Medullary Respiratory Neural Activity During Hypoxia in NREM and REM Sleep in the Cat

2006 ◽  
Vol 95 (2) ◽  
pp. 803-810 ◽  
Author(s):  
Andrew T. Lovering ◽  
Jimmy J. Fraigne ◽  
Witali L. Dunin-Barkowski ◽  
Edward H. Vidruk ◽  
John M. Orem
Keyword(s):  
Respiratory Rate ◽  
Eye Movement ◽  
Rem Sleep ◽  
Neural Activity ◽  
Cell Types ◽  
Respiratory Neurons ◽  
Rapid Eye Movement ◽  
Medullary Respiratory Neurons ◽  
Inspiratory Neurons ◽  
Discharge Rates

Intact unanesthetized cats hyperventilate in response to hypocapnic hypoxia in both wakefulness and sleep. This hyperventilation is caused by increases in diaphragmatic activity during inspiration and expiration. In this study, we recorded 120 medullary respiratory neurons during sleep in hypoxia. Our goal was to understand how these neurons change their activity to increase breathing efforts and frequency in response to hypoxia. We found that the response of medullary respiratory neurons to hypoxia was variable. While the activity of a small majority of inspiratory (58%) and expiratory (56%) neurons was increased in response to hypoxia, the activity of a small majority of preinspiratory (57%) neurons was decreased. Cells that were more active in hypoxia had discharge rates that averaged 183% (inspiratory decrementing), 154% (inspiratory augmenting), 155% (inspiratory), 230% (expiratory decrementing), 191% (expiratory augmenting), and 136% (expiratory) of the rates in normoxia. The response to hypoxia was similar in non-rapid-eye-movement (NREM) and REM sleep. Additionally, changes in the profile of activity were observed in all cell types examined. These changes included advanced, prolonged, and abbreviated patterns of activity in response to hypoxia; for example, some inspiratory neurons prolonged their discharge into expiration during the postinspiratory period in hypoxia but not in normoxia. Although changes in activity of the inspiratory neurons could account for the increased breathing efforts and activity of the diaphragm observed during hypoxia, the mechanisms responsible for the change in respiratory rate were not revealed by our data.

Activity of medullary respiratory neurons during ventilator-induced apnea in sleep and wakefulness

1998 ◽  
Vol 84 (3) ◽  
pp. 922-932 ◽  
Author(s):  
John Orem ◽  
Edward H. Vidruk
Keyword(s):  
Mechanical Ventilation ◽  
Eye Movement ◽  
Residual Activity ◽  
Respiratory Neurons ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Cell Type ◽  
Medullary Respiratory Neurons ◽  
Respiratory Cells ◽  
Adult Cats

Mechanical ventilation of cats in sleep and wakefulness causes apnea, often within two to three cycles of the ventilator. We recorded 137 medullary respiratory neurons in four adult cats during eupnea and during apnea caused by mechanical ventilation. We hypothesized that the residual activity of respiratory neurons during apnea might reveal its cause(s). The results showed that residual activity depended on 1) the amount of nonrespiratory inputs to the cell (cells with more nonrespiratory inputs had greater amounts of residual activity); 2) the cell type (expiratory cells had more residual activity than inspiratory cells); and 3) the state of consciousness (more residual activity in wakefulness and rapid-eye-movement sleep than in non-rapid-eye-movement sleep). None of the cells showed an activation during ventilation that could explain the apnea. Residual activity of approximately one-half of the cells was modulated in phase with the ventilator. The strength of this modulation was quantified by using an effect-size statistic and was found to be weak. The patterns of modulation did not support the idea that mechanoreceptors excite some respiratory cells that, in turn, inhibit others. Indeed, most cells, inspiratory and expiratory, discharged during the deflation-inflation transition of ventilation. Residual activity failed to reveal the cause of apnea but showed that during apnea respiratory neurons act as if they were disinhibited and disfacilitated.

scholarly journals Manipulating neural activity and sleep-dependent memory consolidation

Neuroforum ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Maryam Ghorbani ◽  
Lisa Marshall
Keyword(s):  
Eye Movement ◽  
Neural Activity ◽  
Memory Consolidation ◽  
Nrem Sleep ◽  
Neural Oscillations ◽  
Rapid Eye Movement ◽  
Hippocampus Dependent Memory

AbstractSleep contributes actively to the consolidation of many forms of memory. This review describes the neural oscillations of non-rapid eye movement (NREM) sleep, the structures underlying these oscillations and their relation to hippocampus-dependent memory consolidation. A main focus lies on the relation between inter- and intraregional interactions and their electrophysiological representation. Methods for modulating neural oscillations with the intent of affecting memory consolidation are presented.

scholarly journals The Relationship Between Daily Rapid-Eye Movement Sleep and Cognitive Functioning in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 159-159
Author(s):  
Tiana Broen ◽  
Tomiko Yoneda ◽  
Jonathan Rush ◽  
Jamie Knight ◽  
Nathan Lewis ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Cognitive Functioning ◽  
Eye Movement ◽  
Rem Sleep ◽  
Cognitive Tests ◽  
Rapid Eye Movement ◽  
Targeted Interventions ◽  
The Impact ◽  
The Relationship

