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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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Chen RYT, Evans RC. Comparing tonic and phasic dendritic calcium in cholinergic pedunculopontine neurons and dopaminergic substantia nigra neurons. Eur J Neurosci 2024; 59:1638-1656. [PMID: 38383047 PMCID: PMC10987283 DOI: 10.1111/ejn.16281] [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: 08/28/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/23/2024]
Abstract
Several brainstem nuclei degenerate in Parkinson's disease (PD). In addition to the well-characterized dopaminergic neurons of the substantia nigra pars compacta (SNc), the cholinergic neurons of the pedunculopontine nucleus (PPN) also degenerate in PD. One leading hypothesis of selective vulnerability is that pacemaking activity and the activation of low-threshold L-type calcium current are major contributors to tonic calcium load and cellular stress in SNc dopaminergic neurons. However, it is not yet clear whether the vulnerable PPN cholinergic neurons share this property. Therefore, we used two-photon dendritic calcium imaging and whole-cell electrophysiology to evaluate the role of L-type calcium channels in tonic and phasic dendritic calcium signals in PPN and SNc neurons. In addition, we investigated N- and P/Q-type calcium channel regulation of firing properties and dendritic calcium in PPN neurons. We found that blocking L-type channels reduces tonic firing rate and dendritic calcium levels in SNc neurons. By contrast, the tonic calcium load in PPN neurons did not depend on L-, N- or P/Q-type channels. However, we found that blocking either L-type (with nifedipine) or N- and P/Q-type (with omega-conotoxin MVIIC) channels reduces phasic calcium influx in PPN dendrites. Together, these findings show that L-type calcium channels play different roles in the activity of SNc and PPN neurons, and suggest that low-threshold L-type channels are not responsible for tonic calcium levels in PPN cholinergic neurons and are therefore not likely to be a source of selective vulnerability in these cells.
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Affiliation(s)
- Rita Yu-Tzu Chen
- Department of Neuroscience, Georgetown University Medical Center, Washington DC
| | - Rebekah C. Evans
- Department of Neuroscience, Georgetown University Medical Center, Washington DC
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3
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Wellman LL, Lonart G, Adkins AM, Sanford LD. Regulation of Dark Period Sleep by the Amygdala: A microinjection and optogenetics study. Brain Res 2022; 1781:147816. [PMID: 35131286 PMCID: PMC8901558 DOI: 10.1016/j.brainres.2022.147816] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/21/2022] [Accepted: 02/01/2022] [Indexed: 11/02/2022]
Abstract
The central nucleus of the amygdala (CNA) projects to brainstem regions that generate and regulate rapid eye movement sleep (REM). We used optogenetics to assess the influence of CNA inputs into reticularis pontis oralis (RPO), pedunculopontine tegmentum (PPT) and nucleus subcoeruleus (SubC) on dark period sleep. We compared these results to effects of microinjections into CNA of the GABAA agonist, muscimol (MUS, inhibition of cell bodies) and tetrodotoxin (TTX, inhibition of cell bodies and fibers of passage). For optogenetics, male Wistar rats received excitatory (AAV5-EF1a-DIO -hChR2(H134R)-EYFP) or inhibitory (AAV-EF1a-DIO-eNpHR3.0-EYFP; DIO-eNpHR3.0) opsins into CNA and AAV5-EF1a-mCherry-IRES-WGA-Cre into RPO, PPT, or SubC. This enabled only CNA neurons synaptically connected to each region to express opsin. Optic cannulae for light delivery into CNA and electrodes for determining sleep were implanted. Sleep was recorded with and without blue or amber light stimulation of CNA. Separate rats received MUS or TTX into CNA prior to recording sleep. Optogenetic activation of CNA neurons projecting to RPO enhanced REM and did not alter non-REM (NREM) whereas activation of CNA neurons projecting to PPT or SubC did not significantly affect sleep. Inhibition of CNA neurons projecting to any region did not significantly alter sleep. TTX inactivation of CNA decreased REM and increased NREM whereas muscimol inactivation did not significantly alter sleep. Thus, the amygdala can regulate decreases and increases in REM, and RPO is important for CNA promotion of REM. Fibers passing through CNA, likely from the basolateral nucleus of the amygdala, also play a role in regulating sleep.
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Tisdale RK, Yamanaka A, Kilduff TS. Animal models of narcolepsy and the hypocretin/orexin system: Past, present, and future. Sleep 2021; 44:6031626. [PMID: 33313880 DOI: 10.1093/sleep/zsaa278] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/04/2020] [Indexed: 11/12/2022] Open
Abstract
Animal models have advanced not only our understanding of the etiology and phenotype of the sleep disorder narcolepsy but have also informed sleep/wake regulation more generally. The identification of an inheritable narcolepsy phenotype in dogs in the 1970s allowed the establishment of a breeding colony at Stanford University, resulting in studies that provided the first insights into the genetics and neurotransmitter systems that underlie cataplexy and rapid-eye movement sleep atonia. Although the discovery of the hypocretin/orexin neuropeptides in 1998 initially seemed unrelated to sleep/wake control, the description of the phenotype of the prepro-orexin knockout (KO) mouse as strongly resembling cataplexy, the pathognomonic symptom of narcolepsy, along with identification of a mutation in hypocretin receptor-2 gene as the source of canine narcolepsy, unequivocally established the relationship between this system and narcolepsy. The subsequent discovery of hypocretin neuron degeneration in human narcolepsy demystified a disorder whose etiology had been unknown since its initial description 120 years earlier. These breakthroughs prompted the development of numerous other animal models that have allowed manipulation of the hypocretin/orexin system, thereby advancing our understanding of sleep/wake circuitry. While animal models have greatly informed understanding of this fascinating disorder and the role of the hypocretin/orexin system in sleep/wake control, the question of why these neurons degenerate in human narcolepsy is only beginning to be understood. The development of new immune-mediated narcolepsy models are likely to further inform the etiology of this sleep disorder and animal models will undoubtedly play a critical role in the development of novel narcolepsy therapeutics.
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Affiliation(s)
- Ryan K Tisdale
- Center for Neuroscience, Biosciences Division, SRI International
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Japan
| | - Thomas S Kilduff
- Center for Neuroscience, Biosciences Division, SRI International
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5
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Discharge characteristics of neurons of nucleus reuniens across sleep-wake states in the behaving rat. Behav Brain Res 2021; 410:113325. [PMID: 33910030 DOI: 10.1016/j.bbr.2021.113325] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/06/2021] [Accepted: 04/23/2021] [Indexed: 11/23/2022]
Abstract
The nucleus reuniens (RE) of the ventral midline thalamus is strongly reciprocally connected with the hippocampus (HF) and medial prefrontal cortex (PFC), serving a critical role in affective and cognitive functioning. While midline thalamic nuclei have been implicated in the modulation of states of arousal and consciousness, few studies have addressed RE's role in behavioral state control. Accordingly, as a first line of investigation, we examined the discharge properties of RE neurons in behaving rats throughout the sleep-wake cycle. We analyzed 153 units in RE which demonstrated heterogeneity in discharge rates and pattern of activity across sleep wake states. Using a rate ratio of activity in wake vs. REM, we found that the majority of cells displayed state-related changes and were classified into distinct cell types, exhibiting their highest discharge rates during active waking (AW), REM sleep, or maintaining equivalent activity across AW/REM. We further distinguished cells as either slow firing (SF = < 10 Hz) or fast firing (FF =>10 Hz) cells. The majority of cells, independent of state-related preference, were SF. FF RE cells were primarily wake active and wake/REM cell types. This diverse set of RE neurons are likely modulated by key brainstem and hypothalamic nuclei, which in turn, drive RE to exert strong effects on its cortical targets during waking and REM sleep. RE may not only act as a node in HF-PFC circuitry, but also as a critical thalamic link in ascending arousal and attentional networks.
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Nobleza CMN, Siddiqui M, Shah PV, Balani P, Lopez AR, Khan S. The Relationship of Rapid Eye Movement Sleep Behavior Disorder and Freezing of Gait in Parkinson's Disease. Cureus 2020; 12:e12385. [PMID: 33532150 PMCID: PMC7846434 DOI: 10.7759/cureus.12385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Rapid eye movement sleep behavior disorder (RBD) contributes to injury due to the alteration of the expected atonia during rapid eye movement (REM) sleep. It occurs before the overt signs of Parkinson's disease (PD). The co-expression of PD and RBD is characterized by non-tremor predominant subtype and higher incidence of freezing. Freezing of gait (FOG) is a debilitating symptom seen in PD patients that lead to falls. While this phenomenon is understood poorly, the involvement of the pedunculopontine nucleus (PPN) and the neural circuits that control locomotion and gait have been examined. This network has also the same control for REM sleep and arousal. The close relationship between PD and RBD and FOG's consequences has led us to explore the relationship between RBD and PD with FOG. This review provides an overview of the neural connections that control gait, locomotion, and REM sleep. The neural changes were seen in PD with FOG and RBD, and sensory and motor changes observed in these two diseases. The functional neuroanatomy that controls REM sleep, arousal, and locomotion overlap significantly with multiple neural circuits affected in RBD and PD with FOG. Visual perception dysfunction and motor symptoms that primarily affect gait initiation are common to both patients with RBD and FOG in PD, leading to freezing episodes. Prospective studies should be conducted to elucidate the relationship of RBD and PD with FOG subtype and find innovative treatment approaches and diagnostic tools for PD with FOG.
