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Murphy M, Jiang C, Wang LA, Kozhemiako N, Wang Y, Wang J, Pan JQ, Purcell SM. Electroencephalographic Microstates During Sleep and Wake in Schizophrenia. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:100371. [PMID: 39296796 PMCID: PMC11408315 DOI: 10.1016/j.bpsgos.2024.100371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 09/21/2024] Open
Abstract
Background Aberrant functional connectivity is a hallmark of schizophrenia. The precise nature and mechanism of dysconnectivity in schizophrenia remains unclear, but evidence suggests that dysconnectivity is different in wake versus sleep. Microstate analysis uses electroencephalography (EEG) to investigate large-scale patterns of coordinated brain activity by clustering EEG data into a small set of recurring spatial patterns, or microstates. We hypothesized that this technique would allow us to probe connectivity between brain networks at a fine temporal resolution and uncover previously unknown sleep-specific dysconnectivity. Methods We studied microstates during sleep in patients with schizophrenia by analyzing high-density EEG sleep data from 114 patients with schizophrenia and 79 control participants. We used a polarity-insensitive k-means analysis to extract a set of 6 microstate topographies. Results These 6 states included 4 widely reported canonical microstates. In patients and control participants, falling asleep was characterized by a shift from microstates A, B, and C to microstates D, E, and F. Microstate F was decreased in patients during wake, and microstate E was decreased in patients during sleep. The complexity of microstate transitions was greater in patients than control participants during wake, but this reversed during sleep. Conclusions Our findings reveal behavioral state-dependent patterns of cortical dysconnectivity in schizophrenia. Furthermore, these findings are largely unrelated to previous sleep-related EEG markers of schizophrenia such as decreased sleep spindles. Therefore, these findings are driven by previously undescribed sleep-related pathology in schizophrenia.
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Affiliation(s)
- Michael Murphy
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, Massachusetts
| | - Chenguang Jiang
- Affiliated Wuxi Mental Health Center of Jiangnan University, Wuxi, Jiangsu, China
| | - Lei A. Wang
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Nataliia Kozhemiako
- Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yining Wang
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Jun Wang
- Affiliated Wuxi Mental Health Center of Jiangnan University, Wuxi, Jiangsu, China
| | - Jen Q. Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Shaun M. Purcell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
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Marsh B, Navas-Zuloaga MG, Rosen BQ, Sokolov Y, Delanois JE, Gonzalez OC, Krishnan GP, Halgren E, Bazhenov M. Emergent effects of synaptic connectivity on the dynamics of global and local slow waves in a large-scale thalamocortical network model of the human brain. PLoS Comput Biol 2024; 20:e1012245. [PMID: 39028760 PMCID: PMC11290683 DOI: 10.1371/journal.pcbi.1012245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 07/31/2024] [Accepted: 06/11/2024] [Indexed: 07/21/2024] Open
Abstract
Slow-wave sleep (SWS), characterized by slow oscillations (SOs, <1Hz) of alternating active and silent states in the thalamocortical network, is a primary brain state during Non-Rapid Eye Movement (NREM) sleep. In the last two decades, the traditional view of SWS as a global and uniform whole-brain state has been challenged by a growing body of evidence indicating that SO can be local and can coexist with wake-like activity. However, the mechanisms by which global and local SOs arise from micro-scale neuronal dynamics and network connectivity remain poorly understood. We developed a multi-scale, biophysically realistic human whole-brain thalamocortical network model capable of transitioning between the awake state and SWS, and we investigated the role of connectivity in the spatio-temporal dynamics of sleep SO. We found that the overall strength and a relative balance between long and short-range synaptic connections determined the network state. Importantly, for a range of synaptic strengths, the model demonstrated complex mixed SO states, where periods of synchronized global slow-wave activity were intermittent with the periods of asynchronous local slow-waves. An increase in the overall synaptic strength led to synchronized global SO, while a decrease in synaptic connectivity produced only local slow-waves that would not propagate beyond local areas. These results were compared to human data to validate probable models of biophysically realistic SO. The model producing mixed states provided the best match to the spatial coherence profile and the functional connectivity estimated from human subjects. These findings shed light on how the spatio-temporal properties of SO emerge from local and global cortical connectivity and provide a framework for further exploring the mechanisms and functions of SWS in health and disease.
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Affiliation(s)
- Brianna Marsh
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
- Neuroscience Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - M. Gabriela Navas-Zuloaga
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Burke Q. Rosen
- Neuroscience Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - Yury Sokolov
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Jean Erik Delanois
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California, United States of America
| | - Oscar C. Gonzalez
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Giri P. Krishnan
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Eric Halgren
- Neuroscience Graduate Program, University of California San Diego, La Jolla, California, United States of America
- Departments of Radiology and Neuroscience, University of California San Diego, La Jolla, California, United States of America
| | - Maxim Bazhenov
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
- Neuroscience Graduate Program, University of California San Diego, La Jolla, California, United States of America
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The Feature of Sleep Spindle Deficits in Patients With Schizophrenia With and Without Auditory Verbal Hallucinations. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2023; 8:331-342. [PMID: 34380082 DOI: 10.1016/j.bpsc.2021.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/10/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Previous sleep electroencephalography studies have detected abnormalities in sleep architecture and sleep spindle deficits in schizophrenia (SCZ), but the consistency of these results was not robust, which might be due to the small sample size and the influence of clinical factors such as the various medication therapies and symptom heterogeneity. This study aimed to regard auditory verbal hallucinations (AVHs) as a pointcut to downscale the heterogeneity of SCZ and explore whether some sleep architecture and spindle parameters were more severely impaired in SCZ patients with AVHs compared with those without AVHs. METHODS A total of 90 SCZ patients with AVHs, 92 SCZ patients without AVHs, and 91 healthy control subjects were recruited, and parameters of sleep architecture and spindle activities were compared between groups. The correlation between significant sleep parameters and clinical indicators was analyzed. RESULTS Deficits of sleep spindle activities at prefrontal electrodes and intrahemispheric spindle coherence were observed in both AVH and non-AVH groups, several of which were more serious in the AVH group. In addition, deficits of spindle activities at central and occipital electrodes and interhemispheric spindle coherence mainly manifested accompanying AVH symptoms, most of which were retained in the medication-naive first-episode patients, and were associated with Auditory Hallucination Rating Scale scores. CONCLUSIONS Our results suggest that the underlying mechanism of spindle deficits might be different between SCZ patients with and without AVHs. In the future, the sleep feature of SCZ patients with different symptoms and the influence of clinical factors, such as medication therapy, should be further illustrated.
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Thalamic control of sensory processing and spindles in a biophysical somatosensory thalamoreticular circuit model of wakefulness and sleep. Cell Rep 2023; 42:112200. [PMID: 36867532 PMCID: PMC10066598 DOI: 10.1016/j.celrep.2023.112200] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 01/04/2023] [Accepted: 02/15/2023] [Indexed: 03/04/2023] Open
Abstract
Thalamoreticular circuitry plays a key role in arousal, attention, cognition, and sleep spindles, and is linked to several brain disorders. A detailed computational model of mouse somatosensory thalamus and thalamic reticular nucleus has been developed to capture the properties of over 14,000 neurons connected by 6 million synapses. The model recreates the biological connectivity of these neurons, and simulations of the model reproduce multiple experimental findings in different brain states. The model shows that inhibitory rebound produces frequency-selective enhancement of thalamic responses during wakefulness. We find that thalamic interactions are responsible for the characteristic waxing and waning of spindle oscillations. In addition, we find that changes in thalamic excitability control spindle frequency and their incidence. The model is made openly available to provide a new tool for studying the function and dysfunction of the thalamoreticular circuitry in various brain states.
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Sun S, Wang H. Clocking Epilepsies: A Chronomodulated Strategy-Based Therapy for Rhythmic Seizures. Int J Mol Sci 2023; 24:4223. [PMID: 36835631 PMCID: PMC9962262 DOI: 10.3390/ijms24044223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/08/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Epilepsy is a neurological disorder characterized by hypersynchronous recurrent neuronal activities and seizures, as well as loss of muscular control and sometimes awareness. Clinically, seizures have been reported to display daily variations. Conversely, circadian misalignment and circadian clock gene variants contribute to epileptic pathogenesis. Elucidation of the genetic bases of epilepsy is of great importance because the genetic variability of the patients affects the efficacies of antiepileptic drugs (AEDs). For this narrative review, we compiled 661 epilepsy-related genes from the PHGKB and OMIM databases and classified them into 3 groups: driver genes, passenger genes, and undetermined genes. We discuss the potential roles of some epilepsy driver genes based on GO and KEGG analyses, the circadian rhythmicity of human and animal epilepsies, and the mutual effects between epilepsy and sleep. We review the advantages and challenges of rodents and zebrafish as animal models for epileptic studies. Finally, we posit chronomodulated strategy-based chronotherapy for rhythmic epilepsies, integrating several lines of investigation for unraveling circadian mechanisms underpinning epileptogenesis, chronopharmacokinetic and chronopharmacodynamic examinations of AEDs, as well as mathematical/computational modeling to help develop time-of-day-specific AED dosing schedules for rhythmic epilepsy patients.
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Affiliation(s)
- Sha Sun
- Center for Circadian Clocks, Soochow University, Suzhou 215123, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou 215123, China
| | - Han Wang
- Center for Circadian Clocks, Soochow University, Suzhou 215123, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou 215123, China
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Holter KM, Pierce BE, Gould RW. Metabotropic glutamate receptor function and regulation of sleep-wake cycles. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 168:93-175. [PMID: 36868636 DOI: 10.1016/bs.irn.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Metabotropic glutamate (mGlu) receptors are the most abundant family of G-protein coupled receptors and are widely expressed throughout the central nervous system (CNS). Alterations in glutamate homeostasis, including dysregulations in mGlu receptor function, have been indicated as key contributors to multiple CNS disorders. Fluctuations in mGlu receptor expression and function also occur across diurnal sleep-wake cycles. Sleep disturbances including insomnia are frequently comorbid with neuropsychiatric, neurodevelopmental, and neurodegenerative conditions. These often precede behavioral symptoms and/or correlate with symptom severity and relapse. Chronic sleep disturbances may also be a consequence of primary symptom progression and can exacerbate neurodegeneration in disorders including Alzheimer's disease (AD). Thus, there is a bidirectional relationship between sleep disturbances and CNS disorders; disrupted sleep may serve as both a cause and a consequence of the disorder. Importantly, comorbid sleep disturbances are rarely a direct target of primary pharmacological treatments for neuropsychiatric disorders even though improving sleep can positively impact other symptom clusters. This chapter details known roles of mGlu receptor subtypes in both sleep-wake regulation and CNS disorders focusing on schizophrenia, major depressive disorder, post-traumatic stress disorder, AD, and substance use disorder (cocaine and opioid). In this chapter, preclinical electrophysiological, genetic, and pharmacological studies are described, and, when possible, human genetic, imaging, and post-mortem studies are also discussed. In addition to reviewing the important relationships between sleep, mGlu receptors, and CNS disorders, this chapter highlights the development of selective mGlu receptor ligands that hold promise for improving both primary symptoms and sleep disturbances.
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Affiliation(s)
- Kimberly M Holter
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Bethany E Pierce
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Robert W Gould
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States.
