abstract: The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption. / Dissertation/Thesis / M.A. Psychology 2012

<div>While cognitive control enables the selection of goal-relevant responses, metacontrol enables the selection of context-appropriate control operations. In task switching, metacontrol modulates task-switching efficiency by retrieving the associations between a contextual cue and a particular cognitive control demand. While the automatic retrieval of cognitive control is appealing due to its time and energy efficiency, the effects of different contextual cues have been shown in separate studies and appear to have different characteristics. Here, we devised a single task-switching paradigm to test whether we can observe both list-wide and item-specific metacontrol within subjects. In two experiments, we demonstrated reduced switch costs in lists associated with a high probability of switching as compared with lists with a low probability of switching (i.e., a list-wide switch probability [LWSP] effect). Similarly, we observed an analogous item-specific switch probability (ISSP) effect such that items associated with a high probability of switching incurred smaller switch costs as compared with items associated with a low probability of switching. We also confirmed that both list-wide and item-specific switch probability effects were not dependent on lower-level stimulus-response associations. However, the LWSP and the ISSP effects were uncorrelated, suggesting a lack of dependence. Together, these findings suggest that there are two distinct modes of metacontrol that are deployed in a context-sensitive manner in order to adapt to specific cognitive demands.</div>

<p>Evidence from experimental models of epilepsy support that prolonged seizures (status epilepticus, SE) promote pathological hippocampal synaptodendritic remodeling which contributes to the development of seizures and cognitive decline. One potential mechanism underlying the SE-induced sequelae is microgliosis. </p> <p>Evidence from models of experimental epilepsy supports a significant spatiotemporal correlation between SE-induced decreases in the microtubule associated protein 2 (Map2) loss and microgliosis in the hippocampus. In addition, pharmacological suppression of microgliosis after SE with the drug rapamycin attenuated the losses of Map2 and the dendritic ion channels Kv.4.2 and HCN1 in the hippocampus. This microglia suppression paralleled a recovery of the SE-induced recognition and spatial memory deficits. Based on these studies, we hypothesized that the inhibition of microgliosis during epileptogenesis will attenuate the SE-induced hippocampal dendritic and cognitive pathology. To further investigate the role of microgliosis in the SE-induced dendritic pathology, we tested the efficacy of a more selective inhibitor <a>of the survival and proliferation of </a>microglia, PLX3397, using the pilocarpine model of SE and acquired epilepsy. PLX3397 binds to colony stimulating factor 1 receptor (CSF1R) on microglia and inhibits the downstream signaling responsible for survival and proliferation of these cells. </p> <p>To test this hypothesis, we induced SE in male rats with pilocarpine (280-300mg/kg) <a>while and controls (Ctrl) received saline. </a>Rats were randomly assigned to a diet of either chow alone (vehicle; Veh) or chow with PLX3397 (50mg/kg) for 20 days post-SE. At two weeks post-SE, rats were subjected to novel object recognition (NOR) and Barnes maze (BM) to evaluate hippocampal-dependent recognition memory, and spatial learning and memory, respectively. Following the behavioral assessments, rats were sacrificed for brain analysis at 20 days post-SE. We used histological analysis to determine the amount of microgliosis with IBA1 and dendritic stability with Map2. We used western blotting to measure the protein levels of molecules involved in the crosstalk between microglia and astrocytes: GFAP, IL-6, C3, and iC3b. We also measured the protein levels of the dendritic ion channels Kv4.2 and HCN1, and the synaptic marker PSD95.</p> <p>NOR showed that the Ctrl+Veh and Ctrl+PLX3397 groups spent significantly more time exploring the novel object (<i>p</i> < .05), while the SE+Veh and SE+PLX3397 did not. Similar results were observed in the BM test, Ctrl+Veh and Ctrl+PLX3397 groups had a faster latency to find the target compared to the SE+Veh and SE+PLX3397 groups (<i>p</i> < .05). These data suggest that recognition and spatial memory deficits induced by SE were not attenuated by treatment with PLX3397. We found that the PLX3397 treatment significantly decreased microgliosis in Ctrl+PLX3397 rats compared to Ctrl+Veh rats (<i>p</i> < .05). As expected, we found a significant increase in the number of microglial cells in hippocampi of SE+Veh rats compared to Ctrl+Veh rats (<i>p</i> < .05). Interestingly, in the PLX3397-treated SE group, we observed two distinctive groups which we categorized as responders and non-responders when compared to the SE+Veh group. The SE+PLX responders had significantly decreased microgliosis compared to the SE+Veh group (<i>p</i> < .05). The SE+PLX non-responders had higher levels of microgliosis compared to the SE+Veh group (<i>p</i> < .05). We found levels of GFAP were increased in the SE+Veh group compared to the Ctrl+Veh group (<i>p</i> < .05). Treatment with PLX3397 in the SE group reduced these levels compared to the vehicle treated SE group (<i>p</i> < .05). We also found increases in C3 and iC3b following the induction of SE compared to Ctrl+Veh group (<i>p</i> < .05), and these levels remained similar in the SE+PLX3397 group compare to the SE+Veh group (<i>p</i> > .05). There was a reduction in Map2 immunoreactivity as well as the protein levels of Kv4.2 and PSD95 in the SE+Veh group compared to the Ctrl+Veh group (<i>p</i> < .05). We found that treatment with PLX3397 recovered the SE-induced loss of Map2 labeled dendrites compared to SE+Veh group (<i>p</i> < .05). However, treatment with PLX3397 did not recover the SE-induced reduction Kv4.2 and PSD95 (<i>p</i> > .05). <a>In parallel, we found that a group of SE+PLX3397 animals did not have reduced microgliosis compared to the SE+Veh group (<i>p </i>< .05), and therefore was categorized as a non-responder group. </a></p> Our findings are the first to show that blocking CSF1R signaling with PLX3397 suppressed microgliosis in the hippocampus, partially recovered the SE-induced decline of Map2 immunoreactivity in the hippocampal CA1 region but had no effect in the recognition or spatial memory deficits. These data suggest that while hippocampal microgliosis may play a role in the disruption of dendritic structural stability in the hippocampus it does not seem to critically contribute to the memory decline that occurs during epileptogenesis.

