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Garcia-Rill E. Neuroepigenetics of arousal: Gamma oscillations in the pedunculopontine nucleus. J Neurosci Res 2019; 97:1515-1520. [PMID: 30916810 PMCID: PMC6764922 DOI: 10.1002/jnr.24417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/06/2019] [Indexed: 01/20/2023]
Abstract
Four major discoveries on the function of the pedunculopontine nucleus (PPN) have significantly advanced our understanding of the role of arousal in neurodegenerative disorders. The first was the finding that stimulation of the PPN-induced controlled locomotion on a treadmill in decerebrate animals, the second was the revelation of electrical coupling in the PPN and other arousal and sleep-wake control regions, the third was the determination of intrinsic gamma band oscillations in PPN neurons, and the last was the discovery of gene transcription resulting from the manifestation of gamma activity in the PPN. These discoveries have led to novel therapies such as PPN deep brain stimulation (DBS) for Parkinson's disease (PD), identified the mechanism of action of the stimulant modafinil, determined the presence of separate mechanisms underlying gamma activity during waking versus REM sleep, and revealed the presence of gene transcription during the manifestation of gamma band oscillations. These discoveries set the stage for additional major advances in the treatment of a number of disorders.
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience (CTN), University of Arkansas for Medical Sciences, Little Rock, Arkansas
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2
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Local and Relayed Effects of Deep Brain Stimulation of the Pedunculopontine Nucleus. Brain Sci 2019; 9:brainsci9030064. [PMID: 30889866 PMCID: PMC6468768 DOI: 10.3390/brainsci9030064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/18/2022] Open
Abstract
Our discovery of low-threshold stimulation-induced locomotion in the pedunculopontine nucleus (PPN) led to the clinical use of deep brain stimulation (DBS) for the treatment of disorders such as Parkinson's disease (PD) that manifest gait and postural disorders. Three additional major discoveries on the properties of PPN neurons have opened new areas of research for the treatment of motor and arousal disorders. The description of (a) electrical coupling, (b) intrinsic gamma oscillations, and (c) gene regulation in the PPN has identified a number of novel therapeutic targets and methods for the treatment of a number of neurological and psychiatric disorders. We first delve into the circuit, cellular, intracellular, and molecular organization of the PPN, and then consider the clinical results to date on PPN DBS. This comprehensive review will provide valuable information to explain the network effects of PPN DBS, point to new directions for treatment, and highlight a number of issues related to PPN DBS.
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Garcia‐Rill E, D'Onofrio S, Mahaffey SC, Bisagno V, Urbano FJ. Bottom-up gamma and bipolar disorder, clinical and neuroepigenetic implications. Bipolar Disord 2019; 21:108-116. [PMID: 30506611 PMCID: PMC6441386 DOI: 10.1111/bdi.12735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES This limited review examines the role of the reticular activating system (RAS), especially the pedunculopontine nucleus (PPN), one site of origin of bottom-up gamma, in the symptoms of bipolar disorder (BD). METHODS The expression of neuronal calcium sensor protein 1 (NCS-1) in the brains of BD patients is increased. It has recently been found that all PPN neurons manifest intrinsic membrane beta/gamma frequency oscillations mediated by high threshold calcium channels, suggesting that it is one source of bottom-up gamma. This review specifically addresses the involvement of these channels in the manifestation of BD. RESULTS Excess NCS-1 was found to dampen gamma band oscillations in PPN neurons. Lithium, a first line treatment for BD, was found to decrease the effects of NCS-1 on gamma band oscillations in PPN neurons. Moreover, gamma band oscillations appear to epigenetically modulate gene transcription in PPN neurons, providing a new direction for research in BD. CONCLUSIONS This is an area needing much additional research, especially since the dysregulation of calcium channels may help explain many of the disorders of arousal in, elicit unwanted neuroepigenetic modulation in, and point to novel therapeutic avenues for, BD.
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Affiliation(s)
- Edgar Garcia‐Rill
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Stasia D'Onofrio
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Susan C Mahaffey
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Veronica Bisagno
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas,IFIBYNECONICETUniversidad de Buenos AiresBuenos AiresArgentina
| | - Francisco J Urbano
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas,IFIBYNECONICETUniversidad de Buenos AiresBuenos AiresArgentina
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4
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Almeida-Filho DG, Queiroz CM, Ribeiro S. Memory corticalization triggered by REM sleep: mechanisms of cellular and systems consolidation. Cell Mol Life Sci 2018; 75:3715-3740. [PMID: 30054638 PMCID: PMC11105475 DOI: 10.1007/s00018-018-2886-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 06/27/2018] [Accepted: 07/19/2018] [Indexed: 01/29/2023]
Abstract
Once viewed as a passive physiological state, sleep is a heterogeneous and complex sequence of brain states with essential effects on synaptic plasticity and neuronal functioning. Rapid-eye-movement (REM) sleep has been shown to promote calcium-dependent plasticity in principal neurons of the cerebral cortex, both during memory consolidation in adults and during post-natal development. This article reviews the plasticity mechanisms triggered by REM sleep, with a focus on the emerging role of kinases and immediate-early genes for the progressive corticalization of hippocampus-dependent memories. The body of evidence suggests that memory corticalization triggered by REM sleep is a systemic phenomenon with cellular and molecular causes.
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Affiliation(s)
- Daniel G Almeida-Filho
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59056-450, Brazil
| | - Claudio M Queiroz
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59056-450, Brazil
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59056-450, Brazil.
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Garner JM, Chambers J, Barnes AK, Datta S. Changes in Brain-Derived Neurotrophic Factor Expression Influence Sleep-Wake Activity and Homeostatic Regulation of Rapid Eye Movement Sleep. Sleep 2017; 41:4643005. [PMID: 29462410 PMCID: PMC6018753 DOI: 10.1093/sleep/zsx194] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Study Objectives Brain-derived neurotrophic factor (BDNF) expression and homeostatic regulation of rapid eye movement (REM) sleep are critical for neurogenesis and behavioral plasticity. Accumulating clinical and experimental evidence suggests that decreased BDNF expression is causally linked with the development of REM sleep-associated neuropsychiatric disorders. Therefore, we hypothesize that BDNF plays a role in sleep–wake (S–W) activity and homeostatic regulation of REM sleep. Methods Male and female wild-type (WT; BDNF +/+) and heterozygous BDNF (KD; BDNF +/−) rats were chronically implanted with S–W recording electrodes to quantify baseline S–W activity and REM sleep homeostatic regulatory processes during the light phase. Results Molecular analyses revealed that KD BDNF rats had a 50% decrease in BDNF protein levels. During baseline S–W activity, KD rats exhibited fewer REM sleep episodes that were shorter in duration and took longer to initiate. Also, the baseline S–W activity did not reveal any sex difference. During the 3-hour selective REM sleep deprivation, KD rats failed to exhibit a homeostatic drive for REM sleep and did not exhibit rebound REM sleep during the recovery S–W period. Conclusion Interestingly, both genotypes did not reveal any sex difference in the quality and/or quantity of REM sleep. Collectively, these results, for the first time, unequivocally demonstrate that an intact BDNF system in both sexes is a critical modulator for baseline and homeostatic regulation of REM sleep. This study further suggests that heterozygous BDNF knockdown rats are a useful animal model for the study of the cellular and molecular mechanisms of sleep regulation and cognitive functions of sleep.
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Affiliation(s)
- Jennifer M Garner
- Department of Anesthesiology, Graduate School of Medicine, University of Tennessee, Knoxville, TN.,Department of Psychology, College of Arts and Sciences, Knoxville, TN
| | - Jonathan Chambers
- Department of Anesthesiology, Graduate School of Medicine, University of Tennessee, Knoxville, TN
| | - Abigail K Barnes
- Department of Anesthesiology, Graduate School of Medicine, University of Tennessee, Knoxville, TN.,Department of Psychology, College of Arts and Sciences, Knoxville, TN
| | - Subimal Datta
- Department of Anesthesiology, Graduate School of Medicine, University of Tennessee, Knoxville, TN.,Department of Psychology, College of Arts and Sciences, Knoxville, TN.,Program in Comparative and Experimental Medicine; University of Tennessee, Knoxville, TN
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Datta S, Oliver MD. Cellular and Molecular Mechanisms of REM Sleep Homeostatic Drive: A Plausible Component for Behavioral Plasticity. Front Neural Circuits 2017; 11:63. [PMID: 28959190 PMCID: PMC5603703 DOI: 10.3389/fncir.2017.00063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/29/2017] [Indexed: 01/09/2023] Open
Abstract
Homeostatic regulation of REM sleep drive, as measured by an increase in the number of REM sleep transitions, plays a key role in neuronal and behavioral plasticity (i.e., learning and memory). Deficits in REM sleep homeostatic drive (RSHD) are implicated in the development of many neuropsychiatric disorders. Yet, the cellular and molecular mechanisms underlying this RSHD remain to be incomplete. To further our understanding of this mechanism, the current study was performed on freely moving rats to test a hypothesis that a positive interaction between extracellular-signal-regulated kinase 1 and 2 (ERK1/2) activity and brain-derived neurotrophic factor (BDNF) signaling in the pedunculopontine tegmentum (PPT) is a causal factor for the development of RSHD. Behavioral results of this study demonstrated that a short period (<90 min) of selective REM sleep restriction (RSR) exhibited a strong RSHD. Molecular analyses revealed that this increased RSHD increased phosphorylation and activation of ERK1/2 and BDNF expression in the PPT. Additionally, pharmacological results demonstrated that the application of the ERK1/2 activation inhibitor U0126 into the PPT prevented RSHD and suppressed BDNF expression in the PPT. These results, for the first time, suggest that the positive interaction between ERK1/2 and BDNF in the PPT is a casual factor for the development of RSHD. These findings provide a novel direction in understanding how RSHD-associated specific molecular changes can facilitate neuronal plasticity and memory processing.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
| | - Michael D Oliver
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
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7
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Urbano FJ, Bisagno V, Garcia-Rill E. Arousal and drug abuse. Behav Brain Res 2017; 333:276-281. [PMID: 28729115 DOI: 10.1016/j.bbr.2017.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/08/2017] [Accepted: 07/14/2017] [Indexed: 12/31/2022]
Abstract
The reticular activating system (RAS) is not an amorphous region but distinct nuclei with specific membrane properties that dictate their firing during waking and sleep. The locus coeruleus and raphe nucleus fire during waking and slow wave sleep, with the pedunculopontine nucleus (PPN) firing during both waking and REM sleep, the states manifesting arousal-related EEG activity. Two important discoveries in the PPN in the last 10 years are, 1) that some PPN cells are electrically coupled, and 2) every PPN cell manifests high threshold calcium channels that allow them to oscillate at beta/gamma band frequencies. The role of arousal in drug abuse is considered here in terms of the effects of drugs of abuse on these two mechanisms. Drug abuse and the perception of withdrawal/relapse are mediated by neurobiological processes that occur only when we are awake, not when we are asleep. These relationships focus on the potential role of arousal, more specifically of RAS electrical coupling and gamma band activity, in the addictive process as well as the relapse to drug use.
