Toxicology Commons^™

The Effects Of Pfos Exposure On Zebrafish Dopaminergic Neurodevelopment, Allison G. Fletcher

Departmental Honors & Graduate Capstone Projects

Per- and polyfluoroalkyl substances (PFAS) are a group of environmental contaminants that cause disruptions to the nervous and endocrine systems. Perfluorooctanesulfonate (PFOS) is considered one of the most disruptive PFAS to the nervous system, and may disrupt neurodevelopment of the dopaminergic system, which has been linked to neurodevelopmental disorders like Attention Deficit/Hyperactivity Disorder (ADHD) in humans. I hypothesized that early life PFOS exposure disrupts the development of the dopaminergic system. To test this hypothesis, I exposed zebrafish to 0.05, 0.5, and 5.0 mg/L PFOS through 5 days of embryonic and larval development. To assess acute effects of PFOS on the …

Investigation Of Chondrogenesis, Myogenesis, And Osteogenesis After 2,4-Dtbp, 2-Bp, 4-Bp, 3,5-Dtbc Exposure In Zebrafish, Haley Brashears

All Theses

Synthetic phenolic antioxidants (SPAs) are used in personal care products, food packaging, and water pipes, common SPAs include 2,4-di-tert-butylphenol (2,4-DTBP), 2-tert-butyl phenol (2-BP), and 4-tert-butyl phenol (4-BP). These compounds are detected in the environment and in human biological samples. 2,4-DTBP has been detected in cord plasma, placenta, and breast milk samples. This drives the concern regarding developmental toxicity. In human iPS cells 2,4-DTBP impairs differentiation into somites and osteoblasts. Other SPAs, like 2,6-di-tert-butyl-hydroxytoluene caused increased rates of malformations including yolk and pericardial edema, and spinal curvature in 5-day post fertilization (dpf) zebrafish. …

Early Developmental Exposure To Δ9-Tetrahydrocannabinol Causes Latent Behavioral, Growth, And Bioenergetic Effects In Danio Rerio, Astra Hahm

Honors Theses

Early developmental exposure to Δ9-tetrahydrocannabinol causes latent behavioral, growth, and bioenergetic effects in Danio rerio

(Under the direction of Dr. Kristine Willett)

Δ9-tetrahydrocannabinol (Δ9-THC) is used during pregnancy to mitigate symptoms such as nausea, pain, and insomnia. It is established that Δ9-THC exposure early in life causes adverse effects in children’s development including behavioral disorders. Our goal was to determine the latent and generational impacts on growth, behavior, and mitochondrial bioenergetics following exposure to Δ9-THC. Wildtype (5D) zebrafish were exposed to 0 (0.05% DMSO), 0.08, 0.4, or 1 µM Δ9-THC from 6-96 hours post-fertilization (hpf), then subsequently raised in clean …

Comparing Effects Of Atrazine Exposure On Neuroendocrine Molecular Targets At Two Developmental Exposure Periods In The Zebrafish, Jenna Swihart

The Journal of Purdue Undergraduate Research

No abstract provided.

Observed Effects Of Physiological Melatonin Dosing On Mda-Mb-231 Breast Cancer Cell Proliferation, Wenli Wu

Williams Honors College, Honors Research Projects

This project seeks to evaluate pharmacological dosing of melatonin on the cell proliferation of MDA-MB-231 breast cancer cell line in culture, using the two solubility carriers: DMSO/water and ethanol. This experiment is a component of ongoing research at the Eaton lab which will elucidate melatonin dose-response toxicology in zebrafish and a possible breast cancer xenograft model for novel treatment therapies.

