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Kon K, Ode KL, Mano T, Fujishima H, Takahashi RR, Tone D, Shimizu C, Shiono S, Yada S, Matsuzawa K, Yoshida SY, Yoshida Garçon J, Kaneko M, Shinohara Y, Yamada RG, Shi S, Miyamichi K, Sumiyama K, Kiyonari H, Susaki EA, Ueda HR. Cortical parvalbumin neurons are responsible for homeostatic sleep rebound through CaMKII activation. Nat Commun 2024; 15:6054. [PMID: 39025867 PMCID: PMC11258272 DOI: 10.1038/s41467-024-50168-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 07/01/2024] [Indexed: 07/20/2024] Open
Abstract
The homeostatic regulation of sleep is characterized by rebound sleep after prolonged wakefulness, but the molecular and cellular mechanisms underlying this regulation are still unknown. In this study, we show that Ca2+/calmodulin-dependent protein kinase II (CaMKII)-dependent activity control of parvalbumin (PV)-expressing cortical neurons is involved in homeostatic regulation of sleep in male mice. Prolonged wakefulness enhances cortical PV-neuron activity. Chemogenetic suppression or activation of cortical PV neurons inhibits or induces rebound sleep, implying that rebound sleep is dependent on increased activity of cortical PV neurons. Furthermore, we discovered that CaMKII kinase activity boosts the activity of cortical PV neurons, and that kinase activity is important for homeostatic sleep rebound. Here, we propose that CaMKII-dependent PV-neuron activity represents negative feedback inhibition of cortical neural excitability, which serves as the distributive cortical circuits for sleep homeostatic regulation.
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Affiliation(s)
- Kazuhiro Kon
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Kennedy Krieger Institute, Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Koji L Ode
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
| | - Tomoyuki Mano
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Department of Information Physics and Computing, Graduate School of Information Science and Technology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology, Onna, Okinawa, Japan
| | - Hiroshi Fujishima
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Department of Systems Biology, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
| | - Riina R Takahashi
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Daisuke Tone
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
| | - Chika Shimizu
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
| | - Shinnosuke Shiono
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Saori Yada
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- International Institute for Integrative Sleep Medicine (IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Kyoko Matsuzawa
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
| | - Shota Y Yoshida
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
| | - Junko Yoshida Garçon
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Izumi, Osaka, Japan
| | - Mari Kaneko
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research (BDR), Chuou-ku, Kobe, Hyogo, Japan
| | - Yuta Shinohara
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Division of Molecular Psychoimmunology, Institute for Genetic Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Rikuhiro G Yamada
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Department of Systems Biology, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
| | - Shoi Shi
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- International Institute for Integrative Sleep Medicine (IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Kazunari Miyamichi
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research (BDR), Chuou-ku, Kobe, Hyogo, Japan
| | - Kenta Sumiyama
- Laboratory for Mouse Genetic Engineering, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Laboratory of Animal Genetics and Breeding, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research (BDR), Chuou-ku, Kobe, Hyogo, Japan
| | - Etsuo A Susaki
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan
- Department of Biochemistry and Systems Biomedicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
- Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Suita, Osaka, Japan.
- Department of Information Physics and Computing, Graduate School of Information Science and Technology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
- Department of Systems Biology, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan.
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Ahmad M, Kim J, Dwyer B, Sokoloff G, Blumberg MS. Coincident development and synchronization of sleep-dependent delta in the cortex and medulla. Curr Biol 2024; 34:2570-2579.e5. [PMID: 38772363 PMCID: PMC11187663 DOI: 10.1016/j.cub.2024.04.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 03/27/2024] [Accepted: 04/26/2024] [Indexed: 05/23/2024]
Abstract
In early development, active sleep is the predominant sleep state before it is supplanted by quiet sleep. In rats, the developmental increase in quiet sleep is accompanied by the sudden emergence of the cortical delta rhythm (0.5-4 Hz) around postnatal day 12 (P12). We sought to explain the emergence of the cortical delta by assessing developmental changes in the activity of the parafacial zone (PZ), a medullary structure thought to regulate quiet sleep in adults. We recorded from the PZ in P10 and P12 rats and predicted an age-related increase in neural activity during increasing periods of delta-rich cortical activity. Instead, during quiet sleep, we discovered sleep-dependent rhythmic spiking activity-with intervening periods of total silence-phase locked to a local delta rhythm. Moreover, PZ and cortical delta were coherent at P12 but not at P10. PZ delta was also phase locked to respiration, suggesting sleep-dependent modulation of PZ activity by respiratory pacemakers in the ventral medulla. Disconnecting the main olfactory bulbs from the cortex did not diminish cortical delta, indicating that the influence of respiration on delta at this age is not mediated indirectly through nasal breathing. Finally, we observed an increase in parvalbumin-expressing terminals in the PZ across these ages, supporting a role for local GABAergic inhibition in the PZ's rhythmicity. The unexpected discovery of delta-rhythmic neural activity in the medulla-when cortical delta is also emerging-provides a new perspective on the brainstem's role in regulating sleep and promoting long-range functional connectivity in early development.
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Affiliation(s)
- Midha Ahmad
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Jangjin Kim
- Department of Psychology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Brett Dwyer
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Greta Sokoloff
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA
| | - Mark S Blumberg
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA.
