Multiple Mechanisms of Sleep Regulation: An exploration of local cortical regulation of sleep intensity and global behavioral state
Year: 2024
Type: dissertation
Abstract: Substantial research has demonstrated the importance of sleep to various dimensions, including learning and memory, health, performance, and recovery. The benefits of good sleep are well-characterized; however, we know little about how good sleep is regulated, and more importantly, how we can fix any haywire regulatory mechanisms that may cause sleep disorders. Sleep regulation is typically considered to be under the control of two distinct mechanisms. Subcortical brain regions are associated with circadian functions, or the control of the timing and duration of sleep. Cortical regions are linked to the regulation of sleep intensity and maintenance of sleep homeostasis. Sleep homeostasis refers to the notion that sleep, particularly slow wave non-REM (NREM) sleep, functions to diminish any need for sleep that was accumulated in the previous period of waking activity. Slow wave activity (SWA) is generally accepted as a measure of sleep need due to the well-established observation that SWA increases as sleep need increases, and vice versa. The present study seeks to extend and nuance our current understanding of sleep regulation. Specifically, we artificially induced local sleep deprivations by performing 3-hour continuous injections of wake-promoting artificial cerebrospinal fluid into either the motor or somatosensory cortex of rats, and analyzed the effects on slow wave activity, slow wave energy and sleep duration. Unexpectedly, following the end of our local deprivation period, a reduction in SWA was observed. This reduction in SWA persisted even when the local wake-promoting injections were combined with a 3-hour sleep deprivation. Resultingly, we concluded that our injections likely were not functioning as a traditional sleep deprivation, and that they served as a means of temporarily inhibiting slow wave formation and propagation. In response to this artificially hindered ability to produce slow waves, the brain compensated by sleeping longer. These results suggest a role for local cortical regions in regulating global sleep duration when their ability to generate slow waves is blocked.
Source: Figshare
Author: Kristen N. Monten (16818811)
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W6983610880