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Affiliation(s)
| | - Verónica Bisagno
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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Totty MS, Chesney LA, Geist PA, Datta S. Sleep-Dependent Oscillatory Synchronization: A Role in Fear Memory Consolidation. Front Neural Circuits 2017; 11:49. [PMID: 28729826 PMCID: PMC5498516 DOI: 10.3389/fncir.2017.00049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/21/2017] [Indexed: 12/02/2022] Open
Abstract
Sleep plays an important role in memory consolidation through the facilitation of neuronal plasticity; however, how sleep accomplishes this remains to be completely understood. It has previously been demonstrated that neural oscillations are an intrinsic mechanism by which the brain precisely controls neural ensembles. Inter-regional synchronization of these oscillations is also known to facilitate long-range communication and long-term potentiation (LTP). In the present study, we investigated how the characteristic rhythms found in local field potentials (LFPs) during non-REM and REM sleep play a role in emotional memory consolidation. Chronically implanted bipolar electrodes in the lateral amygdala (LA), dorsal and ventral hippocampus (DH, VH), and the infra-limbic (IL), and pre-limbic (PL) prefrontal cortex were used to record LFPs across sleep-wake activity following each day of a Pavlovian cued fear conditioning paradigm. This resulted in three principle findings: (1) theta rhythms during REM sleep are highly synchronized between regions; (2) the extent of inter-regional synchronization during REM and non-REM sleep is altered by FC and EX; (3) the mean phase difference of synchronization between the LA and VH during REM sleep predicts changes in freezing after cued fear extinction. These results both oppose a currently proposed model of sleep-dependent memory consolidation and provide a novel finding which suggests that the role of REM sleep theta rhythms in memory consolidation may rely more on the relative phase-shift between neural oscillations, rather than the extent of phase synchronization.
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Affiliation(s)
- Michael S Totty
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Logan A Chesney
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Phillip A Geist
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, University of TennesseeKnoxville, TN, United States
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9
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Garcia-Rill E. Bottom-up gamma and stages of waking. Med Hypotheses 2017; 104:58-62. [PMID: 28673592 DOI: 10.1016/j.mehy.2017.05.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 11/25/2022]
Abstract
Gamma activity has been proposed to promote the feed forward or "bottom-up" flow of information from lower to higher regions of the brain during perception. The pedunculopontine nucleus (PPN) modulates waking and REM sleep, and is part of the reticular activating system (RAS). The properties of PPN cells are unique in that all PPN neurons fire maximally at gamma band frequency regardless of electrophysiological or transmitter type, thus proposed as one origin of "bottom-up" gamma. This property is based on the presence of intrinsic membrane oscillations subserved by high threshold, voltage-dependent calcium channels. Moreover, some PPN cells are electrically coupled. Assuming that the population of PPN neurons has the capacity to fire at ∼40Hz coherently, then the population as a whole can be expected to generate a stable gamma band signal. But what if not all the neurons are firing at the peaks of the oscillations? That means that some cells may fire only at the peaks of every second oscillation. Therefore, the population as a whole can be expected to be firing at a net ∼20Hz. If some cells are firing at the peaks of every fourth oscillation, then the PPN as a whole would be firing at ∼10Hz. Firing at rates below 10Hz would imply that the system is seldom firing at the peaks of any oscillation, basically asleep, in slow wave sleep, thus the activation of the RAS is insufficient to promote waking. This hypothesis carries certain implications, one of which is that we awaken in stages as more and more cells are recruited to fire at the peaks of more and more oscillations. For this system, it would imply that, as we awaken, we step from ∼10Hz to ∼20Hz to ∼30Hz to ∼40Hz, that is, in stages and presumably at different levels of awareness. A similar process can be expected to take place as we fall asleep. Awakening can then be considered to be stepwise, not linear. That is, the implication is that the process of waking is a stepwise event, not a gradual increase, suggesting that the brain can spend time at each of these different stages of arousal.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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10
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Role of the pedunculopontine nucleus in controlling gait and sleep in normal and parkinsonian monkeys. J Neural Transm (Vienna) 2017; 125:471-483. [PMID: 28084536 DOI: 10.1007/s00702-017-1678-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/07/2017] [Indexed: 12/20/2022]
Abstract
Patients with Parkinson's disease (PD) develop cardinal motor symptoms, including akinesia, rigidity, and tremor, that are alleviated by dopaminergic medication and/or subthalamic deep brain stimulation. Over the time course of the disease, gait and balance disorders worsen and become resistant to pharmacological and surgical treatments. These disorders generate debilitating motor symptoms leading to increased dependency, morbidity, and mortality. PD patients also experience sleep disturbance that raise the question of a common physiological basis. An extensive experimental and clinical body of work has highlighted the crucial role of the pedunculopontine nucleus (PPN) in the control of gait and sleep, and its potential major role in PD. Here, we summarise our investigations in the monkey PPN in the normal and parkinsonian states. We first examined the anatomy and connectivity of the PPN and the cuneiform nucleus which both belong to the mesencephalic locomotor region. Second, we conducted experiments to demonstrate the specific effects of PPN cholinergic lesions on locomotion in the normal and parkinsonian monkey. Third, we aimed to understand how PPN cholinergic lesions impair sleep in parkinsonian monkeys. Our final goal was to develop a novel model of advanced PD with gait and sleep disorders. We believe that this monkey model, even if it does not attempt to reproduce the exact human disease with all its complexities, represents a good biomedical model to characterise locomotion and sleep in the context of PD.
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11
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D'Onofrio S, Mahaffey S, Garcia-Rill E. Role of calcium channels in bipolar disorder. CURRENT PSYCHOPHARMACOLOGY 2017; 6:122-135. [PMID: 29354402 PMCID: PMC5771645 DOI: 10.2174/2211556006666171024141949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bipolar disorder is characterized by a host of sleep-wake abnormalities that suggests that the reticular activating system (RAS) is involved in these symptoms. One of the signs of the disease is a decrease in high frequency gamma band activity, which accounts for a number of additional deficits. Bipolar disorder has also been found to overexpress neuronal calcium sensor protein 1 (NCS-1). Recent studies showed that elements in the RAS generate gamma band activity that is mediated by high threshold calcium (Ca2+) channels. This mini-review provides a description of recent findings on the role of Ca2+ and Ca2+ channels in bipolar disorder, emphasizing the involvement of arousal-related systems in the manifestation of many of the disease symptoms. This will hopefully bring attention to a much-needed area of research and provide novel avenues for therapeutic development.
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Affiliation(s)
- Stasia D'Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
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12
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Sébille SB, Belaid H, Philippe AC, André A, Lau B, François C, Karachi C, Bardinet E. Anatomical evidence for functional diversity in the mesencephalic locomotor region of primates. Neuroimage 2016; 147:66-78. [PMID: 27956208 DOI: 10.1016/j.neuroimage.2016.12.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/25/2016] [Accepted: 12/05/2016] [Indexed: 01/26/2023] Open
Abstract
The mesencephalic locomotor region (MLR) is a highly preserved brainstem structure in vertebrates. The MLR performs a crucial role in locomotion but also controls various other functions such as sleep, attention, and even emotion. The MLR comprises the pedunculopontine (PPN) and cuneiform nuclei (CuN) but their specific roles are still unknown in primates. Here, we sought to characterise the inputs and outputs of the PPN and CuN to and from the basal ganglia, thalamus, amygdala and cortex, with a specific interest in identifying functional anatomical territories. For this purpose, we used tract-tracing techniques in monkeys and diffusion weighted imaging-based tractography in humans to understand structural connectivity. We found that MLR connections are broadly similar between monkeys and humans. The PPN projects to the sensorimotor, associative and limbic territories of the basal ganglia nuclei, the centre median-parafascicular thalamic nuclei and the central nucleus of the amygdala. The PPN receives motor cortical inputs and less abundant connections from the associative and limbic cortices. In monkeys, we found a stronger connection between the anterior PPN and motor cortex suggesting a topographical organisation of this specific projection. The CuN projected to similar cerebral structures to the PPN in both species. However, these projections were much stronger towards the limbic territories of the basal ganglia and thalamus, to the basal forebrain (extended amygdala) and the central nucleus of the amygdala, suggesting that the CuN is not primarily a motor structure. Our findings highlight the fact that the PPN integrates sensorimotor, cognitive and emotional information whereas the CuN participates in a more restricted network integrating predominantly emotional information.
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Affiliation(s)
- Sophie B Sébille
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France
| | - Hayat Belaid
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Département de Neurochirurgie, Hôpital Pitie Salpêtrière, AP-HP, F-75013 Paris, France
| | - Anne-Charlotte Philippe
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France
| | - Arthur André
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Département de Neurochirurgie, Hôpital Pitie Salpêtrière, AP-HP, F-75013 Paris, France
| | - Brian Lau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France
| | - Chantal François
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France
| | - Carine Karachi
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Département de Neurochirurgie, Hôpital Pitie Salpêtrière, AP-HP, F-75013 Paris, France
| | - Eric Bardinet
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, APHP GH Pitié-Salpêtrière, Institut du cerveau et de la moelle épinière (ICM), F-75013 Paris, France; Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France.
