1
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Bastos-Gonçalves R, Coimbra B, Rodrigues AJ. The mesopontine tegmentum in reward and aversion: From cellular heterogeneity to behaviour. Neurosci Biobehav Rev 2024; 162:105702. [PMID: 38718986 DOI: 10.1016/j.neubiorev.2024.105702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/06/2024] [Accepted: 05/01/2024] [Indexed: 05/18/2024]
Abstract
The mesopontine tegmentum, comprising the pedunculopontine tegmentum (PPN) and the laterodorsal tegmentum (LDT), is intricately connected to various regions of the basal ganglia, motor systems, and limbic systems. The PPN and LDT can regulate the activity of different brain regions of these target systems, and in this way are in a privileged position to modulate motivated behaviours. Despite recent findings, the PPN and LDT have been largely overlooked in discussions about the neural circuits associated with reward and aversion. This review aims to provide a timely and comprehensive resource on past and current research, highlighting the PPN and LDT's connectivity and influence on basal ganglia and limbic, and motor systems. Seminal studies, including lesion, pharmacological, and optogenetic/chemogenetic approaches, demonstrate their critical roles in modulating reward/aversive behaviours. The review emphasizes the need for further investigation into the associated cellular mechanisms, in order to clarify their role in behaviour and contribution for different neuropsychiatric disorders.
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Affiliation(s)
- Ricardo Bastos-Gonçalves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Bárbara Coimbra
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal.
| | - Ana João Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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2
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Juárez Tello A, van der Zouwen CI, Dejas L, Duque-Yate J, Boutin J, Medina-Ortiz K, Suresh JS, Swiegers J, Sarret P, Ryczko D. Dopamine-sensitive neurons in the mesencephalic locomotor region control locomotion initiation, stop, and turns. Cell Rep 2024; 43:114187. [PMID: 38722743 PMCID: PMC11157412 DOI: 10.1016/j.celrep.2024.114187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/31/2024] [Accepted: 04/17/2024] [Indexed: 06/01/2024] Open
Abstract
The locomotor role of dopaminergic neurons is traditionally attributed to their ascending projections to the basal ganglia, which project to the mesencephalic locomotor region (MLR). In addition, descending dopaminergic projections to the MLR are present from basal vertebrates to mammals. However, the neurons targeted in the MLR and their behavioral role are unknown in mammals. Here, we identify genetically defined MLR cells that express D1 or D2 receptors and control different motor behaviors in mice. In the cuneiform nucleus, D1-expressing neurons promote locomotion, while D2-expressing neurons stop locomotion. In the pedunculopontine nucleus, D1-expressing neurons promote locomotion, while D2-expressing neurons evoke ipsilateral turns. Using RNAscope, we show that MLR dopamine-sensitive neurons comprise a combination of glutamatergic, GABAergic, and cholinergic neurons, suggesting that different neurotransmitter-based cell types work together to control distinct behavioral modules. Altogether, our study uncovers behaviorally relevant cell types in the mammalian MLR based on the expression of dopaminergic receptors.
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Affiliation(s)
- Andrea Juárez Tello
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Cornelis Immanuel van der Zouwen
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Léonie Dejas
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Juan Duque-Yate
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Joël Boutin
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Katherine Medina-Ortiz
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jacinthlyn Sylvia Suresh
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jordan Swiegers
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Philippe Sarret
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada; Neurosciences Sherbrooke, Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC, Canada
| | - Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada; Neurosciences Sherbrooke, Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC, Canada.
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3
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Morgenstern NA, Esposito MS. The Basal Ganglia and Mesencephalic Locomotor Region Connectivity Matrix. Curr Neuropharmacol 2024; 22:1454-1472. [PMID: 37559244 PMCID: PMC11097982 DOI: 10.2174/1570159x21666230809112840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 08/11/2023] Open
Abstract
Although classically considered a relay station for basal ganglia (BG) output, the anatomy, connectivity, and function of the mesencephalic locomotor region (MLR) were redefined during the last two decades. In striking opposition to what was initially thought, MLR and BG are actually reciprocally and intimately interconnected. New viral-based, optogenetic, and mapping technologies revealed that cholinergic, glutamatergic, and GABAergic neurons coexist in this structure, which, in addition to extending descending projections, send long-range ascending fibers to the BG. These MLR projections to the BG convey motor and non-motor information to specific synaptic targets throughout different nuclei. Moreover, MLR efferent fibers originate from precise neuronal subpopulations located in particular MLR subregions, defining independent anatomo-functional subcircuits involved in particular aspects of animal behavior such as fast locomotion, explorative locomotion, posture, forelimb- related movements, speed, reinforcement, among others. In this review, we revised the literature produced during the last decade linking MLR and BG. We conclude that the classic framework considering the MLR as a homogeneous output structure passively receiving input from the BG needs to be revisited. We propose instead that the multiple subcircuits embedded in this region should be taken as independent entities that convey relevant and specific ascending information to the BG and, thus, actively participate in the execution and tuning of behavior.
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Affiliation(s)
- Nicolás A. Morgenstern
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
- Faculty of Medicine, University of Lisbon, Instituto De Medicina Molecular João Lobo Antunes, Lisbon, Portugal
| | - Maria S. Esposito
- Department of Medical Physics, Centro Atomico Bariloche, CNEA, CONICET, Av. Bustillo 9500, San Carlos de Bariloche, Rio Negro, Argentina
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4
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Goñi-Erro H, Selvan R, Caggiano V, Leiras R, Kiehn O. Pedunculopontine Chx10 + neurons control global motor arrest in mice. Nat Neurosci 2023; 26:1516-1528. [PMID: 37501003 PMCID: PMC10471498 DOI: 10.1038/s41593-023-01396-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/22/2023] [Indexed: 07/29/2023]
Abstract
Arrest of ongoing movements is an integral part of executing motor programs. Behavioral arrest may happen upon termination of a variety of goal-directed movements or as a global motor arrest either in the context of fear or in response to salient environmental cues. The neuronal circuits that bridge with the executive motor circuits to implement a global motor arrest are poorly understood. We report the discovery that the activation of glutamatergic Chx10-derived neurons in the pedunculopontine nucleus (PPN) in mice arrests all ongoing movements while simultaneously causing apnea and bradycardia. This global motor arrest has a pause-and-play pattern with an instantaneous interruption of movement followed by a short-latency continuation from where it was paused. Mice naturally perform arrest bouts with the same combination of motor and autonomic features. The Chx10-PPN-evoked arrest is different to ventrolateral periaqueductal gray-induced freezing. Our study defines a motor command that induces a global motor arrest, which may be recruited in response to salient environmental cues to allow for a preparatory or arousal state, and identifies a locomotor-opposing role for rostrally biased glutamatergic neurons in the PPN.
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Affiliation(s)
- Haizea Goñi-Erro
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Raghavendra Selvan
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
| | - Vittorio Caggiano
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Meta AI Research, New York, NY, USA
| | - Roberto Leiras
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Ole Kiehn
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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5
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Lacroix-Ouellette P, Dubuc R. Brainstem neural mechanisms controlling locomotion with special reference to basal vertebrates. Front Neural Circuits 2023; 17:910207. [PMID: 37063386 PMCID: PMC10098025 DOI: 10.3389/fncir.2023.910207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Over the last 60 years, the basic neural circuitry responsible for the supraspinal control of locomotion has progressively been uncovered. Initially, significant progress was made in identifying the different supraspinal structures controlling locomotion in mammals as well as some of the underlying mechanisms. It became clear, however, that the complexity of the mammalian central nervous system (CNS) prevented researchers from characterizing the detailed cellular mechanisms involved and that animal models with a simpler nervous system were needed. Basal vertebrate species such as lampreys, xenopus embryos, and zebrafish became models of choice. More recently, optogenetic approaches have considerably revived interest in mammalian models. The mesencephalic locomotor region (MLR) is an important brainstem region known to control locomotion in all vertebrate species examined to date. It controls locomotion through intermediary cells in the hindbrain, the reticulospinal neurons (RSNs). The MLR comprises populations of cholinergic and glutamatergic neurons and their specific contribution to the control of locomotion is not fully resolved yet. Moreover, the downward projections from the MLR to RSNs is still not fully understood. Reporting on discoveries made in different animal models, this review article focuses on the MLR, its projections to RSNs, and the contribution of these neural elements to the control of locomotion. Excellent and detailed reviews on the brainstem control of locomotion have been recently published with emphasis on mammalian species. The present review article focuses on findings made in basal vertebrates such as the lamprey, to help direct new research in mammals, including humans.
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Affiliation(s)
| | - Réjean Dubuc
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
- Department of Physical Activity Sciences, Université du Québec à Montréal, Montréal, QC, Canada
- Research Group for Adapted Physical Activity, Université du Québec à Montréal, Montréal, QC, Canada
- *Correspondence: Réjean Dubuc,
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6
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Nishimaru H, Matsumoto J, Setogawa T, Nishijo H. Neuronal structures controlling locomotor behavior during active and inactive motor states. Neurosci Res 2022; 189:83-93. [PMID: 36549389 DOI: 10.1016/j.neures.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Animal behaviors can be divided into two states according to their motor activity: the active motor state, which involves significant body movements, and the inactive motor state, which refers to when the animal is stationary. The timing and duration of these states are determined by the activity of the neuronal circuits involved in motor control. Among these motor circuits, those that generate locomotion are some of the most studied neuronal networks and are widely distributed from the spinal cord to the cerebral cortex. In this review, we discuss recent discoveries, mainly in rodents using state-of-the-art experimental approaches, of the neuronal mechanisms underlying the initiation and termination of locomotion in the brainstem, basal ganglia, and prefrontal cortex. These findings is discussed with reference to studies on the neuronal mechanism of motor control during sleep and the modulation of cortical states in these structures. Accumulating evidence has unraveled the complex yet highly structured network that controls the transition between motor states.
