{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/120477"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/120477","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Glymphatic flow diurnal variation in the brain inhibited by circadian rhythm disruption and recovered by arginine vasopressin administration","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","abstract_has_math":false,"creators":["Hamed, Eman Elhag Abdel"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Neuroscience","degree_department":null,"school":null,"contributors":["Gillette, Martha","Kong, Hyunjoon","Sutton, Bradley","Christian-Hinman, Catherine"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-05","date_published":"2023-05","updated_at":"2026-07-22T22:24:57Z","subjects":["Glymphatic System","Circadian Rhythm","Circadian Rhythm Disruption","Arginine Vasopressin","Magnetic Resonance Imaging","Mri","Hippocampus","Suprachiasmatic Nucleus","Scn","Brain Fluid Transport","Neurodegeneration","Neuroscience","Pharmacology","Biomedical Engineering"],"languages":["en","eng"],"rights":["© 2022 Eman Elhag Abdel Hamed"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/120477","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gillette, Martha","Kong, Hyunjoon","Sutton, Bradley","Christian-Hinman, Catherine"]},{"key":"dc:creator","label":"Author","values":["Hamed, Eman Elhag Abdel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-05","2022-12-21"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Neuroscience"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Glymphatic System","Circadian Rhythm","Circadian Rhythm Disruption","Arginine Vasopressin","Magnetic Resonance Imaging","Mri","Hippocampus","Suprachiasmatic Nucleus","Scn","Brain Fluid Transport","Neurodegeneration","Neuroscience","Pharmacology","Biomedical Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["© 2022 Eman Elhag Abdel Hamed"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/120477"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","The student, Eman Hamed, accepted the attached license on 2022-12-12 at 22:49.","The student, Eman Hamed, submitted this Dissertation for approval on 2022-12-14 at 14:52.","This Dissertation was approved for publication on 2022-12-21 at 09:14.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18800 on 2023-09-01 at 17:17:54","Sleep is among the most fundamental of all behaviors, yet its restorative, homeostatic processes are not understood. Mounting evidence reveals that restorative sleep removes brain toxins and metabolites and, in turn, alters physiology and metabolism significantly. However, to date, (i) the basis of the process, (ii) counteracting effects of wakefulness periods, (iii) integrative processes from molecular to behavior levels during restorative sleep remain unexplained. The glymphatic system is a network of perivascular spaces surrounding the vasculature in the brain (Iliff et al., 2012a). The cerebrospinal fluid (CSF) passes from the subarachnoid space surrounding the brain and passes into these PVS. Aquaporin-4 (AQP4) channels on the glial cells surrounding the PVS move CSF into the brain parenchyma. Large proteins and metabolic waste products are removed through this flow. Little is known about whether day-night circadian rhythms of physiology affect the glymphatic flow and, consequently, metabolic waste clearance. We hypothesize that there is a diurnal variation of the glymphatic flow that is mitigated by circadian rhythm disruption. Through this flow, CSF entering the interstitial space removes large protein molecules and metabolic waste products, such as amyloid β, from the brain parenchyma (Iliff et al., 2012a). CSF together with interstitial fluid that has washed out from between the cells flows into the perivascular spaces around the veins and is discharged outside the brain (Iliff et al., 2012a). Circadian rhythms, biological processes that display an endogenous, near 24-h oscillation, significantly affect brain physiology, including alterations in sleep architecture (Karatsoreos et al., 2011) (Phillips et al., 2015). Circadian disruption, the continuous shifting of physiology on a 20-h day-night cycle, models non-restorative sleep. In addition, glymphatic flow differs between sleep and awake states, increasing significantly during sleep (Xie et al., 2013). However, it is not known whether or how circadian rhythms affect glymphatic flow. People with circadian rhythm disruption generally wake up feeling less refreshed, similar to the effects of sleep disruption. This observation brings up the question of what effects circadian rhythm disruption could potentially exert on glymphatic fluid transport in the brain and consequently on metabolic waste clearance. Furthermore, elderly patients suffering from neurodegenerative diseases, including Alzheimer’s patients, exhibit altered circadian physiology as well as disrupted sleep. If circadian rhythm disruption negatively affects the fluid transport in the brain and in turn causes waste product accumulation that leads to neurodegenerative disease, is there a way we could reverse that using the glymphatic system itself as a drug delivery model?"