Concussions are the injury and symptoms that can result from transmission of a biomechanical force to the brain. They represent a significant global health burden, and are the subject of a growing body of medical research. A concussion can only be definitively diagnosed by a medical professional based on symptoms, although advanced neuroimaging and biomarker-based approaches are promising future diagnostic tools. There is no treatment for concussion beyond following return-to-work or -play guidelines, which recommend avoiding strenuous physical and cognitive activities until they no longer exacerbate symptoms. Preclinical models of concussion have been used to examine pathophysiological processes underlying symptoms, which is an important step in developing tools for diagnosis and treatment. Historically the clinical translation of preclinical concussion research has been limited, and the use of anaesthesia, and preference for adult male rats may contribute to this. These means of reducing variability are justified, but preclinical research moving forward should address these limitations to translatability by including more clinically relevant subjects and avoiding anaesthesia. To this end, we developed a new preclinical model for pediatric concussion. Our awake closed head injury (ACHI) model is well-suited to this purpose because it produces a helmeted closed-head injury involving vertical and rotational displacement of the head, and does not require anaesthesia. Before the ACHI model can be used to investigate concussion mechanism, diagnosis, and treatment, it needs to be characterized to demonstrate that it produces clinically relevant neurobehavioral and pathological changes. We developed a modified neurologic assessment protocol to test neurologic function immediately after each injury. The Barnes maze, elevated plus maze, open field, and Rotarod were used to measure injury-related changes in cognition, anxiety, and motor function. The Barnes maze reversal task was used to detect more subtle cognitive impairments of executive function. Structural MRI was used to search for visible lesion, hemorrhage, or atrophy; and silver-stain histology was used to detect neurodegeneration. We determined repeated ACHI produced acute neurologic impairment with the NAP, and a mild spatial learning deficit potentially mediated impaired cognitive flexibility in the Barnes maze and reversal training. These were accompanied by neurodegeneration in the optic tract, hippocampus, and ipsilateral cortex during the first week of recovery. Thus, following the internationally recognised definition developed by the concussion in sport group, we demonstrated 1) an “impulsive” force transmitted to the head results in 2) the rapid onset of short-lived neurologic impairment that resolves spontaneously. This occurs 3) with normal structural neuroimaging, and 4) produces cognitive impairment, and LOC in a subset of cases. The ACHI model is the first in Canada to forego anaesthesia, and this is the first demonstration of neurocognitive impairment accompanied by diffuse neurodegeneration in the absence of structural MRI abnormalities after mild traumatic brain injury in juvenile male and female rats. / Graduate

No description available.

