, SNE, IN INE) and sham (CS, SS, SI) with or without training. The animals received an injection of 2mg/kg of nicotine or saline for 9 days. We use a treadmill (continuous training 5 days, 5m / min for 15 minutes), an activity monitor and the Rota Rod (RR). The results were analyzed by an ANOVA and post Holm-Sidak test, p <0.05. We observed increased in all behaviors in the activity monitor, increase of CN than C, S, SS and NSS INE, SN increase compared to NES, the I increase than C, S, SS, ENS, S, NSI and also the IN showed an increase compared to C, S, SS, SNE, SI and NSI (crossing, F10,93 = 2,97), (distance, F10,93 = 2,79), (speed, F10,93 = 2,79) and (activity, F10,93 = 2,81). In RR, CN showed an increase of time spent with the other groups except SNE, and an increase in the SNE, compared to the CS, S, SN, I, IN and I showed an decrease of time compared to C and INE (F10,93 = 3,35). In groups I and and IS we observed an decrease of neurons density in the hippocampus (F6,42 = 31,02), motor cortex M1 (F6,42 = 4,01) and striatum (F6,42 = 23,33). Nicotine did not interfere with the improvement of motor behavior in ischemic animals.

Este trabalho visa avançar o conhecimento sobre a interferência da nicotina no protocolo de treino forçado em gerbilos isquêmicos. Utilizamos 110 Gerbilos, distribuídos em 11 grupos. Grupo controle com animais ingênuos (C), falso operado (S) e isquêmicos (I). Grupos nicotina (CN, SN, SNE, IN e INE) e salina (CS, SS, IS) com ou sem treinamento. Os animais receberam uma injeção de 2mg/kg de nicotina ou salina durante 9 dias. Utilizamos uma esteira motorizada (treino contínuo, 5 dias, 5m/min por 15 minutos), um monitor de atividades e o Rota Rod. Os resultados foram analisados por uma ANOVA e pós teste de Holm-Sidak, p<0,05. Observamos aumento de apresentação de todos comportamentos no monitor de atividades, o CN maior do que os C, S, SS, SNE e INE, o SN maior do que o SNE, o I maior do que os C, S, SS, SNE, IS, INE e ainda, o IN maior do que os C, S, SS, SNE, IS e INE (cruzamento, F10,93 = 2,97), (distância, F10,93 = 2,79), (velocidade, F10,93 = 2,79) e (atividade, F10,93 = 2,81). No Rota Rod o CN apresentou maior tempo de permanência com relação aos outros grupos exceto SNE, já o SNE, em relação aos CS, S, SN, I, IN e o I menor tempo de permanência do que o C e INE (F10,93 = 3,35). Nos grupos I e IS observamos menor densidade de neurônios no hipocampo (F6,42 = 31,02), córtex motor M1 (F6,42 = 4,01) e estriado (F6,42 = 23,33). A nicotina não interferiu com a melhora do comportamento dos animais isquêmicos. / This work aims to advance the knowledge about the interference of nicotine in the forced training protocol in ischemic gerbils. We use 110 gerbils, distributed in 11 groups. Control (C), false operated (S) and ischemic (I). Nicotine groups (CN, SN, SNE, IN INE) and sham (CS, SS, SI) with or without training. The animals received an injection of 2mg/kg of nicotine or saline for 9 days. We use a treadmill (continuous training 5 days, 5m / min for 15 minutes), an activity monitor and the Rota Rod (RR). The results were analyzed by an ANOVA and post Holm-Sidak test, p <0.05. We observed increased in all behaviors in the activity monitor, increase of CN than C, S, SS and NSS INE, SN increase compared to NES, the I increase than C, S, SS, ENS, S, NSI and also the IN showed an increase compared to C, S, SS, SNE, SI and NSI (crossing, F10,93 = 2,97), (distance, F10,93 = 2,79), (speed, F10,93 = 2,79) and (activity, F10,93 = 2,81). In RR, CN showed an increase of time spent with the other groups except SNE, and an increase in the SNE, compared to the CS, S, SN, I, IN and I showed an decrease of time compared to C and INE (F10,93 = 3,35). In groups I and and IS we observed an decrease of neurons density in the hippocampus (F6,42 = 31,02), motor cortex M1 (F6,42 = 4,01) and striatum (F6,42 = 23,33). Nicotine did not interfere with the improvement of motor behavior in ischemic animals.

