Matching Items (31)

Acute tau knockdown in the hippocampus of adult mice causes learning and memory deficits

Description

To date, it has been difficult to elucidate the role of tau in learning and memory during adulthood due to developmental compensation of other microtubule associated proteins in Tau knockout

To date, it has been difficult to elucidate the role of tau in learning and memory during adulthood due to developmental compensation of other microtubule associated proteins in Tau knockout (KO) mice. Here, we generated an adeno-associated virus (AAV) expressing a doxycycline (doxy)-inducible short-hairpin (sh) RNA targeted to tau, and stereotaxically and bilaterally injected 7-month-old C57BL/6 mice with either the AAV-shRNAtau or an AAV expressing a scramble shRNA sequence. Seven days after the injections, all animals were administered doxy for thirty-five days to induce expression of shRNAs, after which they were tested in the open field, rotarod and Morris water maze (MWM) to assess anxiety like behavior, motor coordination and spatial reference memory, respectively. Our results show that reducing tau in the adult hippocampus produces significant impairments in motor coordination, endurance and spatial memory. Tissue analyses shows that tau knockdown reduces hippocampal dendritic spine density and the levels of BDNF and synaptophysin, two proteins involved in memory formation and plasticity. Our approach circumvents the developmental compensation issues observed in Tau KO models and shows that reducing tau levels during adulthood impairs cognition.

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Date Created
  • 2018-05

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Analysis of Egg-Laying Rates of Harpegnathos Saltator Through Different Methods of Observation

Description

Insects have intricate systems they depend on for survival. They live in societies where every individual plays an important role. Ants are a great example of this observation. They are

Insects have intricate systems they depend on for survival. They live in societies where every individual plays an important role. Ants are a great example of this observation. They are known for having structurally sound societies that ensure the livelihood of the colony. The ant species analyzed for this research, Harpegnathos saltator, portrays a structured colony and serves as a useful example of levels of hierarchy. In the colony of H. saltator, one can find a queen, gamergates, workers, and male ants living underground in Southern India. Recording and analyzing egg-laying rates are important in this study because of the amount of information it provides. It is used especially when observing the relationship among the gamergates in colonies with varying colony sizes. Three different methods were used to record the egg-laying rates, each providing insight into valuable information. Results show that the smaller colonies with fewer identified gamergates do share an equal amount of egg-laying. In larger colonies, it appears that there are more active identified gamergates than others. Egg-laying duration times are smaller in colonies with fewer gamergates. It is also found that the presence of brood does not affect egg-laying rates and reproductive inhibition could be a possibility based on two of the colonies observed F65 and F21. Based on the data found, a more active colony that attempts to maintain stability by demonstrating aggression may be affecting the reproduction of gamergates. Future work that would further strengthen the research and conclusions made would involve further observation of colonies, both large and small, with varying numbers of gamergates. More observation involving behavior among gamergates and workers would also be beneficial. Mathematical modeling could also be incorporated to create equations that could determine information about colonies based on size, number of gamergates, and egg-laying rates.

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Date Created
  • 2017-12

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Discrepancies in the Morris water maze versus the IntelliCage in the APP/PS1 mouse model of Alzheimer’s disease; a sex-based examination

Description

Dementia is a collective term used to describe symptoms of cognitive impairment in learning and memory. The most prevalent form of dementia is Alzheimer’s disease (AD). In order to understand