<p>  </p> <p>Posttraumatic stress disorder involves a constellation of neural and behavioral alterations in response to trauma exposure. Aside from symptoms involved in posttraumatic stress disorder diagnosis, patients frequently present with working memory impairments. Working memory training has been established as an effective intervention to reduce posttraumatic stress symptoms. Working memory is associated with posttraumatic stress disorder in that it is commonly impaired in patients and that training can reduce the severity of posttraumatic stress symptoms. Taken together, these points suggest the possibility of a shared mechanism between working memory and posttraumatic stress disorder but working memory has not been studied thoroughly in rodent models of posttraumatic stress disorder. The present study utilizes footshock trauma to induce a posttraumatic stress state in rats and evaluates the effect of trauma and trauma-paired cues on working memory performance. Results demonstrate the emergence of chronic deficits in working memory among traumatized animals three weeks post-trauma. Presentation of trauma-paired cues caused further decrement in working memory performance. Regression analysis indicates that the degree of working memory impairment in response to a trauma-paired cue can be significantly predicted by behavioral phenotypes typic of diagnostic symptoms for posttraumatic stress disorder. This study enhances existing animal models by replicating the clinical observations of working memory deficits associated with posttraumatic stress disorder. This will pave the way for future work to probe underlying mechanistic dysregulation of working memory following trauma exposure and for future development of novel treatment strategies. </p>

<p dir="ltr">Activity-based anorexia (ABA) is a rodent model of anorexia nervosa (AN) that induces several key components of AN, including voluntary reduction in food intake, reduced body weight, hyperactivity, and alterations to the hypothalamic-pituitary-adrenal (HPA) axis. Experiencing ABA during adolescence also effects behavior in social contexts, including contributing to the development of social avoidance even after cessation of exposure to the paradigm and restoration of weight lost during ABA. We used the social partition (SPT), novelty suppressed feeding (NSF), marble burying, and elevated plus maze (EPM) tests to determine the effects of two bouts of adolescent ABA on anxiety-like behavior in weight restored young adult female rats. One-way ANOVA analyses showed that two bouts of adolescent ABA contribute to prolonged increases in general and social avoidance in young adult female rats compared with control rats. To explain our behavioral findings, we next explored the effects of two bouts of adolescent ABA on glial fibrillary acidic protein (GFAP) and corticotropin-releasing hormone receptor 1 (CRFR1) expression in the oval bed nucleus of the stria terminalis (_ovBNST), a brain region involved in anxiety and social behavior. While previous research shows that two bouts of adolescent ABA contribute to HPA axis hyperactivation and _ovBNST inflammation following weight restoration from adolescent ABA, our one-way ANOVA analyses showed no significant differences in GFAP or CRFR1 expression in the _ovBNST across groups. Finally, to explore whether adolescent AN symptoms can predict anxiety in young adult women, we had female university students complete retrospective surveys of adolescent food restriction, eating disorder symptoms (EDEQ), and physical activity, as well as retrospective surveys of worry, behavioral inhibition, childhood adversity, and parental style. Using these variables, we created four adolescent predictor models: 1 (EDEQ; physical activity), 2 (restrictive eating; physical activity), 3 (EDEQ; physical activity; worry; behavioral inhibition; childhood adversity; and parental style), and 4 (restrictive eating; physical activity; worry; behavioral inhibition; childhood adversity; and parental style), which we regressed onto participants’ current generalized anxiety, fear of food, social avoidance, obsessions, compulsions, social physique anxiety, compulsive physical activity, and perceived stress scores. Regressing each predictor model onto these variables revealed that predictor model 1 better predicted and accounted for more variance in all anxiety types compared with predictor model 2. Moreover, predictor model 1 accounted for the most variance in fear of food and social physique anxiety compared with all anxiety types. Finally, predictor models 3 and 4 explained the most additional variance in generalized anxiety and social avoidance compared with all anxiety types. Cumulatively, our data suggest that, while adolescent eating disorder signs and symptoms predict several anxiety types in female university students, the effects of two bouts of ABA during adolescence on anxiety-like behavior in weight restored female rats is limited to specific anxiety-provoking stimuli.</p>

No description available.