Orientador: Sebastiao Roberto Taboga / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T09:02:58Z (GMT). No. of bitstreams: 1 Custodio_AnaMariaGalvan_D.pdf: 7098250 bytes, checksum: 7533cbcab259eabbec9b1cc232deab36 (MD5) Previous issue date: 2007 / Resumo: Diferente da abordagem clássica, a próstata não é um órgão exclusivo do organismo masculino, podendo ser encontrada nas fêmeas de vários mamíferos, incluindo humanos e roedores. A compreensão do desenvolvimento pós-natal e possíveis processos histopatológicos da glândula anexa da mulher são dificultados pela sua localização anatômica parauretral, restringindo seu estudo até então ao material de necropsia. Porém, sua similaridade com a próstata do gerbilo da Mongólia (Meriones unguiculatus) possibilitou a utilização desse animal como um adequado modelo experimental para se averiguar as características morfo-funcionais da glândula. A análise dos componentes epiteliais e estromais da próstata nas idades jovem, adulta e senil do desenvolvimento pós-natal, as alterações histopatológicas decorrentes do envelhecimento e a sua resposta morfológica mediante a suplementação hormonal pela deidroepiandrosterona (DHEA) foi o objetivo deste trabalho. Os resultados foram obtidos a partir das avaliações estruturais, ultra-estruturais, morfométrico-estereológica e sorológicas (dos animais isentos de tratamento) do órgão. A glândula feminina jovem mostrou uma precocidade funcional em comparação à do macho de mesma idade provavelmente associada à ação do estrógeno circulante. Enquanto que a senescência foi marcada pela diminuição dos níveis séricos de esteróides e intensificação das lesões benignas, pré-malignas e malignas já desenvolvidas na idade adulta, porém com menor incidência. A suplementação hormonal promoveu uma instabilidade na homeostase glandular a partir da idade jovem induzindo o desenvolvimento de alterações histopatológicas benignas e pré-malignas, além de conferir uma supraestimulação das células secretoras. A existência de fenótipos celulares modificados foi identificada no epitélio secretor da glândula sendo aparentemente mais intensificado durante a idade senil e posterior à administração hormonal. Assim sendo, a real condição da histopatologia prostática é alarmante, porém pouca atenção ainda é dada a essa glândula do sistema genital feminino, principalmente mediante a senescência e as terapias de suplementação hormonal. Talvez seja necessária uma adaptação da rotina clínica ginecológica mediante a existência deste órgão com o intuito de se monitorar a glândula e prevenir possíveis desconfortos e comprometimentos à saúde da mulher / Abstract: In contrast to the classic boarding, the prostate is not an exclusive gland of the male organism and it can be found in mammal females, including humans and rodents. The precise comprehension of the post-natal development and possible histopathological processes related to this gland are difficult because of its anatomical paraurethral localization and it restricting the study in necropsy material. However, the similarity between the Mongolian gerbil prostate (Meriones unguiculatus) and women one makes it a good animal model to study the morphofunciotional feature of this gland. The analyse of the epithelial and stromal components in the prostate of young, adul and old ages, the histopathological disorders decurrent of aging and their morphological answer related to the hormonal supplementation by deidroepiandrosterona (DHEA) were the objective of this work. The results were based on structural, ultrastructural, morphometric-steriological studies and hormonal analyzes (except the treated animals). The young female prostate showed an early gland functionaly compared to the male in the same age and it was probably associated to the serum stradiol levels. The aging was marked by the reduction of the serum steroids and intensification of the benign, pre-malignant and malignant histopathological alterations. Altought these same changes had already developed in the adult age, they had lesser incidence. Hormonal supplement promoted instability of the gland homeostasis in the young age inducing the development of benign and malign histophatological alterations beyond the high biossinthetic stimulation on the secretory cells. Some modificated cellular phenotypes were identifyed in the gland secretory epithelium and it could be amplifyed during the senesce period and after the hormonal administration. In this way, the real condition of the prostatic histopathology is alarming and few atention is given to this gland wich is too inherent to the female genital system, especially regarding the senescence and therapies of hormonal supplementation. Maybe it is necessary an adaption in the female clinic routin since this female ogan exists and thus the gland could be monitored and some discomforts and damages of the women health could be prevented. / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 118-134). Available also in a digital version from Dissertation Abstracts.

Orientador: Patricia Simone Leite Vilamaior / Resumo: É conhecido que o processo de envelhecimento ocasiona em machos um desequilíbrio hormonal devido à redução gradual da síntese de testosterona pelos testículos, que afeta a maioria dos órgãos sensíveis a hormônios e dentre eles a adrenal, que é responsável pela síntese e secreção de hormônios esteroides como mineralocorticoides, glicocorticoides e andrógenos. Estudos anteriores reconhecem o importante papel da adrenal na regulação do sistema reprodutor e também é conhecido, por meio de estudos com castração, que esta é sensível à redução de andrógenos, no entanto, há pouco entendimento do papel dessa glândula no processo de andropausa e há uma dificuldade em encontrar modelos experimentais representativos, uma vez que há muitas diferenças morfofuncionais entre as adrenais dos roedores e primatas. As adrenais dos gerbilos da Mongólia têm características ultraestruturais peculiares que sugerem uma maior similaridade à dos primatas. Apesar de serem modelos experimentais utilizados em estudos de desregulação endócrina e do sistema reprodutor, há poucos estudos sobre a fisiologia do córtex adrenal dessa espécie. Considerando essa afirmação, esse estudo descreveu pela primeira vez a morfofisiologia da adrenal de gerbilos adultos e durante o envelhecimento, trazendo resultados que demonstram similaridades do córtex adrenal dessa espécie com o humano e de outros primatas, desde a morfologia à expressão de enzimas da biossíntese de cortisol e andrógenos e de receptores de andrógeno e e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aging process in males is known by occasioning a hormonal imbalance due to the gradual reduction in the testicular testosterone synthesis, which affects most of the organs sensitive to this hormone and, among them the, adrenal glands which its cortex is responsible to synthesize and secrete steroidogenic hormones as mineralocorticoids, glucocorticoids, and androgens. Existing research recognizes the significant role played by this gland in the regulation of the reproductive system; it is also known that it is sensitive to the reduction of testosterone caused by castration, although there is still very little scientific understanding of its role in the andropause process. Moreover, Mongolian gerbils are experimental models for studies in reproductive biology and endocrine deregulation, their adrenal glands present a peculiar structure and suggest having more similar morphophysiology to the primates than others rodents, although there have been few investigations about the gerbils' adrenocortical physiology. Considering this, this study has described the morphophysiology of this gland in gerbil for the first time and showed particular similarities between the adrenal cortex of M. unguiculatus and primates, since the morphology, to the expression of enzymes of cortisol and androgens biosynthesis and androgen and estrogen receptors. During aging was an hypertrophy in the adrenal cortex, based on the gradual increase in adrenal absolute weight of the adrenals in the older grou... (Complete abstract click electronic access below) / Mestre