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Ahmad M, Kim J, Dwyer B, Sokoloff G, Blumberg MS. DELTA-RHYTHMIC ACTIVITY IN THE MEDULLA DEVELOPS COINCIDENT WITH CORTICAL DELTA IN SLEEPING INFANT RATS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.16.572000. [PMID: 38168267 PMCID: PMC10760077 DOI: 10.1101/2023.12.16.572000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
In early development, active sleep is the predominant sleep state before it is supplanted by quiet sleep. In rats, the developmental increase in quiet sleep is accompanied by the sudden emergence of the cortical delta rhythm (0.5-4 Hz) around postnatal day 12 (P12). We sought to explain the emergence of cortical delta by assessing developmental changes in the activity of the parafacial zone (PZ), a medullary structure thought to regulate quiet sleep in adults. We recorded from PZ in P10 and P12 rats and predicted an age-related increase in neural activity during increasing periods of delta-rich cortical activity. Instead, during quiet sleep we discovered sleep-dependent rhythmic spiking activity-with intervening periods of total silence-phase-locked to a local delta rhythm. Moreover, PZ and cortical delta were coherent at P12, but not at P10. PZ delta was also phase-locked to respiration, suggesting sleep-dependent modulation of PZ activity by respiratory pacemakers in the ventral medulla. Disconnecting the main olfactory bulbs from the cortex did not diminish cortical delta, indicating that the influence of respiration on delta at this age is not mediated indirectly through nasal breathing. Finally, we observed an increase in parvalbumin-expressing terminals in PZ across these ages, supporting a role for GABAergic inhibition in PZ's rhythmicity. The discovery of delta-rhythmic neural activity in the medulla-when cortical delta is also emerging-opens a new path to understanding the brainstem's role in regulating sleep and synchronizing rhythmic activity throughout the brain.
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Affiliation(s)
- Midha Ahmad
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Jangjin Kim
- Department of Psychology, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Brett Dwyer
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Greta Sokoloff
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242 USA
| | - Mark S Blumberg
- Department of Psychological & Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242 USA
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Tabuena DR, Huynh R, Metcalf J, Richner T, Stroh A, Brunton BW, Moody WJ, Easton CR. Large-scale waves of activity in the neonatal mouse brain in vivo occur almost exclusively during sleep cycles. Dev Neurobiol 2022; 82:596-612. [PMID: 36250606 PMCID: PMC10166374 DOI: 10.1002/dneu.22901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/09/2022] [Accepted: 10/06/2022] [Indexed: 01/30/2023]
Abstract
Spontaneous electrical activity plays major roles in the development of cortical circuitry. This activity can occur highly localized regions or can propagate over the entire cortex. Both types of activity coexist during early development. To investigate how different forms of spontaneous activity might be temporally segregated, we used wide-field trans-cranial calcium imaging over an entire hemisphere in P1-P8 mouse pups. We found that spontaneous waves of activity that propagate to cover the majority of the cortex (large-scale waves; LSWs) are generated at the end of the first postnatal week, along with several other forms of more localized activity. We further found that LSWs are segregated into sleep cycles. In contrast, cortical activity during wake states is more spatially restricted and the few large-scale forms of activity that occur during wake can be distinguished from LSWs in sleep based on their initiation in the motor cortex and their correlation with body movements. This change in functional cortical circuitry to a state that is permissive for large-scale activity may temporally segregate different forms of activity during critical stages when activity-dependent circuit development occurs over many spatial scales. Our data also suggest that LSWs in early development may be a functional precursor to slow sleep waves in the adult, which play critical roles in memory consolidation and synaptic rescaling.
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Affiliation(s)
- Dennis R Tabuena
- Department of Biology, University of Washington, Seattle, Washington, USA.,Graduate Program in Neuroscience, University of Washington, Seattle, Washington, USA
| | - Randy Huynh
- Department of Biology, University of Washington, Seattle, Washington, USA
| | - Jenna Metcalf
- Department of Biology, University of Washington, Seattle, Washington, USA
| | - Thomas Richner
- Institute for Neuroengineering, University of Washington, Seattle, Washington, USA
| | - Albrecht Stroh
- Institute of Pathophysiology, University Medical Center Mainz, Mainz, Germany.,Leibniz Institute for Resilience Research, University Medical Center Mainz, Mainz, Germany
| | - Bingni W Brunton
- Department of Biology, University of Washington, Seattle, Washington, USA.,Institute for Neuroengineering, University of Washington, Seattle, Washington, USA
| | - William J Moody
- Department of Biology, University of Washington, Seattle, Washington, USA.,Institute for Neuroengineering, University of Washington, Seattle, Washington, USA
| | - Curtis R Easton
- Department of Biology, University of Washington, Seattle, Washington, USA
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Georgoulas A, Jones L, Laudiano-Dray MP, Meek J, Fabrizi L, Whitehead K. Sleep-wake regulation in preterm and term infants. Sleep 2021; 44:5889156. [PMID: 32770211 PMCID: PMC7819838 DOI: 10.1093/sleep/zsaa148] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/25/2020] [Indexed: 11/19/2022] Open
Abstract
Study Objectives In adults, wakefulness can be markedly prolonged at the expense of sleep, e.g. to stay vigilant in the presence of a stressor. These extra-long wake bouts result in a heavy-tailed distribution (highly right-skewed) of wake but not sleep durations. In infants, the relative importance of wakefulness and sleep are reversed, as sleep is necessary for brain maturation. Here, we tested whether these developmental pressures are associated with the unique regulation of sleep–wake states. Methods In 175 infants of 28–40 weeks postmenstrual age (PMA), we monitored sleep–wake states using electroencephalography and behavior. We constructed survival models of sleep–wake bout durations and the effect of PMA and other factors, including stress (salivary cortisol), and examined whether sleep is resilient to nociceptive perturbations (a clinically necessary heel lance). Results Wake durations followed a heavy-tailed distribution as in adults and lengthened with PMA and stress. However, differently from adults, active sleep durations also had a heavy-tailed distribution, and with PMA, these shortened and became vulnerable to nociception-associated awakenings. Conclusions Sleep bouts are differently regulated in infants, with especially long active sleep durations that could consolidate this state’s maturational functions. Curtailment of sleep by stress and nociception may be disadvantageous, especially for preterm infants given the limited value of wakefulness at this age. This could be addressed by environmental interventions in the future.