Uma das principais doenças degenerativas, conhecida internacionalmente pelo nome de osteoartrite (OA), é uma condição patológica crônica e prevalente que traz prejuízos sociais, psicológicos e financeiros a 10% da população em geral e a mais de 50% dos idosos. Acima dos 75 anos de idade aproximadamente 85% dos idosos são acometidos por essa doença. A população no Brasil envelhece rápido, envelhecerá em 30 anos tanto quanto a Europa envelheceu em 200 anos. Assim, novas técnicas para o tratamento da OA de joelho são muito relevantes. Este trabalho teve por objetivo estudar os efeitos de uma Terapia Combinada (TC) sobre o comportamento de ratos submetidos a um modelo experimental de osteoartrite de joelho. Ratos Wistar machos e adultos foram submetidos à lesão do joelho direito pela injeção intra-articular de iodoacetato monosódico (IM). Quinze dias após a lesão foram aplicados 3 tratamentos por 14 dias: Laserterapia de Baixa Potência (LBP), Estimulação Elétrica Artificial (EEA) e TC (i.e., LBP + EEA). Foram observados os efeitos agudos e crônicos destes tratamentos sobre o comportamento dos animais em 3 testes comportamentais: campo aberto, analgesímetro e descarga de peso. Os principais resultados do presente estudo indicam que (i) o modelo experimental de OA de joelho proposto foi induzido com sucesso e resultou em déficits agudos e crônicos ao longo de 30 dias de experimento; (ii) o tratamento com LBP resultou em diminuição dos déficits devido à hiperalgesia primária e secundária à lesão, porém não teve impacto sobre a funcionalidade geral do sistema de movimento dos animais; (iii) o treinamento com EEA resultou em diminuição dos déficits de hiperalgesia primária e teve impacto sobre a funcionalidade geral do sistema de movimento e (iv) a TC resultou em diminuição dos déficits de hiperalgesia primária e efeito moderado sobre a hiperalgesia secundária, além de impacto positivo sobre a funcionalidade geral do sistema de movimento. Com base nestes resultados, a TC apresentou efeitos benéficos tanto sobre o controle da dor, quanto para a menor incapacitação e melhor funcionalidade, sendo indicada para combater os efeitos deletérios da OA de joelho sobre o sistema de movimento. / A major degenerative disease, internationally known as osteoarthritis (OA) is a prevalent and chronic pathological condition which results in social, psychological and financial impairments to 10% of the general population and to over 50% of the elderly. Above 75 years of age approximately 85% of the elderly are affected by this disease. In Brazil there is a fast ageing of population who will age during 30 years as much as Europe aged in 200 years. Thus, new techniques for the treatment of knee OA are very relevant. This work aimed to study the effects of a combined therapy (TC) on the behavior of rats submitted to an experimental model of knee osteoarthritis. Male adult Wistar rats underwent right knee injury by intra-articular injection of monosodium iodoacetate (IM). Fifteen days after injury received 3 treatments for 14 days: Low Power Laser Therapy (LBP), Artificial Electrical Stimulation (EEA) and TC (i.e., LBP + EEA). We observed the acute and chronic effects of these treatments on the behavior of animals in 3 behavioral tests: open field, analgesymeter and weight bearing. The main results of this study indicate that (i) the proposed experimental model of knee OA was successfully induced and resulted in acute and chronic deficits over 30 days of experiment, (ii) treatment with LBP resulted in reduction of deficits due to primary and secondary hyperalgesia to the lesion, but had no impact on the overall functionality of the movement system, (iii) the training with EEA resulted in decreased deficits of primary hyperalgesia and impacted the overall functionality of the movement system (iv) the TC resulted in reduction of deficits due to primary hyperalgesia and moderate effect on secondary hyperalgesia, and positive impact on the overall functionality of the movement system. Based on these results, the TC showed beneficial effects on pain control and on less disability and better functionality, thus TC is indicated to combat the deleterious effects of knee OA on the motion system.