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Mayeli A, Wilson JD, Donati FL, LaGoy AD, Ferrarelli F. Sleep spindle alterations relate to working memory deficits in individuals at clinical high-risk for psychosis. Sleep 2022; 45:zsac193. [PMID: 35981865 PMCID: PMC9644126 DOI: 10.1093/sleep/zsac193] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/10/2022] [Indexed: 08/12/2023] Open
Abstract
STUDY OBJECTIVES Sleep spindles are waxing and waning EEG waves exemplifying the main fast oscillatory activity occurring during NREM sleep. Several recent studies have established that sleep spindle abnormalities are present in schizophrenia spectrum disorders, including in early-course and first-episode patients, and those spindle deficits are associated with some of the cognitive impairments commonly observed in these patients. Cognitive deficits are often observed before the onset of psychosis and seem to predict poor functional outcomes in individuals at clinical high-risk for psychosis (CHR). Yet, the presence of spindle abnormalities and their relationship with cognitive dysfunction has not been investigated in CHR. METHODS In this study, overnight high-density (hd)-EEG recordings were collected in 24 CHR and 24 healthy control (HC) subjects. Spindle density, duration, amplitude, and frequency were computed and compared between CHR and HC. Furthermore, WM was assessed for both HC and CHR, and its relationship with spindle parameters was examined. RESULTS CHR had reduced spindle duration in centro-parietal and prefrontal regions, with the largest decrease in the right prefrontal area. Moderation analysis showed that the relation between spindle duration and spindle frequency was altered in CHR relative to HC. Furthermore, CHR had reduced WM performance compared to HC, which was predicted by spindle frequency, whereas in HC spindle frequency, duration, and density all predicted working memory performance. CONCLUSION Altogether, these findings indicate that sleep spindles are altered in CHR individuals, and spindle alterations are associated with their cognitive deficits, thus representing a sleep-specific putative neurophysiological biomarker of cognitive dysfunction in psychosis risk.
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Affiliation(s)
- Ahmad Mayeli
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - James D Wilson
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Alice D LaGoy
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
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Malerba P, Whitehurst L, Mednick SC. The space-time profiles of sleep spindles and their coordination with slow oscillations on the electrode manifold. Sleep 2022; 45:6603295. [PMID: 35666552 PMCID: PMC9366646 DOI: 10.1093/sleep/zsac132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 05/19/2022] [Indexed: 11/17/2022] Open
Abstract
Sleep spindles are important for sleep quality and cognitive functions, with their coordination with slow oscillations (SOs) potentially organizing cross-region reactivation of memory traces. Here, we describe the organization of spindles on the electrode manifold and their relation to SOs. We analyzed the sleep night EEG of 34 subjects and detected spindles and SOs separately at each electrode. We compared spindle properties (frequency, duration, and amplitude) in slow wave sleep (SWS) and Stage 2 sleep (S2); and in spindles that coordinate with SOs or are uncoupled. We identified different topographical spindle types using clustering analysis that grouped together spindles co-detected across electrodes within a short delay (±300 ms). We then analyzed the properties of spindles of each type, and coordination to SOs. We found that SWS spindles are shorter than S2 spindles, and spindles at frontal electrodes have higher frequencies in S2 compared to SWS. Furthermore, S2 spindles closely following an SO (about 10% of all spindles) show faster frequency, shorter duration, and larger amplitude than uncoupled ones. Clustering identified Global, Local, Posterior, Frontal-Right and Left spindle types. At centro-parietal locations, Posterior spindles show faster frequencies compared to other types. Furthermore, the infrequent SO-spindle complexes are preferentially recruiting Global SO waves coupled with fast Posterior spindles. Our results suggest a non-uniform participation of spindles to complexes, especially evident in S2. This suggests the possibility that different mechanisms could initiate an SO-spindle complex compared to SOs and spindles separately. This has implications for understanding the role of SOs-spindle complexes in memory reactivation.
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Affiliation(s)
- Paola Malerba
- Battelle Center for Mathematical Medicine, The Research Institute at Nationwide Children’s Hospital , Columbus, OH , USA
- School of Medicine, The Ohio State University , Columbus, OH , USA
| | - Lauren Whitehurst
- Department of Psychology, University of Kentucky , Lexington, KY , USA
| | - Sara C Mednick
- Department of Cognitive Science, University of California Irvine , Irvine, CA , USA
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Abstract
The conventional wisdom that sleep is a global state, affecting the whole brain uniformly and simultaneously, was overturned by the discovery of local sleep, where individual neuronal populations were found to be asleep and the rest of the brain awake. However, due to the difficulty of monitoring local neuronal states in humans, our understanding of local sleep remains limited. Using simultaneous functional MRI (fMRI) and electroencephalography, we find that the oscillations of brain hemodynamic activity provide signatures of sleep at a local neuronal population level. We show that the fMRI signatures of sleep can be employed to monitor local neuronal states and investigate which brain regions are the first to fall asleep or wake up at wake–sleep transitions. Sleep can be distinguished from wake by changes in brain electrical activity, typically assessed using electroencephalography (EEG). The hallmark of nonrapid-eye-movement (NREM) sleep is the shift from high-frequency, low-amplitude wake EEG to low-frequency, high-amplitude sleep EEG dominated by spindles and slow waves. Here we identified signatures of sleep in brain hemodynamic activity, using simultaneous functional MRI (fMRI) and EEG. We found that, at the transition from wake to sleep, fMRI blood oxygen level–dependent (BOLD) activity evolved from a mixed-frequency pattern to one dominated by two distinct oscillations: a low-frequency (<0.1 Hz) oscillation prominent in light sleep and correlated with the occurrence of spindles, and a high-frequency oscillation (>0.1 Hz) prominent in deep sleep and correlated with the occurrence of slow waves. The two oscillations were both detectable across the brain but exhibited distinct spatiotemporal patterns. During the falling-asleep process, the low-frequency oscillation first appeared in the thalamus, then the posterior cortex, and lastly the frontal cortex, while the high-frequency oscillation first appeared in the midbrain, then the frontal cortex, and lastly the posterior cortex. During the waking-up process, both oscillations disappeared first from the thalamus, then the frontal cortex, and lastly the posterior cortex. The BOLD oscillations provide local signatures of spindle and slow wave activity. They may be employed to monitor the regional occurrence of sleep or wakefulness, track which regions are the first to fall asleep or wake up at the wake–sleep transitions, and investigate local homeostatic sleep processes.
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Lai M, Hegde R, Kelly S, Bannai D, Lizano P, Stickgold R, Manoach DS, Keshavan M. Investigating sleep spindle density and schizophrenia: A meta-analysis. Psychiatry Res 2022; 307:114265. [PMID: 34922240 DOI: 10.1016/j.psychres.2021.114265] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/25/2021] [Accepted: 10/31/2021] [Indexed: 11/26/2022]
Abstract
Sleep abnormalities are an early feature of schizophrenia (SZ) characterized by reductions in sleep spindles that are associated with deficits in brain connectivity and cognitive function. This study investigated sleep spindle density (SSD) differences between SZ, first episode psychosis (FEP), and family high-risk (FHR) populations and matched healthy controls (HC) by investigating recent studies via a meta-analysis. We collected experimental, demographic, and methodological metrics from eligible studies across multiple online databases. 14 total studies survived the inclusion and exclusion criteria for a total of 337 patients and relatives and 339 HC. R-Studio was used to run the meta-analysis via the meta and metaphor packages. A heterogeneity score of I2 = 80% was calculated and thus a random effects model was chosen. We report a large effect size for SSD in patients compared to controls. Furthermore, illness duration was significantly associated with SSD. Our next step to understanding sleep spindles would be to investigate SSD's use as a predictor for SZ or attempt to normalize SSD deficits as a therapeutic option.
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Affiliation(s)
- Matthew Lai
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States
| | - Rachal Hegde
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States
| | - Sinead Kelly
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States; Department of Psychiatry, Harvard Medical School, Boston, MA, United States; Department of Psychiatry, Brigham and Women's Hospital, Boston, MA, United States
| | - Deepthi Bannai
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States
| | - Paulo Lizano
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States; Department of Psychiatry, Harvard Medical School, Boston, MA, United States
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States; Department of Psychiatry, Harvard Medical School, Boston, MA, United States
| | - Dara S Manoach
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States; Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Matcheri Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center, Boston, MA, United States; Department of Psychiatry, Harvard Medical School, Boston, MA, United States.
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Saponati M, Garcia-Ojalvo J, Cataldo E, Mazzoni A. Thalamocortical Spectral Transmission Relies on Balanced Input Strengths. Brain Topogr 2021; 35:4-18. [PMID: 34089121 PMCID: PMC8813837 DOI: 10.1007/s10548-021-00851-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 05/05/2021] [Indexed: 12/27/2022]
Abstract
The thalamus is a key element of sensory transmission in the brain, as it gates and selects sensory streams through a modulation of its internal activity. A preponderant role in these functions is played by its internal activity in the alpha range ([8–14] Hz), but the mechanism underlying this process is not completely understood. In particular, how do thalamocortical connections convey stimulus driven information selectively over the back-ground of thalamic internally generated activity? Here we investigate this issue with a spiking network model of feedforward connectivity between thalamus and primary sensory cortex reproducing the local field potential of both areas. We found that in a feedforward network, thalamic oscillations in the alpha range do not entrain cortical activity for two reasons: (i) alpha range oscillations are weaker in neurons projecting to the cortex, (ii) the gamma resonance dynamics of cortical networks hampers oscillations over the 10–20 Hz range thus weakening alpha range oscillations. This latter mechanism depends on the balance of the strength of thalamocortical connections toward excitatory and inhibitory neurons in the cortex. Our results highlight the relevance of corticothalamic feedback to sustain alpha range oscillations and pave the way toward an integrated understanding of the sensory streams traveling between the periphery and the cortex.
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Affiliation(s)
- Matteo Saponati
- The Biorobotics Institute, Department of Excellence in Robotics and AI, Sant'Anna School of Advanced Studies, Viale Rinaldo Piaggio 34, 56025, Pontedera, IT, Italy.,Dipartimento di Fisica "E. Fermi", Largo Bruno Pontecorvo 3, 56127, Pisa, IT, Italy
| | - Jordi Garcia-Ojalvo
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park Dr. Aiguader 88, 08003, Barcelona, ES, Spain
| | - Enrico Cataldo
- Dipartimento di Fisica "E. Fermi", Largo Bruno Pontecorvo 3, 56127, Pisa, IT, Italy
| | - Alberto Mazzoni
- The Biorobotics Institute, Department of Excellence in Robotics and AI, Sant'Anna School of Advanced Studies, Viale Rinaldo Piaggio 34, 56025, Pontedera, IT, Italy.
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Zhou K, Zhu L, Hou G, Chen X, Chen B, Yang C, Zhu Y. The Contribution of Thalamic Nuclei in Salience Processing. Front Behav Neurosci 2021; 15:634618. [PMID: 33664657 PMCID: PMC7920982 DOI: 10.3389/fnbeh.2021.634618] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 01/11/2021] [Indexed: 12/13/2022] Open
Abstract
The brain continuously receives diverse information about the external environment and changes in the homeostatic state. The attribution of salience determines which stimuli capture attention and, therefore, plays an essential role in regulating emotions and guiding behaviors. Although the thalamus is included in the salience network, the neural mechanism of how the thalamus contributes to salience processing remains elusive. In this mini-review, we will focus on recent advances in understanding the specific roles of distinct thalamic nuclei in salience processing. We will summarize the functional connections between thalamus nuclei and other key nodes in the salience network. We will highlight the convergence of neural circuits involved in reward and pain processing, arousal, and attention control in thalamic structures. We will discuss how thalamic activities represent salience information in associative learning and how thalamic neurons modulate adaptive behaviors. Lastly, we will review recent studies which investigate the contribution of thalamic dysfunction to aberrant salience processing in neuropsychiatric disorders, such as drug addiction, posttraumatic stress disorder (PTSD), and schizophrenia. Based on emerging evidence from both human and rodent research, we propose that the thalamus, different from previous studies that as an information relay, has a broader role in coordinating the cognitive process and regulating emotions.