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Affiliation(s)
- Hiroshi Nishimaru
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; Graduate school of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama 930-0194, Japan.
| | - Jumpei Matsumoto
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; Graduate school of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama 930-0194, Japan
| | - Tsuyoshi Setogawa
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; Graduate school of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama 930-0194, Japan
| | - Hisao Nishijo
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; Graduate school of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama 930-0194, Japan
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7
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Dautan D, Kovács A, Bayasgalan T, Diaz-Acevedo MA, Pal B, Mena-Segovia J. Modulation of motor behavior by the mesencephalic locomotor region. Cell Rep 2021; 36:109594. [PMID: 34433068 PMCID: PMC8641693 DOI: 10.1016/j.celrep.2021.109594] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 05/05/2021] [Accepted: 08/02/2021] [Indexed: 11/09/2022] Open
Abstract
The mesencephalic locomotor region (MLR) serves as an interface between higher-order motor systems and lower motor neurons. The excitatory module of the MLR is composed of the pedunculopontine nucleus (PPN) and the cuneiform nucleus (CnF), and their activation has been proposed to elicit different modalities of movement. However, how the differences in connectivity and physiological properties explain their contributions to motor activity is not well known. Here we report that CnF glutamatergic neurons are more electrophysiologically homogeneous than PPN neurons and have mostly short-range connectivity, whereas PPN glutamatergic neurons are heterogeneous and maintain long-range connections, most notably with the basal ganglia. Optogenetic activation of CnF neurons produces short-lasting muscle activation, driving involuntary motor activity. In contrast, PPN neuron activation produces long-lasting increases in muscle tone that reduce motor activity and disrupt gait. Our results highlight biophysical and functional attributes among MLR neurons that support their differential contribution to motor behavior. Dautan et al. show key differences in the connectivity and physiological properties of neurons of the mesencephalic locomotor region. Although activation of CnF neurons elicits involuntary locomotor responses, activation of PPN neurons increases muscle tone and reduces motor activity, suggesting that PPN encodes a readiness signal that precedes locomotion.
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Affiliation(s)
- Daniel Dautan
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ 07102, USA.
| | - Adrienn Kovács
- Department of Physiology, University of Debrecen, Faculty of Medicine, 4012 Debrecen, Hungary
| | - Tsogbadrakh Bayasgalan
- Department of Physiology, University of Debrecen, Faculty of Medicine, 4012 Debrecen, Hungary
| | - Miguel A Diaz-Acevedo
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ 07102, USA
| | - Balazs Pal
- Department of Physiology, University of Debrecen, Faculty of Medicine, 4012 Debrecen, Hungary
| | - Juan Mena-Segovia
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ 07102, USA.
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8
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Chang SJ, Santamaria AJ, Sanchez FJ, Villamil LM, Saraiva PP, Benavides F, Nunez-Gomez Y, Solano JP, Opris I, Guest JD, Noga BR. Deep brain stimulation of midbrain locomotor circuits in the freely moving pig. Brain Stimul 2021; 14:467-476. [PMID: 33652130 PMCID: PMC9097921 DOI: 10.1016/j.brs.2021.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 01/01/2023] Open
Abstract
Background: Deep brain stimulation (DBS) of the mesencephalic locomotor region (MLR) has been studied as a therapeutic target in rodent models of stroke, parkinsonism, and spinal cord injury. Clinical DBS trials have targeted the closely related pedunculopontine nucleus in patients with Parkinson’s disease as a therapy for gait dysfunction, with mixed reported outcomes. Recent studies suggest that optimizing the MLR target could improve its effectiveness. Objective: We sought to determine if stereotaxic targeting and DBS in the midbrain of the pig, in a region anatomically similar to that previously identified as the MLR in other species, could initiate and modulate ongoing locomotion, as a step towards generating a large animal neuromodulation model of gait. Methods: We implanted Medtronic 3389 electrodes into putative MLR structures in Yucatan micropigs to characterize the locomotor effects of acute DBS in this region, using EMG recordings, joint kinematics, and speed measurements on a manual treadmill. Results: MLR DBS initiated and augmented locomotion in freely moving micropigs. Effective locomotor sites centered around the cuneiform nucleus and stimulation frequency controlled locomotor speed and stepping frequency. Off-target stimulation evoked defensive and aversive behaviors that precluded locomotion in the animals. Conclusion: Pigs appear to have an MLR and can be used to model neuromodulation of this gait-promoting center. These results indicate that the pig is a useful model to guide future clinical studies for optimizing MLR DBS in cases of gait deficiencies associated with such conditions as Parkinson’s disease, spinal cord injury, or stroke.
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Affiliation(s)
- Stephano J Chang
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Division of Neurosurgery, Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Andrea J Santamaria
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Francisco J Sanchez
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Luz M Villamil
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Pedro Pinheiro Saraiva
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Francisco Benavides
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Yohjans Nunez-Gomez
- Department of Pediatric Critical Care, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Juan P Solano
- Department of Pediatric Critical Care, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ioan Opris
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - James D Guest
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Brian R Noga
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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9
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Henrich MT, Geibl FF, Lakshminarasimhan H, Stegmann A, Giasson BI, Mao X, Dawson VL, Dawson TM, Oertel WH, Surmeier DJ. Determinants of seeding and spreading of α-synuclein pathology in the brain. SCIENCE ADVANCES 2020; 6:eabc2487. [PMID: 33177086 PMCID: PMC7673735 DOI: 10.1126/sciadv.abc2487] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/22/2020] [Indexed: 05/22/2023]
Abstract
In Parkinson's disease (PD), fibrillar forms of α-synuclein are hypothesized to propagate through synaptically coupled networks, causing Lewy pathology (LP) and neurodegeneration. To more rigorously characterize the determinants of spreading, preformed α-synuclein fibrils were injected into the mouse pedunculopontine nucleus (PPN), a brain region that manifests LP in PD patients and the distribution of developing α-synuclein pathology compared to that ascertained by anterograde and retrograde connectomic mapping. Within the PPN, α-synuclein pathology was cell-specific, being robust in PD-vulnerable cholinergic neurons but not in neighboring noncholinergic neurons. While nearly all neurons projecting to PPN cholinergics manifested α-synuclein pathology, the kinetics, magnitude, and persistence of the propagated pathology were unrelated to the strength of those connections. Thus, neuronal phenotype governs the somatodendritic uptake of pathological α-synuclein, and while the afferent connectome restricts the subsequent spreading of pathology, its magnitude and persistence is not a strict function of the strength of coupling.
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Affiliation(s)
- Martin T Henrich
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Neurology, Philipps University Marburg, Marburg 35043, Germany
| | - Fanni F Geibl
- Department of Neurology, Philipps University Marburg, Marburg 35043, Germany
| | - Harini Lakshminarasimhan
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Anna Stegmann
- Department of Neurology, Philipps University Marburg, Marburg 35043, Germany
| | - Benoit I Giasson
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Xiaobo Mao
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Valina L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ted M Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Wolfgang H Oertel
- Department of Neurology, Philipps University Marburg, Marburg 35043, Germany
| | - D James Surmeier
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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10
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Chang SJ, Cajigas I, Opris I, Guest JD, Noga BR. Dissecting Brainstem Locomotor Circuits: Converging Evidence for Cuneiform Nucleus Stimulation. Front Syst Neurosci 2020; 14:64. [PMID: 32973468 PMCID: PMC7473103 DOI: 10.3389/fnsys.2020.00064] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/03/2020] [Indexed: 01/06/2023] Open
Abstract
There are a pressing and unmet need for effective therapies for freezing of gait (FOG) and other neurological gait disorders. Deep brain stimulation (DBS) of a midbrain target known as the pedunculopontine nucleus (PPN) was proposed as a potential treatment based on its postulated involvement in locomotor control as part of the mesencephalic locomotor region (MLR). However, DBS trials fell short of expectations, leading many clinicians to abandon this strategy. Here, we discuss the potential reasons for this failure and review recent clinical data along with preclinical optogenetics evidence to argue that another nearby nucleus, the cuneiform nucleus (CnF), may be a superior target.
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Affiliation(s)
- Stephano J. Chang
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
- Division of Neurosurgery, Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Iahn Cajigas
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ioan Opris
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - James D. Guest
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Brian R. Noga
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
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11
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Satoh Y, Tsuji K. Suppressive effect of the swallowing reflex by stimulation of the pedunculopontine tegmental nucleus. Neurosci Res 2020; 169:40-47. [PMID: 32649975 DOI: 10.1016/j.neures.2020.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 10/23/2022]
Abstract
This study investigates whether the swallowing reflex is modulated by stimulation of the pedunculopontine tegmental nucleus (PTg). Sprague-Dawley rats under urethane anesthesia were used. The swallowing reflex was induced by electrical stimulation of the superior laryngeal nerve and was identified by the electromyographic activities from the mylohyoid muscle. The number of swallows was reduced by electrical stimulation of the PTg. The latency of the onset of the first swallow was increased during stimulation of the PTg. The duration of electromyogram bursts of the mylohyoid muscle was significantly shorter during the PTg stimulation than with no stimulation. The number of swallows was reduced, latency of onset of the first swallow increased, the duration of electromyogram bursts of the mylohyoid muscle was significantly shorter and the peak-to-peak amplitude of electromyogram bursts of the mylohyoid muscle was significantly suppressed after microinjection of glutamate into the PTg. These results suggest that the PTg is involved in the control of swallowing.
