Date of Award
Doctor of Philosophy (PhD)
Edwin (Ted) Abel
Memory consolidation is the process through which short-term memories are stabilized for long-term retention. New gene expression is required for this process to occur successfully. Although gene expression is a necessary component for memory consolidation, the targets and regulation of this gene expression are not well understood. The advent of next-generation sequencing technologies has provided a tremendous resource to probe important questions genome-wide in ways that were previously impossible. In this dissertation, I use next-generation sequencing to investigate the transcriptional targets of learning in the hippocampus. Chapter 1 reviews the previous research on the regulation of gene expression during memory consolidation. Previous work has implicated histone acetylation as an epigenomic modification that regulates long-term memory. In Chapter 2, I use RNA-seq to investigate the gene expression changes that occur 30 minutes after contextual fear conditioning. I use recently developed analysis techniques to improve our ability to detect changes and study alternative splicing genome-wide for the first time after learning. Chapter 3 investigates whether these gene expression changes are specific to contextual fear conditioning or shared with other hippocampus-dependent learning tasks such as object-location memory. I find that the transcriptional targets are similar between training paradigms, but their temporal activation differs. In Chapter 4, we use ChIP-seq, Sono-seq and MNase-seq to determine changes in histone acetylation, chromatin accessibility and nucleosome positioning that occur in response to learning. I find only small changes in H3K9/14ac, but large changes in chromatin accessibility. This may suggest that a multitude of histone modifications act in concert to regulate chromatin accessibility during memory consolidation.
Poplawski, Shane Gary, "The Regulation of Gene Expression During Memory Consolidation in the Hippocampus" (2014). Publicly Accessible Penn Dissertations. 1408.