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Affiliation(s)
- Kuikui Zhou
- Shenzhen Key Laboratory of Drug Addiction, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Lin Zhu
- Department of Neonatology, Shenzhen Maternity & Child Healthcare Hospital, The First School of Clinical Medicine, Southern Medical University, Shenzhen, China
| | - Guoqiang Hou
- Shenzhen Key Laboratory of Drug Addiction, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Xueyu Chen
- Department of Neonatology, Shenzhen Maternity & Child Healthcare Hospital, The First School of Clinical Medicine, Southern Medical University, Shenzhen, China
| | - Bo Chen
- Shenzhen Key Laboratory of Drug Addiction, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Chuanzhong Yang
- Department of Neonatology, Shenzhen Maternity & Child Healthcare Hospital, The First School of Clinical Medicine, Southern Medical University, Shenzhen, China
| | - Yingjie Zhu
- Shenzhen Key Laboratory of Drug Addiction, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
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Zhang Y, Quiñones GM, Ferrarelli F. Sleep spindle and slow wave abnormalities in schizophrenia and other psychotic disorders: Recent findings and future directions. Schizophr Res 2020; 221:29-36. [PMID: 31753592 PMCID: PMC7231641 DOI: 10.1016/j.schres.2019.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/31/2019] [Accepted: 11/03/2019] [Indexed: 12/27/2022]
Abstract
Sleep spindles and slow waves are the two main oscillatory activities occurring during NREM sleep. Slow waves are ∼1 Hz, high amplitude, negative-positive deflections that are primarily generated and coordinated within the cortex, whereas sleep spindles are 12-16 Hz, waxing and waning oscillations that are initiated within the thalamus and regulated by thalamo-cortical circuits. In healthy subjects, these oscillations are thought to be responsible for the restorative aspects of sleep and have been increasingly shown to be involved in learning, memory and plasticity. Furthermore, deficits in sleep spindles and, to lesser extent, slow waves have been reported in both chronic schizophrenia (SCZ) and early course psychosis patients. In this article, we will first describe sleep spindle and slow wave characteristics, including their putative functional roles in the healthy brain. We will then review electrophysiological, genetic, and cognitive studies demonstrating spindle and slow wave impairments in SCZ and other psychotic disorders, with particularly emphasis on recent findings in early course patients. Finally, we will discuss how future work, including sleep studies in individuals at clinical high risk for psychosis, may help position spindles and slow waves as candidate biomarkers, as well as novel treatment targets, for SCZ and related psychotic disorders.
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Affiliation(s)
- Yingyi Zhang
- Department of Psychiatry, University of Pittsburgh, USA
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14
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Sharma SK, Mondal A, Mondal A, Upadhyay RK, Hens C. Emergence of bursting in a network of memory dependent excitable and spiking leech-heart neurons. J R Soc Interface 2020; 17:20190859. [PMID: 32574543 DOI: 10.1098/rsif.2019.0859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Excitable cells often produce different oscillatory activities that help us to understand the transmitting and processing of signals in the neural system. The diverse excitabilities of an individual neuron can be reproduced by a fractional-order biophysical model that preserves several previous memory effects. However, it is not completely clear to what extent the fractional-order dynamics changes the firing properties of excitable cells. In this article, we investigate the alternation of spiking and bursting phenomena of an uncoupled and coupled fractional leech-heart (L-H) neurons. We show that a complete graph of heterogeneous de-synchronized neurons in the backdrop of diverse memory settings (a mixture of integer and fractional exponents) can eventually lead to bursting with the formation of cluster synchronization over a certain threshold of coupling strength, however, the uncoupled L-H neurons cannot reveal bursting dynamics. Using the stability analysis in fractional domain, we demarcate the parameter space where the quiescent or steady-state emerges in uncoupled L-H neuron. Finally, a reduced-order model is introduced to capture the activities of the large network of fractional-order model neurons.
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Affiliation(s)
- Sanjeev Kumar Sharma
- Department of Mathematics and Computing, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
| | - Argha Mondal
- Computational Neuroscience Center, University of Washington, Seattle, WA, USA.,Physics and Applied Mathematics Unit, Indian Statistical Institute, BT Road, Kolkata 700108, India
| | - Arnab Mondal
- Department of Mathematics and Computing, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
| | - Ranjit Kumar Upadhyay
- Department of Mathematics and Computing, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India
| | - Chittaranjan Hens
- Physics and Applied Mathematics Unit, Indian Statistical Institute, BT Road, Kolkata 700108, India
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15
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Ritter-Makinson S, Clemente-Perez A, Higashikubo B, Cho FS, Holden SS, Bennett E, Chkhaidze A, Eelkman Rooda OHJ, Cornet MC, Hoebeek FE, Yamakawa K, Cilio MR, Delord B, Paz JT. Augmented Reticular Thalamic Bursting and Seizures in Scn1a-Dravet Syndrome. Cell Rep 2020; 26:54-64.e6. [PMID: 30605686 PMCID: PMC6555418 DOI: 10.1016/j.celrep.2018.12.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/07/2018] [Accepted: 12/03/2018] [Indexed: 11/26/2022] Open
Abstract
Loss of function in the Scn1a gene leads to a severe epileptic encephalopathy called Dravet syndrome (DS). Reduced excitability in cortical inhibitory neurons is thought to be the major cause of DS seizures. Here, in contrast, we show enhanced excitability in thalamic inhibitory neurons that promotes the non-convulsive seizures that are a prominent yet poorly understood feature of DS. In a mouse model of DS with a loss of function in Scn1a, reticular thalamic cells exhibited abnormally long bursts of firing caused by the downregulation of calcium-activated potassium SK channels. Our study supports a mechanism in which loss of SK activity causes the reticular thalamic neurons to become hyperexcitable and promote non-convulsive seizures in DS. We propose that reduced excitability of inhibitory neurons is not global in DS and that non-GABAergic mechanisms such as SK channels may be important targets for treatment. In a mouse model of Dravet syndrome (DS) resulting from voltage-gated sodium channel deficiency, Ritter-Makinson et al. find that inhibitory neurons of the reticular thalamic nucleus are paradoxically hyperexcitable due to compensatory reductions in a potassium SK current. Boosting this SK current treats nonconvulsive seizures in DS mice.
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Affiliation(s)
- Stefanie Ritter-Makinson
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alexandra Clemente-Perez
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Neurosciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bryan Higashikubo
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Frances S Cho
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Neurosciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephanie S Holden
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Neurosciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Eric Bennett
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ana Chkhaidze
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Oscar H J Eelkman Rooda
- Department of Neuroscience, Erasmus MC, Rotterdam, the Netherlands; Department of Neurosurgery, Erasmus MC, Rotterdam, the Netherlands
| | - Marie-Coralie Cornet
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Pediatrics, Catholic University of Louvain, Louvain, Belgium
| | - Freek E Hoebeek
- Department of Neuroscience, Erasmus MC, Rotterdam, the Netherlands; Department of Neurosurgery, Erasmus MC, Rotterdam, the Netherlands; NIDOD Institute, Wilhelmina Children's Hospital, University Medical Center Utrecht and Brain Center Rudolf Magnus, Utrecht, the Netherlands
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, Wako, Japan
| | - Maria Roberta Cilio
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bruno Delord
- Institut des Systèmes Intelligents et de Robotique (ISIR), Sorbonne University, 4 Place Jussieu, 75005 Paris, France
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA; Neurosciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA.
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16
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GABA B receptors: modulation of thalamocortical dynamics and synaptic plasticity. Neuroscience 2020; 456:131-142. [PMID: 32194227 DOI: 10.1016/j.neuroscience.2020.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 01/03/2023]
Abstract
GABAB-receptors (GABAB-Rs) are metabotropic, G protein-coupled receptors for the neurotransmitter GABA. Their activation induces slow inhibitory control of the neuronal excitability mediated by pre- and postsynaptic inhibition. Presynaptically GABAB-Rs reduce GABA and glutamate release inhibiting presynaptic Ca2+ channels in both inhibitory and excitatory synapses while postsynaptic GABAB-Rs induce robust slow hyperpolarization by the activation of K+ channels. GABAB-Rs are activated by non-synaptic or volume transmission, which requires high levels of GABA release, either by the simultaneous discharge of GABAergic interneurons or very intense discharges in the thalamus or by means of the activation of a neurogliaform interneurons in the cortex. The main receptor subunits GABAB1a, GABAB1b and GABAB2 are strongly expressed in neurons and glial cells throughout the central nervous system and GABAB-R activation is related to many neuronal processes such as the modulation of rhythmic activity in several brain regions. In the thalamus, GABAB-Rs modulate the generation of the main thalamic rhythm, spindle waves. In the cerebral cortex, GABAB-Rs also modulate the most prominent emergent oscillatory activity-slow oscillations-as well as faster oscillations like gamma frequency. Further, recent studies evaluating the complexity expressed by the cortical network, a parameter associated with consciousness levels, have found that GABAB-Rs enhance this complexity, while their blockade decreases it. This review summarizes the current results on how the activation of GABAB-Rs affects the interchange of information between brain areas by controlling rhythmicity as well as synaptic plasticity.
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17
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Rosen BQ, Krishnan GP, Sanda P, Komarov M, Sejnowski T, Rulkov N, Ulbert I, Eross L, Madsen J, Devinsky O, Doyle W, Fabo D, Cash S, Bazhenov M, Halgren E. Simulating human sleep spindle MEG and EEG from ion channel and circuit level dynamics. J Neurosci Methods 2019; 316:46-57. [PMID: 30300700 PMCID: PMC6380919 DOI: 10.1016/j.jneumeth.2018.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although they form a unitary phenomenon, the relationship between extracranial M/EEG and transmembrane ion flows is understood only as a general principle rather than as a well-articulated and quantified causal chain. METHOD We present an integrated multiscale model, consisting of a neural simulation of thalamus and cortex during stage N2 sleep and a biophysical model projecting cortical current densities to M/EEG fields. Sleep spindles were generated through the interactions of local and distant network connections and intrinsic currents within thalamocortical circuits. 32,652 cortical neurons were mapped onto the cortical surface reconstructed from subjects' MRI, interconnected based on geodesic distances, and scaled-up to current dipole densities based on laminar recordings in humans. MRIs were used to generate a quasi-static electromagnetic model enabling simulated cortical activity to be projected to the M/EEG sensors. RESULTS The simulated M/EEG spindles were similar in amplitude and topography to empirical examples in the same subjects. Simulated spindles with more core-dominant activity were more MEG weighted. COMPARISON WITH EXISTING METHODS Previous models lacked either spindle-generating thalamic neural dynamics or whole head biophysical modeling; the framework presented here is the first to simultaneously capture these disparate scales. CONCLUSIONS This multiscale model provides a platform for the principled quantitative integration of existing information relevant to the generation of sleep spindles, and allows the implications of future findings to be explored. It provides a proof of principle for a methodological framework allowing large-scale integrative brain oscillations to be understood in terms of their underlying channels and synapses.