Dementia is a collective term used to describe symptoms of cognitive impairment in learning and memory. The most prevalent form of dementia is Alzheimer’s disease (AD). In order to understand the pathological mechanisms associated with AD, animal models have been created. These various mouse models replicate the pathology found in humans with AD. As a consequence of the fact that this disease impairs cognitive abilities in humans, testing apparatuses have been developed to measure impaired cognition in animal models. One of the most common behavioral apparatuses that has been in use for nearly 40 years is the Morris water maze (MWM). In the MWM, animals are tasked to find a hidden platform in a pool of water and thereby are subjected to stress that can unpredictably influence cognitive performance. In an attempt to circumvent such issues, the IntelliCage was designed to remove the external stress of the human experimenter and provide a social environment during task assessment which is fully automated and programable. Additionally, the motivation is water consumption, which is less stressful than escaping a pool. This study examined the difference in performance of male and female cohorts of APP/PS1 and non-transgenic (NonTg) mice in both the MWM and the IntelliCage. Initially, 12-month-old male and female APP/PS1 and NonTg mice were tested in the hippocampal-dependent MWM maze for five days. Next, animals were moved to the IntelliCage and underwent 39 days of testing to assess prefrontal cortical and hippocampal function. The results of this experiment showed significant sex differences in task performance, but inconsistency between the two testing paradigms. Notably, males performed significantly better in the MWM, which is consistent with prior research. Interestingly however, APP/PS1 females showed higher Amyloid-β plaque load and performed significantly better in the more complex tasks of the IntelliCage. This suggests that Aβ plaque load may not directly contribute to cognitive deficits, which is consistent with recent reports in humans with AD. Collectively, these results should inform scientists about the caveats of behavioral paradigms and will aid in determining translation to the human condition.

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Created

Date Created
  • 2020-05

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A Virtual Sholl Analysis of the Neuronal Morphological Impact of Stress in Rats

Description

Stress activates physiological systems within the body to protect oneself against the potential harmful effects of enduring long-term stress. Past studies have shown that structures involved in timing are implicated

Stress activates physiological systems within the body to protect oneself against the potential harmful effects of enduring long-term stress. Past studies have shown that structures involved in timing are implicated in a number of psychological disorders and further are sensitive to stress. In this experiment, Sprague Dawley rats are trained to perform a perspective timing task and are then exposed to twice-daily chronic variable stress for 21 days. Behavioral data are collected, followed by post-mortem tissue analysis of the PFC, hippocampus, and striatum. This study aims to examine the morphological changes in key brain regions such as the hippocampus that appear to be involved in interval timing. Additionally, this study aims to confirm that dendritic complexity in the hippocampus produces consistent data using a classic Sholl analysis versus using a virtual image-stacking software, Neurostackr. The results of this study demonstrate that the expected Gaussian graph produced from a classic Sholl analysis was produced from both a long-shaft and short-shaft neuron found in the hippocampus using the virtual technology. These findings verify that a virtual image-stacking software and Sholl analysis will suffice in place of the traditional method of hand traced neurons on a transparent sheet with concentric circles to count bifurcation points. This virtual method ultimately reduces cost, improves timeliness of data collection, and eliminates some of the subjectivity of human error.

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Date Created
  • 2020-05

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The Effects of Extreme Urban Heat on Behavioral Syndromes of Juvenile Black Widow Spiders, Latrodectus hesperus

Description

Urbanization rapidly alters the environment, leading to a decrease in biodiversity in urban areas. A challenge associated with urbanized areas is the increased heat caused by the urban heat island

Urbanization rapidly alters the environment, leading to a decrease in biodiversity in urban areas. A challenge associated with urbanized areas is the increased heat caused by the urban heat island effect. Heat may have an important impact on arthropods particularly due to their status as ectotherms. Animal behavior reveals how individuals interact with their environment. A behavioral syndrome describes consistent individual differences in behaviors that are correlated across different behavioral contexts or situations. Understanding the Western Black Widow's behavioral responses to the urban heat island effect has important implications for the control of a pest species. In this study, the relationship between rising urban temperatures and voracity, web-building, and cannibalism behaviors of juvenile Western Black Widows was examined. Spiders raised in the urban temperature treatment were predicted to have more aggressive behavioral syndromes, characterized by shorter latencies to forage, greater web-building activity, and shorter latencies to cannibalize as compared to spiders raised in rural or intermediate temperature treatments. A correlation between the latency to attack the first fly and second fly was found, however there were no other correlations evidencing a behavioral syndrome. Temperature was found to affect foraging, web-building, and cannibalism behaviors where spiders in urban areas demonstrated increased activity in all behavioral contexts. The possession of behavioral plasticity rather than a behavioral syndrome is likely what allows Black Widows to be successful urban pests.