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Garcia-Rill E, D’Onofrio S, Mahaffey S. Bottom-up Gamma: the Pedunculopontine Nucleus and Reticular Activating System. TRANSLATIONAL BRAIN RHYTHMICITY 2016; 1:49-53. [PMID: 28691105 PMCID: PMC5497760 DOI: 10.15761/tbr.1000109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Gamma rhythms have been proposed to promote the feed forward or "bottom-up" flow of information from lower to higher regions in the brain during perception. On the other hand, beta rhythms have been proposed to represent feed back or "top-down" influence from higher regions to lower. The pedunculopontine nucleus (PPN) has been implicated in sleep-wake control and arousal, and is part of the reticular activating system (RAS). This review describes the properties of the cells in this nucleus. These properties are unique, and perhaps it is the particular characteristics of these cells that allow the PPN to be involved in a host of functions and disorders. The fact that all PPN neurons fire maximally at gamma band frequency regardless of electrophysiological or transmitter type, make this an unusual cell group. In other regions, for example in the cortex, cells with such a property represent only a sub-population. More importantly, the fact that this cell group's functions are related to the capacity to generate coherent activity at a preferred natural frequency, gamma band, speaks volumes about how the PPN functions. We propose that "bottom-up" gamma band influence arises in the RAS and contributes to the build-up of the background of activity necessary for preconscious awareness and gamma activity at cortical levels.
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Affiliation(s)
- E. Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
| | - S. D’Onofrio
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
| | - S. Mahaffey
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
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14
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Luster BR, Urbano FJ, Garcia-Rill E. Intracellular mechanisms modulating gamma band activity in the pedunculopontine nucleus (PPN). Physiol Rep 2016; 4:4/12/e12787. [PMID: 27354537 PMCID: PMC4923228 DOI: 10.14814/phy2.12787] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/11/2016] [Indexed: 02/04/2023] Open
Abstract
The pedunculopontine nucleus is a part of the reticular activating system, and is active during waking and REM sleep. Previous results showed that all PPN cells tested fired maximally at gamma frequencies when depolarized. This intrinsic membrane property was shown to be mediated by high‐threshold N‐ and P/Q‐type Ca2+ channels. Recent studies show that the PPN contains three independent populations of neurons which can generate gamma band oscillations through only N‐type channels, only P/Q‐type channels, or both N‐ and P/Q‐type channels. This study investigated the intracellular mechanisms modulating gamma band activity in each population of neurons. We performed in vitro patch‐clamp recordings of PPN neurons from Sprague–Dawley rat pups, and applied 1‐sec ramps to induce intrinsic membrane oscillations. Our results show that there are two pathways modulating gamma band activity in PPN neurons. We describe populations of neurons mediating gamma band activity through only N‐type channels and the cAMP/PKA pathway (presumed “REM‐on” neurons), through only P/Q‐type channels and the CaMKII pathway (presumed “Wake‐on” neurons), and a third population which can mediate gamma activity through both N‐type channels and cAMP/PK and P/Q‐type channels and CaMKII (presumed “Wake/REM‐on” neurons). These novel results suggest that PPN gamma oscillations are modulated by two independent pathways related to different Ca2+ channel types.
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Affiliation(s)
- Brennon R Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | | | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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15
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Garcia-Rill E, Luster B, D'Onofrio S, Mahaffey S, Bisagno V, Urbano FJ. Implications of gamma band activity in the pedunculopontine nucleus. J Neural Transm (Vienna) 2016; 123:655-665. [PMID: 26597124 PMCID: PMC4877293 DOI: 10.1007/s00702-015-1485-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 11/10/2015] [Indexed: 01/07/2023]
Abstract
The fact that the pedunculopontine nucleus (PPN) is part of the reticular activating system places it in a unique position to modulate sensory input and fight-or-flight responses. Arousing stimuli simultaneously activate ascending projections of the PPN to the intralaminar thalamus to trigger cortical high-frequency activity and arousal, as well as descending projections to reticulospinal systems to alter posture and locomotion. As such, the PPN has become a target for deep brain stimulation for the treatment of Parkinson's disease, modulating gait, posture, and higher functions. This article describes the latest discoveries on PPN physiology and the role of the PPN in a number of disorders. It has now been determined that high-frequency activity during waking and REM sleep is controlled by two different intracellular pathways and two calcium channels in PPN cells. Moreover, there are three different PPN cell types that have one or both calcium channels and may be active during waking only, REM sleep only, or both. Based on the new discoveries, novel mechanisms are proposed for insomnia as a waking disorder. In addition, neuronal calcium sensor protein-1 (NCS-1), which is over expressed in schizophrenia and bipolar disorder, may be responsible for the dysregulation in gamma band activity in at least some patients with these diseases. Recent results suggest that NCS-1 modulates PPN gamma band activity and that lithium acts to reduce the effects of over expressed NCS-1, accounting for its effectiveness in bipolar disorder.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA.
| | - B Luster
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - S D'Onofrio
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - S Mahaffey
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - V Bisagno
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - F J Urbano
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
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16
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Loizzo JJ. The subtle body: an interoceptive map of central nervous system function and meditative mind-brain-body integration. Ann N Y Acad Sci 2016; 1373:78-95. [PMID: 27164469 DOI: 10.1111/nyas.13065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 12/26/2022]
Abstract
Meditation research has begun to clarify the brain effects and mechanisms of contemplative practices while generating a range of typologies and explanatory models to guide further study. This comparative review explores a neglected area relevant to current research: the validity of a traditional central nervous system (CNS) model that coevolved with the practices most studied today and that provides the first comprehensive neural-based typology and mechanistic framework of contemplative practices. The subtle body model, popularly known as the chakra system from Indian yoga, was and is used as a map of CNS function in traditional Indian and Tibetan medicine, neuropsychiatry, and neuropsychology. The study presented here, based on the Nalanda tradition, shows that the subtle body model can be cross-referenced with modern CNS maps and challenges modern brain maps with its embodied network model of CNS function. It also challenges meditation research by: (1) presenting a more rigorous, neural-based typology of contemplative practices; (2) offering a more refined and complete network model of the mechanisms of contemplative practices; and (3) serving as an embodied, interoceptive neurofeedback aid that is more user friendly and complete than current teaching aids for clinical and practical applications of contemplative practice.
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Affiliation(s)
- Joseph J Loizzo
- Nalanda Institute for Contemplative Science, Weill Cornell Center for Integrative Medicine, New York, New York
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17
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Pedunculopontine Gamma Band Activity and Development. Brain Sci 2015; 5:546-67. [PMID: 26633526 PMCID: PMC4701027 DOI: 10.3390/brainsci5040546] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 12/25/2022] Open
Abstract
This review highlights the most important discovery in the reticular activating system in the last 10 years, the manifestation of gamma band activity in cells of the reticular activating system (RAS), especially in the pedunculopontine nucleus, which is in charge of waking and rapid eye movement (REM) sleep. The identification of different cell groups manifesting P/Q-type Ca(2+) channels that control waking vs. those that manifest N-type channels that control REM sleep provides novel avenues for the differential control of waking vs. REM sleep. Recent discoveries on the development of this system can help explain the developmental decrease in REM sleep and the basic rest-activity cycle.
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18
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Takakusaki K, Chiba R, Nozu T, Okumura T. Brainstem control of locomotion and muscle tone with special reference to the role of the mesopontine tegmentum and medullary reticulospinal systems. J Neural Transm (Vienna) 2015; 123:695-729. [PMID: 26497023 PMCID: PMC4919383 DOI: 10.1007/s00702-015-1475-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 10/13/2015] [Indexed: 01/12/2023]
Abstract
The lateral part of the mesopontine tegmentum contains functionally important structures involved in the control of posture and gait. Specifically, the mesencephalic locomotor region, which may consist of the cuneiform nucleus and pedunculopontine tegmental nucleus (PPN), occupies the interest with respect to the pathophysiology of posture-gait disorders. The purpose of this article is to review the mechanisms involved in the control of postural muscle tone and locomotion by the mesopontine tegmentum and the pontomedullary reticulospinal system. To make interpretation and discussion more robust, the above issue is considered largely based on our findings in the experiments using decerebrate cat preparations in addition to the results in animal experimentations and clinical investigations in other laboratories. Our investigations revealed the presence of functional topographical organizations with respect to the regulation of postural muscle tone and locomotion in both the mesopontine tegmentum and the pontomedullary reticulospinal system. These organizations were modified by neurotransmitter systems, particularly the cholinergic PPN projection to the pontine reticular formation. Because efferents from the forebrain structures as well as the cerebellum converge to the mesencephalic and pontomedullary reticular formation, changes in these organizations may be involved in the appropriate regulation of posture-gait synergy depending on the behavioral context. On the other hand, abnormal signals from the higher motor centers may produce dysfunction of the mesencephalic-reticulospinal system. Here we highlight the significance of elucidating the mechanisms of the mesencephalic-reticulospinal control of posture and locomotion so that thorough understanding of the pathophysiological mechanisms of posture-gait disorders can be made.
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Affiliation(s)
- Kaoru Takakusaki
- Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Midorigaoka-Higashi 2-1, 1-1, Asahikawa, 078-8511, Japan.
| | - Ryosuke Chiba
- Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Midorigaoka-Higashi 2-1, 1-1, Asahikawa, 078-8511, Japan
| | - Tsukasa Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Asahikawa, Japan
| | - Toshikatsu Okumura
- Department of General Medicine, Asahikawa Medical University, Asahikawa, Japan
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Grace KP, Horner RL. Evaluating the Evidence Surrounding Pontine Cholinergic Involvement in REM Sleep Generation. Front Neurol 2015; 6:190. [PMID: 26388832 PMCID: PMC4555043 DOI: 10.3389/fneur.2015.00190] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 08/17/2015] [Indexed: 11/13/2022] Open
Abstract
Rapid eye movement (REM) sleep - characterized by vivid dreaming, motor paralysis, and heightened neural activity - is one of the fundamental states of the mammalian central nervous system. Initial theories of REM sleep generation posited that induction of the state required activation of the "pontine REM sleep generator" by cholinergic inputs. Here, we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i) the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii) the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii) loss-of-function studies show that endogenous cholinergic input to the PTF is not required for REM sleep generation, and (iv) cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail.