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Affiliation(s)
- B Q Rosen
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States.
| | - G P Krishnan
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States.
| | - P Sanda
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States; Institute of Computer Science, Czech Academy of Sciences, Prague, Czech Republic.
| | - M Komarov
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States.
| | - T Sejnowski
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States; The Salk Institute, La Jolla, CA, United States.
| | - N Rulkov
- BioCiruits Institute, University of California, San Diego, La Jolla, CA, United States.
| | - I Ulbert
- Institute of Cognitive Neuroscience and Psychology, Hungarian Academy of Science, Budapest, Hungary; Faculty of Information Technology and Bionics, Peter Pazmany Catholic University, Budapest, Hungary.
| | - L Eross
- Faculty of Information Technology and Bionics, Peter Pazmany Catholic University, Budapest, Hungary; Department of Functional Neurosurgery, National Institute of Clinical Neurosciences, Budapest, Hungary.
| | - J Madsen
- Departments of Neurosurgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States.
| | - O Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, United States.
| | - W Doyle
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, United States.
| | - D Fabo
- Epilepsy Centrum, National Institute of Clinical Neurosciences, Budapest, Hungary.
| | - S Cash
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States; Department of Medicine, University of California, San Diego, La Jolla, CA, United States; Departments of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.
| | - M Bazhenov
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States; Department of Medicine, University of California, San Diego, La Jolla, CA, United States.
| | - E Halgren
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States; Department of Radiology, University of California, San Diego, La Jolla, CA, United States; Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States.
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18
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Khan S, Nobili L, Khatami R, Loddenkemper T, Cajochen C, Dijk DJ, Eriksson SH. Circadian rhythm and epilepsy. Lancet Neurol 2018; 17:1098-1108. [PMID: 30366868 DOI: 10.1016/s1474-4422(18)30335-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/18/2018] [Accepted: 08/31/2018] [Indexed: 12/11/2022]
Abstract
Advances in diagnostic technology, including chronic intracranial EEG recordings, have confirmed the clinical observation of different temporal patterns of epileptic activity and seizure occurrence over a 24-h period. The rhythmic patterns in epileptic activity and seizure occurrence are probably related to vigilance states and circadian variation in excitatory and inhibitory balance. Core circadian genes BMAL1 and CLOCK, which code for transcription factors, have been shown to influence excitability and seizure threshold. Despite uncertainties about the relative contribution of vigilance states versus circadian rhythmicity, including circadian factors such as seizure timing improves sensitivity of seizure prediction algorithms in individual patients. Improved prediction of seizure occurrence opens the possibility for personalised antiepileptic drug-dosing regimens timed to particular phases of the circadian cycle to improve seizure control and to reduce side-effects and risks associated with seizures. Further studies are needed to clarify the pathways through which rhythmic patterns of epileptic activity are generated, because this might also inform future treatment options.
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Affiliation(s)
- Sofia Khan
- Department of Clinical and Experimental Epilepsy, National Hospital for Neurology and Neurosurgery and Institute of Neurology, University College London, London, UK; Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Lino Nobili
- Centre of Sleep Medicine, Centre for Epilepsy Surgery C Munari, Niguarda Hospital, Milan, Italy; Child Neuropsychiatry Unit, IRCCS Giannina Gaslini Pediatric Institute, DINOGMI, University of Genoa, Italy
| | - Ramin Khatami
- Centre for Sleep Research, Sleep Medicine and Epileptology, Klinik Barmelweid AG, Switzerland; Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Tobias Loddenkemper
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Sofia H Eriksson
- Department of Clinical and Experimental Epilepsy, National Hospital for Neurology and Neurosurgery and Institute of Neurology, University College London, London, UK.
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19
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Krishnan GP, Rosen BQ, Chen JY, Muller L, Sejnowski TJ, Cash SS, Halgren E, Bazhenov M. Thalamocortical and intracortical laminar connectivity determines sleep spindle properties. PLoS Comput Biol 2018; 14:e1006171. [PMID: 29949575 PMCID: PMC6039052 DOI: 10.1371/journal.pcbi.1006171] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 07/10/2018] [Accepted: 04/30/2018] [Indexed: 11/19/2022] Open
Abstract
Sleep spindles are brief oscillatory events during non-rapid eye movement (NREM) sleep. Spindle density and synchronization properties are different in MEG versus EEG recordings in humans and also vary with learning performance, suggesting spindle involvement in memory consolidation. Here, using computational models, we identified network mechanisms that may explain differences in spindle properties across cortical structures. First, we report that differences in spindle occurrence between MEG and EEG data may arise from the contrasting properties of the core and matrix thalamocortical systems. The matrix system, projecting superficially, has wider thalamocortical fanout compared to the core system, which projects to middle layers, and requires the recruitment of a larger population of neurons to initiate a spindle. This property was sufficient to explain lower spindle density and higher spatial synchrony of spindles in the superficial cortical layers, as observed in the EEG signal. In contrast, spindles in the core system occurred more frequently but less synchronously, as observed in the MEG recordings. Furthermore, consistent with human recordings, in the model, spindles occurred independently in the core system but the matrix system spindles commonly co-occurred with core spindles. We also found that the intracortical excitatory connections from layer III/IV to layer V promote spindle propagation from the core to the matrix system, leading to widespread spindle activity. Our study predicts that plasticity of intra- and inter-cortical connectivity can potentially be a mechanism for increased spindle density as has been observed during learning.
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Affiliation(s)
- Giri P. Krishnan
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States of America
| | - Burke Q. Rosen
- Departments of Radiology and Neurosciences, UCSD, San Diego, CA, United States of America
| | - Jen-Yung Chen
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States of America
| | - Lyle Muller
- Computational Neurobiology Lab, Salk Institute for Biological Studies, La Jolla, San Diego, CA, United States of America
| | - Terrence J. Sejnowski
- Computational Neurobiology Lab, Salk Institute for Biological Studies, La Jolla, San Diego, CA, United States of America
| | - Sydney S. Cash
- Dept. of Neurology, Massachusetts General Hospital and Harvard University, Boston, MA, United States of America
| | - Eric Halgren
- Departments of Radiology and Neurosciences, UCSD, San Diego, CA, United States of America
| | - Maxim Bazhenov
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States of America
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20
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Distinct Thalamic Reticular Cell Types Differentially Modulate Normal and Pathological Cortical Rhythms. Cell Rep 2018; 19:2130-2142. [PMID: 28591583 DOI: 10.1016/j.celrep.2017.05.044] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/04/2017] [Accepted: 05/12/2017] [Indexed: 01/03/2023] Open
Abstract
Integrative brain functions depend on widely distributed, rhythmically coordinated computations. Through its long-ranging connections with cortex and most senses, the thalamus orchestrates the flow of cognitive and sensory information. Essential in this process, the nucleus reticularis thalami (nRT) gates different information streams through its extensive inhibition onto other thalamic nuclei, however, we lack an understanding of how different inhibitory neuron subpopulations in nRT function as gatekeepers. We dissociated the connectivity, physiology, and circuit functions of neurons within rodent nRT, based on parvalbumin (PV) and somatostatin (SOM) expression, and validated the existence of such populations in human nRT. We found that PV, but not SOM, cells are rhythmogenic, and that PV and SOM neurons are connected to and modulate distinct thalamocortical circuits. Notably, PV, but not SOM, neurons modulate somatosensory behavior and disrupt seizures. These results provide a conceptual framework for how nRT may gate incoming information to modulate brain-wide rhythms.
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21
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Reduced sleep spindle activity point to a TRN-MD thalamus-PFC circuit dysfunction in schizophrenia. Schizophr Res 2017; 180:36-43. [PMID: 27269670 PMCID: PMC5423439 DOI: 10.1016/j.schres.2016.05.023] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/23/2016] [Accepted: 05/25/2016] [Indexed: 11/23/2022]
Abstract
Sleep disturbances have been reliably reported in patients with schizophrenia, thus suggesting that abnormal sleep may represent a core feature of this disorder. Traditional electroencephalographic studies investigating sleep architecture have found reduced deep non-rapid eye movement (NREM) sleep, or slow wave sleep (SWS), and increased REM density. However, these findings have been inconsistently observed, and have not survived meta-analysis. By contrast, several recent EEG studies exploring brain activity during sleep have established marked deficits in sleep spindles in schizophrenia, including first-episode and early-onset patients, compared to both healthy and psychiatric comparison subjects. Spindles are waxing and waning, 12-16Hz NREM sleep oscillations that are generated within the thalamus by the thalamic reticular nucleus (TRN), and are then synchronized and sustained in the cortex. While the functional role of sleep spindles still needs to be fully established, increasing evidence has shown that sleep spindles are implicated in learning and memory, including sleep dependent memory consolidation, and spindle parameters have been associated to general cognitive ability and IQ. In this article we will review the EEG studies demonstrating sleep spindle deficits in patients with schizophrenia, and show that spindle deficits can predict their reduced cognitive performance. We will then present data indicating that spindle impairments point to a TRN-MD thalamus-prefrontal cortex circuit deficit, and discuss about the possible molecular mechanisms underlying thalamo-cortical sleep spindle abnormalities in schizophrenia.
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22
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Krishnan GP, Chauvette S, Shamie I, Soltani S, Timofeev I, Cash SS, Halgren E, Bazhenov M. Cellular and neurochemical basis of sleep stages in the thalamocortical network. eLife 2016; 5:e18607. [PMID: 27849520 PMCID: PMC5111887 DOI: 10.7554/elife.18607] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 10/11/2016] [Indexed: 01/05/2023] Open
Abstract
The link between the combined action of neuromodulators in the brain and global brain states remains a mystery. In this study, using biophysically realistic models of the thalamocortical network, we identified the critical intrinsic and synaptic mechanisms, associated with the putative action of acetylcholine (ACh), GABA and monoamines, which lead to transitions between primary brain vigilance states (waking, non-rapid eye movement sleep [NREM] and REM sleep) within an ultradian cycle. Using ECoG recordings from humans and LFP recordings from cats and mice, we found that during NREM sleep the power of spindle and delta oscillations is negatively correlated in humans and positively correlated in animal recordings. We explained this discrepancy by the differences in the relative level of ACh. Overall, our study revealed the critical intrinsic and synaptic mechanisms through which different neuromodulators acting in combination result in characteristic brain EEG rhythms and transitions between sleep stages.
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Affiliation(s)
- Giri P Krishnan
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Sylvain Chauvette
- Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
- Centre de Recherche de l’Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, Canada
| | - Isaac Shamie
- Departments of Radiology and Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - Sara Soltani
- Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
- Centre de Recherche de l’Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, Canada
| | - Igor Timofeev
- Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
- Centre de Recherche de l’Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, Canada
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, United States
| | - Eric Halgren
- Departments of Radiology and Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - Maxim Bazhenov
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States
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23
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Fogel S, Vien C, Karni A, Benali H, Carrier J, Doyon J. Sleep spindles: a physiological marker of age-related changes in gray matter in brain regions supporting motor skill memory consolidation. Neurobiol Aging 2016; 49:154-164. [PMID: 27815989 DOI: 10.1016/j.neurobiolaging.2016.10.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 09/08/2016] [Accepted: 10/03/2016] [Indexed: 12/21/2022]
Abstract
Sleep is necessary for the optimal consolidation of procedural learning, and in particular, for motor sequential skills. Motor sequence learning remains intact with age, but sleep-dependent consolidation is impaired, suggesting that memory deficits for procedural skills are specifically impacted by age-related changes in sleep. Age-related changes in spindles may be responsible for impaired motor sequence learning consolidation, but the morphological basis for this deficit is unknown. Here, we found that gray matter in the hippocampus and cerebellum was positively correlated with both sleep spindles and offline improvements in performance in young participants but not in older participants. These results suggest that age-related changes in gray matter in the hippocampus relate to spindles and may underlie age-related deficits in sleep-related motor sequence memory consolidation. In this way, spindles can serve as a biological marker for structural brain changes and the related memory deficits in older adults.