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Affiliation(s)
| | - Laura Jones
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Maria Pureza Laudiano-Dray
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Judith Meek
- Elizabeth Garrett Anderson Wing, University College London Hospitals, London, United Kingdom
| | - Lorenzo Fabrizi
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Kimberley Whitehead
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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Glutamatergic Neurons in the Preoptic Hypothalamus Promote Wakefulness, Destabilize NREM Sleep, Suppress REM Sleep, and Regulate Cortical Dynamics. J Neurosci 2021; 41:3462-3478. [PMID: 33664133 PMCID: PMC8051693 DOI: 10.1523/jneurosci.2718-20.2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 01/24/2021] [Accepted: 02/22/2021] [Indexed: 11/21/2022] Open
Abstract
Clinical and experimental data from the last nine decades indicate that the preoptic area of the hypothalamus is a critical node in a brain network that controls sleep onset and homeostasis. By contrast, we recently reported that a group of glutamatergic neurons in the lateral and medial preoptic area increases wakefulness, challenging the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic. Clinical and experimental data from the last nine decades indicate that the preoptic area of the hypothalamus is a critical node in a brain network that controls sleep onset and homeostasis. By contrast, we recently reported that a group of glutamatergic neurons in the lateral and medial preoptic area increases wakefulness, challenging the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic. However, the precise role of these subcortical neurons in the control of behavioral state transitions and cortical dynamics remains unknown. Therefore, in this study, we used conditional expression of excitatory hM3Dq receptors in these preoptic glutamatergic (Vglut2+) neurons and show that their activation initiates wakefulness, decreases non-rapid eye movement (NREM) sleep, and causes a persistent suppression of rapid eye movement (REM) sleep. We also demonstrate, for the first time, that activation of these preoptic glutamatergic neurons causes a high degree of NREM sleep fragmentation, promotes state instability with frequent arousals from sleep, decreases body temperature, and shifts cortical dynamics (including oscillations, connectivity, and complexity) to a more wake-like state. We conclude that a subset of preoptic glutamatergic neurons can initiate, but not maintain, arousals from sleep, and their inactivation may be required for NREM stability and REM sleep generation. Further, these data provide novel empirical evidence supporting the hypothesis that the preoptic area causally contributes to the regulation of both sleep and wakefulness. SIGNIFICANCE STATEMENT Historically, the preoptic area of the hypothalamus has been considered a key site for sleep generation. However, emerging modeling and empirical data suggest that this region might play a dual role in sleep-wake control. We demonstrate that chemogenetic stimulation of preoptic glutamatergic neurons produces brief arousals that fragment sleep, persistently suppresses REM sleep, causes hypothermia, and shifts EEG patterns toward a “lighter” NREM sleep state. We propose that preoptic glutamatergic neurons can initiate, but not maintain, arousal from sleep and gate REM sleep generation, possibly to block REM-like intrusions during NREM-to-wake transitions. In contrast to the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic, we provide further evidence that preoptic neurons also generate wakefulness.
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de Vivo L, Nagai H, De Wispelaere N, Spano GM, Marshall W, Bellesi M, Nemec KM, Schiereck SS, Nagai M, Tononi G, Cirelli C. Evidence for sleep-dependent synaptic renormalization in mouse pups. Sleep 2020; 42:5543176. [PMID: 31374117 PMCID: PMC6802737 DOI: 10.1093/sleep/zsz184] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 06/13/2019] [Indexed: 12/14/2022] Open
Abstract
In adolescent and adult brains several molecular, electrophysiological, and ultrastructural measures of synaptic strength are higher after wake than after sleep [1, 2]. These results support the proposal that a core function of sleep is to renormalize the increase in synaptic strength associated with ongoing learning during wake, to reestablish cellular homeostasis and avoid runaway potentiation, synaptic saturation, and memory interference [2, 3]. Before adolescence however, when the brain is still growing and many new synapses are forming, sleep is widely believed to promote synapse formation and growth. To assess the role of sleep on synapses early in life, we studied 2-week-old mouse pups (both sexes) whose brain is still undergoing significant developmental changes, but in which sleep and wake are easy to recognize. In two strains (CD-1, YFP-H) we found that pups spend ~50% of the day asleep and show an immediate increase in total sleep duration after a few hours of enforced wake, indicative of sleep homeostasis. In YFP-H pups we then used serial block-face electron microscopy to examine whether the axon-spine interface (ASI), an ultrastructural marker of synaptic strength, changes between wake and sleep. We found that the ASI of cortical synapses (layer 2, motor cortex) was on average 33.9% smaller after sleep relative to after extended wake and the differences between conditions were consistent with multiplicative scaling. Thus, the need for sleep-dependent synaptic renormalization may apply also to the young, pre-weaned cerebral cortex, at least in the superficial layers of the primary motor area.
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Affiliation(s)
- Luisa de Vivo
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | - Hirotaka Nagai
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | | | | | - William Marshall
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | - Michele Bellesi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | | | | | - Midori Nagai
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
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Cirelli C, Tononi G. Effects of sleep and waking on the synaptic ultrastructure. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190235. [PMID: 32248785 PMCID: PMC7209920 DOI: 10.1098/rstb.2019.0235] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We summarize here several studies performed in our laboratory, mainly using serial block-face scanning electron microscopy (SBEM), to assess how sleep, spontaneous waking and short sleep deprivation affect the size and number of synapses in the cerebral cortex and hippocampus. With SBEM, we reconstructed thousands of cortical and hippocampal excitatory, axospinous synapses and compared the distribution of their size after several hours of sleep relative to several hours of waking. Because stronger synapses are on average also bigger, the goal was to test a prediction of the synaptic homeostasis hypothesis, according to which overall synaptic strength increases during waking, owing to ongoing learning, and needs to be renormalized during sleep, to avoid saturation and to benefit memory consolidation and integration. Consistent with this hypothesis, we found that the size of the axon–spine interface (ASI), a morphological measure of synaptic strength, was on average smaller after sleep, but with interesting differences between primary cortex and the CA1 region of the hippocampus. In two-week-old mouse pups, the decline in ASI size after sleep was larger, and affected more cortical synapses, compared with one-month-old adolescent mice, suggesting that synaptic renormalization during sleep may be especially important during early development. This work is still in progress and other brain areas need to be tested after sleep, acute sleep loss and chronic sleep restriction. Still, the current results show that a few hours of sleep or waking lead to significant changes in synaptic morphology that can be linked to changes in synaptic efficacy. This article is part of the Theo Murphy meeting issue ‘Memory reactivation: replaying events past, present and future’.