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Date Created
  • 2018-05

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Behavioral Basis of Sensorimotor Control and Learning

Description

Motor learning is the process of improving task execution according to some measure of performance. This can be divided into skill learning, a model-free process, and adaptation, a model-based process.

Motor learning is the process of improving task execution according to some measure of performance. This can be divided into skill learning, a model-free process, and adaptation, a model-based process. Prior studies have indicated that adaptation results from two complementary learning systems with parallel organization. This report attempted to answer the question of whether a similar interaction leads to savings, a model-free process that is described as faster relearning when experiencing something familiar. This was tested in a two-week reaching task conducted on a robotic arm capable of perturbing movements. The task was designed so that the two sessions differed in their history of errors. By measuring the change in the learning rate, the savings was determined at various points. The results showed that the history of errors successfully modulated savings. Thus, this supports the notion that the two complementary systems interact to develop savings. Additionally, this report was part of a larger study that will explore the organizational structure of the complementary systems as well as the neural basis of this motor learning.

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Date Created
  • 2021-05

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The role of skill in determining dominance in the virile crayfish, Faxonius virilis

Description

Studies of animal contests often focus solely on a single static measurement of fighting ability, such as the size or the strength of the individual. However, recent studies have highlighted

Studies of animal contests often focus solely on a single static measurement of fighting ability, such as the size or the strength of the individual. However, recent studies have highlighted the importance of individual variation in the dynamic behaviors used during a fight, such as, assessment strategies, decision making, and fine motor control, as being strong predictors of the outcome of aggression. Here, I combined morphological and behavioral data to discover how these features interact during aggressing interactions in male virile crayfish, Faxonius virilis. I predicted that individual variation in behavioral skill for decision making (i.e., number of strikes thrown), would determine the outcome of contest success in addition to morphological measurements (e.g. body size, relative claw size). To evaluate this prediction, I filmed staged territorial interactions between male F. virilis and later analyzed trial behaviors (e.g. strike, pinches, and bout time) and aggressive outcomes. I found very little support for skill to predict win/loss outcome in trials. Instead, I found that larger crayfish engaged in aggression for longer compared to smaller crayfish, but that larger crayfish did not engage in a greater number of claw strikes or pinches when controlling for encounter duration. Future studies should continue to investigate the role of skill, by using finer-scale techniques such as 3D tracking software, which could track advanced measurements (e.g. speed, angle, and movement efficiency). Such studies would provide a more comprehensive understanding of the relative influence of fighting skill technique on territorial contests.

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Date Created
  • 2021-05

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Chemical Cues Impact Zebrafish Response to Visual Cues

Description

Animals encounter information from different resources simultaneously, integrating input from multiple sensory systems before responding behaviorally. When different cues interact with one another, they may enhance, diminish, or have no

Animals encounter information from different resources simultaneously, integrating input from multiple sensory systems before responding behaviorally. When different cues interact with one another, they may enhance, diminish, or have no impact on their responses. In this project, we test how the presence of chemical cues affect the perception of visual cues. Zebrafish (Danio rerio) often use both chemical cues and visual cues to communicate with shoal mates, to assess predation risk, and to locate food. For example, zebrafish rely on both olfactory cues and visual cues for kin recognition, and they frequently use both chemical and visual cues to search for and to capture prey. In zebrafish, the terminal nerve (TN) constitutes the olfacto-visual centrifugal pathway and connects the olfactory bulb with the retina, thus allowing olfactory perception also to activate visual receptors. Past studies have found that the presence of an olfactory cue can modulate visual sensitivity in zebrafish through the terminal nerve pathway. Alternatively, given that zebrafish are highly social, the presence of social chemical cues may distract individuals from responding to other visual cues, such as food and predator visual cues. Foraging and predator chemical cues, including chemical food cues and alarm cues, may also distract individuals from responding to non-essential visual cues. Here, we test whether the response to a visual cue either increases or decreases when presented in concert with alanine, an amino acid that represents the olfactory cues of zebrafish prey. We found that the presence of chemical cues did not affect whether zebrafish responded to visual cues, but that the fish took longer to respond to visual cues when chemical cues were also present. These findings suggest that different aspects of behavior could be affected by the interaction between sensory modalities. We also found that this impact of delayed response was significant only when the visual cue<br/>was weak compared to the strength of the chemical cue, suggesting that the salience of interacting cues may also have an influence on determining the outcomes of the interactions. Overall, the interactive effects of chemicals on an animal’s response to visual cues may also have wide-ranging impacts on behavior including foraging, mating, and evading predators, and the interaction of cues may affect different aspects of the same behavior.