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Affiliation(s)
- Yoshihide Satoh
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
| | - Kojun Tsuji
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan
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Chambers NE, Lanza K, Bishop C. Pedunculopontine Nucleus Degeneration Contributes to Both Motor and Non-Motor Symptoms of Parkinson's Disease. Front Pharmacol 2020; 10:1494. [PMID: 32009944 PMCID: PMC6974690 DOI: 10.3389/fphar.2019.01494] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 11/19/2019] [Indexed: 12/31/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder characterized by hypokinetic motor features; however, patients also display non-motor symptoms like sleep disorders. The standard treatment for PD is dopamine replacement with L-DOPA; however, symptoms including gait deficits and sleep disorders are unresponsive to L-DOPA. Notably, these symptoms have been linked to aberrant activity in the pedunculopontine nucleus (PPN). Of late, clinical trials involving PPN deep brain stimulation (DBS) have been employed to alleviate gait deficits. Although preclinical evidence implicating PPN cholinergic neurons in gait dysfunction was initially promising, DBS trials fell short of expected outcomes. One reason for the failure of DBS may be that the PPN is a heterogenous nucleus that consists of GABAergic, cholinergic, and glutamatergic neurons that project to a diverse array of brain structures. Second, DBS trials may have been unsuccessful because PPN neurons are susceptible to mitochondrial dysfunction, Lewy body pathology, and degeneration in PD. Therefore, pharmaceutical or gene-therapy strategies targeting specific PPN neuronal populations or projections could better alleviate intractable PD symptoms. Unfortunately, how PPN neuronal populations and their respective projections influence PD motor and non-motor symptoms remains enigmatic. Herein, we discuss normal cellular and neuroanatomical features of the PPN, the differential susceptibility of PPN neurons to PD-related insults, and we give an overview of literature suggesting a role for PPN neurons in motor and sleep deficits in PD. Finally, we identify future approaches directed towards the PPN for the treatment of PD motor and sleep symptoms.
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Affiliation(s)
| | | | - Christopher Bishop
- Department of Psychology, Binghamton University, Binghamton, NY, United States
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13
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Vitale F, Capozzo A, Mazzone P, Scarnati E. Neurophysiology of the pedunculopontine tegmental nucleus. Neurobiol Dis 2019. [DOI: 10.1016/j.nbd.2018.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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14
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Baksa B, Kovács A, Bayasgalan T, Szentesi P, Kőszeghy Á, Szücs P, Pál B. Characterization of functional subgroups among genetically identified cholinergic neurons in the pedunculopontine nucleus. Cell Mol Life Sci 2019; 76:2799-2815. [PMID: 30734834 PMCID: PMC6588655 DOI: 10.1007/s00018-019-03025-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/21/2018] [Accepted: 01/23/2019] [Indexed: 12/19/2022]
Abstract
The pedunculopontine nucleus (PPN) is a part of the reticular activating system which is composed of cholinergic, glutamatergic and GABAergic neurons. Early electrophysiological studies characterized and grouped PPN neurons based on certain functional properties (i.e., the presence or absence of the A-current, spike latency, and low threshold spikes). Although other electrophysiological characteristics of these neurons were also described (as high threshold membrane potential oscillations, great differences in spontaneous firing rate and the presence or absence of the M-current), systematic assessment of these properties and correlation of them with morphological markers are still missing. In this work, we conducted electrophysiological experiments on brain slices of genetically identified cholinergic neurons in the PPN. Electrophysiological properties were compared with rostrocaudal location of the neuronal soma and selected morphometric features obtained with post hoc reconstruction. We found that functional subgroups had different proportions in the rostral and caudal subregions of the nucleus. Neurons with A-current can be divided to early-firing and late-firing neurons, where the latter type was found exclusively in the caudal subregion. Similar to this, different parameters of high threshold membrane potential oscillations also showed characteristic rostrocaudal distribution. Furthermore, based on our data, we propose that high threshold oscillations rather emerge from neuronal somata and not from the proximal dendrites. In summary, we demonstrated the existence and spatial distribution of functional subgroups of genetically identified PPN cholinergic neurons, which are in accordance with differences found in projection and in vivo functional findings of the subregions. Being aware of functional differences of PPN subregions will help the design and analysis of experiments using genetically encoded opto- and chemogenetic markers for in vivo experiments.
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Affiliation(s)
- B Baksa
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - A Kovács
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - T Bayasgalan
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - P Szentesi
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - Á Kőszeghy
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - P Szücs
- Department of Anatomy, Histology and Embriology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Balázs Pál
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary.
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Sébille SB, Rolland AS, Faillot M, Perez-Garcia F, Colomb-Clerc A, Lau B, Dumas S, Vidal SF, Welter ML, Francois C, Bardinet E, Karachi C. Normal and pathological neuronal distribution of the human mesencephalic locomotor region. Mov Disord 2018; 34:218-227. [PMID: 30485555 DOI: 10.1002/mds.27578] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/10/2018] [Accepted: 10/22/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Deep brain stimulation of the pedunculopontine nucleus has been performed to treat dopamine-resistant gait and balance disorders in patients with degenerative diseases. The outcomes, however, are variable, which may be the result of the lack of a well-defined anatomical target. OBJECTIVES The objectives of this study were to identify the main neuronal populations of the pedunculopontine and the cuneiform nuclei that compose the human mesencephalic locomotor region and to compare their 3-dimensional distribution with those found in patients with Parkinson's disease and progressive supranuclear palsy. METHODS We used high-field MRI, immunohistochemistry, and in situ hybridization to characterize the distribution of the different cell types, and we developed software to merge all data within a common 3-dimensional space. RESULTS We found that cholinergic, GABAergic, and glutamatergic neurons comprised the main cell types of the mesencephalic locomotor region, with the peak densities of cholinergic and GABAergic neurons similarly located within the rostral pedunculopontine nucleus. Cholinergic and noncholinergic neuronal losses were homogeneous in the mesencephalic locomotor region of patients, with the peak density of remaining neurons at the same location as in controls. The degree of denervation of the pedunculopontine nucleus was highest in patients with progressive supranuclear palsy, followed by Parkinson's disease patients with falls. CONCLUSIONS The peak density of cholinergic and GABAergic neurons was located similarly within the rostral pedunculopontine nucleus not only in controls but also in pathological cases. The neuronal loss was homogeneously distributed and highest in the pedunculopontine nucleus of patients with falls, which suggests a potential pathophysiological link. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Sophie B Sébille
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France.,Centre de Neuro-Imagerie de Recherche, Paris, France
| | - Anne-Sophie Rolland
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France
| | - Matthieu Faillot
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France.,Neurosurgical Department, La Pitié-Salpêtrière University Hospital, Paris, France
| | | | - Antoine Colomb-Clerc
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France
| | - Brian Lau
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France
| | | | | | - Marie-Laure Welter
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France.,Neurosurgical Department, La Pitié-Salpêtrière University Hospital, Paris, France
| | - Chantal Francois
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France
| | - Eric Bardinet
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France.,Centre de Neuro-Imagerie de Recherche, Paris, France
| | - Carine Karachi
- Sorbonne University, Univ. Pierre & Marie Curie Paris 06, Cnrs, Inserm, AP-HP Pitié-Salpêtrière hospital, Brain and Spinal Cord Institute, Paris, France.,Neurosurgical Department, La Pitié-Salpêtrière University Hospital, Paris, France
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16
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Duysens J, Forner-Cordero A. Walking with perturbations: a guide for biped humans and robots. BIOINSPIRATION & BIOMIMETICS 2018; 13:061001. [PMID: 30109860 DOI: 10.1088/1748-3190/aada54] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper provides an update on the neural control of bipedal walking in relation to bioinspired models and robots. It is argued that most current models or robots are based on the construct of a symmetrical central pattern generator (CPG). However, new evidence suggests that CPG functioning is basically asymmetrical with its flexor half linked more tightly to the rhythm generator. The stability of bipedal gait, which is an important problem for robots and biological systems, is also addressed. While it is not possible to determine how biological biped systems guarantee stability, robot solutions can be useful to propose new hypotheses for biology. In the second part of this review, the focus is on gait perturbations, which is an important topic in robotics in view of the frequent falls of robots when faced with perturbations. From the human physiology it is known that the initial reaction often consists of a brief interruption followed by an adequate response. For instance, the successful recovery from a trip is achieved using some basic reactions (termed elevating and lowering strategies), that depend on the phase of the step cycle of the trip occurrence. Reactions to stepping unexpectedly in a hole depend on comparing expected and real feedback. Implementation of these ideas in models and robotics starts to emerge, with the most advanced robots being able to learn how to fall safely and how to deal with complicated disturbances such as provided by walking on a split-belt.
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Affiliation(s)
- Jacques Duysens
- Biomechatronics Lab., Mechatronics Department, Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, Cidade Universitária 05508-030, São Paulo-SP, Brasil. Department of Kinesiology, FaBeR, Katholieke Universiteit Leuven, Leuven, Belgium
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17
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Héricé C, Patel AA, Sakata S. Circuit mechanisms and computational models of REM sleep. Neurosci Res 2018; 140:77-92. [PMID: 30118737 PMCID: PMC6403104 DOI: 10.1016/j.neures.2018.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/03/2018] [Accepted: 07/10/2018] [Indexed: 01/31/2023]
Abstract
REM sleep was discovered in the 1950s. Many hypothalamic and brainstem areas have been found to contribute to REM sleep. An up-to-date picture of REM-sleep-regulating circuits is reviewed. A brief overview of computational models for REM sleep regulation is provided. Outstanding issues for future studies are discussed.
