Alzheimer’s Disease (AD) is a neurodegenerative disease that is characterized by deficits in learning and memory. AD pathology is associated with neuronal death through the accumulation of amyloid beta (Aβ) plaques in the synapses. Our lab has previously demonstrated that Lipopolysaccharide (LPS), a component of gram-negative bacteria, induces an inflammatory response that increases Aβ found in the brain. Dendritic spines are projections on dendrites that may or may not be synapsing with an axon. Previous research indicates that there is a correlation between the number of properly functioning synapses and the number of dendritic spines. In this study, LPS was administered to induce inflammation, stimulating Aβ production. We then quantified dendritic spine density in order to compare dendritic spine density in the hippocampus of both LPS- and saline-treated groups. Contrary to our hypothesis, we saw a non-significant increase in dendritic spine density following LPS treatment, when compared to saline controls.

There has been mounting concern from both scientists and the public regarding the presence and biological effects of emerging contaminants (ECs) in the environment. ECs can be defined as contaminants that are not currently subject to routine monitoring programs or regulatory standards, but that have the potential to cause adverse environmental or human health effects. These pollutants are being found in increasing levels in aquatic environments, and as such, the possible health impacts of these contaminants have become a growing focus of scientific research. Some classes of ECs, especially those that disrupt neurological development or thyroid hormone levels, have the potential to alter the growth, development, and function of the eyes. For many organisms, eyesight is crucial to survival as it allows them to avoid danger, obtain food, and perform many other important activities. However, reliable methods for testing the effects of ECs on vision are scarce, so the full impact of many ECs remains unknown. As such, this project aimed to determine dependable ways to measure visual development and function in the fathead minnow, a small fish frequently used to screen for chemical toxicity and adverse effects. We found that the feeding assay was a straightforward and promising option for measuring vision because it estimated the average prey capture ability of a group in a relatively short amount of time. We also found that the optomotor assay, while compelling, presented no significant differences between groups for the variables tested. However, there were practical differences observed throughout the trials, indicating that although the assay is complex, further testing and development could transform it into a reliable source of data.

Zebra and Quagga mussels are aquatic and highly invasive freshwater bivalve molluscs native to Eurasia. They have spread at an exponential rate into bodies of water throughout the country by means of our interconnected waterway. Prior analysis of their distribution has determined a consistent global pattern in which a population of zebra mussels initially invades a body of water and subsequently, a population of quagga mussels is established in the same region. Despite differential habitat preferences, both species have been found to live and reproduce in the same location. Since both species exhibit broadcast spawning as a reproductive mechanism, the potential for hybridization exists; this potential was analyzed via evaluating the initial fertilization and early embryonic cleavage stages required for production of viable hybrid offspring. A series of hybridization crosses were performed and compared against a control. Fertilization events observed and analyzed included motility and chemotaxis, the acrosome reaction, sperm binding and entry into the egg cytoplasm, and finally cleavage and early development. Inability to produce viable offspring suggests a hybridization-block has been established between the two species at the level of fertilization or early development.

Some classes of endocrine disrupting compounds in the environment have the ability to alter thyroid function. Such thyroid disrupting compounds are known to influence growth and development, but recent studies suggest that thyroid disruption can also have adverse effects on reproduction. A recent study in the Jeffries lab demonstrated that early-life stage thyroid disruption caused decreased reproductive output in fathead minnows (Pimephales promelas), even after a prolonged period of depuration. However, the mechanisms connecting early life stage thyroid disruption to altered reproduction during adulthood remain elusive. This study sought to determine whether alterations in reproductive success following thyroid disruption were a result of male or female reproductive performance in an effort to narrow potential mechanisms by which thyroid disrupting compounds alter reproduction. The results of this study bring insight to the underlying cause of decreased reproductive output following thyroid inhibition.

Carnivorous plants occupy nutrient-poor soils and have evolved traits that allow them to obtain nutrients by capturing and digesting insects. The pale pitcher plant, Sarracenia alata, uses passive pitfall traps to capture their insect prey. Although studies have examined prey composition for S. alata, it is unknown whether this species is selective in prey capture or whether it captures insects in proportion to their abundance in the environment. The purpose of this study was to compare prey capture of S. alata pitchers with the available insects to determine whether this species is selective in prey capture. The available insects were sampled using artificial sticky traps in the vicinity of the pitchers. The insects in the study were identified first to the taxonomic level of order and then further identified to "morphospecies" as a means of examining preference on a finer scale. The relative proportions of insects in specific orders differed between artificial traps and plants. Although dipterans were a major component of capture in both artificial traps and plants, the relative proportions of morphospecies differed between the two. These results support the hypothesis that S. alata is selective in its prey capture, but further studies are needed that use different methods of measuring the available insects in order to avoid potential bias.