The goal of my thesis was to elucidate the impact of protein-energy malnutrition (PEM, a condition commonly found in aging stroke patients) on outcomes from global ischemia. I first examined the hypothesis that PEM will impair working memory in the adult gerbil as measured in the T-maze. Gerbils were fed an adequate (12.5%) or low protein (2%; PEM) diet for 6wk. Stringent assessment of T-maze performance indicated an improvement with PEM although I was unable to reconcile whether this was increased motivation for the food reward or enhanced working memory.<p> The second hypothesis tested was PEM will decrease expression of plasticity-associated hippocampal mRNA and protein expression following global ischemia in the gerbil. The plasticity markers brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (trkB), and growth-associated protein-43 (GAP-43) were examined in the CA1 hippocampal region post-ischemia. PEM induced in gerbils for 4wk did not alter the global ischemia-induced decrease in CA1 neurons. Ischemia resulted in increased CA1 pyramidal expression of BDNF and trkB mRNA at 1, 3, and 7d post-ischemia and increased trkB protein expression at 3 and 7d. PEM further elevated the increased trkB protein detected at 7d in the fibres. Ischemia resulted in increased GAP-43 protein at 3 and 7d post-ischemia with PEM increasing this expression at 3d in the CA3 and hilar regions in addition to CA1. These findings suggest an increased stress-response and/or hyperexcitability state in the hippocampus of malnourished ischemic animals.<p> Since the reliability of the gerbil model of global ischemia has come into question, the third part of my thesis tested the hypothesis that the influence of pre-existing PEM on global ischemia-induced hippocampal injury can be reliably studied with the 2-vessel occlusion rat model. The impact of PEM on CA1 neuronal death and dendritic damage was examined. Rats received protein adequate (18%) or deficient (2%; PEM) diet for 7-8d prior to global ischemia. PEM did not worsen the decrease in CA1 neurons and dendrites observed at 7d post-ischemia. Importantly, I found that PEM altered blood glucose and acid-base balance during surgery and caused brief hypothermia post-surgically, factors which are important for consistent brain injury.<p> Taken together, these findings reveal (i) that nutritional care, although frequently ignored, can have robust effects on recovery mechanisms after brain ischemia; and (ii) the challenges of studying pre-existing PEM in an established rodent model of stroke.

Since caloric restriction (CR) can modify multiple pathways central to the ischemic cascade and enhance neuroplasticity mechanisms, we hypothesized that CR should exert protective effects following brain ischemia. Previous studies have suggested benefit when CR was administered prior to ischemia. This study investigated whether prolonged CR beginning after global ischemia would result in lasting protection as assessed by performance in the open field, as a measure of functional outcome, and hippocampal CA1 neuronal counts. Adult male Mongolian gerbils were subjected to five minute bilateral carotid artery occlusion (I) or sham surgery (S) with tympanic temperature maintained at 36.5 ± 0.2ºC during the intra-ischemic period. After screening out gerbils with incomplete ischemia, each of the two surgical groups were randomly assigned to control diet (CON) or 30% CR for the duration of the study (60d). Gerbils were tested in the open field on d3, 7, 10, 30 and 60. Ischemic animals on control diet showed a significantly higher level of activity in the open field (impaired habituation) compared to SCON gerbils on all test days (p<0.001). Open field activity was decreased 9% in the ICR group versus ICON gerbils on d7 (p=0.024), suggesting a transient neuroprotective effect. Open field activity of the SCR gerbils began increasing relative to that of SCON gerbils during the last 30 days of the study (p=0.055 on d60), raising the question of suitability of the open field test for long-term studies of CR and ischemia. Brain sections obtained at d60 were stained with hematoxylin & eosin. Hippocampal CA1 neuron counts were reduced 88% by ischemia (p<0.001), and there was no sparing effect of CR. These findings suggest that prolonged CR administered beginning after global ischemia cannot diminish brain injury or enhance long-term recovery.