Rapid eye movement (REM) sleep or paradoxical sleep is an elusive behavioral state. Since its discovery in the 1950s, our knowledge of the neuroanatomy, neurotransmitters and neuropeptides underlying REM sleep regulation has continually evolved in parallel with the development of novel technologies. Although the pons was initially discovered to be responsible for REM sleep, it has since been revealed that many components in the hypothalamus, midbrain, pons, and medulla also contribute to REM sleep. In this review, we first provide an up-to-date overview of REM sleep-regulating circuits in the brainstem and hypothalamus by summarizing experimental evidence from neuroanatomical, neurophysiological and gain- and loss-of-function studies. Second, because quantitative approaches are essential for understanding the complexity of REM sleep-regulating circuits and because mathematical models have provided valuable insights into the dynamics underlying REM sleep genesis and maintenance, we summarize computational studies of the sleep-wake cycle, with an emphasis on REM sleep regulation. Finally, we discuss outstanding issues for future studies.
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Affiliation(s)
- Charlotte Héricé
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Amisha A Patel
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Shuzo Sakata
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK.
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18
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Spike discharge characteristic of the caudal mesencephalic reticular formation and pedunculopontine nucleus in MPTP-induced primate model of Parkinson disease. Neurobiol Dis 2018; 128:40-48. [PMID: 30086388 DOI: 10.1016/j.nbd.2018.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/24/2018] [Accepted: 08/03/2018] [Indexed: 12/20/2022] Open
Abstract
The pedunculopontine nucleus (PPN) included in the caudal mesencephalic reticular formation (cMRF) plays a key role in the control of locomotion and wake state. Regarding its involvement in the neurodegenerative process observed in Parkinson disease (PD), deep brain stimulation of the PPN was proposed to treat levodopa-resistant gait disorders. However, the precise role of the cMRF in the pathophysiology of PD, particularly in freezing of gait and other non-motor symptoms is still not clear. Here, using micro electrode recording (MER) in 2 primates, we show that dopamine depletion did not alter the mean firing rate of the overall cMRF neurons, particularly the putative non-cholinergic ones, but only a decreased activity of the regular neurons sub-group (though to be the cholinergic PPN neurons). Interestingly, a significant increase in the relative proportion of cMRF neurons with a burst pattern discharge was observed after MPTP intoxication. The present results question the hypothesis of an over-inhibition of the CMRF by the basal ganglia output structures in PD. The decreased activity observed in the regular neurons could explain some non-motor symptoms in PD regarding the strong involvement of the cholinergic neurons on the modulation of the thalamo-cortical system. The increased burst activity under dopamine depletion confirms that this specific spike discharge pattern activity also observed in other basal ganglia nuclei and in different pathologies could play a mojor role in the pathophysiology of the disease and could explain several symptoms of PD including the freezing of gait. The present data will have to be replicated in a larger number of animals and will have to investigate more in details how the modification of the spike discharge of the cMRF neurons in the parkinsonian state could alter functions such as locomotion and attentional state. This will ultimely allow a better comprehension of the pathophysiology of freezing of gait.
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19
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Luquin E, Huerta I, Aymerich MS, Mengual E. Stereological Estimates of Glutamatergic, GABAergic, and Cholinergic Neurons in the Pedunculopontine and Laterodorsal Tegmental Nuclei in the Rat. Front Neuroanat 2018; 12:34. [PMID: 29867374 PMCID: PMC5958217 DOI: 10.3389/fnana.2018.00034] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 04/16/2018] [Indexed: 01/29/2023] Open
Abstract
The pedunculopontine tegmental nucleus (PPN) and laterodorsal tegmental nucleus (LDT) are functionally associated brainstem structures implicated in behavioral state control and sensorimotor integration. The PPN is also involved in gait and posture, while the LDT plays a role in reward. Both nuclei comprise characteristic cholinergic neurons intermingled with glutamatergic and GABAergic cells whose absolute numbers in the rat have been only partly established. Here we sought to determine the complete phenotypical profile of each nucleus to investigate potential differences between them. Counts were obtained using stereological methods after the simultaneous visualization of cholinergic and either glutamatergic or GABAergic cells. The two isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67, were separately analyzed. Dual in situ hybridization revealed coexpression of GAD65 and GAD67 mRNAs in ∼90% of GAD-positive cells in both nuclei; thus, the estimated mean numbers of (1) cholinergic, (2) glutamatergic, and (3) GABAergic cells in PPN and LDT, respectively, were (1) 3,360 and 3,650; (2) 5,910 and 5,190; and (3) 4,439 and 7,599. These data reveal significant differences between PPN and LDT in their relative phenotypical composition, which may underlie some of the functional differences observed between them. The estimation of glutamatergic cells was significantly higher in the caudal PPN, supporting the reported functional rostrocaudal segregation in this nucleus. Finally, a small subset of cholinergic neurons (8% in PPN and 5% in LDT) also expressed the glutamatergic marker Vglut2, providing anatomical evidence for a potential corelease of transmitters at specific target areas.
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Affiliation(s)
- Esther Luquin
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Ibone Huerta
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - María S Aymerich
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,Department of Biochemistry and Genetics, School of Science, University of Navarra, Pamplona, Spain
| | - Elisa Mengual
- Division of Neurosciences, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.,Anatomy Department, School of Medicine, University of Navarra, Pamplona, Spain
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20
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French IT, Muthusamy KA. A Review of the Pedunculopontine Nucleus in Parkinson's Disease. Front Aging Neurosci 2018; 10:99. [PMID: 29755338 PMCID: PMC5933166 DOI: 10.3389/fnagi.2018.00099] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 03/22/2018] [Indexed: 01/04/2023] Open
Abstract
The pedunculopontine nucleus (PPN) is situated in the upper pons in the dorsolateral portion of the ponto-mesencephalic tegmentum. Its main mass is positioned at the trochlear nucleus level, and is part of the mesenphalic locomotor region (MLR) in the upper brainstem. The human PPN is divided into two subnuclei, the pars compacta (PPNc) and pars dissipatus (PPNd), and constitutes both cholinergic and non-cholinergic neurons with afferent and efferent projections to the cerebral cortex, thalamus, basal ganglia (BG), cerebellum, and spinal cord. The BG controls locomotion and posture via GABAergic output of the substantia nigra pars reticulate (SNr). In PD patients, GABAergic BG output levels are abnormally increased, and gait disturbances are produced via abnormal increases in SNr-induced inhibition of the MLR. Since the PPN is vastly connected with the BG and the brainstem, dysfunction within these systems lead to advanced symptomatic progression in Parkinson's disease (PD), including sleep and cognitive issues. To date, the best treatment is to perform deep brain stimulation (DBS) on PD patients as outcomes have shown positive effects in ameliorating the debilitating symptoms of this disease by treating pathological circuitries within the parkinsonian brain. It is therefore important to address the challenges and develop this procedure to improve the quality of life of PD patients.
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Affiliation(s)
- Isobel T. French
- Division of Neurosurgery, Department of Surgery, University Malaya, Kuala Lumpur, Malaysia
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21
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Josset N, Roussel M, Lemieux M, Lafrance-Zoubga D, Rastqar A, Bretzner F. Distinct Contributions of Mesencephalic Locomotor Region Nuclei to Locomotor Control in the Freely Behaving Mouse. Curr Biol 2018. [PMID: 29526593 DOI: 10.1016/j.cub.2018.02.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mesencephalic locomotor region (MLR) has been initially identified as a supraspinal center capable of initiating and modulating locomotion. Whereas its functional contribution to locomotion has been widely documented throughout the phylogeny from the lamprey to humans, there is still debate about its exact organization. Combining kinematic and electrophysiological recordings in mouse genetics, our study reveals that glutamatergic neurons of the cuneiform nucleus initiate locomotion and induce running gaits, whereas glutamatergic and cholinergic neurons of the pedunculopontine nucleus modulate locomotor pattern and rhythm, contributing to slow-walking gaits. By initiating, modulating, and accelerating locomotion, our study identifies and characterizes distinct neuronal populations of this functional region important to locomotor command.
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Affiliation(s)
- Nicolas Josset
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Marie Roussel
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Maxime Lemieux
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada
| | - David Lafrance-Zoubga
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Ali Rastqar
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Frederic Bretzner
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 boul. Laurier, Québec, QC G1V 4G2, Canada; Faculty of Medicine, Department of Psychiatry and Neurosciences, Université Laval, Québec, QC G1V 4G2, Canada.
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On the Role of the Pedunculopontine Nucleus and Mesencephalic Reticular Formation in Locomotion in Nonhuman Primates. J Neurosci 2017; 36:4917-29. [PMID: 27147647 DOI: 10.1523/jneurosci.2514-15.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 02/22/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The mesencephalic reticular formation (MRF) is formed by the pedunculopontine and cuneiform nuclei, two neuronal structures thought to be key elements in the supraspinal control of locomotion, muscle tone, waking, and REM sleep. The role of MRF has also been advocated in modulation of state of arousal leading to transition from wakefulness to sleep and it is further considered to be a main player in the pathophysiology of gait disorders seen in Parkinson's disease. However, the existence of a mesencephalic locomotor region and of an arousal center has not yet been demonstrated in primates. Here, we provide the first extensive electrophysiological mapping of the MRF using extracellular recordings at rest and during locomotion in a nonhuman primate (NHP) (Macaca fascicularis) model of bipedal locomotion. We found different neuronal populations that discharged according to a phasic or a tonic mode in response to locomotion, supporting the existence of a locomotor neuronal circuit within these MRF in behaving primates. Altogether, these data constitute the first electrophysiological characterization of a locomotor neuronal system present within the MRF in behaving NHPs under normal conditions, in accordance with several studies done in different experimental animal models. SIGNIFICANCE STATEMENT We provide the first extensive electrophysiological mapping of the two major components of the mesencephalic reticular formation (MRF), namely the pedunculopontine and cuneiform nuclei. We exploited a nonhuman primate (NHP) model of bipedal locomotion with extracellular recordings in behaving NHPs at rest and during locomotion. Different MRF neuronal groups were found to respond to locomotion, with phasic or tonic patterns of response. These data constitute the first electrophysiological evidences of a locomotor neuronal system within the MRF in behaving NHPs.