Behavioral Alterations Following Exposure To A Mixture Of Lead And Atrazine During Early Development In The Zebrafish Model System, Anusha Kv Lakshmi Dharmavathi

The Journal of Purdue Undergraduate Research

Lead (Pb) and atrazine (ATZ) are hazardous environmental toxicants that can exist as a mixture in potable water. Numerous single chemical studies on Pb and ATZ support adverse health outcomes, including neurotoxicity, but mixture studies are limited. Th e aim of this study is to test the hypothesis that Pb and ATZ mixtures result in a greater than additive toxicity, causing increased adverse health outcomes than single chemical exposures. Th e zebrafish model system was exposed to 3 or 30 ppb (µg/L) ATZ, 10 ppb (equivalent to 0.1 µg/dL) or 100 ppb Pb, along with mixtures of each beginning at …

Responses To Fine Particulate Matter (Pm2.5) Exposures In Two Wild-Type Zebrafish Strains, Connor Necaise

Honors Theses

Atmospheric fine particulate matter (PM_2.5) exposure poses great health risks across the globe, causing both acute and chronic illnesses in humans. Therefore, a more complete understanding of the mechanisms in which PM_2.5 induces these adverse health effects is urgently needed. Oxidative stress due to PAHs and other common components of PM_2.5 is a proposed mechanism for its adverse health effects. However, little is known about the actual mechanisms of PM_2.5 damage in humans. This study aimed to distinguish behavioral differences in two lines of zebrafish (AB & 5D) as a result of developmental exposure to …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Test Of Bpa's Estrogenic Effects On Brain Aromatase Expression, Neural Activity, And Locomotive Behavior In Zebrafish Larvae, Ryan J. Mcauley

Cal Poly Humboldt theses and projects

Bisphenol A (BPA) is a well-known endocrine disrupting chemical that mimics the effects of estrogens. Aromatase B (Cyp19a1b) is a brain-specific enzyme that converts testosterone to estrogen and is highly upregulated in response to estrogen receptor activation localized to radial glial cells. During embryonic zebrafish development, there is a small window of time denoted by an increase in neurogenesis and estrogen receptor activity. Previous studies have demonstrated that a low dose BPA exposure (0.1µM) during this window causes hyperlocomotion in larval zebrafish, yet no further explanation for this behavior change has been described. The purpose of this study was to …

Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman

Dissertations, Theses, and Capstone Projects

There is a long history of damage to natural ecosystems from environmental pollution. Many environmental contaminants are man-made and have been released with abandon over the last 100 years including dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs). These chemicals act on similar cellular processes and cause skin lesions, cancer, learning disabilities and reproductive problems in many vertebrates. There are many studies exploring various aspects of TCDD and PCB exposure on model and wild organisms. Few studies however, have compared effects of PCB mixtures on ecosystems to effects of individual PCBs in the lab. The first aim of this thesis is …

Molecular Measurement Of Toxicity In Fish; Case Examples And Policy Implications, Jessica A. Freedman

Senior Honors Projects

Stormwater and oil are common urban contaminants that can be harmful to fish species. One way of recognizing exposed and impaired fish is by monitoring gene expression and gene induction. This study focused on the identification and validation of reference genes for measuring contaminant-induced changes in gene expression due to urban influence. In this study, reference genes (which are genes used to normalize data and remain consistent in varying exposures regardless of organism and tissue type) were established. Six genes were identified as reference genes (ef1a, wdtc1, mtm1, spop, rxrba and tuba1) from a longer list of potential …

Brief Embryonic Strychnine Exposure In Zebrafish Causes Long-Term Adult Behavioral Impairment With Indications Of Embyronic Synaptic Changes, Nicole M. Roy, Brianna Arpie, Joseph Lugo, Elwood Linney, Edward D. Levin, Daniel Cerutti

Biology Faculty Publications

Zebrafish provide a powerful model of the impacts of embryonic toxicant exposure on neural development that may result in long-term behavioral dysfunction. In this study, zebrafish embryos were treated with 1.5mM strychnine for short embryonic time windows to induce transient changes in inhibitory neural signaling, and were subsequently raised in untreated water until adulthood. PCR analysis showed indications that strychnine exposure altered expression of some genes related to glycinergic, GABAergic and glutamatergic neuronal synapses during embryonic development. In adulthood, treated fish showed significant changes in swimming speed and tank diving behavior compared to controls. Taken together, these data show that …