Abstract Previous cross-sectional research suggests that age-related decreases in Rapid-Eye Movement (REM) sleep may contribute to poorer cognitive functioning (CF); however, few studies have examined the relationship at the intraindividual level by measuring habitual sleep over multiple days. Applying a 14-day daily diary design, the current study examines the dynamic relationship between REM sleep and CF in 69 healthy older adults (M age=70.8 years, SD=3.37; 73.9% female; 66.6% completed at least an undergraduate degree). A Fitbit device provided actigraphy indices of REM sleep (minutes and percentage of total sleep time), while CF was measured four times daily on a smartphone via ambulatory cognitive tests that captured processing speed and working memory. This research addressed the following questions: At the within-person level, are fluctuations in quantity of REM sleep associated with fluctuations in next day cognitive measures across days? Do individuals who spend more time in REM sleep on average, perform better on cognitive tests than adults who spend less time in REM sleep? A series of multilevel models were fit to examine the extent to which each index of sleep accounted for daily fluctuations in performance on next day cognitive tests. Results indicated that during nights when individuals had more REM sleep minutes than was typical, they performed better on the working memory task the next morning (estimate = -.003, SE = .002, p = .02). These results highlight the impact of REM sleep on CF, and further research may allow for targeted interventions for earlier treatment of sleep-related cognitive impairment.

Sleep Disorders

2015 ◽  
Author(s):  
Sudhansu Chokroverty
Keyword(s):  
Sleep Apnea ◽  
Sleep Disorders ◽  
Eye Movement ◽  
Rem Sleep ◽  
Sleep Apnea Syndrome ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Circadian Rhythm Sleep Disorders ◽  
Apnea Syndrome ◽  
Sleep Mechanism

Recent research has generated an enormous fund of knowledge about the neurobiology of sleep and wakefulness. Sleeping and waking brain circuits can now be studied by sophisticated neuroimaging techniques that map different areas of the brain during different sleep states and stages. Although the exact biologic functions of sleep are not known, sleep is essential, and sleep deprivation leads to impaired attention and decreased performance. Sleep is also believed to have restorative, conservative, adaptive, thermoregulatory, and consolidative functions. This review discusses the physiology of sleep, including its two independent states, rapid eye movement (REM) and non–rapid eye movement (NREM) sleep, as well as functional neuroanatomy, physiologic changes during sleep, and circadian rhythms. The classification and diagnosis of sleep disorders are discussed generally. The diagnosis and treatment of the following disorders are described: obstructive sleep apnea syndrome, narcolepsy-cataplexy sydrome, idiopathic hypersomnia, restless legs syndrome (RLS) and periodic limb movements in sleep, circadian rhythm sleep disorders, insomnias, nocturnal frontal lobe epilepsy, and parasomnias. Sleep-related movement disorders and the relationship between sleep and psychiatric disorders are also discussed. Tables describe behavioral and physiologic characteristics of states of awareness, the international classification of sleep disorders, common sleep complaints, comorbid insomnia disorders, causes of excessive daytime somnolence, laboratory tests to assess sleep disorders, essential diagnostic criteria for RLS and Willis-Ekbom disease, and drug therapy for insomnia. Figures include polysomnographic recording showing wakefulness in an adult; stage 1, 2, and 3 NREM sleep in an adult; REM sleep in an adult; a patient with sleep apnea syndrome; a patient with Cheyne-Stokes breathing; a patient with RLS; and a patient with dream-enacting behavior; schematic sagittal section of the brainstem of the cat; schematic diagram of the McCarley-Hobson model of REM sleep mechanism; the Lu-Saper “flip-flop” model; the Luppi model to explain REM sleep mechanism; and a wrist actigraph from a man with bipolar disorder. This review contains 14 highly rendered figures, 8 tables, 115 references, and 5 MCQs.

scholarly journals REM Sleep Behavior Disorder (RBD) in Dementia with Lewy Bodies (DLB)

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Po-Chi Chan ◽  
Hsun-Hua Lee ◽  
Chien-Tai Hong ◽  
Chaur-Jong Hu ◽  
Dean Wu
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Dementia With Lewy Bodies ◽  
Clinical Manifestations ◽  
Lewy Bodies ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Rapid Eye Movement ◽  
Sleep Behavior ◽  
Neurologic Disorders

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia, with abnormal dream-enacting behavior during the rapid eye movement (REM) sleep. RBD is either idiopathic or secondary to other neurologic disorders and medications. Dementia with Lewy bodies (DLB) is the third most common cause of dementia, and the typical clinical presentation is rapidly progressive cognitive impairment. RBD is one of the core features of DLB and may occur either in advance or simultaneously with the onset of DLB. The association between RBD with DLB is widely studied. Evidences suggest that both DLB and RBD are possibly caused by the shared underlying synucleinopathy. This review article discusses history, clinical manifestations, possible pathophysiologies, and treatment of DLB and RBD and provides the latest updates.

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