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Mena-Segovia J, Bolam JP. Rethinking the Pedunculopontine Nucleus: From Cellular Organization to Function. Neuron 2017; 94:7-18. [PMID: 28384477 DOI: 10.1016/j.neuron.2017.02.027] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/03/2017] [Accepted: 02/15/2017] [Indexed: 12/21/2022]
Abstract
The pedunculopontine nucleus (PPN) has long been considered an interface between the basal ganglia and motor systems, and its ability to regulate arousal states puts the PPN in a key position to modulate behavior. Despite the large amount of data obtained over recent decades, a unified theory of its function is still incomplete. By putting together classical concepts and new evidence that dissects the influence of its different neuronal subtypes on their various targets, we propose that the PPN and, in particular, cholinergic neurons have a central role in updating the behavioral state as a result of changes in environmental contingencies. Such a function is accomplished by a combined mechanism that simultaneously restrains ongoing obsolete actions while it facilitates new contextual associations.
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Affiliation(s)
- Juan Mena-Segovia
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ 07102, USA.
| | - J Paul Bolam
- MRC Brain Network Dynamics Unit, University of Oxford, Oxford OX1 3TH, UK
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Ozawa H, Yamaguchi T, Hamaguchi S, Yamaguchi S, Ueda S. Three Types of A11 Neurons Project to the Rat Spinal Cord. Neurochem Res 2017; 42:2142-2153. [PMID: 28303496 DOI: 10.1007/s11064-017-2219-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 02/16/2017] [Accepted: 02/28/2017] [Indexed: 12/23/2022]
Abstract
The A11 dopaminergic cell group is the only group among the A8-A16 dopaminergic cell groups that includes neurons innervating the spinal cord, and a decrease in dopaminergic transmission at the spinal cord is thought to contribute to the pathogenesis of restless legs syndrome. However, the mechanisms regulating the neuronal activity of A11 dopaminergic neurons remain to be elucidated. Unraveling the neuronal composition, distribution and connectivity of A11 neurons would provide insights into the mechanisms regulating the spinal dopaminergic system. To address this, we performed immunohistochemistry for calcium-binding proteins such as calbindin (Calb) and parvalbumin (PV), in combination with the retrograde tracer Fluorogold (FG) injected into the spinal cord. Immunohistochemistry for Calb, PV, or tyrosine hydroxylase (TH), a marker for dopaminergic neurons, revealed that there were at least three types of neurons in the A11 region: neurons expressing Calb, TH, or both TH and Calb, whereas there were no PV-immunoreactive (IR) cell bodies. Both Calb- and PV-IR processes were found throughout the entire A11 region, extending in varied directions depending on the level relative to bregma. We found retrogradely labeled FG-positive neurons expressing TH, Calb, or both TH and Calb, as well as FG-positive neurons lacking both TH and Calb. These findings indicate that the A11 region is composed of a variety of neurons that are distinct in their neurochemical properties, and suggest that the diencephalospinal dopamine system may be regulated at the A11region by both Calb-IR and PV-IR processes, and at the terminal region of the spinal cord by Calb-IR processes derived from the A11 region.
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Affiliation(s)
- Hidechika Ozawa
- Department of Anesthesiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Tsuyoshi Yamaguchi
- Department of Histology and Neurobiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi, 321-0293, Japan
| | - Shinsuke Hamaguchi
- Department of Anesthesiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Shigeki Yamaguchi
- Department of Anesthesiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Shuichi Ueda
- Department of Histology and Neurobiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi, 321-0293, Japan.
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25
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Falkenburger B. ExPPNing how acetylcholine improves gait in Parkinson's disease: An Editorial Highlight for 'Deletion of the Vesicular Acetylcholine Transporter from Pedunculopontine/laterodorsal tegmental neurons modifies gait'. J Neurochem 2017; 140:688-691. [PMID: 28058727 DOI: 10.1111/jnc.13899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 12/16/2022]
Abstract
Read the highlighted article 'Deletion of the Vesicular Acetylcholine Transporter from Pedunculopontine/laterodorsal tegmental neurons modifies gait' on page 787.
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Affiliation(s)
- Björn Falkenburger
- Department of Neurology, RWTH University Aachen, Aachen, Germany.,JARA-Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
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26
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Pienaar IS, Vernon A, Winn P. The Cellular Diversity of the Pedunculopontine Nucleus: Relevance to Behavior in Health and Aspects of Parkinson's Disease. Neuroscientist 2016; 23:415-431. [PMID: 27932591 DOI: 10.1177/1073858416682471] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The pedunculopontine nucleus (PPN) is a rostral brainstem structure that has extensive connections with basal ganglia nuclei and the thalamus. Through these the PPN contributes to neural circuits that effect cortical and hippocampal activity. The PPN also has descending connections to nuclei of the pontine and medullary reticular formations, deep cerebellar nuclei, and the spinal cord. Interest in the PPN has increased dramatically since it was first suggested to be a novel target for treating patients with Parkinson's disease who are refractory to medication. However, application of frequency-specific electrical stimulation of the PPN has produced inconsistent results. A central reason for this is that the PPN is not a heterogeneous structure. In this article, we review current knowledge of the neurochemical identity and topographical distribution of neurons within the PPN of both humans and experimental animals, focusing on studies that used neuronally selective targeting strategies to ascertain how the neurochemical heterogeneity of the PPN relates to its diverse functions in relation to movement and cognitive processes. If the therapeutic potential of the PPN is to be realized, it is critical to understand the complex structure-function relationships that exist here.
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Affiliation(s)
- Ilse S Pienaar
- 1 Centre for Neuroinflammation & Neurodegeneration, Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Cane Road, London, UK.,2 Faculty of Health and Life Sciences, Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Anthony Vernon
- 3 Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Philip Winn
- 4 Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
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27
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De Deurwaerdère P, Di Giovanni G, Millan MJ. Expanding the repertoire of L-DOPA's actions: A comprehensive review of its functional neurochemistry. Prog Neurobiol 2016; 151:57-100. [PMID: 27389773 DOI: 10.1016/j.pneurobio.2016.07.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/18/2016] [Accepted: 07/03/2016] [Indexed: 01/11/2023]
Abstract
Though a multi-facetted disorder, Parkinson's disease is prototypically characterized by neurodegeneration of nigrostriatal dopaminergic neurons of the substantia nigra pars compacta, leading to a severe disruption of motor function. Accordingly, L-DOPA, the metabolic precursor of dopamine (DA), is well-established as a treatment for the motor deficits of Parkinson's disease despite long-term complications such as dyskinesia and psychiatric side-effects. Paradoxically, however, despite the traditional assumption that L-DOPA is transformed in residual striatal dopaminergic neurons into DA, the mechanism of action of L-DOPA is neither simple nor entirely clear. Herein, focussing on its influence upon extracellular DA and other neuromodulators in intact animals and experimental models of Parkinson's disease, we highlight effects other than striatal generation of DA in the functional profile of L-DOPA. While not excluding a minor role for glial cells, L-DOPA is principally transformed into DA in neurons yet, interestingly, with a more important role for serotonergic than dopaminergic projections. Moreover, in addition to the striatum, L-DOPA evokes marked increases in extracellular DA in frontal cortex, nucleus accumbens, the subthalamic nucleus and additional extra-striatal regions. In considering its functional profile, it is also important to bear in mind the marked (probably indirect) influence of L-DOPA upon cholinergic, GABAergic and glutamatergic neurons in the basal ganglia and/or cortex, while anomalous serotonergic transmission is incriminated in the emergence of L-DOPA elicited dyskinesia and psychosis. Finally, L-DOPA may exert intrinsic receptor-mediated actions independently of DA neurotransmission and can be processed into bioactive metabolites. In conclusion, L-DOPA exerts a surprisingly complex pattern of neurochemical effects of much greater scope that mere striatal transformation into DA in spared dopaminergic neurons. Their further experimental and clinical clarification should help improve both L-DOPA-based and novel strategies for controlling the motor and other symptoms of Parkinson's disease.
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Affiliation(s)
- Philippe De Deurwaerdère
- CNRS (Centre National de la Recherche Scientifique), Institut des Maladies Neurodégénératives, UMR CNRS 5293, F-33000 Bordeaux, France.
| | - Giuseppe Di Giovanni
- Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, UK; Department of Physiology & Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | - Mark J Millan
- Institut de Recherche Servier, Pole for Therapeutic Innovation in Neuropsychiatry, 78290 Croissy/Seine,Paris, France
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28
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Strumpf H, Noesselt T, Schoenfeld MA, Voges J, Panther P, Kaufmann J, Heinze HJ, Hopf JM. Deep Brain Stimulation of the Pedunculopontine Tegmental Nucleus (PPN) Influences Visual Contrast Sensitivity in Human Observers. PLoS One 2016; 11:e0155206. [PMID: 27167979 PMCID: PMC4864298 DOI: 10.1371/journal.pone.0155206] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/26/2016] [Indexed: 01/24/2023] Open
Abstract
The parapontine nucleus of the thalamus (PPN) is a neuromodulatory midbrain structure with widespread connectivity to cortical and subcortical motor structures, as well as the spinal cord. The PPN also projects to the thalamus, including visual relay nuclei like the LGN and the pulvinar. Moreover, there is intense connectivity with sensory structures of the tegmentum in particular with the superior colliculus (SC). Given the existence and abundance of projections to visual sensory structures, it is likely that activity in the PPN has some modulatory influence on visual sensory selection. Here we address this possibility by measuring the visual discrimination performance (luminance contrast thresholds) in a group of patients with Parkinson’s Disease (PD) treated with deep-brain stimulation (DBS) of the PPN to control gait and postural motor deficits. In each patient we measured the luminance-contrast threshold of being able to discriminate an orientation-target (Gabor-grating) as a function of stimulation frequency (high 60Hz, low 8/10, no stimulation). Thresholds were determined using a standard staircase-protocol that is based on parameter estimation by sequential testing (PEST). We observed that under low frequency stimulation thresholds increased relative to no and high frequency stimulation in five out of six patients, suggesting that DBS of the PPN has a frequency-dependent impact on visual selection processes at a rather elementary perceptual level.
