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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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2
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Inan SY, Yildirim S, Tanriover G, Ilhan B. P/Q type (Ca v2.1) Calcium Channel Blocker ω-Agatoxin IVA Alters Cleaved Caspase-3 and BDNF Expressions in the Rat Brain and Suppresses Seizure Activity. Mol Neurobiol 2024; 61:1861-1872. [PMID: 37798599 DOI: 10.1007/s12035-023-03678-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 09/26/2023] [Indexed: 10/07/2023]
Abstract
High-voltage-gated calcium channels have pivot role in the cellular and molecular mechanisms of various neurological disorders, including epilepsy. Similar to other calcium channels, P/Q-type calcium channels (Cav2.1) are also responsible for vesicle release at synaptic terminals. Up to date, there are very limited reports showing the mechanisms of Cav2.1 in epileptogenesis. In the present study, we investigated the anticonvulsive and neuroprotective effects of ω-agatoxin IVA, a specific Cav2.1 blocker, in a chemical kindling model of epileptogenesis. Righting reflex and inclined plane tests were used to assess motor coordination. Electroencephalography was recorded for electrophysiological monitoring of seizure activity in freely moving rats. Immunohistochemical analyses were performed for brain-derived neurotrophic factor (BDNF) and cleaved caspase-3 expressions in the prefrontal cortex, striatum, hippocampus, and thalamic nucleus. ω-Agatoxin IVA injected into the right lateral ventricle significantly prolonged the onset of seizures in a dose-dependent manner. In addition, repeated intraperitoneal administrations of ω-agatoxin IVA significantly suppressed the development of kindling and epileptic discharges without altering motor coordination. In addition, ω-agatoxin IVA significantly increased BDNF expressions, and decreased cleaved caspase-3 expressions in the brain when compared to PTZ + saline group. Our current study emphasizes the significance of the inhibition of P/Q type calcium channels by ω-agatoxin IVA, which suppresses the development of epileptogenesis and provides a new potential pathway for epilepsy treatment.
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Affiliation(s)
- Salim Yalcin Inan
- Department of Medical Pharmacology, Meram Faculty of Medicine, University of Konya-NE, 42080 Akyokus, Meram, Konya, Turkey.
| | - Sendegul Yildirim
- Department of Histology and Embryology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey
| | - Gamze Tanriover
- Department of Histology and Embryology, Faculty of Medicine, University of Akdeniz, Antalya, Turkey
- Department of Medical Biotechnology, University of Akdeniz, Antalya, Turkey
| | - Barkin Ilhan
- Department of Biophysics, Meram Faculty of Medicine, University of Konya-NE, Konya, Turkey
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3
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Chen RYT, Evans RC. Comparing tonic and phasic calcium in the dendrites of vulnerable midbrain neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555184. [PMID: 37693427 PMCID: PMC10491175 DOI: 10.1101/2023.08.28.555184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Several midbrain nuclei degenerate in Parkinson's Disease (PD). Many of these nuclei share the common characteristics that are thought to contribute to their selective vulnerability, including pacemaking activity and high levels of calcium influx. 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. It is well established that the low-threshold L-type calcium current is a main contributor to tonic calcium in SNc dopaminergic neurons and is hypothesized to contribute to their selective vulnerability. 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 the tonic and phasic activity of PPN neurons and the corresponding dendritic calcium signal and directly compare these characteristics to SNc neurons. We found that blocking L-type channels reduces tonic firing rate and dendritic calcium levels in SNc neurons. By contrast, the calcium load in PPN neurons during pacemaking did not depend on L-type channels. However, we find that blocking L-type 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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4
