Poplawski, Shane Gary

Email Address
ORCID
Disciplines
Research Projects
Organizational Units
Position
Introduction
Research Interests

Filters

2012 - 20142
2
11
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Publication
    NR4A Nuclear Receptors Support Memory Enhancement by Histone Deacetylase Inhibitors
    (2012-10-01) Hawk, Joshua Davis; Poplawski, Shane Gary; Bridi, Morgan; Sulewski, Michael E; Bookout, Angie L; Abel, Ted; Rao, Allison J; Kroener, Brian T; Manglesdorf, David J
    The formation of a long-lasting memory requires a transcription-dependent consolidation period that converts a short-term memory into a long-term memory. Nuclear receptors compose a class of transcription factors that regulate diverse biological processes, and several nuclear receptors have been implicated in memory formation. Here, we examined the potential contribution of nuclear receptors to memory consolidation by measuring the expression of all 49 murine nuclear receptors after learning. We identified 13 nuclear receptors with increased expression after learning, including all 3 members of the Nr4a subfamily. These CREB-regulated Nr4a genes encode ligand-independent “orphan” nuclear receptors. We found that blocking NR4A activity in memory-supporting brain regions impaired long-term memory but did not impact short-term memory in mice. Further, expression of Nr4a genes increased following the memory-enhancing effects of histone deacetylase (HDAC) inhibitors. Blocking NR4A signaling interfered with the ability of HDAC inhibitors to enhance memory. These results demonstrate that the Nr4a gene family contributes to memory formation and is a promising target for improving cognitive function.
  • Publication
    The Regulation of Gene Expression During Memory Consolidation in the Hippocampus
    (2014-01-01) Poplawski, Shane Gary
    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.