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Affiliation(s)
- Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719, USA
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719, USA
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9
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Lemons A, Saré RM, Beebe Smith C. Chronic Sleep Deprivation in Mouse Pups by Means of Gentle Handling. J Vis Exp 2018. [PMID: 30371669 DOI: 10.3791/58150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Sleep is critical for proper development and neural plasticity. Moreover, abnormal sleep patterns are characteristic of many neurodevelopmental disorders. Studying how chronic sleep restriction during development can affect adult behavior may add to our understanding of the emergence of behavioral symptoms of neurodevelopmental disorders. While there are many methods that can be used to restrict sleep in rodents including forced locomotion, constant disruption, presentation of an aversive stimulus, or electric shock, many of these methods are very stressful and cannot be used in neonatal mice. Here, we describe gentle handling, a sleep deprivation technique that can be used chronically throughout development and into adulthood to achieve sleep restriction. Gentle handling involves close observation of the mice throughout the sleep deprivation period and requires the researcher to gently prod the animals whenever they are inactive or display behaviors associated with sleep. Coupled with EEG recordings, gentle handling could be used to selectively disrupt a specific phase of sleep such as rapid eye movement (REM) sleep. The technique of gentle handling is a powerful tool for the study of the effects of chronic sleep restriction even in neonatal mice that circumvents many of the more stressful procedures used for sleep deprivation.
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Affiliation(s)
- Abigail Lemons
- Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health
| | - R Michelle Saré
- Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health
| | - Carolyn Beebe Smith
- Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health;
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10
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Frank MG, Ruby NF, Heller HC, Franken P. Development of Circadian Sleep Regulation in the Rat: A Longitudinal Study Under Constant Conditions. Sleep 2017; 40:2741265. [PMID: 28364421 PMCID: PMC6251512 DOI: 10.1093/sleep/zsw077] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2016] [Indexed: 01/11/2023] Open
Abstract
Study Objectives To better understand the development of sleep, we characterized the development of circadian rhythms in sleep and wakefulness in the artificially-reared, isolated rat pup using an experimental design that minimized the effects of maternal separation. Methods Neonatal rats were reared in constant conditions (dim red light) while electroencephalographic and electromyographic signals were continuously recorded for up to 3 weeks. This time period spanned the preweaned and weaned ages. The distribution of sleep-wake states was analyzed to estimate the emergence of circadian rhythms. Results Overt ~24-hour rhythms in time spent awake and asleep appear by postnatal day (P)17. A marked bi-modal sleep-wake pattern was also observed, evidenced by the appearance of a pronounced ~12-hour component in the periodogram over the subsequent 3 days (P17-P21). This suggested the presence of two ~24-hour components consistent with the dual-oscillator concept. During this 3-day time window, waking bouts became longer resulting in a repartition of the duration of intervals without non-rapid-eye movement (NREM) sleep into short (<30 minutes) and longer inter-NREM sleep episodes. These longer waking bouts did not immediately result in an increase in NREM sleep delta (0.5-4.0 Hz) power, which is an index of sleep homeostasis in adult mammals. The sleep homeostatic response did not fully mature until P25. Conclusions These results demonstrate that the maturation of circadian organization of sleep-wake behavior precedes the expression of mature sleep homeostasis.
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Affiliation(s)
- Marcos G Frank
- Elson S. Floyd College of Medicine, Department of Biomedical Sciences, Washington State University, Spokane WA
- Department of Biology, Stanford University, Stanford, CA
| | - Norman F Ruby
- Department of Biology, Stanford University, Stanford, CA
| | | | - Paul Franken
- Department of Biology, Stanford University, Stanford, CA
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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11
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Gvilia I, Suntsova N, Kostin A, Kalinchuk A, McGinty D, Basheer R, Szymusiak R. The role of adenosine in the maturation of sleep homeostasis in rats. J Neurophysiol 2016; 117:327-335. [PMID: 27784808 DOI: 10.1152/jn.00675.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/24/2016] [Indexed: 01/08/2023] Open
Abstract
Sleep homeostasis in rats undergoes significant maturational changes during postweaning development, but the underlying mechanisms of this process are unknown. In the present study we tested the hypothesis that the maturation of sleep is related to the functional emergence of adenosine (AD) signaling in the brain. We assessed postweaning changes in 1) wake-related elevation of extracellular AD in the basal forebrain (BF) and adjacent lateral preoptic area (LPO), and 2) the responsiveness of median preoptic nucleus (MnPO) sleep-active cells to increasing homeostatic sleep drive. We tested the ability of exogenous AD to augment homeostatic responses to sleep deprivation (SD) in newly weaned rats. In groups of postnatal day (P)22 and P30 rats, we collected dialysate from the BF/LPO during baseline (BSL) wake-sleep, SD, and recovery sleep (RS). HPLC analysis of microdialysis samples revealed that SD in P30 rats results in significant increases in AD levels compared with BSL. P22 rats do not exhibit changes in AD levels in response to SD. We recorded neuronal activity in the MnPO during BSL, SD, and RS at P22/P30. MnPO neurons exhibited adult-like increases in waking neuronal discharge across SD on both P22 and P30, but discharge rates during enforced wake were higher on P30 vs. P22. Central administration of AD (1 nmol) during SD on P22 resulted in increased sleep time and EEG slow-wave activity during RS compared with saline control. Collectively, these findings support the hypothesis that functional reorganization of an adenosinergic mechanism of sleep regulation contributes to the maturation of sleep homeostasis. NEW & NOTEWORTHY Brain mechanisms that regulate the maturation of sleep are understudied. The present study generated first evidence about a potential mechanistic role for adenosine in the maturation of sleep homeostasis. Specifically, we demonstrate that early postweaning development in rats, when homeostatic response to sleep loss become adult like, is characterized by maturational changes in wake-related production/release of adenosine in the brain. Pharmacologically increased adenosine signaling in developing brain facilitates homeostatic responses to sleep deprivation.