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Affiliation(s)
| | - Toemme Noesselt
- Institute for Biological Psychology, Otto-von-Guericke University, Magdeburg, Germany
| | - Mircea Ariel Schoenfeld
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Clinic for Neurology, Otto-von-Guericke University, Magdeburg, Germany
- Kliniken Schmieder, Allensbach, Germany
| | - Jürgen Voges
- Clinic for Stereotactic Neurosurgery, Otto-von-Guericke University, Magdeburg, Germany
| | - Patricia Panther
- Clinic for Stereotactic Neurosurgery, Otto-von-Guericke University, Magdeburg, Germany
| | - Joern Kaufmann
- Clinic for Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Hans-Jochen Heinze
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Clinic for Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Jens-Max Hopf
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Clinic for Neurology, Otto-von-Guericke University, Magdeburg, Germany
- * E-mail:
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29
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Veleanu M, Axen TE, Kristensen MP, Kohlmeier KA. Comparison of bNOS and chat immunohistochemistry in the laterodorsal tegmentum (LDT) and the pedunculopontine tegmentum (PPT) of the mouse from brain slices prepared for electrophysiology. J Neurosci Methods 2016; 263:23-35. [DOI: 10.1016/j.jneumeth.2016.01.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/30/2015] [Accepted: 01/18/2016] [Indexed: 01/16/2023]
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Mena-Segovia J. Structural and functional considerations of the cholinergic brainstem. J Neural Transm (Vienna) 2016; 123:731-736. [PMID: 26945862 DOI: 10.1007/s00702-016-1530-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/19/2016] [Indexed: 12/24/2022]
Abstract
Cholinergic neurons of the brainstem have traditionally been associated with a role in wakefulness as part of the reticular activating system, but their function cannot be explained solely on the basis of their modulation of the brain state. Recent findings about their connectivity and functional heterogeneity suggest a wider role in behavior, where basal ganglia is at the center of their influence. This review focuses on recent findings that suggest an intrinsic functional organization of the cholinergic brainstem that is closely correlated with its connectivity with midbrain and forebrain circuits. Furthermore, recent evidence on the temporal structure of the activation of brainstem cholinergic neurons reveals fundamental aspects about the nature of cholinergic signaling. Consideration of the cholinergic brainstem complex in the context of wider brain circuits is critical to understand its contribution to normal behavior.
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Affiliation(s)
- Juan Mena-Segovia
- Center for Molecular and Behavioral Neuroscience, Aidekman Research Center, Rutgers University, Newark, NJ, 07102, USA.
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31
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Cholinergic excitation from the pedunculopontine tegmental nucleus to the dentate nucleus in the rat. Neuroscience 2016; 317:12-22. [PMID: 26762800 DOI: 10.1016/j.neuroscience.2015.12.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/14/2015] [Accepted: 12/30/2015] [Indexed: 11/24/2022]
Abstract
In spite of the existence of pedunculopontine tegmental nucleus (PPTg) projections to cerebellar nuclei, their nature and functional role is unknown. These fibers may play a crucial role in postural control and may be involved in the beneficial effects induced by deep-brain stimulation (DBS) of brainstem structures in motor disorders. We investigated the effects of PPTg microstimulation on single-unit activity of dentate, fastigial and interpositus nuclei. The effects of PPTg stimulation were also studied in rats whose PPTg neurons were destroyed by ibotenic acid and subsequently subjected to iontophoretically applied cholinergic antagonists. The main response recorded in cerebellar nuclei was a short-latency (1.5-2 ms) and brief (13-15 ms) orthodromic activation. The dentate nucleus was the most responsive to PPTg stimulation. The destruction of PPTg cells reduced the occurrence of PPTg-evoked activation of dentate neurons, suggesting that the effect was due to stimulation of cell bodies and not due to fibers passing through or close to the PPTg. Application of cholinergic antagonists reduced or eliminated the PPTg-evoked response recorded in the dentate nucleus. The results show that excitation is exerted by the PPTg on the cerebellar nuclei, in particular on the dentate nucleus. Taken together with the reduction of nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons in lesioned animals, the iontophoretic experiments suggest that the activation of dentate neurons is due to cholinergic fibers. These data help to explain the effects of DBS of the PPTg on axial motor disabilities in neurodegenerative disorders.
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32
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Petzold A, Valencia M, Pál B, Mena-Segovia J. Decoding brain state transitions in the pedunculopontine nucleus: cooperative phasic and tonic mechanisms. Front Neural Circuits 2015; 9:68. [PMID: 26582977 PMCID: PMC4628121 DOI: 10.3389/fncir.2015.00068] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/15/2015] [Indexed: 02/03/2023] Open
Abstract
Cholinergic neurons of the pedunculopontine nucleus (PPN) are most active during the waking state. Their activation is deemed to cause a switch in the global brain activity from sleep to wakefulness, while their sustained discharge may contribute to upholding the waking state and enhancing arousal. Similarly, non-cholinergic PPN neurons are responsive to brain state transitions and their activation may influence some of the same targets of cholinergic neurons, suggesting that they operate in coordination. Yet, it is not clear how the discharge of distinct classes of PPN neurons organize during brain states. Here, we monitored the in vivo network activity of PPN neurons in the anesthetized rat across two distinct levels of cortical dynamics and their transitions. We identified a highly structured configuration in PPN network activity during slow-wave activity that was replaced by decorrelated activity during the activated state (AS). During the transition, neurons were predominantly excited (phasically or tonically), but some were inhibited. Identified cholinergic neurons displayed phasic and short latency responses to sensory stimulation, whereas the majority of non-cholinergic showed tonic responses and remained at high discharge rates beyond the state transition. In vitro recordings demonstrate that cholinergic neurons exhibit fast adaptation that prevents them from discharging at high rates over prolonged time periods. Our data shows that PPN neurons have distinct but complementary roles during brain state transitions, where cholinergic neurons provide a fast and transient response to sensory events that drive state transitions, whereas non-cholinergic neurons maintain an elevated firing rate during global activation.
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Affiliation(s)
- Anne Petzold
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford Oxford, UK
| | - Miguel Valencia
- Neurosciences Area, CIMA, Universidad de Navarra Pamplona, Spain ; IdiSNA, Navarra Institute for Health Research Pamplona, Spain
| | - Balázs Pál
- Department of Physiology, Faculty of Medicine University of Debrecen Debrecen, Hungary
| | - Juan Mena-Segovia
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford Oxford, UK ; Center for Molecular and Behavioral Neuroscience, Rutgers University Newark, NJ, USA
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33
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Deep brain stimulation of different pedunculopontine targets in a novel rodent model of parkinsonism. J Neurosci 2015; 35:4792-803. [PMID: 25810510 DOI: 10.1523/jneurosci.3646-14.2015] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The pedunculopontine tegmental nucleus (PPTg) has been proposed as a target for deep brain stimulation (DBS) in parkinsonian patients, particularly for symptoms such as gait and postural difficulties refractory to dopaminergic treatments. Several patients have had electrodes implanted aimed at the PPTg, but outcomes have been disappointing, with little evidence that gait and posture are improved. The PPTg is a heterogeneous structure. Consequently, exact target sites in PPTg, possible DBS mechanisms, and potential benefits still need systematic investigation in good animal models. We have investigated the role of PPTg in gait, developed a refined model of parkinsonism including partial loss of the PPTg with bilateral destruction of nigrostriatal dopamine neurons that mimics human pathophysiology, and investigated the effect of DBS at different PPTg locations on gait and posture using a wireless device that lets rats move freely while receiving stimulation. Neither partial nor complete lesions of PPTg caused gait deficits, underlining questions raised previously about the status of PPTg as a motor control structure. The effect of DBS in the refined and standard model of parkinsonism were very different despite minimal behavioral differences in nonstimulation control conditions. Anterior PPTg DBS caused severe episodes of freezing and worsened gait, whereas specific gait parameters were mildly improved by stimulation of posterior PPTg. These results emphasize the critical importance of intra-PPTg DBS location and highlight the need to take PPTg degeneration into consideration when modeling parkinsonian symptoms. They also further implicate a role for PPTg in the pathophysiology of parkinsonism.