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Affiliation(s)
- Chelsea Mae N Nobleza
- Neurology, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Mariah Siddiqui
- Neurology, St. George's University, True Blue, GRD.,Neurology, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Parth V Shah
- Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Prachi Balani
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Angel R Lopez
- Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Safeera Khan
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
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7
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Richardson BD, Sottile SY, Caspary DM. Mechanisms of GABAergic and cholinergic neurotransmission in auditory thalamus: Impact of aging. Hear Res 2020; 402:108003. [PMID: 32703637 DOI: 10.1016/j.heares.2020.108003] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/15/2020] [Accepted: 05/23/2020] [Indexed: 12/18/2022]
Abstract
Age-related hearing loss is a complex disorder affecting a majority of the elderly population. As people age, speech understanding becomes a challenge especially in complex acoustic settings and negatively impacts the ability to accurately analyze the auditory scene. This is in part due to an inability to focus auditory attention on a particular stimulus source while simultaneously filtering out other sound stimuli. The present review examines the impact of aging on two neurotransmitter systems involved in accurate temporal processing and auditory gating in auditory thalamus (medial geniculate body; MGB), a critical brain region involved in the coding and filtering of auditory information. The inhibitory neurotransmitter GABA and its synaptic receptors (GABAARs) are key to maintaining accurate temporal coding of complex sounds, such as speech, throughout the central auditory system. In the MGB, synaptic and extrasynaptic GABAARs mediate fast phasic and slow tonic inhibition respectively, which in turn regulate MGB neuron excitability, firing modes, and engage thalamocortical oscillations that shape coding and gating of acoustic content. Acoustic coding properties of MGB neurons are further modulated through activation of tegmental cholinergic afferents that project to MGB to potentially modulate attention and help to disambiguate difficult to understand or novel sounds. Acetylcholine is released onto MGB neurons and presynaptic terminals in MGB activating neuronal nicotinic and muscarinic acetylcholine receptors (nAChRs, mAChRs) at a subset of MGB afferents to optimize top-down and bottom-up information flow. Both GABAergic and cholinergic neurotransmission is significantly altered with aging and this review will detail how age-related changes in these circuits within the MGB may impact coding of acoustic stimuli.
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Affiliation(s)
- B D Richardson
- WWAMI Medical Education, University of Idaho, Moscow, ID, 83844, USA; Biological Engineering, University of Idaho, Moscow, ID, 83844, USA
| | - S Y Sottile
- Center for Clinical Research Southern Illinois University - School of Medicine, Springfield, IL, 62702, USA
| | - D M Caspary
- Department of Pharmacology Southern Illinois University - School of Medicine, Springfield, IL, 62702, USA.
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8
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Garcia-Rill E. Neuroepigenetics of arousal: Gamma oscillations in the pedunculopontine nucleus. J Neurosci Res 2019; 97:1515-1520. [PMID: 30916810 PMCID: PMC6764922 DOI: 10.1002/jnr.24417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/06/2019] [Indexed: 01/20/2023]
Abstract
Four major discoveries on the function of the pedunculopontine nucleus (PPN) have significantly advanced our understanding of the role of arousal in neurodegenerative disorders. The first was the finding that stimulation of the PPN-induced controlled locomotion on a treadmill in decerebrate animals, the second was the revelation of electrical coupling in the PPN and other arousal and sleep-wake control regions, the third was the determination of intrinsic gamma band oscillations in PPN neurons, and the last was the discovery of gene transcription resulting from the manifestation of gamma activity in the PPN. These discoveries have led to novel therapies such as PPN deep brain stimulation (DBS) for Parkinson's disease (PD), identified the mechanism of action of the stimulant modafinil, determined the presence of separate mechanisms underlying gamma activity during waking versus REM sleep, and revealed the presence of gene transcription during the manifestation of gamma band oscillations. These discoveries set the stage for additional major advances in the treatment of a number of disorders.
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience (CTN), University of Arkansas for Medical Sciences, Little Rock, Arkansas
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9
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Virmani T, Urbano FJ, Bisagno V, Garcia-Rill E. The pedunculopontine nucleus: From posture and locomotion to neuroepigenetics. AIMS Neurosci 2019; 6:219-230. [PMID: 32341978 PMCID: PMC7179357 DOI: 10.3934/neuroscience.2019.4.219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 09/19/2019] [Indexed: 12/04/2022] Open
Abstract
In this review, we discuss first an example of one of the symptoms of PD, freezing of gait (FOG), then we will turn to the use of deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) to treat PD, and the original studies that led to identification of the PPN as one source of locomotor control and why stimulation frequency is critical, and then describe the intrinsic properties of PPN neurons that require beta/gamma stimulation in order to fully activate all types of PPN neurons. Finally, we will describe recent findings on the proteomic and molecular consequences of gamma band activity in PPN neurons, with emphasis on the potential neuroepigenetic sequelae. These considerations will provide essential information for the appropriate refining and testing of PPN DBS as a potential therapy for PD, as well as alternative options.
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Affiliation(s)
- T Virmani
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, Little Rock, AR 72205, USA.,Department of Neurology, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - F J Urbano
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, Little Rock, AR 72205, USA.,Instituto Nacional de Investigaciones Farmacologicas, Argentina
| | - V Bisagno
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, Little Rock, AR 72205, USA.,Universidad de Buenos Aires, Buenos Aires, Argentina
| | - E Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, Little Rock, AR 72205, USA
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10
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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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11
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Byrum SD, Washam CL, Tackett AJ, Garcia-Rill E, Bisagno V, Urbano FJ. Proteomic measures of gamma oscillations. Heliyon 2019; 5:e02265. [PMID: 31497668 PMCID: PMC6722265 DOI: 10.1016/j.heliyon.2019.e02265] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/23/2019] [Accepted: 08/06/2019] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Gamma oscillations serve complex processes, and the first stage of their generation is the reticular activating system (RAS), which mediates the gamma-activity states of waking and paradoxical sleep. We studied whether the pedunculopontine nucleus (PPN), part of the RAS in which every cell manifests intrinsic gamma oscillations, undergoes changes resulting in distinctive protein expression. NEW METHOD We previously found that a histone deacetylation inhibitor, trichostatin A (TSA), acutely (30 min) blocked these oscillations. We developed a proteomic method for sampling stimulated and unstimulated PPN and determining protein expression in 1 mm punches of tissue from brain slices subjected to various treatments. RESULTS We compared brain slices exposed for 30 min to TSA (unstimulated), to the cholinergic agonist carbachol (CAR), known to induce PPN gamma oscillations, or exposed to both TSA + CAR.Comparison with existing methods: Label-free proteomics provides an unbiased and sensitive method to detect protein changes in the PPN. Our approach is superior to antibody-based methods that can lack specificity and can only be done for known targets. Proteomics methods like these have been leveraged to study molecular pathways in numerous systems and disease states. CONCLUSIONS Significant protein changes were seen in two functions essential to the physiology of the PPN: cytoskeletal and intracellular [Ca2+] regulation proteins. TSA decreased, while CAR increased, and TSA + CAR had intermediate effects, on expression of these proteins. These results support the feasibility of the methods developed for determining proteomic changes in small samples of tissue participating in the most complex of brain processes.