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Affiliation(s)
- Irma Gvilia
- Research Service (151A3), Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California; .,Department of Medicine, University of California, Los Angeles, California.,Ilia State University, Tbilisi, Georgia; and
| | - Natalia Suntsova
- Research Service (151A3), Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California.,Department of Medicine, University of California, Los Angeles, California
| | - Andrey Kostin
- Research Service (151A3), Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California
| | - Anna Kalinchuk
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Dennis McGinty
- Research Service (151A3), Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California.,Department of Psychology, University of California, Los Angeles, California
| | - Radhika Basheer
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Ronald Szymusiak
- Research Service (151A3), Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California.,Department of Medicine, University of California, Los Angeles, California
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12
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Pospelov AS, Yukin AY, Blumberg MS, Puskarjov M, Kaila K. Forebrain-independent generation of hyperthermic convulsions in infant rats. Epilepsia 2015; 57:e1-6. [PMID: 26547277 PMCID: PMC4738399 DOI: 10.1111/epi.13230] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2015] [Indexed: 11/30/2022]
Abstract
Febrile seizures are the most common type of convulsive events in children. It is generally assumed that the generalization of these seizures is a result of brainstem invasion by the initial limbic seizure activity. Using precollicular transection in 13‐day‐old rats to isolate the forebrain from the brainstem, we demonstrate that the forebrain is not required for generation of tonic–clonic convulsions induced by hyperthermia or kainate. Compared with sham‐operated littermate controls, latency to onset of convulsions in both models was significantly shorter in pups that had undergone precollicular transection, indicating suppression of the brainstem seizure network by the forebrain in the intact animal. We have shown previously that febrile seizures are precipitated by hyperthermia‐induced respiratory alkalosis. Here, we show that triggering of hyperthermia‐induced hyperventilation and consequent convulsions in transected animals are blocked by diazepam. The present data suggest that the role of endogenous brainstem activity in triggering tonic–clonic seizures should be re‐evaluated in standard experimental models of limbic seizures. Our work sheds new light on the mechanisms that generate febrile seizures in children and, therefore, on how they might be treated.
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Affiliation(s)
- Alexey S Pospelov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Alexey Y Yukin
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Mark S Blumberg
- Departments of Psychology and Biology, University of Iowa, Iowa City, Iowa, U.S.A
| | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
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13
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Cirelli C, Tononi G. Cortical development, electroencephalogram rhythms, and the sleep/wake cycle. Biol Psychiatry 2015; 77:1071-8. [PMID: 25680672 PMCID: PMC4444390 DOI: 10.1016/j.biopsych.2014.12.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 12/10/2014] [Accepted: 12/17/2014] [Indexed: 02/07/2023]
Abstract
During adulthood, electroencephalogram (EEG) recordings are used to distinguish wake, non-rapid eye movement sleep, and rapid eye movement sleep states. The close association between behavioral states and EEG rhythms is reached late during development, after birth in humans and by the end of the second postnatal week in rats and mice. This critical time is also when cortical activity switches from a discontinuous to a continuous pattern. We review the major cellular and network changes that can account for this transition. After this close link is established, new evidence suggests that the slow waves of non-rapid eye movement sleep may function as markers to track cortical development. However, before the EEG can be used to identify behavioral states, two distinct sleep phases--quiet sleep and active sleep--are identified based on behavioral criteria and muscle activity. During this early phase of development, cortical activity is far from being disorganized, despite the presence of long periods of neuronal silence and the poor modulation by behavioral states. Specific EEG patterns, such as spindle bursts and gamma oscillations, have been identified very early on and are believed to play a significant role in the refinement of brain circuits. Because most early EEG patterns do not map to a specific behavioral state, their contribution to the presumptive role of sleep in brain maturation remains to be established and should be a major focus for future research.
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Affiliation(s)
- Chiara Cirelli
- Department of Psychiatry, University of Wisconsin, Madison, Wisconsin..
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14
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Qiu MH, Chen MC, Lu J. Cortical neuronal activity does not regulate sleep homeostasis. Neuroscience 2015; 297:211-8. [PMID: 25864961 DOI: 10.1016/j.neuroscience.2015.03.070] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 02/08/2015] [Accepted: 03/12/2015] [Indexed: 11/29/2022]
Abstract
The neural substrate of sleep homeostasis is unclear, but both cortical and subcortical structures are thought to be involved in sleep regulation. To test whether prior neuronal activity in the cortex or in subcortical regions drives sleep rebound, we systemically administered atropine (100mg/kg) to rats, producing a dissociated state with slow-wave cortical electroencephalogram (EEG) but waking behavior (e.g. locomotion). Atropine injections during the light period produced 6h of slow-wave cortical EEG but also subcortical arousal. Afterward, rats showed a significant increase in non-rapid eye movement (NREM) sleep, compared to the same period on a baseline day. Consistent with the behavioral and cortical EEG state produced by systemic atropine, c-Fos expression was low in the cortex but high in multiple subcortical arousal systems. These data suggest that subcortical arousal and behavior are sufficient to drive sleep homeostasis, while a sleep-like pattern of cortical activity is not sufficient to satisfy sleep homeostasis.
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Affiliation(s)
- M-H Qiu
- State Key Laboratory of Medical Neurobiology and Department of Neurobiology, School of Basic Medical Science, Fudan University, Shanghai 200032, China; Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston 02115, USA.
| | - M C Chen
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston 02115, USA
| | - J Lu
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston 02115, USA.