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Albeely AM, Williams OOF, Perreault ML. GSK-3β Disrupts Neuronal Oscillatory Function to Inhibit Learning and Memory in Male Rats. Cell Mol Neurobiol 2021; 42:1341-1353. [PMID: 33392916 DOI: 10.1007/s10571-020-01020-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/27/2020] [Indexed: 12/25/2022]
Abstract
Alterations in glycogen synthase kinase-3β (GSK-3β) activity have been implicated in disorders of cognitive impairment, including Alzheimer's disease and schizophrenia. Cognitive dysfunction is also characterized by the dysregulation of neuronal oscillatory activity, macroscopic electrical rhythms in brain that are critical to systems communication. A direct functional relationship between GSK-3β and neuronal oscillations has not been elucidated. Therefore, in the present study, using an adeno-associated viral vector containing a persistently active mutant form of GSK-3β, GSK-3β(S9A), the impact of elevated kinase activity in prefrontal cortex (PFC) or ventral hippocampus (vHIP) of rats on neuronal oscillatory activity was evaluated. GSK-3β(S9A)-induced changes in learning and memory were also assessed and the phosphorylation status of tau protein, a substrate of GSK-3β, examined. It was demonstrated that increasing GSK-3β(S9A) activity in either the PFC or vHIP had similar effects on neuronal oscillatory activity, enhancing theta and/or gamma spectral power in one or both regions. Increasing PFC GSK-3β(S9A) activity additionally suppressed high gamma PFC-vHIP coherence. These changes were accompanied by deficits in recognition memory, spatial learning, and/or reversal learning. Elevated pathogenic tau phosphorylation was also evident in regions where GSK-3β(S9A) activity was upregulated. The neurophysiological and learning and memory deficits induced by GSK-3β(S9A) suggest that aberrant GSK-3β signalling may not only play an early role in cognitive decline in Alzheimer's disease but may also have a more central involvement in disorders of cognitive dysfunction through the regulation of neurophysiological network function.
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Affiliation(s)
- Abdalla M Albeely
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd. E, Guelph, ON, N1G 2W1, Canada.,Collaborative Neuroscience Program, University of Guelph, 50 Stone Rd. E, Guelph, ON, Canada
| | - Olivia O F Williams
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd. E, Guelph, ON, N1G 2W1, Canada
| | - Melissa L Perreault
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd. E, Guelph, ON, N1G 2W1, Canada. .,Collaborative Neuroscience Program, University of Guelph, 50 Stone Rd. E, Guelph, ON, Canada.
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5
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Manduca JD, Thériault RK, Perreault ML. Glycogen synthase kinase-3: The missing link to aberrant circuit function in disorders of cognitive dysfunction? Pharmacol Res 2020; 157:104819. [PMID: 32305493 DOI: 10.1016/j.phrs.2020.104819] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/10/2020] [Accepted: 04/07/2020] [Indexed: 12/15/2022]
Abstract
Elevated GSK-3 activity has been implicated in cognitive dysfunction associated with various disorders including Alzheimer's disease, schizophrenia, type 2 diabetes, traumatic brain injury, major depressive disorder and bipolar disorder. Further, aberrant neural oscillatory activity in, and between, cortical regions and the hippocampus is consistently present within these same cognitive disorders. In this review, we will put forth the idea that increased GSK-3 activity serves as a pathological convergence point across cognitive disorders, inducing similar consequent impacts on downstream signaling mechanisms implicated in the maintenance of processes critical to brain systems communication and normal cognitive functioning. In this regard we suggest that increased activation of GSK-3 and neuronal oscillatory dysfunction are early pathological changes that may be functionally linked. Mechanistic commonalities between these disorders of cognitive dysfunction will be discussed and potential downstream targets of GSK-3 that may contribute to neuronal oscillatory dysfunction identified.
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Affiliation(s)
- Joshua D Manduca
- Department of Molecular and Cellular Biology, University of Guelph, ON, Canada
| | | | - Melissa L Perreault
- Department of Molecular and Cellular Biology, University of Guelph, ON, Canada.