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34
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Nosko D, Ferraye MU, Fraix V, Goetz L, Chabardès S, Pollak P, Debû B. Low-frequency versus high-frequency stimulation of the pedunculopontine nucleus area in Parkinson's disease: a randomised controlled trial. J Neurol Neurosurg Psychiatry 2015; 86:674-9. [PMID: 25185212 DOI: 10.1136/jnnp-2013-307511] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 07/29/2014] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To compare the influence of low-frequency (10-25 Hz) versus higher (60-80 Hz) frequency stimulation of the pedunculopontine nucleus area (PPNa) on akinaesia, freezing of gait and daytime sleepiness. METHOD We included nine patients with Parkinson's disease (PD) and severe gait disorders. In this double-blind randomised cross-over study, patients were assessed after 24 h of PPNa stimulation. Assessments included the motor part of the Unified Parkinson's Disease Rating Scale, the Epworth Sleepiness Scale and a behavioural gait assessment. RESULTS Compared with 60-80 Hz, 10-25 Hz PPNa stimulation led to decreased akinaesia, gait difficulties and daytime sleepiness in 7/9 patients. In one patient, these symptoms were aggravated under 10-25 Hz stimulation compared with 60-80 Hz. CONCLUSION These results are in keeping with the benefits of chronic PPNa stimulation for gait and postural difficulties in patients with PD, and with regard to the influence of patients' clinical characteristics, differential neuronal loss in the PPNa and electrode location. We conclude that in patients with PPNa stimulation, low frequency provides a better outcome than high-frequency stimulation.
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Affiliation(s)
- D Nosko
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France University Hospital of Grenoble, Grenoble, France
| | - M U Ferraye
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Nijmegen, The Netherlands
| | - V Fraix
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France University Hospital of Grenoble, Grenoble, France
| | - L Goetz
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France University Hospital of Grenoble, Grenoble, France
| | - S Chabardès
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France University Hospital of Grenoble, Grenoble, France
| | - P Pollak
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France University Hospital of Grenoble, Grenoble, France University Hospital of Geneva, Geneva, Switzerland
| | - B Debû
- University of Grenoble, Grenoble, France INSERM, U836, Grenoble Institute of Neuroscience, Grenoble, France
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35
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Elson JL, Yates A, Pienaar IS. Pedunculopontine cell loss and protein aggregation direct microglia activation in parkinsonian rats. Brain Struct Funct 2015; 221:2319-41. [PMID: 25989851 DOI: 10.1007/s00429-015-1045-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/11/2015] [Indexed: 01/06/2023]
Abstract
We previously reported a loss of cholinergic neurons within the pedunculopontine tegmental nucleus (PPTg) in rats that had been intra-nigrally lesioned with the proteasomal inhibitor lactacystin, with levels of neuronal loss corresponding to that seen in the post-mortem pedunculopontine nucleus (PPN) of advanced Parkinson's disease (PD) patients. Here we reveal lower expression values of the acetylcholine synthesising enzyme, choline acetyltransferase, within the remaining PPTg cholinergic neurons of lesioned rats compared to sham controls. We further characterise this animal model entailing dopaminergic- and non-dopaminergic neurodegeneration by reporting on stereological counts of non-cholinergic neurons, to determine whether the toxin is neuro-type specific. Cell counts between lesioned and sham-lesioned rats were analysed in terms of the topological distribution pattern across the rostro-caudal extent of the PPTg. The study also reports somatic hypotrophy in the remaining non-cholinergic neurons, particularly on the side closest to the nigral lesion. The cytotoxicity affecting the PPTg in this rat model of PD involves overexpression and accumulation of alpha-synuclein (αSYN), affecting cholinergic and non-cholinergic neurons as well as microglia on the lesioned hemispheric side. We ascertained that microglia within the PPTg become fully activated due to the extensive neuronal damage and neuronal death resulting from a lactacystin nigral lesion, displaying a distinct rostro-caudal distribution profile which correlates with PPTg neuronal loss, with the added implication that lactacystin-induced αSYN aggregation might trigger neuronophagia for promoting PPTg cell loss. The data provide critical insights into the mechanisms underlying the lactacystin rat model of PD, for studying the PPTg in health and when modelling neurodegenerative disease.
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Affiliation(s)
- Joanna L Elson
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, NE1 3BZ, UK.,Centre for Human Metabonomics, North-West University, Potchefstroom, South Africa
| | - Abi Yates
- School of Biomedical Sciences, Guy's Campus, King's College London, London, SE13QD, UK
| | - Ilse S Pienaar
- Division of Brain Sciences, Department of Medicine, Centre for Neuroinflammation and Neurodegeneration, Imperial College London, London, W12 ONN, UK. .,Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Ellison Place, Newcastle-upon-Tyne, NE1 8ST, UK.
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Thyroid-stimulating hormone inhibits adipose triglyceride lipase in 3T3-L1 adipocytes through the PKA pathway. PLoS One 2015; 10:e0116439. [PMID: 25590597 PMCID: PMC4295851 DOI: 10.1371/journal.pone.0116439] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/08/2014] [Indexed: 01/04/2023] Open
Abstract
Thyroid-stimulating hormone (TSH) has been shown to play an important role in the regulation of triglyceride (TG) metabolism in adipose tissue. Adipose triglyceride lipase (ATGL) is a rate-limiting enzyme controlling the hydrolysis of TG. Thus far, it is unclear whether TSH has a direct effect on the expression of ATGL. Because TSH function is mediated through the TSH receptor (TSHR), TSHR knockout mice (Tshr-/- mice) (supplemented with thyroxine) were used in this study to determine the effects of TSHR deletion on ATGL expression. These effects were verified in 3T3-L1 adipocytes and potential underlying mechanisms were explored. In the Tshr-/- mice, ATGL expression in epididymal adipose tissue was significantly increased compared with that in Tshr+/+ mice. ATGL expression was observed to increase with the differentiation process of 3T3-L1 preadipocytes. In mature 3T3-L1 adipocytes, TSH significantly suppressed ATGL expression at both the protein and mRNA levels in a dose-dependent manner. Forskolin, which is an activator of adenylate cyclase, suppressed the expression of ATGL in 3T3-L1 adipocytes. The inhibitory effects of TSH on ATGL expression were abolished by H89, which is a protein kinase A (PKA) inhibitor. These results indicate that TSH has an inhibitory effect on ATGL expression in mature adipocytes. The associated mechanism is related to PKA activation.
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37
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Thyrotropin increases hepatic triglyceride content through upregulation of SREBP-1c activity. J Hepatol 2014; 61:1358-64. [PMID: 25016220 DOI: 10.1016/j.jhep.2014.06.037] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 06/12/2014] [Accepted: 06/30/2014] [Indexed: 01/06/2023]
Abstract
BACKGROUND & AIMS Hallmarks of non-alcoholic fatty liver disease (NAFLD) are increased triglyceride accumulation within hepatocytes. The prevalence of NAFLD increases steadily with increasing thyrotropin (TSH) levels. However, the underlying mechanisms are largely unknown. Here, we focused on exploring the effect and mechanism of TSH on the hepatic triglyceride content. METHODS As the function of TSH is mediated through the TSH receptor (TSHR), Tshr(-/-) mice (supplemented with thyroxine) were used. Liver steatosis and triglyceride content were analysed in Tshr(-/-) and Tshr(+/+) mice fed a high-fat or normal chow diet, as well as in Srebp-1c(-/-) and Tshr(-/-)Srebp-1c(-/-) mice. The expression levels of proteins and genes involved in liver triglyceride metabolism was measured. RESULTS Compared with control littermates, the high-fat diet induced a relatively low degree of liver steatosis in Tshr(-/-) mice. Even under chow diet, hepatic triglyceride content was decreased in Tshr(-/-) mice. TSH caused concentration- and time-dependent effects on intracellular triglyceride contents in hepatocytes in vitro. The activity of SREBP-1c, a key regulator involved in triglyceride metabolism and in the pathogenesis of NAFLD, was significantly lower in Tshr(-/-) mice. In Tshr(-/-)Srebp-1c(-/-) mice, the liver triglyceride content showed no significant difference compared with Tshr(+/+)Srebp-1c(-/-) mice. When mice were injected with forskolin (cAMP activator), H89 (inhibitor of PKA) or AICAR (AMPK activator), or HeG2 cells received MK886 (PPARα inhibitor), triglyceride contents presented in a manner dependent on SREBP-1c activity. The mechanism, underlying TSH-induced liver triglyceride accumulation, involved that TSH, through its receptor TSHR, triggered hepatic SREBP-1c activity via the cAMP/PKA/PPARα pathway associated with decreased AMPK, which further increased the expression of genes associated with lipogenesis. CONCLUSIONS TSH increased the hepatic triglyceride content, indicating an essential role for TSH in the pathogenesis of NAFLD.
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Stimulation of the subthalamic nucleus engages the cerebellum for motor function in parkinsonian rats. Brain Struct Funct 2014; 220:3595-609. [PMID: 25124274 DOI: 10.1007/s00429-014-0876-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 08/11/2014] [Indexed: 10/24/2022]
Abstract
Deep brain stimulation (DBS) is effective in managing motor symptoms of Parkinson's disease in well-selected individuals. Recently, research has shown that DBS in the basal ganglia (BG) can alter neural circuits beyond the traditional basal ganglia-thalamus-cortical (BG-TH-CX) loop. For instance, functional imaging showed alterations in cerebellar activity with DBS in the subthalamic nucleus (STN). However, these imaging studies revealed very little about how cell-specific cerebellar activity responds to STN stimulation or if these changes contribute to its efficacy. In this study, we assess whether STN-DBS provides efficacy in managing motor symptoms in Parkinson's disease by recruiting cerebellar activity. We do this by applying STN-DBS in hemiparkinsonian rats and simultaneously recording neuronal activity from the STN, brainstem and cerebellum. We found that STN neurons decreased spiking activity by 55% during DBS (P = 0.038), which coincided with a decrease in most pedunculopontine tegmental nucleus and Purkinje neurons by 29% (P < 0.001) and 28% (P = 0.003), respectively. In contrast, spike activity in the deep cerebellar nuclei increased 45% during DBS (P < 0.001), which was likely from reduced afferent activity of Purkinje cells. Then, we applied STN-DBS at sub-therapeutic current along with stimulation of the deep cerebellar nuclei and found similar improvement in forelimb akinesia as with therapeutic STN-DBS alone. This suggests that STN-DBS can engage cerebellar activity to improve parkinsonian motor symptoms. Our study is the first to describe how STN-DBS in Parkinson's disease alters cerebellar activity using electrophysiology in vivo and reveal a potential for stimulating the cerebellum to potentiate deep brain stimulation of the subthalamic nucleus.
