Honors Theses

Date of Award


Document Type

Undergraduate Thesis


Biomolecular Sciences

First Advisor

Kristine Willett

Relational Format



As of 2019, marijuana legalization and decriminalization is sweeping the globe. Patients are increasingly using cannabis-derived compounds including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) for treatment of diseases as diverse as epilepsy, Parkinson’s disease, and cancer. Furthermore, mothers are claiming that CBD oil decreases uncomfortable pregnancy side effects. While the adverse effects of chronic cannabinoid use and of cannabinoids on pregnancy have been previously investigated, the exact function of the endocannabinoid system, and its primary receptors, cannabinoid receptors 1 and 2, involved in producing these outcomes is still unclear. In this study, two strains of zebrafish embryos, namely fli and cnr2-/- were exposed to varying concentrations of CBD and THC for 96 hpf and their developmental and behavioral outcomes were observed to further determine the role that CB2 plays in embryonic development and organogenesis. Fli larvae had a higher percent incidence of pericardial edema and yolk sac edema when exposed to 0.6 mg/L CBD, whereas CBD treated cnr2-/- were not significantly different than untreated. Fli larvae also showed an increased percent incidence of yolk sac edema at 2.5 mg/L THC and a percent incidence not different from control, or 2.5 mg/L at 1.25 mg/L, whereas cnr2-/- only suffered from yolk sac edema at 2.5 mg/L THC. Behavioral patterns were treatment-dependent, as both THC and CBD showed increased activity at 0.65 mg/L and 0.075 mg/L, respectively. These studies indicate that cannabinoid developmental toxicity depends both on the particular cannabinoid and its interactions with the CB2 receptor. Additional studies are needed to investigate the THC and CBD toxicities in the cnr1-/- to further understand the mechanisms of cannabinoid toxicity.

Available for download on Wednesday, September 02, 2020

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