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6
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Chambers NE, Lanza K, Bishop C. Pedunculopontine Nucleus Degeneration Contributes to Both Motor and Non-Motor Symptoms of Parkinson's Disease. Front Pharmacol 2020; 10:1494. [PMID: 32009944 PMCID: PMC6974690 DOI: 10.3389/fphar.2019.01494] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 11/19/2019] [Indexed: 12/31/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder characterized by hypokinetic motor features; however, patients also display non-motor symptoms like sleep disorders. The standard treatment for PD is dopamine replacement with L-DOPA; however, symptoms including gait deficits and sleep disorders are unresponsive to L-DOPA. Notably, these symptoms have been linked to aberrant activity in the pedunculopontine nucleus (PPN). Of late, clinical trials involving PPN deep brain stimulation (DBS) have been employed to alleviate gait deficits. Although preclinical evidence implicating PPN cholinergic neurons in gait dysfunction was initially promising, DBS trials fell short of expected outcomes. One reason for the failure of DBS may be that the PPN is a heterogenous nucleus that consists of GABAergic, cholinergic, and glutamatergic neurons that project to a diverse array of brain structures. Second, DBS trials may have been unsuccessful because PPN neurons are susceptible to mitochondrial dysfunction, Lewy body pathology, and degeneration in PD. Therefore, pharmaceutical or gene-therapy strategies targeting specific PPN neuronal populations or projections could better alleviate intractable PD symptoms. Unfortunately, how PPN neuronal populations and their respective projections influence PD motor and non-motor symptoms remains enigmatic. Herein, we discuss normal cellular and neuroanatomical features of the PPN, the differential susceptibility of PPN neurons to PD-related insults, and we give an overview of literature suggesting a role for PPN neurons in motor and sleep deficits in PD. Finally, we identify future approaches directed towards the PPN for the treatment of PD motor and sleep symptoms.
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Affiliation(s)
| | | | - Christopher Bishop
- Department of Psychology, Binghamton University, Binghamton, NY, United States
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7
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Bisagno V, Bernardi MA, Sanz Blasco S, Urbano FJ, Garcia-Rill E. Differential effects of HDAC inhibitors on PPN oscillatory activity in vivo. Neuropharmacology 2019; 165:107922. [PMID: 31923766 DOI: 10.1016/j.neuropharm.2019.107922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/28/2019] [Accepted: 12/20/2019] [Indexed: 02/07/2023]
Abstract
The pedunculopontine nucleus (PPN) has long been known to be part of the reticular activating system (RAS) in charge of arousal and REM sleep. We previously showed that in vitro exposure to a HDAC Class I and II mixed inhibitor (TSA), or a specific HDAC class IIa inhibitor (MC 1568), decreased PPN gamma oscillations. Given the lack of information on systemic in vivo treatments on neuronal synaptic properties, the present study was designed to investigate the systemic effect of HDAC inhibitors (HDACi) on PPN rhythmicity. Rat pups were injected (acute, single dose) with TSA (4 or 20 mg/kg), MC1568 (4 or 20 mg/kg), or MS275 (20 or 100 mg/kg). Our results show that MC1568 (20 mg/kg) reduced mean frequency of PPN oscillations at gamma band, while increasing mean input resistance (Rm) of PPN neurons. For TSA (4 and 20 mg/kg), we observed reduced mean frequency of oscillations at gamma band and increased mean Rm of PPN neurons. Systemic administration of 20 mg/kg MC1568 and TSA effects on Rm were washed out after 60 min of in vitro incubation of PPN slices, suggesting an underlying functional recovery of PPN calcium-mediated gamma band oscillations over time. In addition, at a lower dose, 4 mg/kg, MC1568 and TSA induced higher mean amplitude gamma oscillations. Blocking HDAC class I might not have deleterious effects on gamma activity, but, more importantly, the inhibition of HDAC class I (at 100 mg/kg) increased gamma band oscillations. In conclusion, the present results in vivo validate our previous findings in vitro and further expand information on the effects of HDAC inhibition on PPN rhythmicity. PPN neurons require normal activity of HDAC class IIa in order to oscillate at gamma band.
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Affiliation(s)
| | | | | | - Francisco J Urbano
- IFIBYNE, DFBMC-CONICET, FCEN, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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8
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Pal B. Response to "Concerns regarding Baksa et al., Cell Molec. Life Sci., 2019." by Edgar Garcia-Rill and Francisco J. Urbano (CMLS-D-18-0156R1). Cell Mol Life Sci 2019; 76:4583-4587. [PMID: 31691836 PMCID: PMC11105466 DOI: 10.1007/s00018-019-03308-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 10/25/2022]
Affiliation(s)
- Balazs Pal
- Department of Physiology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary.