Uma das principais doenças degenerativas, conhecida internacionalmente pelo nome de osteoartrite (OA), é uma condição patológica crônica e prevalente que traz prejuízos sociais, psicológicos e financeiros a 10% da população em geral e a mais de 50% dos idosos. Acima dos 75 anos de idade aproximadamente 85% dos idosos são acometidos por essa doença. A população no Brasil envelhece rápido, envelhecerá em 30 anos tanto quanto a Europa envelheceu em 200 anos. Assim, novas técnicas para o tratamento da OA de joelho são muito relevantes. Este trabalho teve por objetivo estudar os efeitos de uma Terapia Combinada (TC) sobre o comportamento de ratos submetidos a um modelo experimental de osteoartrite de joelho. Ratos Wistar machos e adultos foram submetidos à lesão do joelho direito pela injeção intra-articular de iodoacetato monosódico (IM). Quinze dias após a lesão foram aplicados 3 tratamentos por 14 dias: Laserterapia de Baixa Potência (LBP), Estimulação Elétrica Artificial (EEA) e TC (i.e., LBP + EEA). Foram observados os efeitos agudos e crônicos destes tratamentos sobre o comportamento dos animais em 3 testes comportamentais: campo aberto, analgesímetro e descarga de peso. Os principais resultados do presente estudo indicam que (i) o modelo experimental de OA de joelho proposto foi induzido com sucesso e resultou em déficits agudos e crônicos ao longo de 30 dias de experimento; (ii) o tratamento com LBP resultou em diminuição dos déficits devido à hiperalgesia primária e secundária à lesão, porém não teve impacto sobre a funcionalidade geral do sistema de movimento dos animais; (iii) o treinamento com EEA resultou em diminuição dos déficits de hiperalgesia primária e teve impacto sobre a funcionalidade geral do sistema de movimento e (iv) a TC resultou em diminuição dos déficits de hiperalgesia primária e efeito moderado sobre a hiperalgesia secundária, além de impacto positivo sobre a funcionalidade geral do sistema de movimento. Com base nestes resultados, a TC apresentou efeitos benéficos tanto sobre o controle da dor, quanto para a menor incapacitação e melhor funcionalidade, sendo indicada para combater os efeitos deletérios da OA de joelho sobre o sistema de movimento. / A major degenerative disease, internationally known as osteoarthritis (OA) is a prevalent and chronic pathological condition which results in social, psychological and financial impairments to 10% of the general population and to over 50% of the elderly. Above 75 years of age approximately 85% of the elderly are affected by this disease. In Brazil there is a fast ageing of population who will age during 30 years as much as Europe aged in 200 years. Thus, new techniques for the treatment of knee OA are very relevant. This work aimed to study the effects of a combined therapy (TC) on the behavior of rats submitted to an experimental model of knee osteoarthritis. Male adult Wistar rats underwent right knee injury by intra-articular injection of monosodium iodoacetate (IM). Fifteen days after injury received 3 treatments for 14 days: Low Power Laser Therapy (LBP), Artificial Electrical Stimulation (EEA) and TC (i.e., LBP + EEA). We observed the acute and chronic effects of these treatments on the behavior of animals in 3 behavioral tests: open field, analgesymeter and weight bearing. The main results of this study indicate that (i) the proposed experimental model of knee OA was successfully induced and resulted in acute and chronic deficits over 30 days of experiment, (ii) treatment with LBP resulted in reduction of deficits due to primary and secondary hyperalgesia to the lesion, but had no impact on the overall functionality of the movement system, (iii) the training with EEA resulted in decreased deficits of primary hyperalgesia and impacted the overall functionality of the movement system (iv) the TC resulted in reduction of deficits due to primary hyperalgesia and moderate effect on secondary hyperalgesia, and positive impact on the overall functionality of the movement system. Based on these results, the TC showed beneficial effects on pain control and on less disability and better functionality, thus TC is indicated to combat the deleterious effects of knee OA on the motion system.