Dissertation
The idiothetic development of the rat cerebellar system
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Autumn 2025
DOI: 10.25820/etd.008238
Abstract
To interact effectively with the environment, animals must distinguish between sensory feedback arising from their own movements (reafference) and that arising from external sources (exafference). Only self-generated movements are accompanied by motor copies—corollary discharges—that enable the brain, particularly the cerebellum, to compare expected and actual sensory consequences. These comparisons underlie the formation of internal models that predict the sensory outcomes of movement. In rats, internal models emerge gradually over the first three postnatal weeks, but the mechanisms driving this development remain unclear. Using spontaneous twitches during active (REM) sleep, we investigated the developing contributions of discrete self-generated movements on cerebellar structures, including the inferior olive (IO), to construct internal models. At postnatal day (P) 12, we found that the interpositus nucleus (IP) revealed robust responses to twitches but few responses to external stimulation, unless the cortex was ablated or suppressed with urethane—manipulations that disinhibit IP by removing cerebellar cortical inhibition. Similarly, at P12, the IO responds to twitches with corollary discharge signals but fails to respond to externally generated stimuli. This selective sensitivity to self-generated input shifts by P20, when the IO begins responding to external stimuli as it does in adults. Furthermore, pharmacological lesions of IO climbing fibers at P12 eliminated twitch-related responses in IP, confirming the IO as their source. Finally, to test whether IO-derived corollary discharge is necessary for internal model formation, we lesioned climbing fibers at P12 or P19 and recorded from the ventrolateral thalamus (VL) at P20. Only lesions at P12 disrupted the expression of the internal model in VL. Together, these findings demonstrate that self-generated twitches provide a unique developmental context for corollary discharge and reafference to establish cerebellar internal models.
Details
- Title: Subtitle
- The idiothetic development of the rat cerebellar system
- Creators
- Angela May Rose Richardson
- Contributors
- Mark S. Blumberg (Advisor)Bengi Baran (Committee Member)Ryan LaLumiere (Committee Member)Krystal Parker (Committee Member)Hanna Stevens (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Neuroscience
- Date degree season
- Autumn 2025
- DOI
- 10.25820/etd.008238
- Publisher
- University of Iowa
- Number of pages
- ix, 98 pages
- Copyright
- Copyright 2025 Angela May Rose Richardson
- Language
- English
- Date submitted
- 12/10/2025
- Description illustrations
- Illustrations, graphs, charts
- Description bibliographic
- Includes bibliographical references (pages 76-98).
- Public Abstract (ETD)
For animals to move smoothly and adapt to a changing world, the brain must know the difference between movements it makes itself and those caused by outside forces. This ability depends on the cerebellum, a brain structure that builds internal models to predict how the body moves through space. In newborns, these models do not yet exist they must develop through experience. In this dissertation, I show in infant rats that the earliest and most important of these experiences come from the animal s own movements during sleep. I show that these sleep-related movements provide crucial training signals to the cerebellum, shaping how its circuits become predictive internal models. By revealing how early self-generated activity guides brain development, this research helps explain how movement and sleep work together to build the foundations of adaptive behavior.
- Academic Unit
- Interdisciplinary Graduate Program in Neuroscience
- Record Identifier
- 9985134948202771
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