Fischer 344 (F344) rats may be useful for studying impairments in social interactions because they exhibit reduced play behavior compared to Sprague-Dawley (SD) rats. The purpose of this investigation was to explore F344 rats as a model of early social interaction deficits and to determine if oxytocin (OT) activity mediated attachment behavior. To this end, we conducted three experiments measuring the preference of a dam-paired odor in postnatal day (PD) 12 F344 and SD rats. In Experiment 1, PD 11 pups were conditioned with a dam- or neutral-paired odor and tested for odor preference on PD 12. Experiments 2 and 3 used the same protocol as Experiment 1, except in Experiments 2 and 3, pups received an injection of OT (0, 250, 500, or 1000 ng, IC) or OT antagonist (OTA) (0.1, 0.3, or 1 mg/kg, IP) prior to the start of conditioning. Preference for the dam-paired odor did not differ between rat strains, however both male and female F344 pups showed a greater preference for the maternal odor when treated with OT. Male rats showed this enhanced preference at 500 ng OT while females required 1000 ng OT. OT did not alter odor preference in SD pups and OTA did not alter either rat strain’s preference. In conclusion, F344 rat pups do not have attachment deficits but may be useful for testing compounds to treat attachment disorders. It is possible that maternal attachment differs from other social behaviors, such as play behavior. Exogenous OT administration enhanced attachment but only in F344 rats. These data suggest further research on OT in F344 rats is warranted. In addition, it has been suggested that, since ASD affects more boys than girls, the problem may lie with AVP rather than OT. Therefore, other mechanisms may be involved in the development of social behaviors and perhaps the development of maternal attachment. Further testing of other neurochemicals such as dopamine and AVP as well as examining other stages of development (i.e., adolescence and adulthood) may be useful in identifying new therapeutics for ASD.

No description available.

Changes in both sleep architecture and cognition are common with age. Typically these changes have a negative connotation: sleep fragmentation, insomnia, and deep sleep loss as well as forgetfulness, lack of focus, and even dementia and Alzheimer’s disease. Research has shown that psychosocial stressors, such as isolation from family and friends or loss of a loved one can also have significant negative effects on sleep architecture and cognitive capabilities. This leaves the elderly in a particularly vulnerable situation: suffering from cognitive decline and sleep dysregulation already, and more likely to respond negatively to psychosocial stressors. Taking all of these factors into account, it’s surprising that little research has been done to elucidate the mechanisms behind aged subjects’ enhanced vulnerability to new onset psychosocial stress. Our lab embarked on a series of studies to test the effects of age and psychosocial stress on sleep architecture and cognition. Our first study measured sleep stages in young adult and aged F344 rats during their resting and active periods. Animals were behaviorally characterized on the Morris water maze and gene expression profiles of their parietal cortices were taken. We confirmed previous studies that found impaired cognition and decreased resting deep sleep with age. However, it was increased active deep sleep that correlated best with poor cognitive performance. In the second study rats were subjected to immobilization (restraint stress) immediately preceding their final water maze task. Hippocampi were prepared for synaptic electrophysiology and trunk blood was taken for corticosterone measurement after post-stress sleep architecture data was collected. Young subjects responded to acute stress with decreased cognition, elevated CORT levels and altered sleep architecture. In contrast, stressed aged subjects were statistically indistinguishable from control aged subjects, suggesting that aged rats are less responsive to an acute psychosocial stress event. Together, these studies suggest that alleviating sleep dysregulation could therapeutically benefit cognition psychosocial stress resilience.

Environmental exposures causing ingestions of toxic chemicals, such as the polycyclic aromatic hydrocarbon 2-aminoanthracene (2-AA), may increase the risk of developing cancer and other diseases such as diabetes. To understand the mode of action of 2-AA as it relates to diabetogenic processes and pancreatic cancer, 2-AA binding to soluble protein mixtures was investigated using a novel technique called dynamic isoelectric anisotropy ligand binding assay (DIABLA). Twenty four post-weaning 3-4 week old Fischer-344 (F-344) male rats were fed 0 mg/kg (control), 50 mg/kg (low dose), 75 mg/kg (medium dose) and 100 mg/kg (high dose) 2-AA diet for 14 and 28 days. Total proteins extracted from the pancreas and liver were evaluated for their binding potential using DIABLA. This technique utilizes capillary isoelectric focusing and fluorescence anisotropy to separate proteins in their active form as well as evaluate the chemical interactions. Isoelectric point (pI) values for protein binding as well as experimental mass spectra data were determined. Investigation of 2-AA binding through screening a complex mixture of proteins is a step towards understanding the mode of action and the biological activities.