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Affiliation(s)
- Kevin P Grace
- Department of Medicine, University of Toronto , Toronto, ON , Canada
| | - Richard L Horner
- Department of Medicine, University of Toronto , Toronto, ON , Canada ; Department of Physiology, University of Toronto , Toronto, ON , Canada
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Luster B, D'Onofrio S, Urbano F, Garcia-Rill E. High-threshold Ca2+ channels behind gamma band activity in the pedunculopontine nucleus (PPN). Physiol Rep 2015; 3:3/6/e12431. [PMID: 26109189 PMCID: PMC4510632 DOI: 10.14814/phy2.12431] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is part of the Reticular Activating System, and active during waking and REM sleep. Previous results showed that all PPN cells plateau at gamma frequencies and intrinsic membrane oscillations in PPN neurons are mediated by high-threshold N- and P/Q-type Ca2+ channels. The present study was designed to determine whether some PPN cells have only N-, only P/Q-, or both N- and P/Q-type Ca2+ channels. We used patch-clamp recordings in PPN cells in slices from anesthetized rat pups in the presence of synaptic receptor blockers (SB) and Tetrodotoxin (TTX), and applied ramps to induce intrinsic membrane oscillations. We found that all PPN cell types showed gamma oscillations in the presence of SB+TTX when using current ramps. In 50% of cells, the N-type Ca2+ channel blocker ω-Conotoxin-GVIA (ω-CgTx) reduced gamma oscillation amplitude, while subsequent addition of the P/Q-type blocker ω-Agatoxin-IVA (ω-Aga) blocked the remaining oscillations. Another 20% manifested gamma oscillations that were not significantly affected by the addition of ω-CgTx, however, ω-Aga blocked the remaining oscillations. In 30% of cells, ω-Aga had no effect on gamma oscillations, while ω-CgTx blocked them. These novel results confirm the segregation of populations of PPN cells as a function of the calcium channels expressed, that is, the presence of cells in the PPN that manifest gamma band oscillations through only N-type, only P/Q-type, and both N-type and P/Q-type Ca2+ channels.
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Affiliation(s)
- Brennon Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Stasia D'Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Francisco Urbano
- IFIBYNE-CONICET University of Buenos Aires, Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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Garcia-Rill E, D’Onofrio S, Mahaffey S, Bisagno V, Urbano FJ. Pedunculopontine arousal system physiology-Implications for schizophrenia. Sleep Sci 2015; 8:82-91. [PMID: 26483949 PMCID: PMC4608902 DOI: 10.1016/j.slsci.2015.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/23/2015] [Accepted: 04/30/2015] [Indexed: 01/24/2023] Open
Abstract
Schizophrenia is characterized by major sleep/wake disturbances including increased vigilance and arousal, decreased slow wave sleep, and increased REM sleep drive. Other arousal-related symptoms include sensory gating deficits as exemplified by decreased habituation of the blink reflex. There is also dysregulation of gamma band activity, suggestive of disturbances in a host of arousal-related mechanisms. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of the disease. Recent discoveries on the physiology of the pedunculopontine nucleus help explain many of these disorders of arousal in, and point to novel therapeutic avenues for, schizophrenia.
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Key Words
- CaMKII, calcium/calmodulin-dependent protein kinase
- Calcium channels
- EEG, electroencephalogram
- EPSC, excitatory postsynaptic potential
- GABA, γ aminobutyric acid
- Gamma band activity
- InsP, inositol 1,4,5-triphosphate receptor protein
- KA, kainic acid
- NCS-1, neuronal calcium sensor protein 1
- NMDA, n methyl d aspartic acid
- Neuronal calcium sensor protein
- P50 potential
- PGO, ponto-geniculo-occipital
- PPN, pedunculopontine nucleus
- Pf, parafascicular nucleus
- RAS, reticular activating system
- REM, rapid eye movement
- SWS, slow wave sleep
- SubCD, subcoeruleus dorsalis
- cAMP, cyclic adenosine monophosphate
- ω-Aga, ω-agatoxin-IVA
- ω-CgTx, ω-conotoxin-GVIA
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Stasia D’Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Veronica Bisagno
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - Francisco J. Urbano
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
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Garcia-Rill E, Luster B, Mahaffey S, Bisagno V, Urbano FJ. Pedunculopontine arousal system physiology - Implications for insomnia. Sleep Sci 2015; 8:92-9. [PMID: 26483950 PMCID: PMC4608886 DOI: 10.1016/j.slsci.2015.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 06/08/2015] [Accepted: 06/12/2015] [Indexed: 01/09/2023] Open
Abstract
We consider insomnia a disorder of waking rather than a disorder of sleep. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of insomnia, mainly representing an overactive waking drive. We determined that high frequency activity during waking and REM sleep is controlled by two different intracellular pathways and channel types in PPN cells. We found three different PPN cell types that have one or both channels and may be active during waking only, REM sleep only, or both. These discoveries point to a specific mechanism and novel therapeutic avenues for insomnia.
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Key Words
- CaMKII, calcium/calmodulin-dependent protein kinase
- Calcium channels
- EEG, electroencephalogram
- Gamma band activity
- KA, kainic acid
- N-type calcium channel
- NCS-1, neuronal calcium sensor protein 1
- NMDA, n methyl d aspartic acid
- Neuronal calcium sensor protein
- P/Q-type calcium channel
- PGO, ponto-geniculo-occipital
- PPN, pedunculopontine nucleus
- RAS, reticular activating system
- REM, rapid eye movement
- SWS, slow wave sleep
- cAMP, cyclic adenosine monophosphate
- ω-Aga, ω-agatoxin-IVA
- ω-CgTx, ω-conotoxin-GVIA
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Brennon Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Veronica Bisagno
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Argentina
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Urbano FJ, D'Onofrio SM, Luster BR, Beck PB, Hyde JR, Bisagno V, Garcia-Rill E. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep. Front Neurol 2014; 5:210. [PMID: 25368599 PMCID: PMC4202729 DOI: 10.3389/fneur.2014.00210] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/01/2014] [Indexed: 11/13/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is a major component of the reticular activating system (RAS) that regulates waking and REM sleep, states of high-frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine PPN, intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD). Cortical gamma band activity participates in sensory perception, problem solving, and memory. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. That is, the RAS may play an early permissive role in volition. Our latest results suggest that (1) the manifestation of gamma band activity during waking may employ a separate intracellular pathway compared to that during REM sleep, (2) neuronal calcium sensor (NCS-1) protein, which is over expressed in schizophrenia and bipolar disorder, modulates gamma band oscillations in the PPN in a concentration-dependent manner, (3) leptin, which undergoes resistance in obesity resulting in sleep dysregulation, decreases sodium currents in PPN neurons, accounting for its normal attenuation of waking, and (4) following our discovery of electrical coupling in the RAS, we hypothesize that there are cell clusters within the PPN that may act in concert. These results provide novel information on the mechanisms controlling high-frequency activity related to waking and REM sleep by elements of the RAS.
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Affiliation(s)
- Francisco J Urbano
- IFIBYNE & ININFA-CONICET, University of Buenos Aires , Buenos Aires , Argentina
| | - Stasia M D'Onofrio
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock, AR , USA
| | - Brennon R Luster
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock, AR , USA
| | - Paige B Beck
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock, AR , USA
| | - James Robert Hyde
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock, AR , USA
| | - Veronica Bisagno
- IFIBYNE & ININFA-CONICET, University of Buenos Aires , Buenos Aires , Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock, AR , USA
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Knapp CM, Ciraulo DA, Datta S. Mechanisms underlying sleep-wake disturbances in alcoholism: focus on the cholinergic pedunculopontine tegmentum. Behav Brain Res 2014; 274:291-301. [PMID: 25151622 DOI: 10.1016/j.bbr.2014.08.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 12/24/2022]
Abstract
Sleep-wake (S-W) disturbances are frequently associated with alcohol use disorders (AUD), occurring during periods of active drinking, withdrawal, and abstinence. These S-W disturbances can persist after months or even years of abstinence, suggesting that chronic alcohol consumption may have enduring negative effects on both homeostatic and circadian sleep processes. It is now generally accepted that S-W disturbances in alcohol-dependent individuals are a significant cause of relapse in drinking. Although significant progress has been made in identifying the socio-economic burden and health risks of alcohol addiction, the underlying neurobiological mechanisms that lead to S-W disorders in AUD are poorly understood. Marked progress has been made in understanding the basic neurobiological mechanisms of how different sleep stages are normally regulated. This review article in seeking to explain the neurobiological mechanisms underlying S-W disturbances associated with AUD, describes an evidence-based, easily testable, novel hypothesis that chronic alcohol consumption induces neuroadaptive changes in the cholinergic cell compartment of the pedunculopontine tegmentum (CCC-PPT). These changes include increases in N-methyl-d-aspartate (NMDA) and kainate receptor sensitivity and a decrease in gamma-aminobutyric acid (GABAB)-receptor sensitivity in the CCC-PPT. Together these changes are the primary pathophysiological mechanisms that underlie S-W disturbances in AUD. This review is targeted for both basic neuroscientists in alcohol addiction research and clinicians who are in search of new and more effective therapeutic interventions to treat and/or eliminate sleep disorders associated with AUD.
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Affiliation(s)
- Clifford M Knapp
- Laboratory of Sleep and Cognitive Neuroscience, Boston University Psychiatry Associates Clinical Studies Unit, Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Boston, MA 02118, USA
| | - Domenic A Ciraulo
- Laboratory of Sleep and Cognitive Neuroscience, Boston University Psychiatry Associates Clinical Studies Unit, Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Boston, MA 02118, USA
| | - Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Boston University Psychiatry Associates Clinical Studies Unit, Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Boston, MA 02118, USA.