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9
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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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10
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Garcia-Rill E, Urbano FJ. Concerns regarding Baksa B, Kovacs A, Bayasgalan T, Szentesi P, Koseghy A, Szucs P, Balazs P. Characterization of functional subgroups among genetically identified cholinergic neurons in the pedunculopontine nucleus. Cell Molec. Life Sci. 2019-04-02. Cell Mol Life Sci 2019; 76:4581-4582. [PMID: 31570964 PMCID: PMC6858958 DOI: 10.1007/s00018-019-03307-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/19/2019] [Accepted: 09/16/2019] [Indexed: 01/07/2023]
Affiliation(s)
- Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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11
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Urbano FJ, Bisagno V, Garcia-Rill E. Gamma oscillations in the pedunculopontine nucleus are regulated by F-actin: neuroepigenetic implications. Am J Physiol Cell Physiol 2019; 318:C282-C288. [PMID: 31747316 DOI: 10.1152/ajpcell.00374.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pedunculopontine nucleus (PPN) is part of the reticular activating system (RAS) in charge of arousal and rapid eye movement sleep. The presence of high-frequency membrane oscillations in the gamma-band range in the PPN has been extensively demonstrated both in vivo and in vitro. Our group previously described histone deacetylation (HDAC) inhibition in vitro induced protein changes in F-actin cytoskeleton and intracellular Ca2+ concentration regulation proteins in the PPN. Here, we present evidence that supports the presence of a fine balance between HDAC function and calcium calmodulin kinase II-F-actin interactions in the PPN. We modified F-actin polymerization in vitro by using jasplakinolide (1 μM, a promoter of F-actin stabilization), or latrunculin-B (1 μM, an inhibitor of actin polymerization). Our results showed that shifting the balance in either direction significantly reduced PPN gamma oscillation as well as voltage-dependent calcium currents.
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Affiliation(s)
- Francisco J Urbano
- Instituto de Investigaciones Farmacológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Veronica Bisagno
- Instituto de Fisiología, Biología Molecular, y Neurociencias, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arakansas
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12
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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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Vitale F, Capozzo A, Mazzone P, Scarnati E. Neurophysiology of the pedunculopontine tegmental nucleus. Neurobiol Dis 2019. [DOI: 10.1016/j.nbd.2018.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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14
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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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Baksa B, Kovács A, Bayasgalan T, Szentesi P, Kőszeghy Á, Szücs P, Pál B. Characterization of functional subgroups among genetically identified cholinergic neurons in the pedunculopontine nucleus. Cell Mol Life Sci 2019; 76:2799-2815. [PMID: 30734834 PMCID: PMC6588655 DOI: 10.1007/s00018-019-03025-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/21/2018] [Accepted: 01/23/2019] [Indexed: 12/19/2022]
Abstract
The pedunculopontine nucleus (PPN) is a part of the reticular activating system which is composed of cholinergic, glutamatergic and GABAergic neurons. Early electrophysiological studies characterized and grouped PPN neurons based on certain functional properties (i.e., the presence or absence of the A-current, spike latency, and low threshold spikes). Although other electrophysiological characteristics of these neurons were also described (as high threshold membrane potential oscillations, great differences in spontaneous firing rate and the presence or absence of the M-current), systematic assessment of these properties and correlation of them with morphological markers are still missing. In this work, we conducted electrophysiological experiments on brain slices of genetically identified cholinergic neurons in the PPN. Electrophysiological properties were compared with rostrocaudal location of the neuronal soma and selected morphometric features obtained with post hoc reconstruction. We found that functional subgroups had different proportions in the rostral and caudal subregions of the nucleus. Neurons with A-current can be divided to early-firing and late-firing neurons, where the latter type was found exclusively in the caudal subregion. Similar to this, different parameters of high threshold membrane potential oscillations also showed characteristic rostrocaudal distribution. Furthermore, based on our data, we propose that high threshold oscillations rather emerge from neuronal somata and not from the proximal dendrites. In summary, we demonstrated the existence and spatial distribution of functional subgroups of genetically identified PPN cholinergic neurons, which are in accordance with differences found in projection and in vivo functional findings of the subregions. Being aware of functional differences of PPN subregions will help the design and analysis of experiments using genetically encoded opto- and chemogenetic markers for in vivo experiments.