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Affiliation(s)
- Stephanie D. Byrum
- Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Charity L. Washam
- Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Alan J. Tackett
- Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Garcia-Rill E, Saper CB, Rye DB, Kofler M, Nonnekes J, Lozano A, Valls-Solé J, Hallett M. Focus on the pedunculopontine nucleus. Consensus review from the May 2018 brainstem society meeting in Washington, DC, USA. Clin Neurophysiol 2019; 130:925-940. [PMID: 30981899 PMCID: PMC7365492 DOI: 10.1016/j.clinph.2019.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/15/2019] [Accepted: 03/22/2019] [Indexed: 12/12/2022]
Abstract
The pedunculopontine nucleus (PPN) is located in the mesopontine tegmentum and is best delimited by a group of large cholinergic neurons adjacent to the decussation of the superior cerebellar peduncle. This part of the brain, populated by many other neuronal groups, is a crossroads for many important functions. Good evidence relates the PPN to control of reflex reactions, sleep-wake cycles, posture and gait. However, the precise role of the PPN in all these functions has been controversial and there still are uncertainties in the functional anatomy and physiology of the nucleus. It is difficult to grasp the extent of the influence of the PPN, not only because of its varied functions and projections, but also because of the controversies arising from them. One controversy is its relationship to the mesencephalic locomotor region (MLR). In this regard, the PPN has become a new target for deep brain stimulation (DBS) for the treatment of parkinsonian gait disorders, including freezing of gait. This review is intended to indicate what is currently known, shed some light on the controversies that have arisen, and to provide a framework for future research.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - C B Saper
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - David B Rye
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - M Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - J Nonnekes
- Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, the Netherlands
| | - A Lozano
- Division of Neurosurgery, University of Toronto and Krembil Neuroscience Centre, University Health Network, Toronto, Canada
| | - J Valls-Solé
- Neurology Department, Hospital Clínic, University of Barcelona, IDIBAPS (Institut d'Investigació Biomèdica August Pi i Sunyer), Barcelona, Spain
| | - M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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13
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Local and Relayed Effects of Deep Brain Stimulation of the Pedunculopontine Nucleus. Brain Sci 2019; 9:brainsci9030064. [PMID: 30889866 PMCID: PMC6468768 DOI: 10.3390/brainsci9030064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/18/2022] Open
Abstract
Our discovery of low-threshold stimulation-induced locomotion in the pedunculopontine nucleus (PPN) led to the clinical use of deep brain stimulation (DBS) for the treatment of disorders such as Parkinson's disease (PD) that manifest gait and postural disorders. Three additional major discoveries on the properties of PPN neurons have opened new areas of research for the treatment of motor and arousal disorders. The description of (a) electrical coupling, (b) intrinsic gamma oscillations, and (c) gene regulation in the PPN has identified a number of novel therapeutic targets and methods for the treatment of a number of neurological and psychiatric disorders. We first delve into the circuit, cellular, intracellular, and molecular organization of the PPN, and then consider the clinical results to date on PPN DBS. This comprehensive review will provide valuable information to explain the network effects of PPN DBS, point to new directions for treatment, and highlight a number of issues related to PPN DBS.
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14
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Garcia‐Rill E, D'Onofrio S, Mahaffey SC, Bisagno V, Urbano FJ. Bottom-up gamma and bipolar disorder, clinical and neuroepigenetic implications. Bipolar Disord 2019; 21:108-116. [PMID: 30506611 PMCID: PMC6441386 DOI: 10.1111/bdi.12735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES This limited review examines the role of the reticular activating system (RAS), especially the pedunculopontine nucleus (PPN), one site of origin of bottom-up gamma, in the symptoms of bipolar disorder (BD). METHODS The expression of neuronal calcium sensor protein 1 (NCS-1) in the brains of BD patients is increased. It has recently been found that all PPN neurons manifest intrinsic membrane beta/gamma frequency oscillations mediated by high threshold calcium channels, suggesting that it is one source of bottom-up gamma. This review specifically addresses the involvement of these channels in the manifestation of BD. RESULTS Excess NCS-1 was found to dampen gamma band oscillations in PPN neurons. Lithium, a first line treatment for BD, was found to decrease the effects of NCS-1 on gamma band oscillations in PPN neurons. Moreover, gamma band oscillations appear to epigenetically modulate gene transcription in PPN neurons, providing a new direction for research in BD. CONCLUSIONS This is an area needing much additional research, especially since the dysregulation of calcium channels may help explain many of the disorders of arousal in, elicit unwanted neuroepigenetic modulation in, and point to novel therapeutic avenues for, BD.
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Affiliation(s)
- Edgar Garcia‐Rill
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Stasia D'Onofrio
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Susan C Mahaffey
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas
| | - Veronica Bisagno
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas,IFIBYNECONICETUniversidad de Buenos AiresBuenos AiresArgentina
| | - Francisco J Urbano
- Center for Translational NeuroscienceUniversity of Arkansas for Medical SciencesLittle RockArkansas,IFIBYNECONICETUniversidad de Buenos AiresBuenos AiresArgentina
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15
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Abstract
Wakefulness, rapid eye movement (REM) sleep, and non-rapid eye movement (NREM) sleep are characterized by distinct electroencephalogram (EEG), electromyogram (EMG), and autonomic profiles. The circuit mechanism coordinating these changes during sleep-wake transitions remains poorly understood. The past few years have witnessed rapid progress in the identification of REM and NREM sleep neurons, which constitute highly distributed networks spanning the forebrain, midbrain, and hindbrain. Here we propose an arousal-action circuit for sleep-wake control in which wakefulness is supported by separate arousal and action neurons, while REM and NREM sleep neurons are part of the central somatic and autonomic motor circuits. This model is well supported by the currently known sleep and wake neurons. It can also account for the EEG, EMG, and autonomic profiles of wake, REM, and NREM states and several key features of their transitions. The intimate association between the sleep and autonomic/somatic motor control circuits suggests that a primary function of sleep is to suppress motor activity.
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Affiliation(s)
- Danqian Liu
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, and Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA;
| | - Yang Dan
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, and Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA;
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Thome J, Densmore M, Koppe G, Terpou B, Théberge J, McKinnon MC, Lanius RA. Back to the Basics: Resting State Functional Connectivity of the Reticular Activation System in PTSD and its Dissociative Subtype. CHRONIC STRESS (THOUSAND OAKS, CALIF.) 2019; 3:2470547019873663. [PMID: 32440600 PMCID: PMC7219926 DOI: 10.1177/2470547019873663] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 08/09/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND Brainstem and midbrain neuronal circuits that control innate, reflexive responses and arousal are increasingly recognized as central to the neurobiological framework of post-traumatic stress disorder (PTSD). The reticular activation system represents a fundamental neuronal circuit that plays a critical role not only in generating arousal but also in coordinating innate, reflexive responding. Accordingly, the present investigation aims to characterize the resting state functional connectivity of the reticular activation system in PTSD and its dissociative subtype. METHODS We investigated patterns of resting state functional connectivity of a central node of the reticular activation system, namely, the pedunculopontine nuclei, among individuals with PTSD (n = 77), its dissociative subtype (PTSD+DS; n = 48), and healthy controls (n = 51). RESULTS Participants with PTSD and PTSD+DS were characterized by within-group pedunculopontine nuclei resting state functional connectivity to brain regions involved in innate threat processing and arousal modulation (i.e., midbrain, amygdala, ventromedial prefrontal cortex). Critically, this pattern was most pronounced in individuals with PTSD+DS, as compared to both control and PTSD groups. As compared to participants with PTSD and controls, individuals with PTSD+DS showed enhanced pedunculopontine nuclei resting state functional connectivity to the amygdala and the parahippocampal gyrus as well as to the anterior cingulate and the ventromedial prefrontal cortex. No group differences emerged between PTSD and control groups. In individuals with PTSD+DS, state derealization/depersonalization was associated with reduced resting state functional connectivity between the left pedunculopontine nuclei and the anterior nucleus of the thalamus. Altered connectivity in these regions may restrict the thalamo-cortical transmission necessary to integrate internal and external signals at a cortical level and underlie, in part, experiences of depersonalization and derealization. CONCLUSIONS The present findings extend the current neurobiological model of PTSD and provide emerging evidence for the need to incorporate brainstem structures, including the reticular activation system, into current conceptualizations of PTSD and its dissociative subtype.
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Affiliation(s)
- Janine Thome
- Department of Psychiatry, Western
University, London, Ontario, Canada
- Department of Theoretical Neuroscience,
Central
Institute of Mental Health Mannheim, Medical
Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Department of Psychiatry,
Central
Institute of Mental Health Mannheim, Medical
Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Maria Densmore
- Department of Psychiatry, Western
University, London, Ontario, Canada
- Imaging Division,
Lawson
Health Research Institute, London, Ontario,
Canada
| | - Georgia Koppe
- Department of Theoretical Neuroscience,
Central
Institute of Mental Health Mannheim, Medical
Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Department of Psychiatry,
Central
Institute of Mental Health Mannheim, Medical
Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Braeden Terpou
- Department of Psychiatry, Western
University, London, Ontario, Canada
- Department of Neuroscience, Western
University, London, Ontario, Canada
| | - Jean Théberge
- Department of Psychiatry, Western
University, London, Ontario, Canada
- Imaging Division,
Lawson
Health Research Institute, London, Ontario,
Canada
- Department of Medical Biophysics,
Western University, London, Ontario, Canada
| | - Margaret C. McKinnon
- Homewood Research Institute, Guelph,
Ontario, Canada
- Mood Disorder Programs, St. Joseph's
Healthcare, Hamilton, Ontario, Canada
- Department of Psychiatry and Behavioral
Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Ruth A. Lanius
- Department of Psychiatry, Western
University, London, Ontario, Canada
- Imaging Division,
Lawson
Health Research Institute, London, Ontario,
Canada
- Department of Neuroscience, Western
University, London, Ontario, Canada
- Homewood Research Institute, Guelph,
Ontario, Canada
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17
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Billard MW, Bahari F, Kimbugwe J, Alloway KD, Gluckman BJ. The systemDrive: a Multisite, Multiregion Microdrive with Independent Drive Axis Angling for Chronic Multimodal Systems Neuroscience Recordings in Freely Behaving Animals. eNeuro 2018; 5:ENEURO.0261-18.2018. [PMID: 30627656 PMCID: PMC6325560 DOI: 10.1523/eneuro.0261-18.2018] [Citation(s) in RCA: 8] [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: 07/03/2018] [Revised: 12/06/2018] [Accepted: 12/11/2018] [Indexed: 02/07/2023] Open
Abstract
A multielectrode system that can address widely separated targets at multiple sites across multiple brain regions with independent implant angling is needed to investigate neural function and signaling in systems and circuits of small animals. Here, we present the systemDrive, a novel multisite, multiregion microdrive that is capable of moving microwire electrode bundles into targets along independent and nonparallel drive trajectories. Our design decouples the stereotaxic surgical placement of individual guide cannulas for each trajectory from the placement of a flexible drive structure. This separation enables placement of many microwire multitrodes along widely spaced and independent drive axes with user-set electrode trajectories and depths from a single microdrive body, and achieves stereotaxic precision with each. The system leverages tight tube-cannula tolerances and geometric constraints on flexible drive axes to ensure concentric alignment of electrode bundles within guide cannulas. Additionally, the headmount and microdrive both have an open-center design to allow for the placement of additional sensing modalities. This design is the first, in the context of small rodent chronic research, to provide the capability to finely position microwires through multiple widely distributed cell groups, each with stereotaxic precision, along arbitrary and nonparallel trajectories that are not restricted to emanate from a single source. We demonstrate the use of the systemDrive in male Long-Evans rats to observe simultaneous single-unit and multiunit activity from multiple widely separated sleep-wake regulatory brainstem cell groups, along with cortical and hippocampal activity, during free behavior over multiple many-day continuous recording periods.