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Garcia-Rill E, Kezunovic N, D'Onofrio S, Luster B, Hyde J, Bisagno V, Urbano FJ. Gamma band activity in the RAS-intracellular mechanisms. Exp Brain Res 2014; 232:1509-22. [PMID: 24309750 PMCID: PMC4013218 DOI: 10.1007/s00221-013-3794-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 11/21/2013] [Indexed: 11/29/2022]
Abstract
Gamma band activity participates in sensory perception, problem solving, and memory. This review considers recent evidence showing that cells in the reticular activating system (RAS) exhibit gamma band activity, and describes the intrinsic membrane properties behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus, intralaminar parafascicular nucleus, and pontine SubCoeruleus nucleus dorsalis all fire in the gamma band range when maximally activated, but no higher. The mechanisms involve high-threshold, voltage-dependent P/Q-type calcium channels, or sodium-dependent subthreshold oscillations. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness and provide the essential stream of information for the formulation of many of our actions. We address three necessary next steps resulting from these discoveries: an intracellular mechanism responsible for maintaining gamma band activity based on persistent G-protein activation, separate intracellular pathways that differentiate between gamma band activity during waking versus during REM sleep, and an intracellular mechanism responsible for the dysregulation in gamma band activity in schizophrenia. These findings open several promising research avenues that have not been thoroughly explored. What are the effects of sleep or REM sleep deprivation on these RAS mechanisms? Are these mechanisms involved in memory processing during waking and/or during REM sleep? Does gamma band processing differ during waking versus REM sleep after sleep or REM sleep deprivation?
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Affiliation(s)
- E Garcia-Rill
- Department of Neurobiology and Developmental Sciences, Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA,
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Petrovic J, Ciric J, Lazic K, Kalauzi A, Saponjic J. Lesion of the pedunculopontine tegmental nucleus in rat augments cortical activation and disturbs sleep/wake state transitions structure. Exp Neurol 2013; 247:562-71. [DOI: 10.1016/j.expneurol.2013.02.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 01/30/2013] [Accepted: 02/13/2013] [Indexed: 10/27/2022]
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27
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Stefani A, Peppe A, Galati S, Bassi MS, D'Angelo V, Pierantozzi M. The serendipity case of the pedunculopontine nucleus low-frequency brain stimulation: chasing a gait response, finding sleep, and cognition improvement. Front Neurol 2013; 4:68. [PMID: 23761781 PMCID: PMC3672779 DOI: 10.3389/fneur.2013.00068] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 05/22/2013] [Indexed: 11/22/2022] Open
Abstract
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an efficacious therapy for Parkinson’s disease (PD) but its effects on non-motor facets may be detrimental. The low-frequency stimulation (LFS) of the pedunculopontine nucleus (PPN or the nucleus tegmenti pedunculopontini – PPTg-) opened new perspectives. In our hands, PPTg-LFS revealed a modest influence on gait but increased sleep quality and degree of attentiveness. At odds with potential adverse events following STN-DBS, executive functions, under PPTg-ON, ameliorated. A recent study comparing both targets found that only PPTg-LFS improved night-time sleep and daytime sleepiness. Chances are that different neurosurgical groups influence either the PPN sub-portion identified as pars dissipata (more interconnected with GPi/STN) or the caudal PPN region known as pars compacta, preferentially targeting intralaminar and associative nucleus of the thalamus. Yet, the wide electrical field delivered affects a plethora of en passant circuits, and a fine distinction on the specific pathways involved is elusive. This review explores our angle of vision, by which PPTg-LFS activates cholinergic and glutamatergic ascending fibers, influencing non-motor behaviors.
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Affiliation(s)
- Alessandro Stefani
- Department of Neuroscience, "Tor Vergata" University , Rome , Italy ; IRCCS, Fondazione Santa Lucia , Rome , Italy
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O'Malley MW, Datta S. REM Sleep Regulating Mechanisms in the Cholinergic Cell Compartment of the Brainstem. ACTA ACUST UNITED AC 2013; 8:58-66. [PMID: 25400382 DOI: 10.5958/j.0974-0155.8.2.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Rapid eye movement (REM) sleep is a highly evolved yet paradoxical behavioral state (highly activated brain in a paralyzed body) in mammalian species. Since the discovery of REM sleep and its physiological distinction from other sleep states1, a vast number of studies in neurosciences have been dedicated toward understanding the mechanisms and functions of this behavioral state. Collectively, studies have shown that each of the physiological events that characterize the behavioral state of REM sleep is executed by distinct cell groups located in the brainstem. These cell groups are discrete components of a widely distributed network, rather than a single REM sleep center. The final activity within each of these executive cell groups is controlled by the ratio of cholinergic neurotransmission emanating from the pedunculopontine tegmentum (PPT) to aminergic neurotransmission emanating from the locus coeruleus (LC) and raphe nucleus (RN). In this review, we summarize the most recent findings on the cellular and molecular mechanisms in the PPT cholinergic cell compartment that underlie the regulation of REM sleep. This up-to-date review should allow clinicians and researchers to better understand the effects of drugs and neurologic disease on REM sleep.
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Affiliation(s)
- Matthew W O'Malley
- Laboratory of Sleep and Cognitive Neuroscience, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, Massachusetts 02118 ; Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, Massachusetts 02118
| | - Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, Massachusetts 02118 ; Department of Psychiatry, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, Massachusetts 02118 ; Department of Neurology, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, Massachusetts 02118
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Simon C, Hayar A, Garcia-Rill E. Developmental changes in glutamatergic fast synaptic neurotransmission in the dorsal subcoeruleus nucleus. Sleep 2012; 35:407-17. [PMID: 22379247 DOI: 10.5665/sleep.1706] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES The dorsal subcoeruleus nucleus (SubCD) is involved in the generation of rapid eye movement sleep (REM), a state distinguished by high-frequency EEG activity, muscle atonia, and ponto-geniculo-occipital (PGO) waves. Activation of the SubCD by injection of the glutamate (GLU) receptor agonist kainic acid (KA) produced a REM sleep-like state with muscle atonia. We tested the hypothesis that developmental changes in the GLU excitability of SubCD neurons could underlie the developmental decrease in REM sleep that occurs in the rat from postnatal days 10-30. DESIGN Sagittal sections containing the SubCD were cut using 9-15 day old rat pups. Whole-cell patch clamp recordings were performed on SubCD neurons and responses were measured following electrical stimulation or bath application of the GLU receptor agonists N-methyl-D-aspartic acid (NMDA) or KA. MEASUREMENTS AND RESULTS Pharmacological or electrical stimulation increased non-cholinergic excitatory postsynaptic currents (EPSCs) in SubCD neurons, which were blocked by GLU receptor antagonists. Although no developmental changes were observed in the relative contribution of AMPA/KA and NMDA receptors to the responses, there was a developmental decrease in the half-width duration of both evoked and miniature EPSCs. Bath application of NMDA or KA revealed a developmental decrease in the direct response of SubCD neurons to these agonists. CONCLUSIONS The SubCD receives glutamatergic input, which may be involved in activation of SubCD neurons during REM sleep. A developmental decrease in the glutamatergic excitability of these neurons could underlie the developmental decrease in REM sleep observed in humans and rodents.
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Affiliation(s)
- Christen Simon
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Urbano FJ, Kezunovic N, Hyde J, Simon C, Beck P, Garcia-Rill E. Gamma band activity in the reticular activating system. Front Neurol 2012; 3:6. [PMID: 22319508 PMCID: PMC3269033 DOI: 10.3389/fneur.2012.00006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 01/06/2012] [Indexed: 12/24/2022] Open
Abstract
This review considers recent evidence showing that cells in three regions of the reticular activating system (RAS) exhibit gamma band activity, and describes the mechanisms behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanisms behind this ceiling effect have been recently elucidated. We describe recent findings showing that every cell in the PPN have high-threshold, voltage-dependent P/Q-type calcium channels that are essential, while N-type calcium channels are permissive, to gamma band activity. Every cell in the Pf also showed that P/Q-type and N-type calcium channels are responsible for this activity. On the other hand, every SubCD cell exhibited sodium-dependent subthreshold oscillations. A novel mechanism for sleep–wake control based on well-known transmitter interactions, electrical coupling, and gamma band activity is described. The data presented here on inherent gamma band activity demonstrates the global nature of sleep–wake oscillation that is orchestrated by brainstem–thalamic mechanism, and questions the undue importance given to the hypothalamus for regulation of sleep–wakefulness. The discovery of gamma band activity in the RAS follows recent reports of such activity in other subcortical regions like the hippocampus and cerebellum. We hypothesize that, rather than participating in the temporal binding of sensory events as seen in the cortex, gamma band activity manifested in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking and paradoxical sleep. Most of our thoughts and actions are driven by pre-conscious processes. We speculate that continuous sensory input will induce gamma band activity in the RAS that could participate in the processes of pre-conscious awareness, and provide the essential stream of information for the formulation of many of our actions.
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Affiliation(s)
- Francisco J Urbano
- Instituto de Fisiología, Biología Molecular y Neurociencias, Consejo Nacional de Investigaciones Científicas y Técnicas, University of Buenos Aires Buenos Aires, Argentina
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31
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Abstract
All five muscarinic receptor subtypes and mRNAs are found widely in the brain stem, with M₂ muscarinic receptors most concentrated in the hindbrain. Three cholinergic cell groups, Ch5: pedunculopontine (PPT); Ch6: laterodorsal tegmental (LDT); Ch8: parabigeminal (PBG), are found in the tegmentum. Ch5,6 neurons are activated by arousing and reward-activating stimuli, and inhibited via M₂-like autoreceptors. Ch5,6 ascending projections activate many forebrain regions, including thalamus, basal forebrain, and orexin/hypocretin neurons (via M₃ receptors) for waking arousal and attention. Ch5,6 activation of dopamine neurons of the ventral tegmental area and substantia nigra (via M₅ receptors) increases reward-seeking and energizes motor functions. M₅ receptors on dopamine neurons facilitate brain-stimulation reward, opiate rewards and locomotion, and male ultrasonic vocalizations during mating in rodents. Ch5 cholinergic activation of superior colliculus intermediate layers facilitates fast saccades and approach turns, accompanied by nicotinic and muscarinic inhibition of the startle reflex in pons. Ch8 PBG neurons project to the outer layers of the superior colliculus only, where M₂ receptors are associated with retinotectal terminals. Ch5,6 descending projections to dorsal pontine reticular formation contribute to M₂-dependent REM sleep.
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Affiliation(s)
- John S Yeomans
- Department of Psychology, University of Toronto, Toronto, ON, Canada.