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Affiliation(s)
- B Baksa
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - A Kovács
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - T Bayasgalan
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - P Szentesi
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - Á Kőszeghy
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - P Szücs
- Department of Anatomy, Histology and Embriology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Balázs Pál
- Department of Physiology, University of Debrecen, Faculty of Medicine, Nagyerdei krt 98, Debrecen, 4012, Hungary.
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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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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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Rezaei Haddad A, Lythe V, Green AL. Deep Brain Stimulation for Recovery of Consciousness in Minimally Conscious Patients After Traumatic Brain Injury: A Systematic Review. Neuromodulation 2019; 22:373-379. [DOI: 10.1111/ner.12944] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 01/05/2019] [Accepted: 02/06/2019] [Indexed: 10/27/2022]
Affiliation(s)
- Ali Rezaei Haddad
- Medical Sciences Divisional Office University of Oxford, John Radcliffe Hospital Oxford UK
- Neurosurgical Department Oxford University Hospitals Oxford UK
| | - Vanessa Lythe
- Green Templeton College, University of Oxford Oxford UK
| | - Alexander L. Green
- Neurosurgical Department Oxford University Hospitals Oxford UK
- Nuffield Department of Surgical Sciences University of Oxford Oxford UK
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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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20
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Wen Q, Gao S, Zhen M. Caenorhabditis elegans excitatory ventral cord motor neurons derive rhythm for body undulation. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2017.0370. [PMID: 30201835 DOI: 10.1098/rstb.2017.0370] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2018] [Indexed: 12/25/2022] Open
Abstract
The intrinsic oscillatory activity of central pattern generators underlies motor rhythm. We review and discuss recent findings that address the origin of Caenorhabditis elegans motor rhythm. These studies propose that the A- and mid-body B-class excitatory motor neurons at the ventral cord function as non-bursting intrinsic oscillators to underlie body undulation during reversal and forward movements, respectively. Proprioception entrains their intrinsic activities, allows phase-coupling between members of the same class motor neurons, and thereby facilitates directional propagation of undulations. Distinct pools of premotor interneurons project along the ventral nerve cord to innervate all members of the A- and B-class motor neurons, modulating their oscillations, as well as promoting their bi-directional coupling. The two motor sub-circuits, which consist of oscillators and descending inputs with distinct properties, form the structural base of dynamic rhythmicity and flexible partition of the forward and backward motor states. These results contribute to a continuous effort to establish a mechanistic and dynamic model of the C. elegans sensorimotor system. C. elegans exhibits rich sensorimotor functions despite a small neuron number. These findings implicate a circuit-level functional compression. By integrating the role of rhythm generation and proprioception into motor neurons, and the role of descending regulation of oscillators into premotor interneurons, this numerically simple nervous system can achieve a circuit infrastructure analogous to that of anatomically complex systems. C. elegans has manifested itself as a compact model to search for general principles of sensorimotor behaviours.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- Quan Wen
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, People's Republic of China .,Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
| | - Shangbang Gao
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Mei Zhen
- The Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital; Department of Molecular Genetics, Department of Physiology, University of Toronto, Toronto, Ontario M5G 1XS, Canada
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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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Kang YJ, Lewis HES, Young MW, Govindaiah G, Greenfield LJ, Garcia-Rill E, Lee SH. Cell Type-specific Intrinsic Perithreshold Oscillations in Hippocampal GABAergic Interneurons. Neuroscience 2018; 376:80-93. [PMID: 29462702 PMCID: PMC5978001 DOI: 10.1016/j.neuroscience.2018.02.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 01/01/2023]
Abstract
The hippocampus plays a critical role in learning, memory, and spatial processing through coordinated network activity including theta and gamma oscillations. Recent evidence suggests that hippocampal subregions (e.g., CA1) can generate these oscillations at the network level, at least in part, through GABAergic interneurons. However, it is unclear whether specific GABAergic interneurons generate intrinsic theta and/or gamma oscillations at the single-cell level. Since major types of CA1 interneurons (i.e., parvalbumin-positive basket cells (PVBCs), cannabinoid type 1 receptor-positive basket cells (CB1BCs), Schaffer collateral-associated cells (SCAs), neurogliaform cells and ivy cells) are thought to play key roles in network theta and gamma oscillations in the hippocampus, we tested the hypothesis that these cells generate intrinsic perithreshold oscillations at the single-cell level. We performed whole-cell patch-clamp recordings from GABAergic interneurons in the CA1 region of the mouse hippocampus in the presence of synaptic blockers to identify intrinsic perithreshold membrane potential oscillations. The majority of PVBCs (83%), but not the other interneuron subtypes, produced intrinsic perithreshold gamma oscillations if the membrane potential remained above -45 mV. In contrast, CB1BCs, SCAs, neurogliaform cells, ivy cells, and the remaining PVBCs (17%) produced intrinsic theta, but not gamma, oscillations. These oscillations were prevented by blockers of persistent sodium current. These data demonstrate that the major types of hippocampal interneurons produce distinct frequency bands of intrinsic perithreshold membrane oscillations.