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Affiliation(s)
- Stuart Fogel
- Functional Neuroimaging Unit, Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montreal, Canada; Department of Psychology, University of Montreal, Montreal, Canada; School of Psychology, University of Ottawa, Ottawa, Canada; University of Ottawa Institute of Mental Health Research, Ottawa, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, Canada
| | - Catherine Vien
- Functional Neuroimaging Unit, Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montreal, Canada; Department of Psychology, University of Montreal, Montreal, Canada
| | - Avi Karni
- Laboratory for Human Brain & Learning, Sagol Department of Neurobiology & the E.J. Safra Brain Research Center, University of Haifa, Haifa, Israel
| | - Habib Benali
- Functional Neuroimaging Unit, Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montreal, Canada; Functional Neuroimaging Laboratory, INSERM, Paris, France
| | - Julie Carrier
- Functional Neuroimaging Unit, Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montreal, Canada; Department of Psychology, University of Montreal, Montreal, Canada; Centre d'études Avancées en Médecine du Sommeil, Hôpital du Sacré-Cœur de Montréal, Montreal, Canada
| | - Julien Doyon
- Functional Neuroimaging Unit, Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Montreal, Canada; Department of Psychology, University of Montreal, Montreal, Canada.
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Niknazar M, Krishnan GP, Bazhenov M, Mednick SC. Coupling of Thalamocortical Sleep Oscillations Are Important for Memory Consolidation in Humans. PLoS One 2015; 10:e0144720. [PMID: 26671283 PMCID: PMC4699460 DOI: 10.1371/journal.pone.0144720] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/22/2015] [Indexed: 11/22/2022] Open
Abstract
Sleep, specifically non-rapid eye movement (NREM) sleep, is thought to play a critical role in the consolidation of recent memories. Two main oscillatory activities observed during NREM, cortical slow oscillations (SO, 0.5–1.0Hz) and thalamic spindles (12–15Hz), have been shown to independently correlate with memory improvement. Yet, it is not known how these thalamocortical events interact, or the significance of this interaction, during the consolidation process. Here, we found that systemic administration of the GABAergic drug (zolpidem) increased both the phase-amplitude coupling between SO and spindles, and verbal memory improvement in humans. These results suggest that thalamic spindles that occur during transitions to the cortical SO Up state are optimal for memory consolidation. Our study predicts that the timely interactions between cortical and thalamic events during consolidation, contribute to memory improvement and is mediated by the level of inhibitory neurotransmission.
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Affiliation(s)
- Mohammad Niknazar
- Department of Cell Biology & Neuroscience, University of California Riverside, 900 University Ave, Riverside, CA, 92521, United States of America
- Department of Psychology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, United States of America
| | - Giri P. Krishnan
- Department of Cell Biology & Neuroscience, University of California Riverside, 900 University Ave, Riverside, CA, 92521, United States of America
| | - Maxim Bazhenov
- Department of Cell Biology & Neuroscience, University of California Riverside, 900 University Ave, Riverside, CA, 92521, United States of America
- * E-mail: (MB); (SCM)
| | - Sara C. Mednick
- Department of Psychology, University of California Riverside, 900 University Ave, Riverside, CA, 92521, United States of America
- * E-mail: (MB); (SCM)
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Lewis LD, Voigts J, Flores FJ, Schmitt LI, Wilson MA, Halassa MM, Brown EN. Thalamic reticular nucleus induces fast and local modulation of arousal state. eLife 2015; 4:e08760. [PMID: 26460547 PMCID: PMC4686423 DOI: 10.7554/elife.08760] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/24/2015] [Indexed: 02/06/2023] Open
Abstract
During low arousal states such as drowsiness and sleep, cortical neurons exhibit rhythmic slow wave activity associated with periods of neuronal silence. Slow waves are locally regulated, and local slow wave dynamics are important for memory, cognition, and behaviour. While several brainstem structures for controlling global sleep states have now been well characterized, a mechanism underlying fast and local modulation of cortical slow waves has not been identified. Here, using optogenetics and whole cortex electrophysiology, we show that local tonic activation of thalamic reticular nucleus (TRN) rapidly induces slow wave activity in a spatially restricted region of cortex. These slow waves resemble those seen in sleep, as cortical units undergo periods of silence phase-locked to the slow wave. Furthermore, animals exhibit behavioural changes consistent with a decrease in arousal state during TRN stimulation. We conclude that TRN can induce rapid modulation of local cortical state. DOI:http://dx.doi.org/10.7554/eLife.08760.001 We usually think of sleep as a global state: that the entire brain is either asleep or awake. However, recent evidence has suggested that smaller regions of the brain can show sleep-like activity while the rest of the brain remains awake. It is not clear why or how these sleep-like patterns of brain activity appear, and whether they are related to the drowsy behaviour that occurs when one is about to fall asleep. Lewis, Voigts et al. investigated how this process works in mice using a technique called optogenetics. This technique makes it possible to genetically engineer mice so that the activity of particular areas of the brain can be switched on or off by light. Lewis, Voigts et al. used light to stimulate different regions of the brain and tracked the resulting brain activity using tiny electrodes that are capable of detecting the activity of individual neurons. The experiments show that stimulating one part of a deep brain structure called the thalamic reticular nucleus causes just one small part of the brain to switch from being awake to producing sleep-like brain wave patterns. When a larger area is stimulated, the whole brain switches into this sleep-like pattern. Stimulation of the thalamic reticular nucleus also caused the animals to become drowsy and they were more likely to fall asleep, which suggests that sleep-like activity in small parts of the brain may contribute to drowsiness. Lewis, Voigts et al.’s findings identify a brain switch that can influence whether an animal is awake or asleep. Importantly, they show that sleep can be independently controlled in small brain regions, and that the thalamic reticular nucleus contains a ‘map’ that allows it to induce sleep in just one region, or across the whole brain. Memories are strengthened during sleep, so the next challenge is to study whether the thalamic reticular nucleus influences memory formation. The findings also suggest that further study of this brain region may be useful for understanding how the sleep and awake states are controlled by particular neurons. DOI:http://dx.doi.org/10.7554/eLife.08760.002
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Affiliation(s)
- Laura D Lewis
- Society of Fellows, Harvard University, Cambridge, United States.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, United States.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Jakob Voigts
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Francisco J Flores
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.,Department of Anesthesia, Harvard Medical School, Boston, United States.,Department of Anesthesia, Massachusetts General Hospital, Boston, United States
| | - L Ian Schmitt
- Neuroscience Institute, New York University, New York, United States
| | - Matthew A Wilson
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.,Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Michael M Halassa
- Neuroscience Institute, New York University, New York, United States
| | - Emery N Brown
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.,Department of Anesthesia, Harvard Medical School, Boston, United States.,Department of Anesthesia, Massachusetts General Hospital, Boston, United States.,Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, United States.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States
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26
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Lustenberger C, O’Gorman RL, Pugin F, Tüshaus L, Wehrle F, Achermann P, Huber R. Sleep spindles are related to schizotypal personality traits and thalamic glutamine/glutamate in healthy subjects. Schizophr Bull 2015; 41:522-31. [PMID: 25074975 PMCID: PMC4332948 DOI: 10.1093/schbul/sbu109] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Schizophrenia is a severe mental disorder affecting approximately 1% of the worldwide population. Yet, schizophrenia-like experiences (schizotypy) are very common in the healthy population, indicating a continuum between normal mental functioning and the psychosis found in schizophrenic patients. A continuum between schizotypy and schizophrenia would be supported if they share the same neurobiological origin. Two such neurobiological markers of schizophrenia are: (1) a reduction of sleep spindles (12-15 Hz oscillations during nonrapid eye movement sleep), likely reflecting deficits in thalamo-cortical circuits and (2) increased glutamine and glutamate (Glx) levels in the thalamus. Thus, this study aimed to investigate whether sleep spindles and Glx levels are related to schizotypal personality traits in healthy subjects. METHODS Twenty young male subjects underwent 2 all-night sleep electroencephalography recordings (128 electrodes). Sleep spindles were detected automatically. After those 2 nights, thalamic Glx levels were measured by magnetic resonance spectroscopy. Subjects completed a magical ideation scale to assess schizotypy. RESULTS Sleep spindle density was negatively correlated with magical ideation (r = -.64, P < .01) and thalamic Glx levels (r = -.70, P < .005). No correlation was found between Glx levels in the thalamus and magical ideation (r = .12, P > .1). CONCLUSIONS The common relationship of sleep spindle density with schizotypy and thalamic Glx levels indicates a neurobiological overlap between nonclinical schizotypy and schizophrenia. Thus, sleep spindle density and magical ideation may reflect the anatomy and efficiency of the thalamo-cortical system that shows pronounced impairment in patients with schizophrenia.