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Datta S, O'Malley MW, Patterson EH. Calcium/calmodulin kinase II in the pedunculopontine tegmental nucleus modulates the initiation and maintenance of wakefulness. J Neurosci 2011; 31:17007-16. [PMID: 22114270 PMCID: PMC3229030 DOI: 10.1523/jneurosci.3981-11.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/03/2011] [Accepted: 10/05/2011] [Indexed: 12/15/2022] Open
Abstract
The pedunculopontine tegmentum nucleus (PPT) is critically involved in the regulation of wakefulness (W) and rapid eye movement (REM) sleep, but our understanding of the mechanisms of this regulation remains incomplete. The present study was designed to determine the role of PPT intracellular calcium/calmodulin kinase (CaMKII) signaling in the regulation of W and sleep. To achieve this aim, three different concentrations (0.5, 1.0, and 2.0 nmol) of the CaMKII activation inhibitor, KN-93, were microinjected bilaterally (100 nl/site) into the PPT of freely moving rats, and the effects on W, slow-wave sleep (SWS), REM sleep, and levels of phosphorylated CaMKII (pCaMKII) expression in the PPT were quantified. These effects, which were concentration-dependent and affected wake-sleep variables for 3 h, resulted in decreased W, due to reductions in the number and duration of W episodes; increased SWS and REM sleep, due to increases in episode duration; and decreased levels of pCaMKII expression in the PPT. Regression analyses revealed that PPT levels of pCaMKII were positively related with the total percentage of time spent in W (R(2) = 0.864; n = 28 rats; p < 0.001) and negatively related with the total percentage of time spent in sleep (R(2) = 0.863; p < 0.001). These data provide the first direct evidence that activation of intracellular CaMKII signaling in the PPT promotes W and suppresses sleep. These findings are relevant for designing a drug that could treat excessive sleepiness by promoting alertness.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, and Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
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Simon C, Kezunovic N, Williams DK, Urbano FJ, Garcia-Rill E. Cholinergic and glutamatergic agonists induce gamma frequency activity in dorsal subcoeruleus nucleus neurons. Am J Physiol Cell Physiol 2011; 301:C327-35. [PMID: 21543743 DOI: 10.1152/ajpcell.00093.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dorsal subcoeruleus nucleus (SubCD) is involved in generating two signs of rapid eye movement (REM) sleep: muscle atonia and ponto-geniculo-occipital (PGO) waves. We tested the hypothesis that single cell and/or population responses of SubCD neurons are capable of generating gamma frequency activity in response to intracellular stimulation or receptor agonist activation. Whole cell patch clamp recordings (immersion chamber) and population responses (interface chamber) were conducted on 9- to 20-day-old rat brain stem slices. All SubCD neurons (n = 103) fired at gamma frequency when subjected to depolarizing steps. Two statistically distinct populations of neurons were observed, which were distinguished by their high (>80 Hz, n = 24) versus low (35-80 Hz, n = 16) initial firing frequencies. Both cell types exhibited subthreshold oscillations in the gamma range (n = 43), which may underlie the gamma band firing properties of these neurons. The subthreshold oscillations were blocked by the sodium channel blockers tetrodotoxin (TTX, n = 21) extracellularly and N-(2,6-dimethylphenylcarbamoylmethyl)triethylammonium bromide (QX-314) intracellularly (n = 5), indicating they were sodium channel dependent. Gamma frequency subthreshold oscillations were observed in response to the nonspecific cholinergic receptor agonist carbachol (CAR, n = 11, d = 1.08) and the glutamate receptor agonists N-methyl-d-aspartic acid (NMDA, n = 12, d = 1.09) and kainic acid (KA, n = 13, d = 0.96), indicating that cholinergic and glutamatergic inputs may be involved in the activation of these subthreshold currents. Gamma band activity also was observed in population responses following application of CAR (n = 4, P < 0.05), NMDA (n = 4, P < 0.05) and KA (n = 4, P < 0.05). Voltage-sensitive, sodium channel-dependent gamma band activity appears to be a part of the intrinsic membrane properties of SubCD neurons.
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Affiliation(s)
- Christen Simon
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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34
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Profice P, Mazzone P, Pilato F, Dileone M, Insola A, Ranieri F, Di Lazzaro V. Neurophysiological evaluation of the pedunculopontine nucleus in humans. J Neural Transm (Vienna) 2011; 118:1423-9. [PMID: 21479864 DOI: 10.1007/s00702-011-0644-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 03/28/2011] [Indexed: 12/19/2022]
Abstract
The pedunculopontine nucleus (PPTg) is constituted by a heterogeneous cluster of neurons located in caudal mesencephalic tegmentum which projects to the thalamus to trigger thalamocortical rhythms and the brainstem to modulate muscle tone and locomotion. It has been investigated as potential deep brain stimulation (DBS) target for treating Parkinson's disease (PD) symptoms. Neurophysiological studies conducted in humans using DBS electrodes for exploring functional properties of PPTg in vivo, reviewed in this paper, demonstrated that the functional connections between PPTg and cortex, basal ganglia, brainstem network involved in sleep/wake control, and spinal cord can be explored in vivo and provided useful insights about the physiology of this nucleus and pathophysiology of PD.
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Affiliation(s)
- P Profice
- Institute of Neurology, Università Cattolica, L.go A. Gemelli 8, 00168, Rome, Italy
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35
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Simon C, Hayar A, Garcia-Rill E. Responses of developing pedunculopontine neurons to glutamate receptor agonists. J Neurophysiol 2011; 105:1918-31. [PMID: 21346216 DOI: 10.1152/jn.00953.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is involved in the generation and maintenance of waking and rapid eye movement (REM) sleep, forming part of the reticular activating system. The PPN receives glutamatergic afferents from other mesopontine nuclei, and glutamatergic input is believed to be involved in the generation of arousal states. We tested the hypothesis that, from postnatal days 9 to 17 in the rat, there are developmental changes in the glutamate receptor subtypes that contribute to the responses of PPN neurons. Whole cell patch-clamp recordings were conducted using brainstem slices from 9- to 17-day-old rats. All cells (types I, II, and III; randomly selected or thalamic-projecting) responded to bath application of the glutamate receptor agonists N-methyl-d-aspartic acid (NMDA) and kainic acid (KA). A developmental decrease in the contribution of the NMDA receptor and developmental increase in the contribution of the KA receptor was observed following electrical stimulation-induced glutamate input. These changes were also observed following bath application in different cell types (randomly selected vs. thalamic-projecting). KA bath application produced an increase in the paired-pulse ratio (PPR) and a decrease in the frequency of miniature excitatory postsynaptic currents (mEPSCs), suggesting that presynaptic KA autoreceptors may decrease the probability of synaptic glutamate input. In contrast, NMDA application produced no changes in the PPR or mEPSCs. Changes in glutamatergic excitability of PPN cell types could underlie the developmental decrease in REM sleep.
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Affiliation(s)
- Christen Simon
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA
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36
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Glutamate microinjection at the medial preoptic area enhances slow wave sleep in rats. Behav Brain Res 2011; 217:240-3. [DOI: 10.1016/j.bbr.2010.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 10/21/2010] [Accepted: 11/01/2010] [Indexed: 01/03/2023]
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37
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Simon C, Wallace-Huitt T, Thapa P, Skinner RD, Garcia-Rill E. Effects of glutamate receptor agonists on the p13 auditory evoked potential and startle response in the rat. Front Neurol 2011; 2:3. [PMID: 21441978 PMCID: PMC3031992 DOI: 10.3389/fneur.2011.00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 01/13/2011] [Indexed: 11/13/2022] Open
Abstract
The P13 potential is the rodent equivalent of the P50 potential, which is an evoked response recorded at the vertex (Vx) 50 ms following an auditory stimulus in humans. Both the P13 and P50 potentials are only present during waking and rapid eye movement (REM) sleep, and are considered to be measures of level of arousal. The source of the P13 and P50 potentials appears to be the pedunculopontine nucleus (PPN), a brainstem nucleus with indirect ascending projections to the cortex through the intralaminar thalamus, mediating arousal, and descending inhibitory projections to the caudal pontine reticular formation (CPRF), which mediates the auditory startle response (SR). We tested the hypothesis that intracranial microinjection (ICM) of glutamate (GLU) or GLU receptor agonists will increase the activity of PPN neurons, resulting in an increased P13 potential response, and decreased SR due to inhibitory projections from the PPN to the CPRF, in freely moving animals. Cannulae were inserted into the PPN to inject neuroactive agents, screws were inserted into the Vx in order to record the P13 potential, and electrodes inserted into the dorsal nuchal muscle to record electromyograms and SR amplitude. Our results showed that ICM of GLU into the PPN dose-dependently increased the amplitude of the P13 potential and decreased the amplitude of the SR. Similarly, ICM of N-methyl-d-aspartic acid or kainate into the PPN increased the amplitude of the P13 potential. These findings indicate that glutamatergic input to the PPN plays a role in arousal control in vivo, and changes in glutamatergic input, or excitability of PPN neurons, could be implicated in a number of neuropsychiatric disorders with the common symptoms of hyperarousal and REM sleep dysregulation.
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Affiliation(s)
- Christen Simon
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | | | - Priyenka Thapa
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | - Robert D. Skinner
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical SciencesLittle Rock, AR, USA
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38
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Desarnaud F, Macone BW, Datta S. Activation of extracellular signal-regulated kinase signaling in the pedunculopontine tegmental cells is involved in the maintenance of sleep in rats. J Neurochem 2011; 116:577-87. [PMID: 21166678 DOI: 10.1111/j.1471-4159.2010.07146.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Considerable evidence suggests that receptor-mediated excitation and inhibition of brainstem pedunculopontine tegmental (PPT) neurons are critically involved in the regulation of sleep-wake states. However, the molecular mechanisms operating within the PPT-controlling sleep-wake states remain relatively unknown. This study was designed to examine sleep-wake state-associated extracellular-signal-regulated kinase 1 and 2 (ERK1/2) transduction changes in the PPT of freely moving rats. The results of this study demonstrate that the levels of ERK1/2 expression, phosphorylation, and activity in the PPT increased with increased amount of time spent in sleep. The sleep-associated increases in ERK1/2 expression, phosphorylation, and activity were not observed in the cortex, or in the immediately adjacent medial pontine reticular formation. The results of regression analyses revealed significant positive relationships between the levels of ERK1/2 expression, phosphorylation, and activity in the PPT and amounts of time spent in slow-wave sleep, rapid eye movement sleep, and total sleep. Additionally, these regression analyses revealed significant negative relationships between the levels of ERK1/2 expression, phosphorylation, and activity in the PPT and amounts of time spent in wakefulness. Collectively, these results, for the first time, suggest that the increased ERK1/2 signaling in the PPT is associated with maintenance of sleep via suppression of wakefulness.
