Dissertation
Sleep and sleep loss on hippocampal memory and plasticity
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Autumn 2023
DOI: 10.25820/etd.006975
Abstract
Sleep facilitates memory storage, and sleep loss leads to impairments in memory, especially for types of memory that are dependent on the hippocampus. The importance of sleep for memory consolidation has been well documented, but there are questions about the mechanisms underlying this sleep-dependent process. Many labs have used different methods to try and identify these mechanisms but have achieved conflicting results. This might be because many widely used methods of sleep deprivation are reliant on exogenous stimulation to keep the animals awake, and that external stimulation is capable of producing its own effects on memory and plasticity, independent of the impact on sleep. Previous work from the lab has used exogenous methods of sleep deprivation to reveal that cAMP signaling may be the mechanism for memory consolidation in sleep. Reduced cAMP signaling cascades explain many of the deficits that are observed in sleep deprivation, including memory problems and impaired hippocampal plasticity. There remain questions about where and when these deficits initiate in the hippocampus, what components of the pathway can be rescued, and if there are differences in how the stages of sleep contribute to memory consolidation and plasticity. To address the role of sleep in memory and plasticity, this proposal aims to dive deep into the role of cAMP signaling, and study both the effects of decreasing sleep, and increasing the amount of time spent in a specific sleep stage using endogenous neural circuits to manipulate sleep/wake in the absence of external stimulation.
Details
- Title: Subtitle
- Sleep and sleep loss on hippocampal memory and plasticity
- Creators
- Emily Nicole Walsh
- Contributors
- Edwin (Ted) Abel (Advisor)Mark Blumberg (Committee Member)Gordon Buchanan (Committee Member)Jason Radley (Committee Member)Stefan Strack (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Neuroscience
- Date degree season
- Autumn 2023
- DOI
- 10.25820/etd.006975
- Publisher
- University of Iowa
- Number of pages
- xii, 157 pages
- Copyright
- Copyright 2023 Emily Nicole Walsh
- Grant note
- The study was supported by the National Institutes of Health R01 Grant MH117964 to Ted Abel, and the University of Iowa Hawkeye Intellectual and Developmental Disability Research Center (P50 HD 103556; Lane Strathearn and Ted Abel, multi PIs). This work was also supported by the Ballard and Seashore Dissertation Fellowship from the University of Iowa Graduate College to Emily Walsh. (55) This work was supported by the Ballard and Seashore Dissertation Fellowship from the University of Iowa Graduate College to Emily Walsh, and the National Institutes of Health Predoctoral Training Grant T32-NS007421 (PI Daniel Tranel). These experiments were also supported by the National Institutes of Health R01 Grant MH117964 and R01 Grant AG062398 to Ted Abel. Ted Abel is the Roy J. Carver Chair of Neuroscience. (102)
- Language
- English
- Date submitted
- 11/30/2023
- Description illustrations
- Illustrations, tables, graphs, charts
- Description bibliographic
- Includes bibliographical references (pages 139-157).
- Public Abstract (ETD)
Sleep is needed to strengthen new memories, and if sleep is prevented, memory for new information is lost. Memory that relies on the hippocampus, a structure of the brain that is important for learning facts about the environment, is particularly vulnerable to sleep loss. Over the years, sleep deprivation studies have aimed to understand what mechanisms are required to strengthen hippocampal memories in sleep. These studies revealed changes within the cells of the hippocampus that may explain these deficits.
In this thesis, I use tools to change the patterns of activity in the brain to study what it takes to protect memories from the effect of sleep-deprivation and to understand how the problems emerge. One strategy that I use is to increase the activity of a molecule which is depleted in the hippocampus by sleep loss. I find that if I can boost the activity of this signaling molecule during sleep loss it protects the hippocampus from loss of function. To understand why sleep loss impacts the hippocampus the way that it does, I used techniques to activate the regions of the brain that are responsible for sleep and wake. These results suggest that activity of particular brain circuitry can be stimulated to prevent some of these changes in the hippocampus.
The goal of this research was to understand what processes are required during sleep to protect and strengthen memory. The ultimate goal is that such research will allow us to one day develop better medicines for conditions with sleep-loss.
- Academic Unit
- Interdisciplinary Graduate Program in Neuroscience
- Record Identifier
- 9984546541502771
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