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Affiliation(s)
- Myles W. Billard
- Department of Engineering Science and Mechanics, Penn State University, University Park, Pennsylvania 16802
- Center for Neural Engineering, Penn State University, University Park, Pennsylvania 16802
| | - Fatemeh Bahari
- Department of Engineering Science and Mechanics, Penn State University, University Park, Pennsylvania 16802
- Center for Neural Engineering, Penn State University, University Park, Pennsylvania 16802
| | - John Kimbugwe
- Center for Neural Engineering, Penn State University, University Park, Pennsylvania 16802
| | - Kevin D. Alloway
- Center for Neural Engineering, Penn State University, University Park, Pennsylvania 16802
- Department of Neural and Behavioral Sciences, Penn State University, University Park, Pennsylvania 16802
| | - Bruce J. Gluckman
- Department of Engineering Science and Mechanics, Penn State University, University Park, Pennsylvania 16802
- Center for Neural Engineering, Penn State University, University Park, Pennsylvania 16802
- Department of Neurosurgery, Penn State University, University Park, Pennsylvania 16802
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18
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Urbano FJ, Bisagno V, Mahaffey S, Lee SH, Garcia-Rill E. Class II histone deacetylases require P/Q-type Ca 2+ channels and CaMKII to maintain gamma oscillations in the pedunculopontine nucleus. Sci Rep 2018; 8:13156. [PMID: 30177751 PMCID: PMC6120910 DOI: 10.1038/s41598-018-31584-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/07/2018] [Indexed: 12/22/2022] Open
Abstract
Epigenetic mechanisms (i.e., histone post-translational modification and DNA methylation) play a role in regulation of gene expression. The pedunculopontine nucleus (PPN), part of the reticular activating system, manifests intrinsic gamma oscillations generated by voltage-dependent, high threshold N- and P/Q-type Ca2+ channels. We studied whether PPN intrinsic gamma oscillations are affected by inhibition of histone deacetylation. We showed that, a) acute in vitro exposure to the histone deacetylation Class I and II inhibitor trichostatin A (TSA, 1 μM) eliminated oscillations in the gamma range, but not lower frequencies, b) pre-incubation with TSA (1 μM, 90-120 min) also decreased gamma oscillations, c) Ca2+ currents (ICa) were reduced by TSA, especially on cells with P/Q-type channels, d) a HDAC Class I inhibitor MS275 (500 nM), and a Class IIb inhibitor Tubastatin A (150-500 nM), failed to affect gamma oscillations, e) MC1568, a HDAC Class IIa inhibitor (1 μM), blocked gamma oscillations, and f) the effects of both TSA and MC1568 were blunted by blockade of CaMKII with KN-93 (1 μM). These results suggest a cell type specific effect on gamma oscillations when histone deacetylation is blocked, suggesting that gamma oscillations through P/Q-type channels modulated by CaMKII may be linked to processes related to gene transcription.
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Affiliation(s)
- Francisco J Urbano
- Center for Translational Neuroscience, Department Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA.,IFIBYNE, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Verónica Bisagno
- ININFA, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Susan Mahaffey
- Center for Translational Neuroscience, Department Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Sang-Hun Lee
- Center for Translational Neuroscience, Department Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA.,Department Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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19
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Di Giovanni G, Chagraoui A, Puginier E, Galati S, De Deurwaerdère P. Reciprocal interaction between monoaminergic systems and the pedunculopontine nucleus: Implication in the mechanism of L-DOPA. Neurobiol Dis 2018; 128:9-18. [PMID: 30149181 DOI: 10.1016/j.nbd.2018.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/19/2018] [Accepted: 08/23/2018] [Indexed: 01/31/2023] Open
Abstract
The pedunculopontine nucleus (PPN) is part of the mesencephalic locomotor region (MLR) and has been involved in the control of gait, posture, locomotion, sleep, and arousal. It likely participates in some motor and non-motor symptoms of Parkinson's disease and is regularly proposed as a surgical target to ameliorate gait, posture and sleep disorders in Parkinsonian patients. The PPN overlaps with the monoaminergic systems including dopamine, serotonin and noradrenaline in the modulation of the above-mentioned functions. All these systems are involved in Parkinson's disease and the mechanism of the anti-Parkinsonian agents, mostly L-DOPA. This suggests that PPN interacts with monoaminergic neurons and vice versa. Some evidence indicates that the PPN sends cholinergic, glutamatergic and even gabaergic inputs to mesencephalic dopaminergic cells, with the data regarding serotonergic or noradrenergic cells being less well known. Similarly, the control exerted by the PPN on dopaminergic neurons, is multiple and complex, and more extensively explored than the other monoaminergic systems. The data on the influence of monoaminergic systems on PPN neuron activity are rather scarce. While there is evidence that the PPN influences the therapeutic response of L-DOPA, it is still difficult to discerne the reciprocal action of the PPN and monoaminergic systems in this action. Additional data are required to better understand the functional organization of monoaminergic inputs to the MLR including the PPN to get a clearer picture of their interaction.
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Affiliation(s)
- Giuseppe Di Giovanni
- Department of Physiology & Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, UK.
| | - Abdeslam Chagraoui
- Normandie Univ, UNIROUEN, INSERM, U1239, CHU Rouen, Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Emilie Puginier
- Normandie Univ, UNIROUEN, INSERM, U1239, CHU Rouen, Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Salvatore Galati
- Parkinson and movement Disorders Center Neurocenter of Southern Switzerland, Ospedale Civico di Lugano, Lugano, Switzerland
| | - Philippe De Deurwaerdère
- Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5287), 146 rue Léo Saignat, B.P.281, F-33000 Bordeaux Cedex, France.