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Affiliation(s)
- Caroline Lustenberger
- Child Development Center, University Children’s Hospital Zurich, Zurich, Switzerland;,Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Ruth L. O’Gorman
- Children Research Center, University Children’s Hospital Zurich, Zurich, Switzerland;,MR Center, University Children’s Hospital Zurich, Zurich, Switzerland;,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Fiona Pugin
- Child Development Center, University Children’s Hospital Zurich, Zurich, Switzerland;,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Laura Tüshaus
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland;,Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Flavia Wehrle
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland;,Division of Neonatology, University Hospital Zurich, Zurich, Switzerland
| | - Peter Achermann
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland;,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland;,Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Reto Huber
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland; Children Research Center, University Children's Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; University Clinics for Child and Adolescent Psychiatry, Zurich, Switzerland
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27
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Halassa MM, Chen Z, Wimmer RD, Brunetti PM, Zhao S, Zikopoulos B, Wang F, Brown EN, Wilson MA. State-dependent architecture of thalamic reticular subnetworks. Cell 2014; 158:808-821. [PMID: 25126786 DOI: 10.1016/j.cell.2014.06.025] [Citation(s) in RCA: 216] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/22/2014] [Accepted: 06/06/2014] [Indexed: 10/24/2022]
Abstract
Behavioral state is known to influence interactions between thalamus and cortex, which are important for sensation, action, and cognition. The thalamic reticular nucleus (TRN) is hypothesized to regulate thalamo-cortical interactions, but the underlying functional architecture of this process and its state dependence are unknown. By combining the first TRN ensemble recording with psychophysics and connectivity-based optogenetic tagging, we found reticular circuits to be composed of distinct subnetworks. While activity of limbic-projecting TRN neurons positively correlates with arousal, sensory-projecting neurons participate in spindles and show elevated synchrony by slow waves during sleep. Sensory-projecting neurons are suppressed by attentional states, demonstrating that their gating of thalamo-cortical interactions is matched to behavioral state. Bidirectional manipulation of attentional performance was achieved through subnetwork-specific optogenetic stimulation. Together, our findings provide evidence for differential inhibition of thalamic nuclei across brain states, where the TRN separately controls external sensory and internal limbic processing facilitating normal cognitive function. PAPERFLICK:
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Affiliation(s)
- Michael M Halassa
- Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA; Department of Neuroscience & Physiology, New York University Langone Medical Center, New York, NY 10016, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Zhe Chen
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
| | - Ralf D Wimmer
- Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA; Department of Neuroscience & Physiology, New York University Langone Medical Center, New York, NY 10016, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Philip M Brunetti
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shengli Zhao
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Basilis Zikopoulos
- Department of Health Sciences and Program in Neuroscience, Boston University, Boston, MA 02215, USA
| | - Fan Wang
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew A Wilson
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Synchronization of isolated downstates (K-complexes) may be caused by cortically-induced disruption of thalamic spindling. PLoS Comput Biol 2014; 10:e1003855. [PMID: 25255217 PMCID: PMC4177663 DOI: 10.1371/journal.pcbi.1003855] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 08/12/2014] [Indexed: 11/19/2022] Open
Abstract
Sleep spindles and K-complexes (KCs) define stage 2 NREM sleep (N2) in humans. We recently showed that KCs are isolated downstates characterized by widespread cortical silence. We demonstrate here that KCs can be quasi-synchronous across scalp EEG and across much of the cortex using electrocorticography (ECOG) and localized transcortical recordings (bipolar SEEG). We examine the mechanism of synchronous KC production by creating the first conductance based thalamocortical network model of N2 sleep to generate both spontaneous spindles and KCs. Spontaneous KCs are only observed when the model includes diffuse projections from restricted prefrontal areas to the thalamic reticular nucleus (RE), consistent with recent anatomical findings in rhesus monkeys. Modeled KCs begin with a spontaneous focal depolarization of the prefrontal neurons, followed by depolarization of the RE. Surprisingly, the RE depolarization leads to decreased firing due to disrupted spindling, which in turn is due to depolarization-induced inactivation of the low-threshold Ca2+ current (IT). Further, although the RE inhibits thalamocortical (TC) neurons, decreased RE firing causes decreased TC cell firing, again because of disrupted spindling. The resulting abrupt removal of excitatory input to cortical pyramidal neurons then leads to the downstate. Empirically, KCs may also be evoked by sensory stimuli while maintaining sleep. We reproduce this phenomenon in the model by depolarization of either the RE or the widely-projecting prefrontal neurons. Again, disruption of thalamic spindling plays a key role. Higher levels of RE stimulation also cause downstates, but by directly inhibiting the TC neurons. SEEG recordings from the thalamus and cortex in a single patient demonstrated the model prediction that thalamic spindling significantly decreases before KC onset. In conclusion, we show empirically that KCs can be widespread quasi-synchronous cortical downstates, and demonstrate with the first model of stage 2 NREM sleep a possible mechanism whereby this widespread synchrony may arise. EEG in the most common stage of human sleep is dominated by K-complexes (KCs) and sleep spindles (bursts of 10–14 Hz oscillations) occupying the thalamus and cortex. Recently, we discovered that KCs are brief moments when the cortex becomes almost completely silent. Here, using recordings directly from the cortex of epileptic patients, we show that KCs can be quasi-synchronous across widespread cortical areas, and ask what mechanism could produce such a phenomenon. We created the first network model of realistic cortical and thalamic neurons, which spontaneously generate KCs as well as sleep spindles. We showed that the membrane channels in the reticular nucleus of the thalamus can be inactivated by excitatory inputs from the cortex, and this disrupts the spindle-generating network, which can trigger widespread cortical silence. The model prediction that thalamic spindle disruption occurs prior to KC was then observed in simultaneous recordings from the human thalamus and cortex. Understanding the cellular and network mechanisms whereby KCs arise is crucial to understanding its roles in maintaining sleep and consolidating memories.
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Simen AA, Ma J, Svetnik V, Mayleben D, Maynard J, Roth A, Mixson L, Mogg R, Shera D, George L, Mast TC, Beals C, Stoch A, Struyk A, Shire N, Fraser I. Efavirenz modulation of sleep spindles and sleep spectral profile. J Sleep Res 2014; 24:66-73. [PMID: 25113527 DOI: 10.1111/jsr.12196] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 05/06/2014] [Indexed: 01/20/2023]
Abstract
Non-nucleoside reverse transcriptase inhibitors are important antiretroviral agents for the treatment of human immunodeficiency virus. Some non-nucleoside reverse transcriptase inhibitors, in particular efavirenz, have prominent effects on sleep, cognition and psychiatric variables that limit their tolerability. To avoid confounds due to drug-drug and drug-disease interactions, we assessed the effects of efavirenz in healthy volunteers on sleep, cognition and psychological endpoints during the first week of treatment. Forty healthy male subjects were randomized to receive placebo or efavirenz 600 mg nightly for 7 days after completion of a 3-day placebo run-in period. Treatment with efavirenz was associated with reduced time to sleep onset in the Maintenance of Wakefulness Test, an increase in non-rapid eye movement sleep, a large exposure-related decrease in sigma band spectral density and sleep spindle density during non-rapid eye movement sleep, and reduced performance on an attention switching task. Because efavirenz has been shown to have serotonin 2A receptor partial-agonist properties, we reasoned that antagonism of serotonin 2A receptor signalling in the thalamic reticular nucleus, which generates sleep spindles and promotes attention, may be responsible. Consistent with predictions, treatment of healthy volunteers with a single dose of a serotonin 2A receptor antagonist was found to significantly suppress sigma band spectral density in an exposure-related manner and modulated the overall spectral profile in a manner highly similar to that observed with efavirenz, consistent with the notion that efavirenz exhibits serotonin 2A receptor partial-agonist pharmacology in humans.
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Affiliation(s)
- Arthur A Simen
- Merck Research Laboratories, Merck Sharp and Dohme, North Wales, PA, USA
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Dtchetgnia Djeundam SR, Yamapi R, Kofane TC, Aziz-Alaoui MA. Deterministic and stochastic bifurcations in the Hindmarsh-Rose neuronal model. CHAOS (WOODBURY, N.Y.) 2013; 23:033125. [PMID: 24089961 DOI: 10.1063/1.4818545] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We analyze the bifurcations occurring in the 3D Hindmarsh-Rose neuronal model with and without random signal. When under a sufficient stimulus, the neuron activity takes place; we observe various types of bifurcations that lead to chaotic transitions. Beside the equilibrium solutions and their stability, we also investigate the deterministic bifurcation. It appears that the neuronal activity consists of chaotic transitions between two periodic phases called bursting and spiking solutions. The stochastic bifurcation, defined as a sudden change in character of a stochastic attractor when the bifurcation parameter of the system passes through a critical value, or under certain condition as the collision of a stochastic attractor with a stochastic saddle, occurs when a random Gaussian signal is added. Our study reveals two kinds of stochastic bifurcation: the phenomenological bifurcation (P-bifurcations) and the dynamical bifurcation (D-bifurcations). The asymptotical method is used to analyze phenomenological bifurcation. We find that the neuronal activity of spiking and bursting chaos remains for finite values of the noise intensity.
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Affiliation(s)
- S R Dtchetgnia Djeundam
- Laboratory of Mechanics and Materials, Department of Physics, Faculty of Science, University of Yaoundé I, Box 812, Yaoundé, Cameroon
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Sustaining sleep spindles through enhanced SK2-channel activity consolidates sleep and elevates arousal threshold. J Neurosci 2013; 32:13917-28. [PMID: 23035101 DOI: 10.1523/jneurosci.2313-12.2012] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sleep spindles are synchronized 11-15 Hz electroencephalographic (EEG) oscillations predominant during nonrapid-eye-movement sleep (NREMS). Rhythmic bursting in the reticular thalamic nucleus (nRt), arising from interplay between Ca(v)3.3-type Ca(2+) channels and Ca(2+)-dependent small-conductance-type 2 (SK2) K(+) channels, underlies spindle generation. Correlative evidence indicates that spindles contribute to memory consolidation and protection against environmental noise in human NREMS. Here, we describe a molecular mechanism through which spindle power is selectively extended and we probed the actions of intensified spindling in the naturally sleeping mouse. Using electrophysiological recordings in acute brain slices from SK2 channel-overexpressing (SK2-OE) mice, we found that nRt bursting was potentiated and thalamic circuit oscillations were prolonged. Moreover, nRt cells showed greater resilience to transit from burst to tonic discharge in response to gradual depolarization, mimicking transitions out of NREMS. Compared with wild-type littermates, chronic EEG recordings of SK2-OE mice contained less fragmented NREMS, while the NREMS EEG power spectrum was conserved. Furthermore, EEG spindle activity was prolonged at NREMS exit. Finally, when exposed to white noise, SK2-OE mice needed stronger stimuli to arouse. Increased nRt bursting thus strengthens spindles and improves sleep quality through mechanisms independent of EEG slow waves (<4 Hz), suggesting SK2 signaling as a new potential therapeutic target for sleep disorders and for neuropsychiatric diseases accompanied by weakened sleep spindles.
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Fellin T, Ellenbogen JM, De Pittà M, Ben-Jacob E, Halassa MM. Astrocyte regulation of sleep circuits: experimental and modeling perspectives. Front Comput Neurosci 2012; 6:65. [PMID: 22973222 PMCID: PMC3428699 DOI: 10.3389/fncom.2012.00065] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 08/10/2012] [Indexed: 12/20/2022] Open
Abstract
Integrated within neural circuits, astrocytes have recently been shown to modulate brain rhythms thought to mediate sleep function. Experimental evidence suggests that local impact of astrocytes on single synapses translates into global modulation of neuronal networks and behavior. We discuss these findings in the context of current conceptual models of sleep generation and function, each of which have historically focused on neural mechanisms. We highlight the implications and the challenges introduced by these results from a conceptual and computational perspective. We further provide modeling directions on how these data might extend our knowledge of astrocytic properties and sleep function. Given our evolving understanding of how local cellular activities during sleep lead to functional outcomes for the brain, further mechanistic and theoretical understanding of astrocytic contribution to these dynamics will undoubtedly be of great basic and translational benefit.
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Affiliation(s)
- Tommaso Fellin
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
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33
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Interactions between core and matrix thalamocortical projections in human sleep spindle synchronization. J Neurosci 2012; 32:5250-63. [PMID: 22496571 DOI: 10.1523/jneurosci.6141-11.2012] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sleep spindles are bursts of 11-15 Hz that occur during non-rapid eye movement sleep. Spindles are highly synchronous across the scalp in the electroencephalogram (EEG) but have low spatial coherence and exhibit low correlation with the EEG when simultaneously measured in the magnetoencephalogram (MEG). We developed a computational model to explore the hypothesis that the spatial coherence spindles in the EEG is a consequence of diffuse matrix projections of the thalamus to layer 1 compared with the focal projections of the core pathway to layer 4 recorded in the MEG. Increasing the fanout of thalamocortical connectivity in the matrix pathway while keeping the core pathway fixed led to increased synchrony of the spindle activity in the superficial cortical layers in the model. In agreement with cortical recordings, the latency for spindles to spread from the core to the matrix was independent of the thalamocortical fanout but highly dependent on the probability of connections between cortical areas.