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Martinez-Gonzalez C, van Andel J, Bolam JP, Mena-Segovia J. Divergent motor projections from the pedunculopontine nucleus are differentially regulated in Parkinsonism. Brain Struct Funct 2014; 219:1451-62. [PMID: 23708060 PMCID: PMC4072066 DOI: 10.1007/s00429-013-0579-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/10/2013] [Indexed: 01/28/2023]
Abstract
The pedunculopontine nucleus (PPN) is composed of neurons with different connectivity patterns that express different neurochemical markers, display distinct firing characteristics and are topographically organized in functional domains across its rostro-caudal axis. Previous reports have shown that the caudal region of the PPN is interconnected with motor regions of both the basal ganglia and brainstem/medulla. The co-distribution of ascending and descending motor outputs raises the question as to whether the PPN provides a coordinated or differential modulation of its targets in the basal ganglia and the medulla. To address this, we retrogradely labeled neurons in the two main PPN pathways involved in motor control and determined whether they project to one or both structures, their neurochemical phenotype, and their activity in normal and dopamine depleted rats, as indicated by Egr-1 expression. We show that ascending and descending motor pathways from the PPN arise largely from separate neurons that intermingle in the same region of the PPN, but have a distinct neurochemical composition and are differentially regulated in the Parkinsonian state. Thus, neurons projecting to the subthalamic nucleus consist of cholinergic, calbindin- and calretinin-expressing neurons, and Egr-1 is upregulated following a 6-hydroxydopamine lesion. In contrast, a larger proportion of neurons projecting to the gigantocellular nucleus are cholinergic, none express calbindin and the expression of Egr-1 is not changed by the dopamine lesion. Our results suggest that ascending and descending motor connections of the PPN are largely mediated by different sets of neurons and there are cell type-specific changes in Parkinsonian rats.
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Affiliation(s)
- Cristina Martinez-Gonzalez
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - Judith van Andel
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - J. Paul Bolam
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
| | - Juan Mena-Segovia
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH UK
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Capozzo A, Vitale F, Mattei C, Mazzone P, Scarnati E. Continuous stimulation of the pedunculopontine tegmental nucleus at 40 Hz affects preparative and executive control in a delayed sensorimotor task and reduces rotational movements induced by apomorphine in the 6-OHDA parkinsonian rat. Behav Brain Res 2014; 271:333-42. [PMID: 24959863 DOI: 10.1016/j.bbr.2014.06.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/13/2014] [Accepted: 06/16/2014] [Indexed: 12/21/2022]
Abstract
The pedunculopontine tegmental nucleus (PPTg) relays basal ganglia signals to the thalamus, lower brainstem and spinal cord. Using the 6-hydroxydopamine (6-OHDA) rat model of parkinsonism, we investigated whether deep brain stimulation (DBS) of the PPTg (40 Hz, 60 μs, 200-400 μA) may influence the preparative and executive phases in a conditioned behavioural task, and the motor asymmetries induced by apomorphine. In the conditioned task, rats had to press two levers according to a fixed delay paradigm. The 6-OHDA lesion was placed in the right medial forebrain bundle, i.e. contralaterally to the preferred forepaw used by rats to press levers in the adopted task. The stimulating electrode was implanted in the right PPTg, i.e. contralateral to left side, which was expected to be most affected. The lesion significantly reduced correct responses from 63.4% to 16.6%. PPTg-DBS effects were episodic; however, when rats successfully performed in the task (18.9%), reaction time (468.8 ± 36.5 ms) was significantly increased (589.9 ± 45.9 ms), but not improved by PPTg-DBS (646.7 ± 33.8 ms). Movement time was significantly increased following the lesion (649.2 ± 42.6 ms vs. 810.9 ± 53.0 ms), but significantly reduced by PPTg-DBS (820.4 ± 39.4 ms) compared to sham PPTg-DBS (979.8 ± 47.6 ms). In a second group of lesioned rats, rotations induced by apomorphine were significantly reduced by PPTg-DBS compared to sham PPTg-DBS (12.2 ± 0.6 vs. 9.5 ± 0.4 mean turns/min). Thus, it appears that specific aspects of motor deficits in 6-OHDA-lesioned rats may be modulated by PPTg-DBS.
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Affiliation(s)
- Annamaria Capozzo
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of L'Aquila, Via Vetoio, Coppito 2, I-67100 L'Aquila, Italy
| | - Flora Vitale
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of L'Aquila, Via Vetoio, Coppito 2, I-67100 L'Aquila, Italy
| | - Claudia Mattei
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of L'Aquila, Via Vetoio, Coppito 2, I-67100 L'Aquila, Italy
| | - Paolo Mazzone
- Unit of Functional Neurosurgery, CTO Alesini Hospital ASL Rome C, Via San Nemesio 21, 00145 Rome, Italy
| | - Eugenio Scarnati
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of L'Aquila, Via Vetoio, Coppito 2, I-67100 L'Aquila, Italy.
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Mazzei-Silva EC, de Oliveira RC, dos Anjos Garcia T, Falconi-Sobrinho LL, Almada RC, Coimbra NC. Intrinsic connections within the pedunculopontine tegmental nucleus are critical to the elaboration of post-ictal antinociception. Synapse 2014; 68:369-77. [PMID: 24782316 DOI: 10.1002/syn.21749] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 04/16/2014] [Accepted: 04/23/2014] [Indexed: 12/21/2022]
Abstract
This study investigated the intrinsic connections of a key-structure of the endogenous pain inhibitory system, the pedunculopontine tegmental nucleus (PPTN), in post-ictal antinociceptive process through synaptic inactivation of the PPTN with cobalt chloride. Male Wistar rats (n = 6 or 7 per group), weighing 250-280 g, had the tail-flick baseline recorded and were submitted to a stereotaxic surgery for the introduction of a guide-cannula aiming at the PPTN. After 5 days of postoperative recovery, cobalt chloride (1 mM/0.2 µL) or physiological saline (0.2 µL) were microinjected into the PPTN and after 5 min, the tail-withdrawal latency was measured again at 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 min after seizures evoked by intraperitoneal injection of pentylenetetrazole (64 mg/kg). The synaptic inactivation of PPTN decreased the post-ictal antinociceptive phenomenon, suggesting the involvement of PPTN intrinsic connections in the modulation of pain, during tonic-clonic seizures. These results showed that the PPTN may be crucially involved in the neural network that organizes the post-ictal analgesia.
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Affiliation(s)
- Elaine Cristina Mazzei-Silva
- Departament of Pharmacology, Laboratory of Neuroanatomy and Neuropsychobiology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
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Boucetta S, Cissé Y, Mainville L, Morales M, Jones BE. Discharge profiles across the sleep-waking cycle of identified cholinergic, GABAergic, and glutamatergic neurons in the pontomesencephalic tegmentum of the rat. J Neurosci 2014; 34:4708-27. [PMID: 24672016 PMCID: PMC3965793 DOI: 10.1523/jneurosci.2617-13.2014] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 02/19/2014] [Accepted: 02/22/2014] [Indexed: 01/04/2023] Open
Abstract
Distributed within the laterodorsal tegmental and pedunculopontine tegmental nuclei (LDT and PPT), cholinergic neurons in the pontomesencephalic tegmentum have long been thought to play a critical role in stimulating cortical activation during waking (W) and paradoxical sleep (PS, also called REM sleep), yet also in promoting PS with muscle atonia. However, the discharge profile and thus precise roles of the cholinergic neurons have remained uncertain because they lie intermingled with GABAergic and glutamatergic neurons, which might also assume these roles. By applying juxtacellular recording and labeling in naturally sleeping-waking, head-fixed rats, we investigated the discharge profiles of histochemically identified cholinergic, GABAergic, and glutamatergic neurons in the LDT, SubLDT, and adjoining medial part of the PPT (MPPT) in relation to sleep-wake states, cortical activity, and muscle tone. We found that all cholinergic neurons were maximally active during W and PS in positive correlation with fast (γ) cortical activity, as "W/PS-max active neurons." Like cholinergic neurons, many GABAergic and glutamatergic neurons were also "W/PS-max active." Other GABAergic and glutamatergic neurons were "PS-max active," being minimally active during W and maximally active during PS in negative correlation with muscle tone. Conversely, some glutamatergic neurons were "W-max active," being maximally active during W and minimally active during PS in positive correlation with muscle tone. Through different discharge profiles, the cholinergic, GABAergic, and glutamatergic neurons of the LDT, SubLDT, and MPPT thus appear to play distinct roles in promoting W and PS with cortical activation, PS with muscle atonia, or W with muscle tone.
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Affiliation(s)
- Soufiane Boucetta
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada, and
| | - Youssouf Cissé
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada, and
| | - Lynda Mainville
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada, and
| | - Marisela Morales
- National Institute on Drug Abuse, Neuronal Networks Section, National Institutes of Health, Baltimore, Maryland 21224
| | - Barbara E. Jones
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada, and
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Olvera-Cortés ME, Gutiérrez-Guzmán BE, López-Loeza E, Hernández-Pérez JJ, López-Vázquez MÁ. Serotonergic modulation of hippocampal theta activity in relation to hippocampal information processing. Exp Brain Res 2013; 230:407-26. [DOI: 10.1007/s00221-013-3679-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/07/2013] [Indexed: 10/26/2022]
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