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Affiliation(s)
- Frank Desarnaud
- Department of Laboratory of Sleep and Cognitive Neuroscience, Boston University School of Medicine, Boston, Massachusetts, USA
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39
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Datta S, Desarnaud F. Protein kinase A in the pedunculopontine tegmental nucleus of rat contributes to regulation of rapid eye movement sleep. J Neurosci 2010; 30:12263-73. [PMID: 20844122 PMCID: PMC3327880 DOI: 10.1523/jneurosci.1563-10.2010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/24/2010] [Accepted: 06/29/2010] [Indexed: 11/21/2022] Open
Abstract
Intracellular signaling mechanisms within the pedunculopontine tegmental (PPT) nucleus for the regulation of recovery rapid eye movement (REM) sleep following REM sleep deprivation remain unknown. This study was designed to determine the role of PPT intracellular cAMP-dependent protein kinase A (cAMP-PKA) in the regulation of recovery REM sleep in freely moving rats. The results show that a brief period (3 h) of selective REM sleep deprivation caused REM sleep rebound associated with increased PKA activity and expression of the PKA catalytic subunit protein (PKA-CU) in the PPT. Local application of a cAMP-PKA-activation-selective inhibitor, RpCAMPS (0.55, 1.1, and 2.2 nmol/100 nl; n = 8 rats/group), bilaterally into the PPT, reduced PKA activity and PKA-CU expression in the PPT, and suppressed the recovery REM sleep, in a dose-dependent manner. Regression analyses revealed significant positive relationships between: PPT levels of PKA activity and the total percentages of REM sleep recovery (Rsqr = 0.944; n = 40 rats); PPT levels of PKA-CU expression and the total percentages of REM sleep recovery (Rsqr = 0.937; n = 40 rats); PPT levels of PKA-CU expression and PKA activity (Rsqr = 0.945; n = 40 rats). Collectively, these results provide evidence that activation of intracellular PKA in the PPT contributes to REM sleep recovery following REM sleep deprivation.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
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40
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Simon C, Kezunovic N, Ye M, Hyde J, Hayar A, Williams DK, Garcia-Rill E. Gamma band unit activity and population responses in the pedunculopontine nucleus. J Neurophysiol 2010; 104:463-74. [PMID: 20463196 DOI: 10.1152/jn.00242.2010] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The pedunculopontine nucleus (PPN) is involved in the activated states of waking and paradoxical sleep, forming part of the reticular activating system (RAS). The studies described tested the hypothesis that single unit and/or population responses of PPN neurons are capable of generating gamma band frequency activity. Whole cell patch clamp recordings (immersion chamber) and population responses (interface chamber) were conducted on 9- to 20-day-old rat brain stem slices. Regardless of cell type (I, II, or III) or type of response to the nonselective cholinergic receptor agonist carbachol (excitation, inhibition, biphasic), almost all PPN neurons fired at gamma band frequency, but no higher, when subjected to depolarizing steps (50 +/- 2 Hz, mean +/- SE). Nonaccommodating neurons fired at 18-100 Hz throughout depolarizing steps, while most accommodating neurons exhibited gamma band frequency of action potentials followed by gamma band membrane oscillations. These oscillations were blocked by the sodium channel blocker tetrodotoxin (TTX), suggesting that at least some are mediated by sodium currents. Population responses in the PPN showed that carbachol induced peaks of activation in the theta and gamma range, while glutamatergic receptor agonists induced overall increases in activity at theta and gamma frequencies, although in differing patterns. Gamma band activity appears to be a part of the intrinsic membrane properties of PPN neurons, and the population as a whole generates different patterns of gamma band activity under the influence of specific transmitters. Given sufficient excitation, the PPN may impart gamma band activation on its targets.
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Affiliation(s)
- Christen Simon
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
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Ye M, Hayar A, Strotman B, Garcia-Rill E. Cholinergic modulation of fast inhibitory and excitatory transmission to pedunculopontine thalamic projecting neurons. J Neurophysiol 2010; 103:2417-32. [PMID: 20181729 PMCID: PMC2867582 DOI: 10.1152/jn.01143.2009] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 02/21/2010] [Indexed: 11/22/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is part of the cholinergic arm of the reticular activating system, which is mostly active during waking and rapid-eye movement sleep. The PPN projects to the thalamus and receives cholinergic inputs from the laterodorsal tegmental nucleus and contralateral PPN. We employed retrograde labeling and whole cell recordings to determine the modulation of GABAergic, glycinergic, and glutamatergic transmission to PPN thalamic projecting neurons, and their postsynaptic responses to the nonspecific cholinergic agonist carbachol. M2 and M4 muscarinic receptor-modulated inhibitory postsynaptic responses were observed in 73% of PPN output neurons; in 12.9%, M1 and nicotinic receptor-mediated excitation was detected; and muscarinic and nicotinic-modulated fast inhibitory followed by slow excitatory biphasic responses were evident in 6.7% of cells. A significant increase in the frequency of spontaneous excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents during carbachol application was observed in 66.2% and 65.2% of efferent neurons, respectively. This effect was blocked by a M1 antagonist or nonselective muscarinic blocker, indicating that glutamatergic, GABAergic, and/or glycinergic neurons projecting to PPN output neurons are excited through muscarinic receptors. Decreases in the frequency of miniature EPSCs, and amplitude of electrical stimulation-evoked EPSCs, were blocked by a M2 antagonist, suggesting the presence of M2Rs at terminals of presynaptic glutamatergic neurons. Carbachol-induced multiple types of postsynaptic responses, enhancing both inhibitory and excitatory fast transmission to PPN thalamic projecting neurons through muscarinic receptors. These results provide possible implications for the generation of different frequency oscillations in PPN thalamic projecting neurons during distinct sleep-wake states.
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Affiliation(s)
- Meijun Ye
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Datta S. Cellular and chemical neuroscience of mammalian sleep. Sleep Med 2010; 11:431-40. [PMID: 20359944 DOI: 10.1016/j.sleep.2010.02.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/05/2010] [Accepted: 02/12/2010] [Indexed: 11/18/2022]
Abstract
Extraordinary strides have been made toward understanding the complexities and regulatory mechanisms of sleep over the past two decades thanks to the help of rapidly evolving technologies. At its most basic level, mammalian sleep is a restorative process of the brain and body. Beyond its primary restorative purpose, sleep is essential for a number of vital functions. Our primary research interest is to understand the cellular and molecular mechanisms underlying the regulation of sleep and its cognitive functions. Here I will reflect on our own research contributions to 50 years of extraordinary advances in the neurobiology of slow-wave sleep (SWS) and rapid eye movement (REM) sleep regulation. I conclude this review by suggesting some potential future directions to further our understanding of the neurobiology of sleep.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Departments of Psychiatry, Neurology, and Neuroscience, Boston University School of Medicine, 85 East Newton Street, Suite: M-902, Boston, MA 02118, USA.
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Effects of eszopiclone and zolpidem on sleep-wake behavior, anxiety-like behavior and contextual memory in rats. Behav Brain Res 2010; 210:54-66. [PMID: 20153782 DOI: 10.1016/j.bbr.2010.02.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 02/02/2010] [Accepted: 02/03/2010] [Indexed: 11/23/2022]
Abstract
At present, eszopiclone and zolpidem are the most commonly prescribed drugs for treating insomnia. Despite the established relationship between sleep disturbance and anxiety, it remains unknown whether targeted treatment for insomnia may affect acute anxiety. Therefore, the objective of this study was to examine the effects of three different doses (1, 3, and 10mg/kg) of eszopiclone and zolpidem on the states of sleep and wakefulness, levels of anxiety-like behavior, and long-term contextual memory in footshock-induced anxious rats. The results of this study demonstrated that the administration of eszopiclone and zolpidem both were equally effective in attenuating footshock stressor-induced suppression of slow-wave sleep (SWS). The administration of eszopiclone at 1mg/kg or zolpidem at 1 and 3mg/kg doses showed a tendency for attenuating stressor-induced suppression of REM sleep. However, the REM sleep attenuating effects of these drugs disappeared when they were administered at higher doses. The administration of eszopiclone at 3 and 10mg/kg doses and zolpidem at all three doses reduced the power of electroencephalographic theta band frequencies during wakefulness. In addition, the administration of eszopiclone at 1 and 3mg/kg doses suppressed stressor-induced anxiety-like behavior. The administration of zolpidem at 1, 3, or 10mg/kg doses was not effective in attenuating stressor-induced anxiety-like behavior. Contextual memory after administration of eszopiclone at 1mg/kg dose had no effects, but was reduced significantly with increased dosage. Contextual memory after administration of zolpidem, at all three doses, was severely disrupted. The results of this study suggest that eszopiclone at a low dose could be used effectively to control anxiety and anxiety-induced insomnia.
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Stack EC, Desarnaud F, Siwek DF, Datta S. A novel role for calcium/calmodulin kinase II within the brainstem pedunculopontine tegmentum for the regulation of wakefulness and rapid eye movement sleep. J Neurochem 2009; 112:271-81. [PMID: 19860859 DOI: 10.1111/j.1471-4159.2009.06452.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Considerable evidence suggests that the brainstem pedunculopontine tegmentum (PPT) neurons are critically involved in the regulation of rapid eye movement (REM) sleep and wakefulness (W); however, the molecular mechanisms operating within the PPT to regulate these two behavioral states remain relatively unknown. Here we demonstrate that the levels of calcium/calmodulin kinase II (CaMKII) and phosphorylated CaMKII expression in the PPT decreased and increased with 'low W with high REM sleep' and 'high W/low REM sleep' periods, respectively. These state-specific expression changes were not observed in the cortex, or in the immediately adjacent medial pontine reticular formation. Next, we demonstrate that CaMKII activity in the PPT is negatively and positively correlated with the 'low W with high REM sleep' and 'high W/low REM sleep' periods, respectively. These differences in correlations were not seen in the medial pontine reticular formation CaMKII activity. Finally, we demonstrate that with increased PPT CaMKII activity observed during high W/low REM sleep, there were marked shifts in the expression of genes that are involved in components of various signal transduction pathways. Collectively, these results for the first time suggest that the increased CaMKII activity within PPT neurons is associated with increased W at the expense of REM sleep, and this process is accomplished through the activation of a specific gene expression profile.