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15
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Tiriac A, Del Rio-Bermudez C, Blumberg MS. Self-generated movements with "unexpected" sensory consequences. Curr Biol 2014; 24:2136-2141. [PMID: 25131675 DOI: 10.1016/j.cub.2014.07.053] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/19/2014] [Accepted: 07/21/2014] [Indexed: 02/08/2023]
Abstract
The nervous systems of diverse species, including worms and humans, possess mechanisms for distinguishing between sensations arising from self-generated (i.e., expected) movements from those arising from other-generated (i.e., unexpected) movements [1-3]. To make this critical distinction, animals generate copies, or corollary discharges, of motor commands [4, 5]. Corollary discharge facilitates the selective gating of reafferent signals arising from self-generated movements, thereby enhancing detection of novel stimuli [6-10]. However, for a developing nervous system, such sensory gating would be counterproductive if it impedes transmission of the very activity upon which activity-dependent mechanisms depend [11]. In infant rats during active (or REM) sleep--a behavioral state that predominates in early infancy [12-16]--neural circuits within the brainstem [17, 18] trigger hundreds of thousands of myoclonic twitches each day [19]. The putative contribution of these self-generated movements to the activity-dependent development of the sensorimotor system is supported by the observation that reafference from twitching limbs reliably and substantially triggers brain activity [20-23]. In contrast, under identical testing conditions, even the most vigorous wake movements reliably fail to trigger reafferent brain activity [21-23]. One hypothesis that accounts for this paradox is that twitches, uniquely among self-generated movements, lack corollary discharge [23]. Here, we test this hypothesis in newborn rats by manipulating the degree to which self-generated movements are expected and, therefore, their presumed recruitment of corollary discharge. We show that twitches, although self-generated, are processed as if they are unexpected.
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Affiliation(s)
- Alexandre Tiriac
- Department of Psychology, University of Iowa, Iowa City, IA 52242, USA; Delta Center, University of Iowa, Iowa City, IA 52242, USA
| | | | - Mark S Blumberg
- Department of Psychology, University of Iowa, Iowa City, IA 52242, USA; Delta Center, University of Iowa, Iowa City, IA 52242, USA; Department of Biology, University of Iowa, Iowa City, IA 52242, USA.
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16
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Nelson AB, Faraguna U, Zoltan JT, Tononi G, Cirelli C. Sleep patterns and homeostatic mechanisms in adolescent mice. Brain Sci 2014; 3:318-43. [PMID: 23772316 PMCID: PMC3682503 DOI: 10.3390/brainsci3010318] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Sleep changes were studied in mice (n = 59) from early adolescence to adulthood (postnatal days P19–111). REM sleep declined steeply in early adolescence, while total sleep remained constant and NREM sleep increased slightly. Four hours of sleep deprivation starting at light onset were performed from ages P26 through adulthood (>P60). Following this acute sleep deprivation all mice slept longer and with more consolidated sleep bouts, while NREM slow wave activity (SWA) showed high interindividual variability in the younger groups, and increased consistently only after P42. Three parameters together explained up to 67% of the variance in SWA rebound in frontal cortex, including weight-adjusted age and increase in alpha power during sleep deprivation, both of which positively correlated with the SWA response. The third, and strongest predictor was the SWA decline during the light phase in baseline: mice with high peak SWA at light onset, resulting in a large SWA decline, were more likely to show no SWA rebound after sleep deprivation, a result that was also confirmed in parietal cortex. During baseline, however, SWA showed the same homeostatic changes in adolescents and adults, declining in the course of sleep and increasing across periods of spontaneous wake. Thus, we hypothesize that, in young adolescent mice, a ceiling effect and not the immaturity of the cellular mechanisms underlying sleep homeostasis may prevent the SWA rebound when wake is extended beyond its physiological duration.
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Affiliation(s)
- Aaron B. Nelson
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; E-Mails: (A.B.N.); (U.F.); (J.T.Z.); (G.T.)
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ugo Faraguna
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; E-Mails: (A.B.N.); (U.F.); (J.T.Z.); (G.T.)
| | - Jeffrey T. Zoltan
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; E-Mails: (A.B.N.); (U.F.); (J.T.Z.); (G.T.)
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; E-Mails: (A.B.N.); (U.F.); (J.T.Z.); (G.T.)
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; E-Mails: (A.B.N.); (U.F.); (J.T.Z.); (G.T.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-608-263-9236; Fax: +1-608-263-9340
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17
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Smith CB, Walker K, Badawi N, Waters KA, MacLean JE. Impact of sleep and breathing in infancy on outcomes at three years of age for children with cleft lip and/or palate. Sleep 2014; 37:919-25. [PMID: 24790270 DOI: 10.5665/sleep.3660] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
STUDY OBJECTIVES To evaluate the relationship between sleep disordered breathing (SDB) in early infancy and outcomes at 3 years of age in children with cleft lip and/or palate (CL/P). DESIGN Observational follow-up study. SETTING Multidisciplinary CL/P clinic, tertiary centre. PARTICIPANTS Children with CL/P who participated in a study of sleep and breathing in infancy. MEASUREMENTS AND RESULTS The families of 52 children were approached for this follow-up study. The children underwent neurocognitive (Bayley Scales of Infant and Toddler Development, Third Edition; BSID-III), quality of life (Infant/Toddler Quality of Life Questionnaire; ITQOL), and growth assessments at 3 years. The families of 33 children (66%) completed follow-up at 36.7 ± 1.4 months. The apnea-hypopnea index (AHI) in infancy was 23.9 ± 18.0 events/h. Mean group BSID-III scores fell within the standardized normal range (10 ± 3) for all domains; however, language scores were lower than control children. Quality of life scores and growth parameter z-scores were similar to published control data. PSG variables in infancy showed significant relationships with outcomes at 3 years of age; lower percentage of AS/REM sleep was associated with lower cognition score; more obstructive events were associated with lower global behavior ITQOL score; and higher number of respiratory events in infancy was associated with lower weight z-score. CONCLUSION Neurocognition, quality of life, and growth measures from children with CL/P fall within a normal range; however, scores in the language domain are lower than controls. Sleep and respiratory elements of SDB in infancy appear to modify these outcomes at 3 years of age.