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Date Created
  • 2021-05

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In Andy's Shoes: A Children's Book and Manual on the Expression of Autism Spectrum Disorder

Description

The purpose of this project was to research the expression of Autism Spectrum Disorder in children and create a children’s book that can help the peers of individuals with a

The purpose of this project was to research the expression of Autism Spectrum Disorder in children and create a children’s book that can help the peers of individuals with a diagnosis to understand what the disorder entails and potentially gain a new sense of empathy for peers of all levels of physical and mental abilities. The research component includes interviews with individuals deemed knowledgeable about ASD, including occupational therapists, behavioral analysts, and parents, as well as a literature review of research studies on the expression of Autism in children. This written portion of the project may also serve as a manual for individuals who have little to no knowledge of ASD, as it dives deeper into the content of the book and research, while remaining easily understandable and clear to those without any prior knowledge or experience with ASD. It could prove especially useful for those in professions that come into contact with individuals with Autism, but do not necessarily require psychology courses or training as a prerequisite for the role, such as teachers and some health professionals.

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Date Created
  • 2021-05

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Automobile Idling Reduction Program

Description

Description
By avoiding vehicle idling for three minutes every day of the year can reduce 1.4 million metric tons annually, which is equivalent to taking 320,000 cars off the road

Description
By avoiding vehicle idling for three minutes every day of the year can reduce 1.4 million metric tons annually, which is equivalent to taking 320,000 cars off the road for the entire year (Canada.ca, 2016). The Automobile Idle Reduction Program (AIRP) is an outreach initiative to prevent carbon emissions from being released into the air by automobiles idling in Maricopa County. The initiative establishes a campaign to promote behavioral changes that target high idling industries: freight and delivery, schools and drive- thru facilities.

Background
Globally, carbon emissions negatively alter the air we breathe and is a leading cause in climate change. These problems adversely affect the global environment and human health. Additionally, they have cancer causing agents in the particulate matter. Unfortunately, over the years, Maricopa County has failed to meet air quality standards for particulate matter pollution which effects the health of residents. By not meeting the air quality standards, Maricopa County can receive sanctions and the Environmental Protection Agency can reject Arizona’s State Implementation Plan. This looming threat can financially impinge the economy of Maricopa County, potentially costing taxpayers a substantial increase in taxes.

Strategy and Solution
To battle the creation of carbon emissions and particulate matter, AIRP has developed a strategy for each industry. In partnership with the Maricopa County Air Quality Department, AIRP will introduce the freight and delivery companies to the Diesel Emission Reduction Act (DERA) Grant promotion to facilitate and fiscally assist with changing older diesel engines into higher efficiency engines that burn cleaner. Provide educators a fifth to eighth grade state approved education program to teach students the importance of vehicle idling reduction at no cost. And work with community organizations to offer a discount at their stores for those patrons who choose to turn their engine off and order inside, rather than idling in the drive-thru facilities. The campaign will market the interest of AIRP to the general public through purposefully placed billboards, light rail wraps, social media pushes, handouts and vinyl stickers.

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Date Created
  • 2020-05-13