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Abstract
AbstractSchizophrenia is a disorder characterized by a variety of symptoms, which among others include hallucinations, delusions and passivity experiences. It has been found that individuals with schizophrenia misattribute their own thoughts and actions to an outside agency (source monitoring deficits), which could account for psychotic experiences such as that of hearing voices. In order to explain the source-monitoring deficits as well as psychosis, it has been proposed that mechanisms that enable anticipation and recognition of sensory consequences of one’s own actions are impaired in schizophrenia. Importantly, such mechanisms may require accurate cortical sensory representations such as in the primary somatosensory cortex (S1). The establishment and maintenance of cortical sensory representations has been found to utilize a sleep-related brain rhythm known as spindling. Namely, in the perinatal period in humans and animals, and possibly also thereafter, spontaneous activity in the sensory periphery drives spindle activity in the developing cortical sensory areas, which then contributes to the formation of sensory representations that match bodily features. For example, muscle twitch-spindle sequences during sleep facilitate the formation and maintenance of S1 in accordance with the layout of musculature. This process has been proposed to continue throughout the lifespan and may be particularly important during periods of bodily changes (adolescence, menopause). In schizophrenia, the amount of sleep spindle activity is markedly reduced, which would be expected to result in insufficient cortical sensory representations and have relevance for the relative inability of individuals with schizophrenia to accurately recognize self-initiated actions.
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Similarities between cortical “up” states during slow wave sleep and wakefulness: the implications for schizophrenia. Transl Neurosci 2012. [DOI: 10.2478/s13380-012-0004-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractNegative and positive symptoms are defining features of schizophrenia. This illness is commonly associated with a number of cognitive and affective deficits as well as with some more specific sleep abnormalities. It has been previously proposed that psychosis and positive symptoms in schizophrenia could be understood as disorders of internal brain dynamics. This proposed disordered network interplay might be particularly displayed during sleep when modulation by the senses is at the minimum. It is argued here that sleep abnormalities in schizophrenia inform our understanding of the pathomechanisms involved in psychosis. More specifically, sleep spindle initiation in NREM sleep and the preparation of sensory pathways for upcoming motor actions during wakefulness may share a common mechanism, and this shared mechanism is suggested to be impaired in schizophrenia.
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Vukadinovic Z, Rosenzweig I. Abnormalities in thalamic neurophysiology in schizophrenia: could psychosis be a result of potassium channel dysfunction? Neurosci Biobehav Rev 2011; 36:960-8. [PMID: 22138503 DOI: 10.1016/j.neubiorev.2011.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 11/11/2011] [Accepted: 11/20/2011] [Indexed: 10/14/2022]
Abstract
Psychosis in schizophrenia is associated with source-monitoring deficits whereby self-initiated behaviors become attributed to outside sources. One of the proposed functions of the thalamus is to adjust sensory responsiveness in accordance with the behavioral contextual cues. The thalamus is markedly affected in schizophrenia, and thalamic dysfunction may here result in reduced ability to adjust sensory responsiveness to ongoing behavior. One of the ways in which the thalamus accomplishes the adjustment of sensory processing is by a neurophysiological shift to post-inhibitory burst firing mode prior to and during certain exploratory actions. Reduced amount of thalamic burst firing may result from increased neuronal excitability secondary to a reported potassium channel dysfunction in schizophrenia. Pharmacological agents that reduce the excitability of thalamic cells and thereby promote burst firing by and large tend to have antipsychotic effects.
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Affiliation(s)
- Zoran Vukadinovic
- Montefiore Medical Center, Albert Einstein College of Medicine, Department of Psychiatry and Behavioral Sciences, 111 E 210th Street, Bronx, NY 10467, USA.
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37
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Abstract
Spindle oscillations are commonly observed during stage 2 of non-rapid eye movement sleep. During sleep spindles, the cerebral cortex and thalamus interact through feedback connections. Both initiation and termination of spindle oscillations are thought to originate in the thalamus based on thalamic recordings and computational models, although some in vivo results suggest otherwise. Here, we have used computer modeling and in vivo multisite recordings from the cortex and the thalamus in cats to examine the involvement of the cortex in spindle oscillations. We found that although the propagation of spindles depended on synaptic interaction within the thalamus, the initiation and termination of spindle sequences critically involved corticothalamic influences.
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Abstract
BACKGROUND The thalamic reticular nucleus (TRN) is a shell-shaped gamma amino butyric acid (GABA)ergic nucleus, which is uniquely placed between the thalamus and the cortex, because it receives excitatory afferents from both cortical and thalamic neurons and sends inhibitory projections to all nuclei of the dorsal thalamus. METHOD A review of the evidence suggesting that the TRN is implicated in the neurobiology of schizophrenia. RESULTS TRN-thalamus circuits are implicated in bottom-up as well as top-down processing. TRN projections to nonspecific nuclei of the dorsal thalamus mediate top-down processes, including attentional modulation, which are initiated by cortical afferents to the TRN. TRN-thalamus circuits are also involved in bottom-up activities, including sensory gating and the transfer to the cortex of sleep spindles. Intriguingly, deficits in attention and sensory gating have been consistently found in schizophrenics, including first-break and chronic patients. Furthermore, high-density electroencephalographic studies have revealed a marked reduction in sleep spindles in schizophrenics. CONCLUSION On the basis of our current knowledge on the molecular and anatomo-functional properties of the TRN, we suggest that this thalamic GABAergic nucleus may be involved in the neurobiology of schizophrenia.
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Affiliation(s)
- Fabio Ferrarelli
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin at Madison, 6001 Research Park Boulevard, Madison, WI 53719,Department of Psychiatry, Catholic University of the Sacred Heart, Rome, Italy
| | - Giulio Tononi
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin at Madison, 6001 Research Park Boulevard, Madison, WI 53719,To whom correspondence should be addressed; tel: 608-263-6063, fax: 608-263-0265, e-mail:
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Fogel SM, Smith CT. The function of the sleep spindle: a physiological index of intelligence and a mechanism for sleep-dependent memory consolidation. Neurosci Biobehav Rev 2010; 35:1154-65. [PMID: 21167865 DOI: 10.1016/j.neubiorev.2010.12.003] [Citation(s) in RCA: 421] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/30/2010] [Accepted: 12/09/2010] [Indexed: 11/26/2022]
Abstract
Until recently, the electrophysiological mechanisms involved in strengthening new memories into a more permanent form during sleep have been largely unknown. The sleep spindle is an event in the electroencephalogram (EEG) characterizing Stage 2 sleep. Sleep spindles may reflect, at the electrophysiological level, an ideal mechanism for inducing long-term synaptic changes in the neocortex. Recent evidence suggests the spindle is highly correlated with tests of intellectual ability (e.g.; IQ tests) and may serve as a physiological index of intelligence. Further, spindles increase in number and duration in sleep following new learning and are correlated with performance improvements. Spindle density and sigma (14-16Hz) spectral power have been found to be positively correlated with performance following a daytime nap, and animal studies suggest the spindle is involved in a hippocampal-neocortical dialogue necessary for memory consolidation. The findings reviewed here collectively provide a compelling body of evidence that the function of the sleep spindle is related to intellectual ability and memory consolidation.
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Affiliation(s)
- Stuart M Fogel
- University of Montreal, Montreal, Quebec, Canada, H3W 1W5.
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Lopez J, Hoffmann R, Armitage R. Reduced sleep spindle activity in early-onset and elevated risk for depression. J Am Acad Child Adolesc Psychiatry 2010; 49:934-43. [PMID: 20732629 PMCID: PMC2946379 DOI: 10.1016/j.jaac.2010.05.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 05/24/2010] [Accepted: 05/25/2010] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Sleep disturbances are common in major depressive disorder (MDD), although polysomnographic (PSG) abnormalities are more prevalent in adults than in children and adolescents with MDD. Sleep spindle activity (SPA) is associated with neuroplasticity mechanisms during brain maturation and is more abundant in childhood and adolescence than in adulthood, and as such, may be a more sensitive measure of sleep alteration than PSG in early-onset depression. This study investigated SPA changes related to early-onset MDD, comparing individuals already ill with MDD and individuals at high-risk for MDD with healthy nondepressed controls. METHOD The study included 63 participants (8 to 15 years of age): 21 currently depressed individuals, 21 individuals at high risk for MDD based on positive family history of MDD, and 21 healthy control individuals with no personal or family history of psychiatric illness. All participants maintained a regular sleep/wake schedule for 5 days, followed by 2 nights in the laboratory. SPA was analyzed in Stage 2 of non-rapid eye movement sleep. RESULTS SPA differed significantly between groups, particularly in the late part of the night (F(2,62) = 7.3, p = .001). Although the difference was greatest between the MDD and healthy control groups, both the MDD (p = .0004) and at high-risk groups (p = .02) had significantly lower SPA compared with healthy controls. SPA deficit was more prominent in females than in males (F(5,62) = 5.19, p = .005). CONCLUSIONS Low SPA characterizes youths with MDD and those at high risk for MDD, particularly girls, suggesting that early-onset depression and risk for the MDD are associated with decreased neuroplasticity.
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Affiliation(s)
- Jorge Lopez
- Sleep and Chronophysiology Laboratory, University of Michigan, Department of Psychiatry, 4250 Plymouth Road, Ann Arbor, MI 48109, USA.
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41
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Kovács K, SÃk A, Ricketts C, Timofeev I. Subcellular distribution of low-voltage activated T-type Ca2+ channel subunits (Cav3.1 and Cav3.3) in reticular thalamic neurons of the cat. J Neurosci Res 2010; 88:448-60. [DOI: 10.1002/jnr.22200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kane A, Hutchison WD, Hodaie M, Lozano AM, Dostrovsky JO. Enhanced synchronization of thalamic theta band local field potentials in patients with essential tremor. Exp Neurol 2009; 217:171-6. [PMID: 19233174 DOI: 10.1016/j.expneurol.2009.02.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2008] [Revised: 01/05/2009] [Accepted: 02/04/2009] [Indexed: 11/29/2022]
Abstract
Local field potentials (LFPs) were recorded in 13 patients from pairs of microelectrodes driven through thalamus during functional localization prior to implantation of a thalamic deep brain stimulation electrode for treatment of tremor or pain. Six patients had a history of essential tremor (ET), 3 of multiple sclerosis, and the remaining 4 had symptoms of chronic pain. Specific to the ET group was the observation that oscillatory field potentials recorded from the two microelectrodes in the motor thalamus (ventralis intermedius--Vim, ventralis oralis posterior--Vop) were highly coherent at frequencies characteristic of pathological tremor (4-7 Hz). This stands in contrast to the significantly more desynchronized state observed in the somatosensory thalamus (ventralis caudalis--Vc) for that frequency band. In addition, higher frequency coherent oscillations typically associated with physiological tremor (8-12 Hz) were observed in the ET patients in motor thalamus and Vc and in motor thalamus of pain patients. An examination of the inter-frequency correlation of the LFPs in Vim and Vop showed that the low frequency theta waves correlated with high frequency oscillations in the beta and gamma ranges. These findings are consistent with and extend those of other studies suggesting that alterations in thalamic oscillatory activity are involved in the pathophysiology of ET and furthermore suggest that increased synchronization in the 4-7 Hz range is related to the occurrence of tremor in the ET patient group. Furthermore, they support the idea that therapies such as lesions and high frequency stimulation of the motor thalamus are effective in reducing tremor symptoms since they destroy the abnormal low frequency synchronization in motor thalamus.