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Affiliation(s)
- Courtney B Smith
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, NSW, Australia ; Medical Program, University of New South, Sydney, NSW, Australia
| | - Karen Walker
- Discipline of Paediatrics & Child Health, University of Sydney, Sydney, NSW, Australia ; Neonatal Intensive Care Unit, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Nadia Badawi
- Discipline of Paediatrics & Child Health, University of Sydney, Sydney, NSW, Australia ; Neonatal Intensive Care Unit, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Karen A Waters
- Discipline of Paediatrics & Child Health, University of Sydney, Sydney, NSW, Australia ; Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Joanna E MacLean
- Department of Pediatrics & The Women & Children's Research Institute, University of Alberta, Edmonton, AB, Canada ; Discipline of Paediatrics & Child Health, University of Sydney, Sydney, NSW, Australia ; Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, NSW, Australia
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18
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Blumberg MS, Gall AJ, Todd WD. The development of sleep-wake rhythms and the search for elemental circuits in the infant brain. Behav Neurosci 2014; 128:250-63. [PMID: 24708298 DOI: 10.1037/a0035891] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Despite the predominance of sleep in early infancy, developmental science has yet to play a major role in shaping concepts and theories about sleep and its associated ultradian and circadian rhythms. Here we argue that developmental analyses help us to elucidate the relative contributions of the brainstem and forebrain to sleep-wake control and to dissect the neural components of sleep-wake rhythms. Developmental analysis also makes it clear that sleep-wake processes in infants are the foundation for those of adults. For example, the infant brainstem alone contains a fundamental sleep-wake circuit that is sufficient to produce transitions among wakefulness, quiet sleep, and active sleep. In addition, consistent with the requirements of a "flip-flop" model of sleep-wake processes, this brainstem circuit supports rapid transitions between states. Later in development, strengthening bidirectional interactions between the brainstem and forebrain contribute to the consolidation of sleep and wake bouts, the elaboration of sleep homeostatic processes, and the emergence of diurnal or nocturnal circadian rhythms. The developmental perspective promoted here critically constrains theories of sleep-wake control and provides a needed framework for the creation of fully realized computational models. Finally, with a better understanding of how this system is constructed developmentally, we will gain insight into the processes that govern its disintegration due to aging and disease.
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Affiliation(s)
| | | | - William D Todd
- Department of Neurology, Beth Israel Deaconess Medical Center
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Todd WD, Gall AJ, Weiner JA, Blumberg MS. Distinct retinohypothalamic innervation patterns predict the developmental emergence of species-typical circadian phase preference in nocturnal Norway rats and diurnal nile grass rats. J Comp Neurol 2012; 520:3277-92. [PMID: 22431036 PMCID: PMC3676184 DOI: 10.1002/cne.23098] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
How does the brain develop differently to support nocturnality in some mammals, but diurnality in others? To answer this question, one might look to the suprachiasmatic nucleus (SCN), which is entrained by light via the retinohypothalamic tract (RHT). However, because the SCN is more active during the day in all mammals studied thus far, it alone cannot determine circadian phase preference. In adult Norway rats (Rattus norvegicus), which are nocturnal, the RHT also projects to the ventral subparaventricular zone (vSPVZ), an adjacent region that expresses an in-phase pattern of SCN-vSPVZ neuronal activity. In contrast, in adult Nile grass rats (Arvicanthis niloticus), which are diurnal, an anti-phase pattern of SCN-vSPVZ neuronal activity is expressed. We hypothesized that these species differences result in part from a weak or absent RHT-to-vSPVZ projection in grass rats. Here, using a developmental comparative approach, we assessed species differences in behavior, hypothalamic activity, and RHT anatomy. We report that a robust retina-to-vSPVZ projection develops in Norway rats around the end of the second postnatal week when nocturnal wakefulness and the in-phase pattern of neuronal activity emerge. In grass rats, however, such a projection does not develop and the emergence of the anti-phase pattern during the second postnatal week is accompanied by increased diurnal wakefulness. When considered within the context of previously published reports on RHT projections in a variety of species, the current findings suggest that how and when the retina connects to the hypothalamus differentially shapes brain and behavior to produce animals that occupy opposing temporal niches.
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Affiliation(s)
- William D. Todd
- Program in Behavioral and Cognitive Neuroscience, Department of Psychology, University of Iowa, Iowa City, IA, 52242, USA
| | - Andrew J. Gall
- Program in Behavioral and Cognitive Neuroscience, Department of Psychology, University of Iowa, Iowa City, IA, 52242, USA
| | - Joshua A. Weiner
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Mark S. Blumberg
- Program in Behavioral and Cognitive Neuroscience, Department of Psychology, University of Iowa, Iowa City, IA, 52242, USA
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20
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Gall AJ, Todd WD, Blumberg MS. Development of SCN connectivity and the circadian control of arousal: a diminishing role for humoral factors? PLoS One 2012; 7:e45338. [PMID: 23028945 PMCID: PMC3441626 DOI: 10.1371/journal.pone.0045338] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 08/20/2012] [Indexed: 11/19/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) is part of a wake-promoting circuit comprising the dorsomedial hypothalamus (DMH) and locus coeruleus (LC). Although widely considered a "master clock," the SCN of adult rats is also sensitive to feedback regarding an animal's behavioral state. Interestingly, in rats at postnatal day (P)2, repeated arousing stimulation does not increase neural activation in the SCN, despite doing so in the LC and DMH. Here we show that, by P8, the SCN is activated by arousing stimulation and that selective destruction of LC terminals with DSP-4 blocks this activational effect. We next show that bidirectional projections among the SCN, DMH, and LC are nearly absent at P2 but present at P8. Despite the relative lack of SCN connectivity with downstream structures at P2, day-night differences in sleep-wake activity are observed, suggesting that the SCN modulates behavior at this age via humoral factors. To test this hypothesis, we lesioned the SCN at P1 and recorded sleep-wake behavior at P2: Day-night differences in sleep and wake were eliminated. We next performed precollicular transections at P2 and P8 that isolate the SCN and DMH from the brainstem and found that day-night differences in sleep-wake behavior were retained at P2 but eliminated at P8. Finally, the SCN or DMH was lesioned at P8: When recorded at P21, rats with either lesion exhibited similarly fragmented wake bouts and no evidence of circadian modulation of wakefulness. These results suggest an age-related decline in the SCN's humoral influence on sleep-wake behavior that coincides with the emergence of bidirectional connectivity among the SCN, DMH, and LC.