Doctor of Philosophy / Department of Anatomy and Physiology / Michael J. Kenney / It is well established that normal aging is associated with progressive increases in efferent sympathetic nerve discharge (SND). Type II diabetes, obesity, heart failure, and hypertension are pathologies that have been attributed to both the processes of aging and sympathetic dysfunction, exemplifying the importance of understanding central regulation of SND during aging. However, the central mechanisms mediating altered SND with advancing age remain unclear. The rostral ventral lateral medulla (RVLM) is a brainstem region critically involved in setting the basal level of sympathetic outflow and cardiovascular function. Indeed, the RVLM is the only presympathetic region that when bilaterally inactivated results in profound reductions in both SND and arterial pressure. Glutamatergic influences in RVLM activity are powerfully inhibited by tonic GABAergic neural inputs originating from the caudal ventral lateral medulla (CVLM); effects that are mediated by GABAA receptors located on presympathetic neuronal cell bodies within the RVLM. In the present study we proposed that reductions in GABA[subscript A] receptor subunit gene expression may reflect withdrawal of GABAergic tone in the RVLM thereby contributing to the basal sympathetic activation that occurs with advancing age. Therefore, the objective of the current study was to identify age-related changes in the constitutive expression of genes related to GABAergic and muscarinic, nicotinic and dopaminergic receptor systems due to their reported involvement in modulating GABA[subscript A] receptor function, in the RVLM of adult young (3-5 mo. old), middle-aged (12 mo. old), weight stable presenescent (24-25 mo. old) and senescent (>24 mo. old) Fischer 344 (F344) rats using a commercially available real-time PCR array. Real-time analysis revealed nonuniform and age-associated changes in the RVLM GABA, muscarinic, nicotinic and dopaminergic neurotransmitter gene expression profile between young and middle-aged F344 rats. Heterogeneous expression of genes related to these neurotransmitters was also observed between presenescent and senescent F344 rats. Our results suggest that potential changes in neurotransmitter synthesis and degradation, uptake, transport, signaling and receptor subunit composition may account for the sympathoexcitatory state that is commonly observed in the aged.

Obesity is a worldwide problem affecting both children and adults. Genetic, physiological, environmental, psychological, social and economic factors interact in varying degrees, influencing body weight and fat distribution and the progress of obesity. Moreover, some anthropogenic chemicals have proven to be endocrine disrupting chemicals (EDCs) with the potential to interfere with different actions of hormones in the body. EDCs may thereby disrupt homeostasis, modifying developmental, behavioral and immune functions in humans and animals, and also promoting adiposity. Because hormones generally act at low concentrations, small changes in the endocrine system may lead to extensive effects. Based on data from experimental and epidemiological studies this thesis elucidates the relationship between a large number of environmental contaminants and obesity. The experimental studies demonstrated that fructose supplementation in the drinking water resulted in unfavorable metabolic alterations such as a higher liver somatic index (LSI), an increase in plasma triglycerides and increased plasma levels of apo A-I. Fructose in combination with exposure to bisphenol A (BPA) increased liver fat content and plasma levels of apo A-I in juvenile female Fischer 344 rats. The experimental studies also showed that the retro-peritoneal fat, which in rats is a distinct fat depot easy to distinguish and dissect, correlated well with the measurements of total fat mass analyzed with MRI, and could therefore be used as a substitute for total fat mass in rats. The epidemiological studies showed that circulating levels of persistent organic pollutants (POPs) were related to fat mass measured by DXA. OCDD, HCB, TNC, DDE and the less chlorinated PCBs were positively related to fat mass, while the more highly chlorinated PCBs showed a negative association. Further, circulating levels of BPA were positively associated with levels of the hormones adiponectin and leptin, but negatively related with ghrelin, hormones which are involved in the regulation of hunger and satiety. However, serum BPA levels were not related to measures of fat mass in the elderly individuals in the PIVUS cohort. This thesis concludes that environmental contaminants such as BPA and POPs most likely are contributors, along with genetic, social and behavioral factors, to the development of obesity.

Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2017-10-03T13:27:09Z No. of bitstreams: 1 MARIA_NOEL__MARZANO_RODRIGUES_PETRUZZI_TES.pdf: 3641098 bytes, checksum: 3aa8ce331659fd0a8d765be0dc6f3d45 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-10-04T12:34:26Z (GMT) No. of bitstreams: 1 MARIA_NOEL__MARZANO_RODRIGUES_PETRUZZI_TES.pdf: 3641098 bytes, checksum: 3aa8ce331659fd0a8d765be0dc6f3d45 (MD5) / Made available in DSpace on 2017-10-04T12:36:41Z (GMT). No. of bitstreams: 1 MARIA_NOEL__MARZANO_RODRIGUES_PETRUZZI_TES.pdf: 3641098 bytes, checksum: 3aa8ce331659fd0a8d765be0dc6f3d45 (MD5) Previous issue date: 2017-06-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A late diagnosis of oral squamous cell carcinoma is related to high morbidity and mortality rates, as well as recurrence after treatment. Hence, there is an increasing interest in the validation of biological markers, chemoprevention strategies, and adjuvant treatment alternatives for combating oral cancer. The present Thesis evaluated the anticancer effect of cannabidiol (CBD) in a validated experimental murine model of oral carcinogenesis. Fifteen Fischer 344 rats were randomly divided into three groups of five animals each and subjected to a 7,12-dimethylbenzanthracene (DMBA) topical application on the ventral mucosa of their tongues, thrice a week. From the 2nd to the 12th week, they received intraperitoneally-administered vehicle (group 1), CBD 5 mg/kg (group 2), or CBD 10 mg/kg (group 3). After euthanasia, the tongues were dissected, processed and assessed by histological and immunohistochemical analysis. Group 2 and group 3 showed inhibition of severe oral epithelial dysplasia and carcinoma, and exhibited lower cell proliferation as compared to group 1. The null hypothesis was rejected when results showed statistical significance at a 0.05 level (confidence interval = 95%). In sequence are presented three manuscripts, first one regarding the original experiment and the two subsequent ones providing overall theoretical support. / O diagn?stico tardio do carcinoma espinocelular oral est? relacionado a um alto ?ndice de morbi-mortalidade e recorr?ncia ap?s o tratamento. Portanto, h? um crescente interesse na valida??o de marcadores biol?gicos que contribuam para o diagn?stico precoce, novas estrat?gias de quimiopreven??o e recursos adjuvantes para o tratamento dessa neoplasia maligna. A presente Tese centrou-se na avalia??o do efeito anticarcinog?nico do canabidiol (CBD) em um modelo experimental consagrado para a indu??o de altera??es epiteliais, com risco de malignidade, na mucosa oral de murinos. Para tanto, 15 ratos Fischer 344 foram aleatoriamente divididos em tr?s grupos, onde todos os animais tiveram o ventre de suas l?nguas expostas ao 7,12-dimetilbenzantraceno (DMBA) tr?s vezes por semana. A partir da segunda semana os grupos receberam por via intraperitoneal, ve?culo (grupo 1), 5 mg/Kg ou 10 mg/Kg de CBD (grupos 2 e 3, respectivamente). Na d?cima segunda semana ap?s o in?cio do experimento realizou-se a eutan?sia dos animais, dissec??o das l?nguas e processamento dos esp?cimes. As an?lises foram realizadas por meio das t?cnicas histol?gicas de rotina e imunoistoqu?mica. Observou-se a inibi??o do desenvolvimento de displasia oral severa e carcinoma, bem como a modula??o dos ?ndices de prolifera??o celular nos grupos 2 e 3 em rela??o ao grupo 1. A hip?tese nula p?de ser rejeitada, uma vez que os resultados obtidos apresentaram n?vel de signific?ncia de 0,05 (intervalo de confian?a = 95%). A seguir, apresentam-se tr?s artigos cient?ficos que descrevem primeiramente o experimento original desenvolvido e, em sequ?ncia, as revis?es da literatura para subsidiar a discuss?o do tema proposto.

Stress reaction is usually activated by the brain, when homeostasis is or perceived to be threatened. The stress signals are transmitted from the brain by two main branches; the sympathoadrenomedullary and the hypothalamo-pituitary-adrenal (HPA) axes and employ neural, humoral and immune pathways to cope with the stressor. Because of its potency, the stress reaction has to be precisely regulated. The HPA axis is regulated by feedback loops where its end product, corticosterone in laboratory rat and mouse, inhibits its activity. The effect of corticosterone does not depend only on the concentration of corticosterone but also on local metabolism of glucocorticoids via oxo-reduction catalyzed by the enzyme 11β -hydroxysteroid dehydrogenase 1 (encoded by the Hsd11b1 gene), which intracellularly regenerates active corticosterone from inactive 11-dehydrocorticosterone, or by extra-adrenal de novo steroidogenesis of glucocorticoids. We focused on analysis of stress response in experimental animals differing in HPA axis responsivity (Fischer 344 rats (F344) vs. Lewis rats (LEW) and germ-free (GF) vs. specific pathogen free mice (SPF)) with special emphasis on regulation of stress response, glucocorticoid regeneration and influence of gut microbiota. We found that stress modulated local regeneration of...