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20
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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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21
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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: 3] [Impact Index Per Article: 0.5] [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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22
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Aitta-aho T, Hay YA, Phillips BU, Saksida LM, Bussey TJ, Paulsen O, Apergis-Schoute J. Basal Forebrain and Brainstem Cholinergic Neurons Differentially Impact Amygdala Circuits and Learning-Related Behavior. Curr Biol 2018; 28:2557-2569.e4. [DOI: 10.1016/j.cub.2018.06.064] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/30/2018] [Accepted: 06/25/2018] [Indexed: 11/26/2022]
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23
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Garcia-Rill E, Mahaffey S, Hyde JR, Urbano FJ. Bottom-up gamma maintenance in various disorders. Neurobiol Dis 2018; 128:31-39. [PMID: 29353013 DOI: 10.1016/j.nbd.2018.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/02/2018] [Accepted: 01/10/2018] [Indexed: 11/30/2022] Open
Abstract
Maintained gamma band activity is a key element of higher brain function, participating in perception, executive function, and memory. The pedunculopontine nucleus (PPN), as part of the reticular activating system (RAS), is a major source of the "bottom-up" flow of gamma activity to higher regions. However, interruption of gamma band activity is associated with a number of neurological and psychiatric disorders. This review will focus on the role of the PPN in activating higher regions to induce arousal and descending pathways to modulate posture and locomotion. As such, PPN deep brain stimulation (DBS) can not only help regulate arousal and stepping, but continuous application may help maintain necessary levels of gamma band activity for a host of other brain processes. We will explore the potential future applications of PPN DBS for a number of disorders that are characterized by disturbances in gamma band maintenance.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - S Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | - F J Urbano
- IFIBYNE (CONICET-UBA), DFBMC, Universidad de Buenos Aires, Buenos Aires, Argentina
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24
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McKillop LE, Vyazovskiy VV. Sleep- and Wake-Like States in Small Networks In Vivo and In Vitro. Handb Exp Pharmacol 2018; 253:97-121. [PMID: 30443784 DOI: 10.1007/164_2018_174] [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] [Indexed: 12/22/2022]
Abstract
Wakefulness and sleep are highly complex and heterogeneous processes, involving multiple neurotransmitter systems and a sophisticated interplay between global and local networks of neurons and non-neuronal cells. Macroscopic approaches applied at the level of the whole organism, view sleep as a global behaviour and allow for investigation into aspects such as the effects of insufficient or disrupted sleep on cognitive function, metabolism, thermoregulation and sensory processing. While significant progress has been achieved using such large-scale approaches, the inherent complexity of sleep-wake regulation has necessitated the development of methods which tackle specific aspects of sleep in isolation. One way this may be achieved is by investigating specific cellular or molecular phenomena in the whole organism in situ, either during spontaneous or induced sleep-wake states. This approach has greatly advanced our knowledge about the electrophysiology and pharmacology of ion channels, specific receptors, intracellular pathways and the small networks implicated in the control and regulation of the sleep-wake cycle. Importantly though, there are a variety of external and internal factors that influence global behavioural states which are difficult to control for using these approaches. For this reason, over the last few decades, ex vivo experimental models have become increasingly popular and have greatly advanced our understanding of many fundamental aspects of sleep, including the neuroanatomy and neurochemistry of sleep states, sleep regulation, the origin and dynamics of specific sleep oscillations, network homeostasis as well as the functional roles of sleep. This chapter will focus on the use of small neuronal networks as experimental models and will highlight the most significant and novel insights these approaches have provided.
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Affiliation(s)
- Laura E McKillop
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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25
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Temporal-Spatial Profiling of Pedunculopontine Galanin-Cholinergic Neurons in the Lactacystin Rat Model of Parkinson's Disease. Neurotox Res 2017; 34:16-31. [PMID: 29218504 DOI: 10.1007/s12640-017-9846-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/22/2017] [Accepted: 11/22/2017] [Indexed: 12/17/2022]
Abstract
Parkinson's disease (PD) is conventionally seen as resulting from single-system neurodegeneration affecting nigrostriatal dopaminergic neurons. However, accumulating evidence indicates multi-system degeneration and neurotransmitter deficiencies, including cholinergic neurons which degenerate in a brainstem nucleus, the pedunculopontine nucleus (PPN), resulting in motor and cognitive impairments. The neuropeptide galanin can inhibit cholinergic transmission, while being upregulated in degenerating brain regions associated with cognitive decline. Here we determined the temporal-spatial profile of progressive expression of endogenous galanin within degenerating cholinergic neurons, across the rostro-caudal axis of the PPN, by utilizing the lactacystin-induced rat model of PD. First, we show progressive neuronal death affecting nigral dopaminergic and PPN cholinergic neurons, reflecting that seen in PD patients, to facilitate use of this model for assessing the therapeutic potential of bioactive peptides. Next, stereological analyses of the lesioned brain hemisphere found that the number of PPN cholinergic neurons expressing galanin increased by 11%, compared to sham-lesioned controls, and increasing by a further 5% as the neurodegenerative process evolved. Galanin upregulation within cholinergic PPN neurons was most prevalent closest to the intra-nigral lesion site, suggesting that galanin upregulation in such neurons adapt intrinsically to neurodegeneration, to possibly neuroprotect. This is the first report on the extent and pattern of galanin expression in cholinergic neurons across distinct PPN subregions in both the intact rat CNS and lactacystin-lesioned rats. The findings pave the way for future work to target galanin signaling in the PPN, to determine the extent to which upregulated galanin expression could offer a viable treatment strategy for ameliorating PD symptoms associated with cholinergic degeneration.
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26
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Urbano FJ, Bisagno V, Garcia-Rill E. Arousal and drug abuse. Behav Brain Res 2017; 333:276-281. [PMID: 28729115 DOI: 10.1016/j.bbr.2017.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/08/2017] [Accepted: 07/14/2017] [Indexed: 12/31/2022]
Abstract
The reticular activating system (RAS) is not an amorphous region but distinct nuclei with specific membrane properties that dictate their firing during waking and sleep. The locus coeruleus and raphe nucleus fire during waking and slow wave sleep, with the pedunculopontine nucleus (PPN) firing during both waking and REM sleep, the states manifesting arousal-related EEG activity. Two important discoveries in the PPN in the last 10 years are, 1) that some PPN cells are electrically coupled, and 2) every PPN cell manifests high threshold calcium channels that allow them to oscillate at beta/gamma band frequencies. The role of arousal in drug abuse is considered here in terms of the effects of drugs of abuse on these two mechanisms. Drug abuse and the perception of withdrawal/relapse are mediated by neurobiological processes that occur only when we are awake, not when we are asleep. These relationships focus on the potential role of arousal, more specifically of RAS electrical coupling and gamma band activity, in the addictive process as well as the relapse to drug use.
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Affiliation(s)
| | - Verónica Bisagno
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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27
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Garcia-Rill E. Bottom-up gamma and stages of waking. Med Hypotheses 2017; 104:58-62. [PMID: 28673592 DOI: 10.1016/j.mehy.2017.05.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 11/25/2022]
Abstract
Gamma activity has been proposed to promote the feed forward or "bottom-up" flow of information from lower to higher regions of the brain during perception. The pedunculopontine nucleus (PPN) modulates waking and REM sleep, and is part of the reticular activating system (RAS). The properties of PPN cells are unique in that all PPN neurons fire maximally at gamma band frequency regardless of electrophysiological or transmitter type, thus proposed as one origin of "bottom-up" gamma. This property is based on the presence of intrinsic membrane oscillations subserved by high threshold, voltage-dependent calcium channels. Moreover, some PPN cells are electrically coupled. Assuming that the population of PPN neurons has the capacity to fire at ∼40Hz coherently, then the population as a whole can be expected to generate a stable gamma band signal. But what if not all the neurons are firing at the peaks of the oscillations? That means that some cells may fire only at the peaks of every second oscillation. Therefore, the population as a whole can be expected to be firing at a net ∼20Hz. If some cells are firing at the peaks of every fourth oscillation, then the PPN as a whole would be firing at ∼10Hz. Firing at rates below 10Hz would imply that the system is seldom firing at the peaks of any oscillation, basically asleep, in slow wave sleep, thus the activation of the RAS is insufficient to promote waking. This hypothesis carries certain implications, one of which is that we awaken in stages as more and more cells are recruited to fire at the peaks of more and more oscillations. For this system, it would imply that, as we awaken, we step from ∼10Hz to ∼20Hz to ∼30Hz to ∼40Hz, that is, in stages and presumably at different levels of awareness. A similar process can be expected to take place as we fall asleep. Awakening can then be considered to be stepwise, not linear. That is, the implication is that the process of waking is a stepwise event, not a gradual increase, suggesting that the brain can spend time at each of these different stages of arousal.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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D'Onofrio S, Mahaffey S, Garcia-Rill E. Role of calcium channels in bipolar disorder. CURRENT PSYCHOPHARMACOLOGY 2017; 6:122-135. [PMID: 29354402 PMCID: PMC5771645 DOI: 10.2174/2211556006666171024141949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bipolar disorder is characterized by a host of sleep-wake abnormalities that suggests that the reticular activating system (RAS) is involved in these symptoms. One of the signs of the disease is a decrease in high frequency gamma band activity, which accounts for a number of additional deficits. Bipolar disorder has also been found to overexpress neuronal calcium sensor protein 1 (NCS-1). Recent studies showed that elements in the RAS generate gamma band activity that is mediated by high threshold calcium (Ca2+) channels. This mini-review provides a description of recent findings on the role of Ca2+ and Ca2+ channels in bipolar disorder, emphasizing the involvement of arousal-related systems in the manifestation of many of the disease symptoms. This will hopefully bring attention to a much-needed area of research and provide novel avenues for therapeutic development.
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Affiliation(s)
- Stasia D'Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
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29
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Garcia-Rill E, D’Onofrio S, Mahaffey S. Bottom-up Gamma: the Pedunculopontine Nucleus and Reticular Activating System. TRANSLATIONAL BRAIN RHYTHMICITY 2016; 1:49-53. [PMID: 28691105 PMCID: PMC5497760 DOI: 10.15761/tbr.1000109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Gamma rhythms have been proposed to promote the feed forward or "bottom-up" flow of information from lower to higher regions in the brain during perception. On the other hand, beta rhythms have been proposed to represent feed back or "top-down" influence from higher regions to lower. The pedunculopontine nucleus (PPN) has been implicated in sleep-wake control and arousal, and is part of the reticular activating system (RAS). This review describes the properties of the cells in this nucleus. These properties are unique, and perhaps it is the particular characteristics of these cells that allow the PPN to be involved in a host of functions and disorders. The fact that all PPN neurons fire maximally at gamma band frequency regardless of electrophysiological or transmitter type, make this an unusual cell group. In other regions, for example in the cortex, cells with such a property represent only a sub-population. More importantly, the fact that this cell group's functions are related to the capacity to generate coherent activity at a preferred natural frequency, gamma band, speaks volumes about how the PPN functions. We propose that "bottom-up" gamma band influence arises in the RAS and contributes to the build-up of the background of activity necessary for preconscious awareness and gamma activity at cortical levels.