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Affiliation(s)
- Andrew J. Gall
- Department of Psychology, University of Iowa, Iowa City, Iowa, United States of America
| | - William D. Todd
- Department of Psychology, University of Iowa, Iowa City, Iowa, United States of America
| | - Mark S. Blumberg
- Department of Psychology, University of Iowa, Iowa City, Iowa, United States of America
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21
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Activation of inactivation process initiates rapid eye movement sleep. Prog Neurobiol 2012; 97:259-76. [PMID: 22521402 DOI: 10.1016/j.pneurobio.2012.04.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 04/01/2012] [Accepted: 04/02/2012] [Indexed: 02/07/2023]
Abstract
Interactions among REM-ON and REM-OFF neurons form the basic scaffold for rapid eye movement sleep (REMS) regulation; however, precise mechanism of their activation and cessation, respectively, was unclear. Locus coeruleus (LC) noradrenalin (NA)-ergic neurons are REM-OFF type and receive GABA-ergic inputs among others. GABA acts postsynaptically on the NA-ergic REM-OFF neurons in the LC and presynaptically on the latter's projection terminals and modulates NA-release on the REM-ON neurons. Normally during wakefulness and non-REMS continuous release of NA from the REM-OFF neurons, which however, is reduced during the latter phase, inhibits the REM-ON neurons and prevents REMS. At this stage GABA from substantia nigra pars reticulate acting presynaptically on NA-ergic terminals on REM-ON neurons withdraws NA-release causing the REM-ON neurons to escape inhibition and being active, may be even momentarily. A working-model showing neurochemical-map explaining activation of inactivation process, showing contribution of GABA-ergic presynaptic inhibition in withdrawing NA-release and dis-inhibition induced activation of REM-ON neurons, which in turn activates other GABA-ergic neurons and shutting-off REM-OFF neurons for the initiation of REMS-generation has been explained. Our model satisfactorily explains yet unexplained puzzles (i) why normally REMS does not appear during waking, rather, appears following non-REMS; (ii) why cessation of LC-NA-ergic-REM-OFF neurons is essential for REMS-generation; (iii) factor(s) which does not allow cessation of REM-OFF neurons causes REMS-loss; (iv) the association of changes in levels of GABA and NA in the brain during REMS and its deprivation and associated symptoms; v) why often dreams are associated with REMS.
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Gvilia I, Suntsova N, Angara B, McGinty D, Szymusiak R. Maturation of sleep homeostasis in developing rats: a role for preoptic area neurons. Am J Physiol Regul Integr Comp Physiol 2011; 300:R885-94. [PMID: 21325650 DOI: 10.1152/ajpregu.00727.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study evaluated the hypothesis that developmental changes in hypothalamic sleep-regulatory neuronal circuits contribute to the maturation of sleep homeostasis in rats during the fourth postnatal week. In a longitudinal study, we quantified electrographic measures of sleep during baseline and in response to sleep deprivation (SD) on postnatal days 21/29 (P21/29) and P22/30 (experiment 1). During 24-h baseline recordings on P21, total sleep time (TST) during the light and dark phases did not differ significantly. On P29, TST during the light phase was significantly higher than during the dark phase. Mean duration of non-rapid-eye-movement (NREM) sleep bouts was significantly longer on P29 vs. P21, indicating improved sleep consolidation. On both P22 and P30, rats exhibited increased NREM sleep amounts and NREM electroencephalogram delta power during recovery sleep (RS) compared with baseline. Increased NREM sleep bout length during RS was observed only on P30. In experiment 2, we quantified activity of GABAergic neurons in median preoptic nucleus (MnPN) and ventrolateral preoptic area (VLPO) during SD and RS in separate groups of P22 and P30 rats using c-Fos and glutamic acid decarboxylase (GAD) immunohistochemistry. In P22 rats, numbers of Fos(+)GAD(+) neurons in VLPO did not differ among experimental conditions. In P30 rats, Fos(+)GAD(+) counts in VLPO were elevated during RS. MnPN neuronal activity was state-dependent in P22 rats, but Fos(+)GAD(+) cell counts were higher in P30 rats. These findings support the hypothesis that functional emergence of preoptic sleep-regulatory neurons contributes to the maturation of sleep homeostasis in the developing rat brain.
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Affiliation(s)
- Irma Gvilia
- Research Service (151A3), VA Greater Los Angeles, 16111 Plummer St., North Hills, CA 91344, USA.
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23
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Dygalo NN, Kalinina TS, Shishkina G. Evidence that negative regulation of wakefulness in neonatal rats is an intrinsic function of the brain α2A-adrenergic receptors. Neurosci Lett 2010; 486:224-7. [PMID: 20884323 DOI: 10.1016/j.neulet.2010.09.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 09/16/2010] [Accepted: 09/18/2010] [Indexed: 11/25/2022]
Abstract
Previously, it was proposed that sedative and anesthetic effects of alpha2-adrenergic receptor (alpha2-AR) agonists may be exerted via neuronal networks normally implicated in the regulation of wakefulness. The aim of this study was to evaluate the role of A subtype of alpha2-ARs in the development of drug-independent anesthetic state induced by hypothermia in newborn rats. Using short interfering RNA (siRNA) gene-targeting strategy, we found that down-regulation of the brainstem alpha2A-AR expression resulted in a delay in the onset of hypothermia-induced anesthesia assessed by loss of righting reflex. Involvement of the brain alpha2A-ARs in this delay was confirmed by inability of clonidine, a subtype-nonselective alpha2-AR agonist, to prolong duration of hypothermia-induced anesthesia in siRNA-treated animals, while significant prolongation of this anesthetic state by the alpha2A-AR agonist was observed in control pups. The data suggest that negative regulation of the animal's waking state is an intrinsic function of the brainstem alpha2A-ARs activated by exogenous agonists, as well as by endogenous noradrenaline, also.
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Affiliation(s)
- Nikolay N Dygalo
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Lavrentjev av., 10, Novosibirsk 630090, Russia
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