Life Sciences Commons^™

Cacna1g Transcript Knockdown Analysis Via In Situ Hybridization, Jennifer (Shih-En) Chen

Undergraduate Honors Theses

The pedunculopontine nucleus (PPN) comprises the mesencephalic locomotor region (MLR) of the midbrain. It contains glutamatergic, cholinergic, and GABAergic interneurons, but only glutamatergic neurons influence locomotion, which is our focus here. The PPN receives upstream and downstream input from the basal ganglia. It projects to the reticular formation of the brainstem, which connects to the spinal cord. The PPN is involved in a wide range of physiological and behavioral processes, but our focus is locomotion. We hypothesize that the PPN influences the reticular activating system (RAS) of the medulla and thus the central pattern generators (CPG) in the spinal cord …

Attentional Dysfunction In Schizophrenia: The Effects Of Dual Orexin Receptor Blockade On An Nmda Receptor Hypofunction Model, Paige Little

Undergraduate Honors Theses

Hypofunctionality at the N-Methyl-D-aspartic acid receptor (NMDAR) is a commonly used model of the neurodevelopmental disorder schizophrenia due to the complex circuitry changes that follow NMDAR blockade. While these animal models are very popular for modeling the cognitive deficits seen in schizophrenia, actual treatments for this disorder remain sparse. Orexins (hypocretins) are neuropeptides that are capable of modulating activity along pathways relevant to attention, but are rarely tested for their efficacy in attenuating attentional dysfunction. This study was conducted to determine if systemic administration of the dual orexin receptor antagonist filorexant (MK-6096) was able to attenuate sustained attentional dysfunction induced …

Mysteries And Uncertainties In Tracing Cryptic Viral Infections, Melaina Jacoby

Undergraduate Honors Theses

Viruses are the most abundant biological entities on Earth. Viral impacts are evident from the level of individual cells and population all the way up to ecosystems and global elemental cycles. Since bacteriophages (viruses that infect bacteria) were first identified in the early twentieth century, the study of these fascinating entities has shown how viral dynamics within ecosystems can influence microbially-mediated processes at a large scale. Viral infections can impact hosts and host-mediated processes in in multiple ways, one of which is through cryptic infections. This state, in which a bacterium may harbor a cryptic phage infection, is known as …

Effects Of Gamete Age On Development In Asterias Forbesi, Amanda Yeo

Undergraduate Honors Theses

For broadcast spawning organisms like echinoderms, the timing of the union of gametes is essential for successful fertilization. However, the release of gametes is not always synchronous and the success of fertilization is highly dependent upon a number of factors including: the number and distribution of spawning adults, the timing of gamete release, the dispersal of gametes, the interaction of gametes within the water column, turbulence in the water column, and the phenotypic properties (e.g. size) of the gametes themselves. Previous studies have shown that the longer sperm is in the water column the greater their mobility decreases and they …

Three Centuries Of Vegetation Change In The William & Mary College Woods Reconstructed Using Phytoliths, Timothy Terlizzi

Undergraduate Honors Theses

The College Woods, west of William & Mary’s campus, consists of ~900 acres of protected southern mixed hardwood forest. The woods surround Lake Matoaka, a former millpond established in ~1700. Despite the rich history of the area, little is known about how the dominant vegetative landcover has shifted over the last 300 years. This study set out to quantify the modern vegetation within the College Woods via the phytolith assemblages within the soil and identify shifts in the assemblages since the creation of Lake Matoaka and whether these changes are distinct from the vegetation that existed in the area before …

Characterizing The Microbiome Of Floral Nectar Of Asclepias Syriaca And Other Asclepias Species, Heather Natterer

Undergraduate Honors Theses

In recent decades, Danaus plexippus (the monarch butterfly) has experienced a drastic decrease in population size due to urbanization, climate change, and habitat loss. The primary habitat and food source of D. plexippus is plant species that are within the genus Asclepias (milkweed). The preservation and propagation of Asclepias spp. is necessary to combat D. plexippus’s population declines. A plant’s reproductive success is dependent upon its ability to attract pollinators, which is linked to the plant’s nectar qualities. We propose that, in turn, these nectar qualities may be influenced by the nectar microbiome. This study aims to better understand the …

Welcoming The Game Changer Of Human Society: A Defense Of The Moral Permissibility And Obligations Of Human Genetic Engineering, Yongkang Li

Undergraduate Honors Theses

In 2018, a Chinese scientist, Jiankun He, announced the birth of two HIV-resistant babies through his experiment of human genetic engineering. This incidence has soon shocked the entire scientific community and invoked public outrage towards He’s corrupt moral integrity.

However, this event should also act as a harbinger to the human society that the technique of human genetic engineering is rapidly approaching maturity. In that case, how should we respond?

This thesis focuses on the moral issues surrounding human genetic engineering and advertises an accepting moral attitude to this booming technology. This thesis will first discuss the types of human …

Proteomic Analysis Of Mycobacteriophage Crimd, William Moeller

Undergraduate Honors Theses

Bacteriophages represent a large portion of the biomatter on our planet, and many of them have yet to be fully characterized. Here we discuss the proteomic analysis of a particular Bacteriophage, Mycobacteriophage CrimD. This phage was discovered on the Campus of William & Mary and has had its genome characterized. We took the next logical step of proteomic analysis.

In our analyses we made use high pressure liquid chromatography paired with linear ion trap mass spectrometry to analyze the proteome of CrimD at specific time points after the infection of its host, Mycobacterium smegmatis. Additionally, we used nanospray ionization with …

Effects Of Xanomeline On Attention In Rats, Grace Smith

Undergraduate Honors Theses

The cholinergic system plays a large role in regulating attentional processing. Diseases such as Alzheimer’s Disease are known to degrade cholinergic neurons and deactivate cholinergic M1 receptors. Dysfunction in the cholinergic system results in a wide range of cognitive deficits, including a decrease in attention. The cholinergic system has been a focus of drug research to help modulate acetylcholine levels in order to relieve AD symptoms. Xanomeline is a drug previously used in this endeavor that works via agonism of acetylcholine M1 and M4 receptors. Cognitive improvements of Xanomeline administration in AD are thought to be due to agonism of …

Rapid Morphological Divergence In Three Introduced Cichlid Species, Khalil Russell

Undergraduate Honors Theses

Cichlids are well-known for their capacity to exploit trophic niches in their environments through rapid speciation and morphological diversification; the best-documented case of such diversification in cichlids occurred in the African Rift Valley. With numerous species established in Florida, the purpose of this study was to explore how members of the family Cichlidae have managed to invade so successfully by focusing on morphological differences between native and non-native (Floridian) populations of three cichlid species: Pelmatolapia mariae, Mayaheros urophthalmus, and Parachromis managuensis. Using both linear measurements and 2D landmark geometric morphometry, I found that all three species have diverged in …