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Affiliation(s)
- Edward C Stack
- Laboratory of Sleep and Cognitive Neurosciences, Boston University School of Medicine, Boston, Massachusetts, USA
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Datta S, Siwek DF, Stack EC. Identification of cholinergic and non-cholinergic neurons in the pons expressing phosphorylated cyclic adenosine monophosphate response element-binding protein as a function of rapid eye movement sleep. Neuroscience 2009; 163:397-414. [PMID: 19540313 DOI: 10.1016/j.neuroscience.2009.06.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 06/11/2009] [Accepted: 06/12/2009] [Indexed: 10/20/2022]
Abstract
Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of rapid eye movement (REM) sleep. In the present study performed on rats, phosphorylated cyclic AMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high rapid eye movement sleep (HR, approximately 27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With HR, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low rapid eye movement sleep (LR, approximately 2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr=0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr=0.88), PnO (Rsqr=0.87), and SubCD (Rsqr=0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr=0.70) and DRN (Rsqr=0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are inactive. More importantly, the regression analysis indicated that pCREB activation in approximately 98% of PPT cholinergic neurons, was caused by REM sleep. Moreover the results indicate that during REM sleep, PPT intracellular PKA activation and a transcriptional cascade involving pCREB occur exclusively in the cholinergic neurons.
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Affiliation(s)
- S Datta
- Laboratory of Sleep and Cognitive Neuroscience, Boston University School of Medicine, 85 East Newton Street, Suite M-902, Boston, MA 02118, USA.
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Revel FG, Gottowik J, Gatti S, Wettstein JG, Moreau JL. Rodent models of insomnia: A review of experimental procedures that induce sleep disturbances. Neurosci Biobehav Rev 2009; 33:874-99. [DOI: 10.1016/j.neubiorev.2009.03.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 03/04/2009] [Accepted: 03/04/2009] [Indexed: 12/21/2022]
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Garcia-Rill E, Charlesworth A, Heister D, Ye M, Hayar A. The developmental decrease in REM sleep: the role of transmitters and electrical coupling. Sleep 2008; 31:673-90. [PMID: 18517037 PMCID: PMC2398758 DOI: 10.1093/sleep/31.5.673] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
STUDY OBJECTIVES This mini-review considers certain factors related to the developmental decrease in rapid eye movement (REM) sleep, which occurs in favor of additional waking time, and its relationship to developmental factors that may influence its potential role in brain development. DESIGN Specifically, we discuss some of the theories proposed for the occurrence of REM sleep and agree with the classic notion that REM sleep is, at the least, a mechanism that may play a role in the maturation of thalamocortical pathways. The developmental decrease in REM sleep occurs gradually from birth until close to puberty in the human, and in other mammals it is brief and coincides with eye and ear opening and the beginning of massive exogenous activation. Therefore, the purported role for REM sleep may change to involve a number of other functions with age. MEASUREMENTS AND RESULTS We describe recent findings showing that morphologic and physiologic properties as well as cholinergic, gamma amino-butyric acid, kainic acid, n-methyl-d-aspartic acid, noradrenergic, and serotonergic synaptic inputs to mesopontine cholinergic neurons, as well as the degree of electrical coupling between mostly noncholinergic mesopontine neurons and levels of the neuronal gap-junction protein connexin 36, change dramatically during this critical period in development. A novel mechanism for sleep-wake control based on well-known transmitter interactions, as well as electrical coupling, is described. CONCLUSION We hypothesize that a dysregulation of this process could result in life-long disturbances in arousal and REM sleep drive, leading to hypervigilance or hypovigilance such as that observed in a number of disorders that have a mostly postpubertal age of onset.
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology & Developmental Science, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Saponjic J, Radulovacki M, Carley DW. Modulation of respiratory pattern and upper airway muscle activity by the pedunculopontine tegmentum: role of NMDA receptors. Sleep Breath 2007; 10:195-202. [PMID: 17031714 DOI: 10.1007/s11325-006-0075-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pedunculopontine tegmental nucleus (PPT) is postulated to have important functions relevant to the regulation of rapid eye movement (REM) sleep and arousal, and various motor control systems including respiration. We have recently shown that pharmacologic activation of a neuronal subpopulation within the PPT, induced by micropipette injection of glutamate in nanoliter volumes, can produce respiratory rhythm disturbances and changes in genioglossus muscle activity in anesthetized rats. The aim of this study was to determine whether the respiratory pattern disturbance and increased genioglossus muscle tone induced by glutamate injection within the PPT are mediated by activation of N-methyl-D-aspartate (NMDA) receptors within the PPT. Experiments were performed in eight adult male spontaneously breathing Sprague-Dawley rats anesthetized using nembutal. Respiratory movements were monitored by piezoelectric strain gauge. Three-barrel glass pipettes were used to pressure inject glutamate (as a probe for respiratory modulating sites), ketamine (an NMDA channel blocker), and oil-red dye (to aid in histological verification of the injection sites) within the PPT. Electroencephalograms were recorded from the sensorimotor cortex, the hippocampus, and the pons, contralateral to the injection site. Electromyograms (EMGs) were recorded from the genioglossus muscle. The typical response to glutamate injection within the PPT respiratory-modulating region was immediate apnea followed by tachypnea and increased genioglossal tonic activity. The noncompetitive NMDA receptor channel-antagonist ketamine, injected at the same site and in the same volume as glutamate (5 nl), blocked respiratory dysrhythmia and genioglossal EMG responses to subsequent glutamate injections. For the first time, the present results suggest that respiratory rhythm and upper airway muscle tone are controlled by the activation of pedunculopontine tegmental nucleus NMDA receptors.
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Affiliation(s)
- Jasna Saponjic
- Department of Medicine, University of Illinois, Chicago, IL, 60612, USA.
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Maclean RR, Datta S. The relationship between anxiety and sleep-wake behavior after stressor exposure in the rat. Brain Res 2007; 1164:72-80. [PMID: 17644077 PMCID: PMC1994477 DOI: 10.1016/j.brainres.2007.06.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 12/30/2022]
Abstract
Disturbed sleep is a common subjective complaint among individuals diagnosed with anxiety disorders. In rodents, sleep is often recorded after exposure to various foot-shock paradigms designed to induce an anxiety state. Although differences in sleep-wake architecture are noted, the relationship to specific level of anxiety is often assumed or absent. Utilizing the elevated plus-maze (EPM) after exposure to escapable shock (ES), inescapable shock (IS) or fear conditioning (FC), resulting differences in sleep architecture were compared to an objective measure of anxiety. Male Wistar rats were implanted with EEG, EMG and hippocampal theta electrodes to record sleep-wake behavior. After recovery and recording of baseline sleep, rats were exposed to one of five manipulations: ES, IS, FC or control (CES or CIS; utilizing either chamber with no shock exposure). Shortly after experimental manipulation, the EPM was employed to quantify traditional and ethological measures of anxiety and polygraphic signs of sleep-wake behavior were recorded continuously for 6 h. Although no significance was observed in EPM measurements across groups, profound differences in sleep architecture were present. Individual correlation analysis revealed no differences in anxiety level and total percentage of time spent in sleep-wake states. These results indicate that differences in sleep architecture after foot-shock exposure may not be simply due to increased anxiety. Rather, individual anxiety may be exacerbated by disrupted sleep. To fully understand the relationship between anxiety and sleep-wake behavior, a more objective analysis of anxiety after stressor exposure is mandated.
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Affiliation(s)
- Robert Ross Maclean
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, 85 E. Newton St. M-902, Boston, MA 02118, USA
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Datta S. Activation of pedunculopontine tegmental PKA prevents GABAB receptor activation-mediated rapid eye movement sleep suppression in the freely moving rat. J Neurophysiol 2007; 97:3841-50. [PMID: 17409165 DOI: 10.1152/jn.00263.2007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The pedunculopontine tegmental (PPT) GABAergic system plays a crucial role in the regulation of rapid eye movement (REM) sleep. I recently reported that the activation of PPT GABA(B) receptors suppressed REM sleep by inhibiting REM-on cells. One of the important mechanisms for GABA(B) receptor activation-mediated physiological action is the inhibition of the intracellular cAMP-dependent protein kinase A (cAMP-PKA) signaling pathway. Accordingly, I hypothesized that the PPT GABA(B) receptor activation-mediated REM sleep suppression effect could be mediated through inhibition of cAMP-PKA activation. To test this hypothesis, a GABA(B) receptor selective agonist, baclofen hydrochloride (baclofen), cAMP-PKA activator, Sp-adenosine 3',5'-cyclic monophosphothioate triethylamine (SpCAMPS), and vehicle control were microinjected into the PPT in selected combinations to determine effects on sleep-waking states of chronically instrumented, freely moving rats. Microinjection of SpCAMPS (1.5 nmol) induced REM sleep within a short latency (12.1 +/- 3.6 min) compared with vehicle control microinjection (60.0 +/- 6.5 min). On the contrary, microinjection of baclofen (1.5 nmol) suppressed REM sleep by delaying its appearance for approximately 183 min; however, the suppression of REM sleep by baclofen was prevented by a subsequent microinjection of SpCAMPS. These results provide evidence that the activation of cAMP-PKA within the PPT can successfully block the GABA(B) receptor activation-mediated REM sleep suppression effect. These findings suggest that the PPT GABA(B) receptor activation-mediated REM sleep regulating mechanism involves inactivation of cAMP-PKA signaling in the freely moving rat.
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Affiliation(s)
- Subimal Datta
- Sleep and Cognitive Neuroscience Lab., Dept. of Psychiatry, Boston Univ. School of Medicine, M-902, 715 Albany St., Boston, MA 02118, USA.
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