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Glymphatic flow diurnal variation in the brain inhibited by circadian rhythm disruption and recovered by arginine vasopressin administration"]}]}],"canonical_facts":{"dc:contributor":["Gillette, Martha","Kong, Hyunjoon","Sutton, Bradley","Christian-Hinman, Catherine"],"dc:creator":["Hamed, Eman Elhag Abdel"],"dc:date":["2023-05","2022-12-21"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","The student, Eman Hamed, accepted the attached license on 2022-12-12 at 22:49.","The student, Eman Hamed, submitted this Dissertation for approval on 2022-12-14 at 14:52.","This Dissertation was approved for publication on 2022-12-21 at 09:14.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18800 on 2023-09-01 at 17:17:54","Sleep is among the most fundamental of all behaviors, yet its restorative, homeostatic processes are not understood. Mounting evidence reveals that restorative sleep removes brain toxins and metabolites and, in turn, alters physiology and metabolism significantly. However, to date, (i) the basis of the process, (ii) counteracting effects of wakefulness periods, (iii) integrative processes from molecular to behavior levels during restorative sleep remain unexplained. The glymphatic system is a network of perivascular spaces surrounding the vasculature in the brain (Iliff et al., 2012a). The cerebrospinal fluid (CSF) passes from the subarachnoid space surrounding the brain and passes into these PVS. Aquaporin-4 (AQP4) channels on the glial cells surrounding the PVS move CSF into the brain parenchyma. Large proteins and metabolic waste products are removed through this flow. Little is known about whether day-night circadian rhythms of physiology affect the glymphatic flow and, consequently, metabolic waste clearance. We hypothesize that there is a diurnal variation of the glymphatic flow that is mitigated by circadian rhythm disruption. Through this flow, CSF entering the interstitial space removes large protein molecules and metabolic waste products, such as amyloid β, from the brain parenchyma (Iliff et al., 2012a). CSF together with interstitial fluid that has washed out from between the cells flows into the perivascular spaces around the veins and is discharged outside the brain (Iliff et al., 2012a). Circadian rhythms, biological processes that display an endogenous, near 24-h oscillation, significantly affect brain physiology, including alterations in sleep architecture (Karatsoreos et al., 2011) (Phillips et al., 2015). Circadian disruption, the continuous shifting of physiology on a 20-h day-night cycle, models non-restorative sleep. In addition, glymphatic flow differs between sleep and awake states, increasing significantly during sleep (Xie et al., 2013). However, it is not known whether or how circadian rhythms affect glymphatic flow. People with circadian rhythm disruption generally wake up feeling less refreshed, similar to the effects of sleep disruption. This observation brings up the question of what effects circadian rhythm disruption could potentially exert on glymphatic fluid transport in the brain and consequently on metabolic waste clearance. Furthermore, elderly patients suffering from neurodegenerative diseases, including Alzheimer’s patients, exhibit altered circadian physiology as well as disrupted sleep. If circadian rhythm disruption negatively affects the fluid transport in the brain and in turn causes waste product accumulation that leads to neurodegenerative disease, is there a way we could reverse that using the glymphatic system itself as a drug delivery model?"],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/120477"],"dc:language":["en","eng"],"dc:rights":["© 2022 Eman Elhag Abdel Hamed"],"dc:subject":["Glymphatic System","Circadian Rhythm","Circadian Rhythm Disruption","Arginine Vasopressin","Magnetic Resonance Imaging","Mri","Hippocampus","Suprachiasmatic Nucleus","Scn","Brain Fluid Transport","Neurodegeneration","Neuroscience","Pharmacology","Biomedical Engineering"],"dc:title":["Glymphatic flow diurnal variation in the brain inhibited by circadian rhythm disruption and recovered by arginine vasopressin administration"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Neuroscience"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:57Z"}