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Affiliation(s)
- Abdoul Kane
- Department of Physiology, University of Toronto, Toronto, ON, Canada
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43
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Roy S, Krueger JM, Rector DM, Wan Y. A network model for activity-dependent sleep regulation. J Theor Biol 2008; 253:462-8. [PMID: 18511082 PMCID: PMC2592512 DOI: 10.1016/j.jtbi.2008.03.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 03/23/2008] [Accepted: 03/26/2008] [Indexed: 10/22/2022]
Abstract
We develop and characterize a dynamical network model for activity-dependent sleep regulation. Specifically, in accordance with the activity-dependent theory for sleep, we view organism sleep as emerging from the local sleep states of functional units known as cortical columns; these local sleep states evolve through integration of local activity inputs, loose couplings with neighboring cortical columns, and global regulation (e.g. by the circadian clock). We model these cortical columns as coupled or networked activity-integrators that transition between sleep and waking states based on thresholds on the total activity. The model dynamics for three canonical experiments (which we have studied both through simulation and system-theoretic analysis) match with experimentally observed characteristics of the cortical-column network. Most notably, assuming connectedness of the network graph, our model predicts the recovery of the columns to a synchronized state upon temporary overstimulation of a single column and/or randomization of the initial sleep and activity-integration states. In analogy with other models for networked oscillators, our model also predicts the possibility for such phenomena as mode-locking.
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Affiliation(s)
- Sandip Roy
- Department of Electrical Engineering, Washington State University, P.O. Box 642752, Pullman, WA 99164, USA.
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44
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Oscillations and synchrony in large-scale cortical network models. J Biol Phys 2008; 34:279-99. [PMID: 19669478 DOI: 10.1007/s10867-008-9079-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 04/11/2008] [Indexed: 10/21/2022] Open
Abstract
Intrinsic neuronal and circuit properties control the responses of large ensembles of neurons by creating spatiotemporal patterns of activity that are used for sensory processing, memory formation, and other cognitive tasks. The modeling of such systems requires computationally efficient single-neuron models capable of displaying realistic response properties. We developed a set of reduced models based on difference equations (map-based models) to simulate the intrinsic dynamics of biological neurons. These phenomenological models were designed to capture the main response properties of specific types of neurons while ensuring realistic model behavior across a sufficient dynamic range of inputs. This approach allows for fast simulations and efficient parameter space analysis of networks containing hundreds of thousands of neurons of different types using a conventional workstation. Drawing on results obtained using large-scale networks of map-based neurons, we discuss spatiotemporal cortical network dynamics as a function of parameters that affect synaptic interactions and intrinsic states of the neurons.
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45
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Moxon KA, Devilbiss DM, Chapin JK, Waterhouse BD. Influence of norepinephrine on somatosensory neuronal responses in the rat thalamus: a combined modeling and in vivo multi-channel, multi-neuron recording study. Brain Res 2007; 1147:105-23. [PMID: 17368434 PMCID: PMC4529675 DOI: 10.1016/j.brainres.2007.02.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 01/25/2007] [Accepted: 02/02/2007] [Indexed: 10/23/2022]
Abstract
Norepinephrine released within primary sensory circuits from locus coeruleus afferent fibers can produce a spectrum of modulatory actions on spontaneous or sensory-evoked activity of individual neurons. Within the ventral posterior medial thalamus, membrane currents modulated by norepinephrine have been identified. However, the relationship between the cellular effects of norepinephrine and the impact of norepinephrine release on populations of neurons encoding sensory signals is still open to question. To address this lacuna in understanding the net impact of the noradrenergic system on sensory signal processing, a computational model of the rat trigeminal somatosensory thalamus was generated. The effects of independent manipulation of different cellular actions of norepinephrine on simulated afferent input to the computational model were then examined. The results of these simulations aided in the design of in vivo neural ensemble recording experiments where sensory-driven responses of thalamic neurons were measured before and during locus coeruleus activation in waking animals. Together the simulated and experimental results reveal several key insights regarding the regulation of neural network operation by norepinephrine including: 1) cell-specific modulatory actions of norepinephrine, 2) mechanisms of norepinephrine action that can improve the tuning of the network and increase the signal-to-noise ratio of cellular responses in order to enhance network representation of salient stimulus features and 3) identification of the dynamic range of thalamic neuron function through which norepinephrine operates.
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Affiliation(s)
- Karen A Moxon
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA.
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46
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Yousif NAB, Denham M. A population-based model of the nonlinear dynamics of the thalamocortical feedback network displays intrinsic oscillations in the spindling (7-14 Hz) range. Eur J Neurosci 2005; 22:3179-87. [PMID: 16367784 DOI: 10.1111/j.1460-9568.2005.04496.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The thalamocortical network is modelled using the Wilson-Cowan equations for neuronal population activity. We show that this population model with biologically derived parameters possesses intrinsic nonlinear oscillatory dynamics, and that the frequency of oscillation lies within the spindle range. Spindle oscillations are an early sleep oscillation characterized by high-frequency bursts of action potentials followed by a period of quiescence, at a frequency of 7-14 Hz. Spindles are generally regarded as being generated by intrathalamic circuitry, as decorticated thalamic slices and the isolated thalamic reticular nucleus exhibit spindles. However, the role of cortical feedback has been shown to regulate and synchronize the oscillation. Previous modelling studies have mainly used conductance-based models and hence the mechanism relied upon the inclusion of ionic currents, particularly the T-type calcium current. Here we demonstrate that spindle-frequency oscillatory activity can also arise from the nonlinear dynamics of the thalamocortical circuit, and we use bifurcation analysis to examine the robustness of this oscillation in terms of the functional range of the parameters used in the model. The results suggest that the thalamocortical circuit has intrinsic nonlinear population dynamics which are capable of providing robust support for oscillatory activity within the frequency range of spindle oscillations.
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Affiliation(s)
- Nada A B Yousif
- Centre for Theoretical and Computational Neuroscience, University of Plymouth, A223 Portland Square, Drake Circus, Plymouth PL4 8AA, UK.
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Cymbalyuk G, Shilnikov A. Coexistence of tonic spiking oscillations in a leech neuron model. J Comput Neurosci 2005; 18:255-63. [PMID: 15830162 DOI: 10.1007/s10827-005-0354-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 01/18/2005] [Accepted: 01/19/2005] [Indexed: 10/25/2022]
Abstract
The leech neuron model studied here has a remarkable dynamical plasticity. It exhibits a wide range of activities including various types of tonic spiking and bursting. In this study we apply methods of the qualitative theory of dynamical systems and the bifurcation theory to analyze the dynamics of the leech neuron model with emphasis on tonic spiking regimes. We show that the model can demonstrate bi-stability, such that two modes of tonic spiking coexist. Under a certain parameter regime, both tonic spiking modes are represented by the periodic attractors. As a bifurcation parameter is varied, one of the attractors becomes chaotic through a cascade of period-doubling bifurcations, while the other remains periodic. Thus, the system can demonstrate co-existence of a periodic tonic spiking with either periodic or chaotic tonic spiking. Pontryagin's averaging technique is used to locate the periodic orbits in the phase space.
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Affiliation(s)
- Gennady Cymbalyuk
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA.
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48
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Rowe DL. A FRAMEWORK FOR INVESTIGATING THALAMOCORTICAL ACTIVITY IN MULTISTAGE INFORMATION PROCESSING. J Integr Neurosci 2005; 4:5-26. [PMID: 16035138 DOI: 10.1142/s0219635205000707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 02/21/2005] [Indexed: 11/18/2022] Open
Abstract
A framework for investigating information processing in cortico-thalamocortical (cortico-TC) networks is presented, that in part can be used to model and interpret individual changes in electroencephalographic spectra and event-related potentials such as those from the Brain Resource International Database. Scientific work covering neurophysiology, TC firing modes, and TC models are explored in the framework to explain how the brain might process complex information in a multistage process. It is proposed that the thalamus and the cortico-TC system have unique ionic properties and transmission delays (in humans), which are suited to the function of taking "snapshots" or samples of complex environmental stimuli, rather than continuous data streams. This leads to careful and sequential coordination of stimulus and response processes, and increases the probability of information transfer and the resulting information complexity in higher cortical regions. Given the scope of this framework, the multidimensional and standardized Brain Resource International Database provides a pertinent set of measures for both testing hypotheses generated from the model, and for fitting the model to experimental data to investigate mechanisms underlying information processing.
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Affiliation(s)
- Donald L Rowe
- The Brain Dynamics Center, University of Sydney and Westmead Hospital, NSW 2145, Australia.
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Abstract
When the brain goes from wakefulness to sleep, cortical neurons begin to undergo slow oscillations in their membrane potential that are synchronized by thalamocortical circuits and reflected in EEG slow waves. To provide a self-consistent account of the transition from wakefulness to sleep and of the generation of sleep slow waves, we have constructed a large-scale computer model that encompasses portions of two visual areas and associated thalamic and reticular thalamic nuclei. Thousands of model neurons, incorporating several intrinsic currents, are interconnected with millions of thalamocortical, corticothalamic, and both intra- and interareal corticocortical connections. In the waking mode, the model exhibits irregular spontaneous firing and selective responses to visual stimuli. In the sleep mode, neuromodulatory changes lead to slow oscillations that closely resemble those observed in vivo and in vitro. A systematic exploration of the effects of intrinsic currents and network parameters on the initiation, maintenance, and termination of slow oscillations shows the following. 1) An increase in potassium leak conductances is sufficient to trigger the transition from wakefulness to sleep. 2) The activation of persistent sodium currents is sufficient to initiate the up-state of the slow oscillation. 3) A combination of intrinsic and synaptic currents is sufficient to maintain the up-state. 4) Depolarization-activated potassium currents and synaptic depression terminate the up-state. 5) Corticocortical connections synchronize the slow oscillation. The model is the first to integrate intrinsic neuronal properties with detailed thalamocortical anatomy and reproduce neural activity patterns in both wakefulness and sleep, thereby providing a powerful tool to investigate the role of sleep in information transmission and plasticity.
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Affiliation(s)
- Sean Hill
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719-1176, USA.
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50
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Fuentealba P, Timofeev I, Bazhenov M, Sejnowski TJ, Steriade M. Membrane bistability in thalamic reticular neurons during spindle oscillations. J Neurophysiol 2004; 93:294-304. [PMID: 15331618 PMCID: PMC2915789 DOI: 10.1152/jn.00552.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The thalamic reticular (RE) nucleus is a major source of inhibition in the thalamus. It plays a crucial role in regulating the excitability of thalamocortical networks and in generating some sleep rhythms. Current-clamp intracellular recordings of RE neurons in cats under barbiturate anesthesia revealed the presence of membrane bistability in approximately 20% of neurons. Bistability consisted of two alternate membrane potentials, separated by approximately 17-20 mV. While non-bistable (common) RE neurons fired rhythmic spike-bursts during spindles, bistable RE neurons fired tonically, with burst modulation, throughout spindle sequences. Bistability was strongly voltage dependent and only expressed under resting conditions (i.e. no current injection). The transition from the silent to the active state was a regenerative event that could be activated by brief depolarization, whereas brief hyperpolarizations could switch the membrane potential from the active to the silent state. These effects outlasted the current pulses. Corticothalamic stimulation could also switch the membrane potential from silent to active states. Addition of QX-314 in the recording micropipette either abolished or disrupted membrane bistability, suggesting I(Na(p)) to be responsible for its generation. Thalamocortical cells presented various patterns of spindling that reflected the membrane bistability in RE neurons. Finally, experimental data and computer simulations predicted a role for RE neurons' membrane bistability in inducing various patterns of spindling in target thalamocortical cells. We conclude that membrane bistability of RE neurons is an intrinsic property, likely generated by I(Na(p)) and modulated by cortical influences, as well as a factor that determines different patterns of spindle rhythms in thalamocortical neurons.
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Affiliation(s)
- Pablo Fuentealba
- Laboratoire de Neurophysiologie, Faculté de Médecine, Université Laval, Québec, G1K 7P4, Canada
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