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Affiliation(s)
- E. Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
| | - S. D’Onofrio
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
| | - S. Mahaffey
- Center for Translational Neuroscience, Department of Neurobiology, University of Arkansas for Medical Sciences., Little Rock, AR
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Luster BR, Urbano FJ, Garcia-Rill E. Intracellular mechanisms modulating gamma band activity in the pedunculopontine nucleus (PPN). Physiol Rep 2016; 4:4/12/e12787. [PMID: 27354537 PMCID: PMC4923228 DOI: 10.14814/phy2.12787] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/11/2016] [Indexed: 02/04/2023] Open
Abstract
The pedunculopontine nucleus is a part of the reticular activating system, and is active during waking and REM sleep. Previous results showed that all PPN cells tested fired maximally at gamma frequencies when depolarized. This intrinsic membrane property was shown to be mediated by high‐threshold N‐ and P/Q‐type Ca2+ channels. Recent studies show that the PPN contains three independent populations of neurons which can generate gamma band oscillations through only N‐type channels, only P/Q‐type channels, or both N‐ and P/Q‐type channels. This study investigated the intracellular mechanisms modulating gamma band activity in each population of neurons. We performed in vitro patch‐clamp recordings of PPN neurons from Sprague–Dawley rat pups, and applied 1‐sec ramps to induce intrinsic membrane oscillations. Our results show that there are two pathways modulating gamma band activity in PPN neurons. We describe populations of neurons mediating gamma band activity through only N‐type channels and the cAMP/PKA pathway (presumed “REM‐on” neurons), through only P/Q‐type channels and the CaMKII pathway (presumed “Wake‐on” neurons), and a third population which can mediate gamma activity through both N‐type channels and cAMP/PK and P/Q‐type channels and CaMKII (presumed “Wake/REM‐on” neurons). These novel results suggest that PPN gamma oscillations are modulated by two independent pathways related to different Ca2+ channel types.
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Affiliation(s)
- Brennon R Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | | | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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31
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Urbano FJ, Luster BR, D'Onofrio S, Mahaffey S, Garcia-Rill E. Recording Gamma Band Oscillations in Pedunculopontine Nucleus Neurons. J Vis Exp 2016. [PMID: 27684729 DOI: 10.3791/54685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Synaptic efferents from the PPN are known to modulate the neuronal activity of several intralaminar thalamic regions (e.g., the centrolateral/parafascicular; Cl/Pf nucleus). The activation of either the PPN or Cl/Pf nuclei in vivo has been described to induce the arousal of the animal and an increment in gamma band activity in the cortical electroencephalogram (EEG). The cellular mechanisms for the generation of gamma band oscillations in Reticular Activating System (RAS) neurons are the same as those found to generate gamma band oscillations in other brains nuclei. During current-clamp recordings of PPN neurons (from parasagittal slices from 9 - 25 day-old rats), the use of depolarizing square steps rapidly activated voltage-dependent potassium channels that prevented PPN neurons from being depolarized beyond -25 mV. Injecting 1 - 2 sec long depolarizing current ramps gradually depolarized PPN membrane potential resting values towards 0 mV. However, injecting depolarizing square pulses generated gamma-band oscillations of membrane potential that showed to be smaller in amplitude compared to the oscillations generated by ramps. All experiments were performed in the presence of voltage-gated sodium channels and fast synaptic receptors blockers. It has been shown that the activation of high-threshold voltage-dependent calcium channels underlie gamma-band oscillatory activity in PPN neurons. Specific methodological and pharmacological interventions are described here, providing the necessary tools to induce and sustain PPN subthreshold gamma band oscillation in vitro.
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Affiliation(s)
| | - Brennon R Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences
| | - Stasia D'Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences;
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32
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Garcia-Rill E, Luster B, D'Onofrio S, Mahaffey S, Bisagno V, Urbano FJ. Implications of gamma band activity in the pedunculopontine nucleus. J Neural Transm (Vienna) 2016; 123:655-665. [PMID: 26597124 PMCID: PMC4877293 DOI: 10.1007/s00702-015-1485-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 11/10/2015] [Indexed: 01/07/2023]
Abstract
The fact that the pedunculopontine nucleus (PPN) is part of the reticular activating system places it in a unique position to modulate sensory input and fight-or-flight responses. Arousing stimuli simultaneously activate ascending projections of the PPN to the intralaminar thalamus to trigger cortical high-frequency activity and arousal, as well as descending projections to reticulospinal systems to alter posture and locomotion. As such, the PPN has become a target for deep brain stimulation for the treatment of Parkinson's disease, modulating gait, posture, and higher functions. This article describes the latest discoveries on PPN physiology and the role of the PPN in a number of disorders. It has now been determined that high-frequency activity during waking and REM sleep is controlled by two different intracellular pathways and two calcium channels in PPN cells. Moreover, there are three different PPN cell types that have one or both calcium channels and may be active during waking only, REM sleep only, or both. Based on the new discoveries, novel mechanisms are proposed for insomnia as a waking disorder. In addition, neuronal calcium sensor protein-1 (NCS-1), which is over expressed in schizophrenia and bipolar disorder, may be responsible for the dysregulation in gamma band activity in at least some patients with these diseases. Recent results suggest that NCS-1 modulates PPN gamma band activity and that lithium acts to reduce the effects of over expressed NCS-1, accounting for its effectiveness in bipolar disorder.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA.
| | - B Luster
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - S D'Onofrio
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - S Mahaffey
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St., Little Rock, AR, 72205, USA
| | - V Bisagno
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - F J Urbano
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
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33
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Goetz L, Piallat B, Bhattacharjee M, Mathieu H, David O, Chabardès S. The primate pedunculopontine nucleus region: towards a dual role in locomotion and waking state. J Neural Transm (Vienna) 2016; 123:667-678. [PMID: 27216823 DOI: 10.1007/s00702-016-1577-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/12/2016] [Indexed: 10/21/2022]
Abstract
The mesencephalic reticular formation (MRF) mainly composed by the pedunculopontine and the cuneiform nuclei is involved in the control of several fundamental brain functions such as locomotion, rapid eye movement sleep and waking state. On the one hand, the role of MRF neurons in locomotion has been investigated for decades in different animal models, including in behaving nonhuman primate (NHP) using extracellular recordings. On the other hand, MRF neurons involved in the control of waking state have been consistently shown to constitute the cholinergic component of the reticular ascending system. However, a dual control of the locomotion and waking state by the same groups of neurons in NHP has never been demonstrated in NHP. Here, using microelectrode recordings in behaving NHP, we recorded 38 neurons in the MRF that were followed during transition between wakefulness (TWS) and sleep, i.e., until the emergence of sleep episodes characterized by typical cortical slow wave activity (SWA). We found that the MRF neurons, mainly located in the pedunculopontine nucleus region, modulated their activity during TWS with a decrease in firing rate during SWA. Of interest, we could follow some MRF neurons from locomotion to SWA and found that they also modulated their firing rate during locomotion and TWS. These new findings confirm the role of MRF neurons in both functions. They suggest that the MRF is an integration center that potentially allows to fine tune waking state and locomotor signals in order to establish an efficient locomotion.
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Affiliation(s)
- Laurent Goetz
- University of Grenoble Alpes, 38000, Grenoble, France.,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France
| | - Brigitte Piallat
- University of Grenoble Alpes, 38000, Grenoble, France.,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France
| | - Manik Bhattacharjee
- University of Grenoble Alpes, 38000, Grenoble, France.,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France
| | - Hervé Mathieu
- University of Grenoble Alpes, 38000, Grenoble, France.,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France.,Unité Mixte de Service IRMaGe, Grenoble Alpes Hospital, 38000, Grenoble, France.,Unité Mixte de Service 3552, CNRS, 38000, Grenoble, France
| | - Olivier David
- University of Grenoble Alpes, 38000, Grenoble, France.,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France
| | - Stéphan Chabardès
- University of Grenoble Alpes, 38000, Grenoble, France. .,INSERM, U1216, Grenoble Institut des Neurosciences, 38000, Grenoble, France. .,Clinique de neurochirurgie Pôle PALCROS, CHU Grenoble Alpes, 38000, Grenoble, France.
