Date of Award

5-2026

Degree Type

Thesis

Degree Name

Master of Science in Biomedical Sciences

First Advisor

Jocelyn Lippman-Bell, PhD

Second Advisor

Michelle Kanther, PhD

Third Advisor

Heather Montie, PhD

Abstract

Early-life seizures (ELS) occur during a critical period of brain development, potentially impacting brain function later in life. For example, deficits in learning and memory and neurological disorders like epilepsy are consequences that are often associated with ELS, though there is currently no way to predict which patients will develop these consequences and no way to prevent their development. Therefore, this study aims to explore novel molecular mechanisms that could contribute to the development of ELS consequences with a long-term goal of finding novel therapeutic targets to hinder their development. To accomplish this, changes in gene expression were examined after a three-day seizure induction protocol in larval zebrafish. Starting at 5 dpf, one group of fish (the ELS group) was exposed to pentylenetetrazol (PTZ) for 40 minutes per day, while the handling control (HC) clutch mates were handled similarly but not exposed to PTZ. Fish were euthanized 1 hour after the final day of seizures and RNA was extracted from the heads of the fish to be used in an RNA sequencing experiment. From this data, five genes were chosen that had significantly increased gene expression in the ELS group compared to the HC group: klf9, fkbp5, klf13, per1a and nr4a3. These genes and/or their protein products had functions relevant to seizures and were also linked to each other functionally, co-expressed or co-localized. In the current study, results from the sequencing for each gene were validated at the 1-hour time point using RT-qPCR with additional clutches of HC and ELS zebrafish, and a second timeline was added, 24 hours post-ELS. The RT-qPCR results for each gene validated the RNA sequence data and showed expression levels for all the genes returned to HC expression levels by 24 hours post-ELS. These expression changes were then evaluated for localization within the zebrafish brain using RNAscope. RNAscope imaging revealed widespread elevation of fkbp5, klf9 and klf13 throughout the brain 1-hour post-ELS compared to HC. While there was a decrease in expression by 24-hours to similar levels as HC for the genes, klf9 and fkbp5 expression remain elevated in the forebrain, an area for higher order cognitive function including learning and memory, and fkbp5 and klf13 remained elevated in the optic tectum, an area implicated in seizure initiation. Taken together, the data from the current study present five novel genes for future study into the molecular mechanisms underlying ELS-induced cognitive deficits and increase seizure behavior.

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