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34
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Garcia-Rill E, D’Onofrio S, Luster B, Mahaffey S, Urbano FJ, Phillips C. The 10 Hz Frequency: A Fulcrum For Transitional Brain States. TRANSLATIONAL BRAIN RHYTHMICITY 2016; 1:7-13. [PMID: 27547831 PMCID: PMC4990355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A 10 Hz rhythm is present in the occipital cortex when the eyes are closed (alpha waves), in the precentral cortex at rest (mu rhythm), in the superior and middle temporal lobe (tau rhythm), in the inferior olive (projection to cerebellar cortex), and in physiological tremor (underlying all voluntary movement). These are all considered resting rhythms in the waking brain which are "replaced" by higher frequency activity with sensorimotor stimulation. That is, the 10 Hz frequency fulcrum is replaced on the one hand by lower frequencies during sleep, or on the other hand by higher frequencies during volition and cognition. The 10 Hz frequency fulcrum is proposed as the natural frequency of the brain during quiet waking, but is replaced by higher frequencies capable of permitting more complex functions, or by lower frequencies during sleep and inactivity. At the center of the transition shifts to and from the resting rhythm is the reticular activating system, a phylogenetically preserved area of the brain essential for preconscious awareness.
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Affiliation(s)
- E. Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, US
| | - S. D’Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, US
| | - B. Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, US
| | - S. Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, US
| | - F. J. Urbano
- IFIBYNE-CONICET, University of Buenos Aires, Argentina
| | - C. Phillips
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, US
- Department of Physical Therapy, Arkansas State University, Jonesboro, AR, 72401
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35
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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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36
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Nam H, Kerman IA. Distribution of catecholaminergic presympathetic-premotor neurons in the rat lower brainstem. Neuroscience 2016; 324:430-45. [PMID: 26946268 DOI: 10.1016/j.neuroscience.2016.02.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/11/2016] [Accepted: 02/26/2016] [Indexed: 11/15/2022]
Abstract
We previously characterized the organization of presympathetic-premotor neurons (PSPMNs), which send descending poly-synaptic projections with collaterals to skeletal muscle and the adrenal gland. Such neurons may play a role in shaping integrated adaptive responses, and many of them were found within well-characterized regions of noradrenergic cell populations suggesting that some of the PSPMNs are catecholaminergic. To address this issue, we used retrograde trans-synaptic tract-tracing with attenuated pseudorabies virus (PRV) recombinants combined with multi-label immunofluorescence to identify PSPMNs expressing tyrosine hydroxylase (TH). Our findings indicate that TH-immunoreactive (ir) PSPMNs are present throughout the brainstem within multiple cell populations, including the A1, C1, C2, C3, A5 and A7 cell groups along with the locus coeruleus (LC) and the nucleus subcoeruleus (SubC). The largest numbers of TH-ir PSPMNs were located within the LC and SubC. Within SubC and the A7 cell group, about 70% of TH-ir neurons were PSPMNs, which was a significantly greater fraction of neurons than in the other brain regions we examined. These findings indicate that TH-ir neurons near the pontomesencephalic junction that are distributed across the LC, SubC, and the A7 may play a prominent role in somatomotor-sympathetic integration, and that the major functional role of the A7 and SubC noradrenergic cell groups maybe in the coordination of concomitant activation of somatomotor and sympathetic outflows. These neurons may participate in mediating homeostatic adaptations that require simultaneous activation of sympathetic and somatomotor nerves in the periphery.
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Affiliation(s)
- H Nam
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States; Cell Molecular and Developmental Biology Theme, Graduate Biomedical Sciences Program, University of Alabama at Birmingham, Birmingham, AL, United States
| | - I A Kerman
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States.
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37
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Fifel K, Piggins H, Deboer T. Modeling sleep alterations in Parkinson's disease: How close are we to valid translational animal models? Sleep Med Rev 2016; 25:95-111. [DOI: 10.1016/j.smrv.2015.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 02/18/2015] [Accepted: 02/18/2015] [Indexed: 10/23/2022]
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38
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Pedunculopontine Gamma Band Activity and Development. Brain Sci 2015; 5:546-67. [PMID: 26633526 PMCID: PMC4701027 DOI: 10.3390/brainsci5040546] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 12/25/2022] Open
Abstract
This review highlights the most important discovery in the reticular activating system in the last 10 years, the manifestation of gamma band activity in cells of the reticular activating system (RAS), especially in the pedunculopontine nucleus, which is in charge of waking and rapid eye movement (REM) sleep. The identification of different cell groups manifesting P/Q-type Ca(2+) channels that control waking vs. those that manifest N-type channels that control REM sleep provides novel avenues for the differential control of waking vs. REM sleep. Recent discoveries on the development of this system can help explain the developmental decrease in REM sleep and the basic rest-activity cycle.
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39
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Ríos A, Barrientos R, Alatorre A, Delgado A, Perez-Capistran T, Chuc-Meza E, García-Ramirez M, Querejeta E. Dopamine-dependent modulation of rat globus pallidus excitation by nicotine acetylcholine receptors. Exp Brain Res 2015; 234:605-16. [DOI: 10.1007/s00221-015-4491-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/30/2015] [Indexed: 11/24/2022]
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40
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Khanday M, Mallick B. REM sleep modulation by perifornical orexinergic inputs to the pedunculo-pontine tegmental neurons in rats. Neuroscience 2015; 308:125-33. [DOI: 10.1016/j.neuroscience.2015.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 12/27/2022]
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41
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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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42
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Grace KP, Horner RL. Evaluating the Evidence Surrounding Pontine Cholinergic Involvement in REM Sleep Generation. Front Neurol 2015; 6:190. [PMID: 26388832 PMCID: PMC4555043 DOI: 10.3389/fneur.2015.00190] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 08/17/2015] [Indexed: 11/13/2022] Open
Abstract
Rapid eye movement (REM) sleep - characterized by vivid dreaming, motor paralysis, and heightened neural activity - is one of the fundamental states of the mammalian central nervous system. Initial theories of REM sleep generation posited that induction of the state required activation of the "pontine REM sleep generator" by cholinergic inputs. Here, we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i) the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii) the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii) loss-of-function studies show that endogenous cholinergic input to the PTF is not required for REM sleep generation, and (iv) cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail.
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Affiliation(s)
- Kevin P Grace
- Department of Medicine, University of Toronto , Toronto, ON , Canada
| | - Richard L Horner
- Department of Medicine, University of Toronto , Toronto, ON , Canada ; Department of Physiology, University of Toronto , Toronto, ON , Canada
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43
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Orzeł-Gryglewska J, Matulewicz P, Jurkowlaniec E. Brainstem system of hippocampal theta induction: The role of the ventral tegmental area. Synapse 2015; 69:553-75. [PMID: 26234671 DOI: 10.1002/syn.21843] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 07/03/2015] [Accepted: 07/22/2015] [Indexed: 12/13/2022]
Abstract
This article summarizes the results of studies concerning the influence of the ventral tegmental area (VTA) on the hippocampal theta rhythm. Temporary VTA inactivation resulted in transient loss of the hippocampal theta. Permanent destruction of the VTA caused a long-lasting depression of the power of the theta and it also had some influence on the frequency of the rhythm. Activation of glutamate (GLU) receptors or decrease of GABAergic tonus in the VTA led to enhancement of dopamine release and increased hippocampal theta power. High time and frequency cross-correlation was detected for the theta band between the VTA and hippocampus during paradoxical sleep and active waking. Thus, the VTA may belong to the broad network involved in theta rhythm regulation. This article also presents a model of brainstem-VTA-hippocampal interactions in the induction of the hippocampal theta rhythm. The projections from the VTA which enhance theta rhythm are incorporated into the main theta generation pathway, in which the septum acts as the central node. The neuronal activity that may be responsible for the ability of the VTA to regulate theta probably derives from the structures associated with rapid eye movement (sleep) (REM) sleep or with sensorimotor activity (i.e., mainly from the pedunculopontine and laterodorsal tegmental nuclei and also from the raphe).
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Affiliation(s)
| | - Paweł Matulewicz
- Department of Animal and Human Physiology, University of Gdańsk, Gdańsk, 80-308, Poland
| | - Edyta Jurkowlaniec
- Department of Animal and Human Physiology, University of Gdańsk, Gdańsk, 80-308, Poland
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Luster B, D'Onofrio S, Urbano F, Garcia-Rill E. High-threshold Ca2+ channels behind gamma band activity in the pedunculopontine nucleus (PPN). Physiol Rep 2015; 3:3/6/e12431. [PMID: 26109189 PMCID: PMC4510632 DOI: 10.14814/phy2.12431] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is part of the Reticular Activating System, and active during waking and REM sleep. Previous results showed that all PPN cells plateau at gamma frequencies and intrinsic membrane oscillations in PPN neurons are mediated by high-threshold N- and P/Q-type Ca2+ channels. The present study was designed to determine whether some PPN cells have only N-, only P/Q-, or both N- and P/Q-type Ca2+ channels. We used patch-clamp recordings in PPN cells in slices from anesthetized rat pups in the presence of synaptic receptor blockers (SB) and Tetrodotoxin (TTX), and applied ramps to induce intrinsic membrane oscillations. We found that all PPN cell types showed gamma oscillations in the presence of SB+TTX when using current ramps. In 50% of cells, the N-type Ca2+ channel blocker ω-Conotoxin-GVIA (ω-CgTx) reduced gamma oscillation amplitude, while subsequent addition of the P/Q-type blocker ω-Agatoxin-IVA (ω-Aga) blocked the remaining oscillations. Another 20% manifested gamma oscillations that were not significantly affected by the addition of ω-CgTx, however, ω-Aga blocked the remaining oscillations. In 30% of cells, ω-Aga had no effect on gamma oscillations, while ω-CgTx blocked them. These novel results confirm the segregation of populations of PPN cells as a function of the calcium channels expressed, that is, the presence of cells in the PPN that manifest gamma band oscillations through only N-type, only P/Q-type, and both N-type and P/Q-type Ca2+ channels.
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Affiliation(s)
- Brennon Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Stasia D'Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Francisco Urbano
- IFIBYNE-CONICET University of Buenos Aires, Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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Rhythmic Firing of Pedunculopontine Tegmental Nucleus Neurons in Monkeys during Eye Movement Task. PLoS One 2015; 10:e0128147. [PMID: 26030664 PMCID: PMC4452564 DOI: 10.1371/journal.pone.0128147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 04/22/2015] [Indexed: 11/19/2022] Open
Abstract
The pedunculopontine tegmental nucleus (PPTN) has been thought to be involved in the control of behavioral state. Projections to the entire thalamus and reciprocal connections with the basal ganglia nuclei suggest a potential role for the PPTN in the control of various rhythmic behaviors, including waking/sleeping and locomotion. Recently, rhythmic activity in the local field potentials was recorded from the PPTN of patients with Parkinson's disease who were treated with levodopa, suggesting that rhythmic firing is a feature of the functioning PPTN and might change with the behaving conditions even within waking. However, it remains unclear whether and how single PPTN neurons exhibit rhythmic firing patterns during various behaving conditions, including executing conditioned eye movement behaviors, seeking reward, or during resting. We previously recorded from PPTN neurons in healthy monkeys during visually guided saccade tasks and reported task-related changes in firing rate, and in this paper, we reanalyzed these data and focused on their firing patterns. A population of PPTN neurons demonstrated a regular firing pattern in that the coefficient of variation of interspike intervals was lower than what would be expected of theoretical random and irregular spike trains. Furthermore, a group of PPTN neurons exhibited a clear periodic single spike firing that changed with the context of the behavioral task. Many of these neurons exhibited a periodic firing pattern during highly active conditions, either the fixation condition during the saccade task or the free-viewing condition during the intertrial interval. We speculate that these task context-related changes in rhythmic firing of PPTN neurons might regulate the monkey's attentional and vigilance state to perform the task.
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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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Bordas C, Kovacs A, Pal B. The M-current contributes to high threshold membrane potential oscillations in a cell type-specific way in the pedunculopontine nucleus of mice. Front Cell Neurosci 2015; 9:121. [PMID: 25904846 PMCID: PMC4388076 DOI: 10.3389/fncel.2015.00121] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/17/2015] [Indexed: 11/24/2022] Open
Abstract
The pedunculopontine nucleus is known as a cholinergic nucleus of the reticular activating system, participating in regulation of sleep and wakefulness. Besides cholinergic neurons, it consists of GABAergic and glutamatergic neurons as well. According to classical and recent studies, more subgroups of neurons were defined. Groups based on the neurotransmitter released by a neuron are not homogenous, but can be further subdivided. The PPN neurons do not only provide cholinergic and non-cholinergic inputs to several subcortical brain areas but they are also targets of cholinergic and other different neuromodulatory actions. Although cholinergic neuromodulation has been already investigated in the nucleus, one of its characteristic targets, the M-type potassium current has not been described yet. Using slice electrophysiology, we provide evidence in the present work that cholinergic neurons possess M-current, whereas GABAergic neurons lack it. The M-current contributes to certain functional differences of cholinergic and GABAergic neurons, as spike frequency adaptation, action potential firing frequency or the amplitude difference of medium afterhyperpolarizations (AHPs). Furthermore, we showed that high threshold membrane potential oscillation with high power, around 20 Hz frequency is a functional property of almost all cholinergic cells, whereas GABAergic neurons have only low amplitude oscillations. Blockade of the M-current abolished the oscillatory activity at 20 Hz, and largely diminished it at other frequencies. Taken together, the M-current seems to be characteristic for PPN cholinergic neurons. It provides a possibility for modulating gamma band activity of these cells, thus contributing to neuromodulatory regulation of the reticular activating system.
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Affiliation(s)
- Csilla Bordas
- Faculty of Medicine, Department of Physiology, University of Debrecen Debrecen, Hungary
| | - Adrienn Kovacs
- Faculty of Medicine, Department of Physiology, University of Debrecen Debrecen, Hungary
| | - Balazs Pal
- Faculty of Medicine, Department of Physiology, University of Debrecen Debrecen, Hungary
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Garcia-Rill E, D’Onofrio S, Mahaffey S, Bisagno V, Urbano FJ. Pedunculopontine arousal system physiology-Implications for schizophrenia. Sleep Sci 2015; 8:82-91. [PMID: 26483949 PMCID: PMC4608902 DOI: 10.1016/j.slsci.2015.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/23/2015] [Accepted: 04/30/2015] [Indexed: 01/24/2023] Open
Abstract
Schizophrenia is characterized by major sleep/wake disturbances including increased vigilance and arousal, decreased slow wave sleep, and increased REM sleep drive. Other arousal-related symptoms include sensory gating deficits as exemplified by decreased habituation of the blink reflex. There is also dysregulation of gamma band activity, suggestive of disturbances in a host of arousal-related mechanisms. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of the disease. Recent discoveries on the physiology of the pedunculopontine nucleus help explain many of these disorders of arousal in, and point to novel therapeutic avenues for, schizophrenia.
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Key Words
- CaMKII, calcium/calmodulin-dependent protein kinase
- Calcium channels
- EEG, electroencephalogram
- EPSC, excitatory postsynaptic potential
- GABA, γ aminobutyric acid
- Gamma band activity
- InsP, inositol 1,4,5-triphosphate receptor protein
- KA, kainic acid
- NCS-1, neuronal calcium sensor protein 1
- NMDA, n methyl d aspartic acid
- Neuronal calcium sensor protein
- P50 potential
- PGO, ponto-geniculo-occipital
- PPN, pedunculopontine nucleus
- Pf, parafascicular nucleus
- RAS, reticular activating system
- REM, rapid eye movement
- SWS, slow wave sleep
- SubCD, subcoeruleus dorsalis
- cAMP, cyclic adenosine monophosphate
- ω-Aga, ω-agatoxin-IVA
- ω-CgTx, ω-conotoxin-GVIA
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Stasia D’Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Veronica Bisagno
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - Francisco J. Urbano
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
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Datta S. Mysteries of pedunculopontine nucleus physiology: Towards a deeper understanding of arousal and neuropsychiatric disorders. Sleep Sci 2015; 8:53-5. [PMID: 26483944 PMCID: PMC4608880 DOI: 10.1016/j.slsci.2015.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Garcia-Rill E, Luster B, Mahaffey S, Bisagno V, Urbano FJ. Pedunculopontine arousal system physiology - Implications for insomnia. Sleep Sci 2015; 8:92-9. [PMID: 26483950 PMCID: PMC4608886 DOI: 10.1016/j.slsci.2015.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 06/08/2015] [Accepted: 06/12/2015] [Indexed: 01/09/2023] Open
Abstract
We consider insomnia a disorder of waking rather than a disorder of sleep. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of insomnia, mainly representing an overactive waking drive. We determined that high frequency activity during waking and REM sleep is controlled by two different intracellular pathways and channel types in PPN cells. We found three different PPN cell types that have one or both channels and may be active during waking only, REM sleep only, or both. These discoveries point to a specific mechanism and novel therapeutic avenues for insomnia.
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Key Words
- CaMKII, calcium/calmodulin-dependent protein kinase
- Calcium channels
- EEG, electroencephalogram
- Gamma band activity
- KA, kainic acid
- N-type calcium channel
- NCS-1, neuronal calcium sensor protein 1
- NMDA, n methyl d aspartic acid
- Neuronal calcium sensor protein
- P/Q-type calcium channel
- PGO, ponto-geniculo-occipital
- PPN, pedunculopontine nucleus
- RAS, reticular activating system
- REM, rapid eye movement
- SWS, slow wave sleep
- cAMP, cyclic adenosine monophosphate
- ω-Aga, ω-agatoxin-IVA
- ω-CgTx, ω-conotoxin-GVIA
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Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Brennon Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Veronica Bisagno
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Argentina
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