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Affiliation(s)
- Young-Jin Kang
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | | | - Mason William Young
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Gubbi Govindaiah
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Lazar John Greenfield
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Department of Neurology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Sang-Hun Lee
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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23
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Gao S, Guan SA, Fouad AD, Meng J, Kawano T, Huang YC, Li Y, Alcaire S, Hung W, Lu Y, Qi YB, Jin Y, Alkema M, Fang-Yen C, Zhen M. Excitatory motor neurons are local oscillators for backward locomotion. eLife 2018; 7:e29915. [PMID: 29360035 PMCID: PMC5780044 DOI: 10.7554/elife.29915] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/22/2017] [Indexed: 01/16/2023] Open
Abstract
Cell- or network-driven oscillators underlie motor rhythmicity. The identity of C. elegans oscillators remains unknown. Through cell ablation, electrophysiology, and calcium imaging, we show: (1) forward and backward locomotion is driven by different oscillators; (2) the cholinergic and excitatory A-class motor neurons exhibit intrinsic and oscillatory activity that is sufficient to drive backward locomotion in the absence of premotor interneurons; (3) the UNC-2 P/Q/N high-voltage-activated calcium current underlies A motor neuron's oscillation; (4) descending premotor interneurons AVA, via an evolutionarily conserved, mixed gap junction and chemical synapse configuration, exert state-dependent inhibition and potentiation of A motor neuron's intrinsic activity to regulate backward locomotion. Thus, motor neurons themselves derive rhythms, which are dually regulated by the descending interneurons to control the reversal motor state. These and previous findings exemplify compression: essential circuit properties are conserved but executed by fewer numbers and layers of neurons in a small locomotor network.
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Affiliation(s)
- Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of EducationCollege of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Sihui Asuka Guan
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Anthony D Fouad
- Department of BioengineeringSchool of Engineering and Applied Science, University of PennsylvaniaPhiladelphiaUnited States
| | - Jun Meng
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Taizo Kawano
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Yung-Chi Huang
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Yi Li
- Key Laboratory of Molecular Biophysics of the Ministry of EducationCollege of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Salvador Alcaire
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Yangning Lu
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Yingchuan Billy Qi
- Neurobiology Section, Division of Biological SciencesUniversity of CaliforniaSan DiegoUnited States
| | - Yishi Jin
- Neurobiology Section, Division of Biological SciencesUniversity of CaliforniaSan DiegoUnited States
| | - Mark Alkema
- Department of NeurobiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Christopher Fang-Yen
- Department of BioengineeringSchool of Engineering and Applied Science, University of PennsylvaniaPhiladelphiaUnited States
- Department of NeuroscienceUniversity of PennsylvaniaPhiladelphiaUnited States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
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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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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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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, Hyde J, Garcia-Rill E. Interaction between neuronal calcium sensor protein 1 and lithium in pedunculopontine neurons. Physiol Rep 2017; 5:e13246. [PMID: 28408639 PMCID: PMC5392530 DOI: 10.14814/phy2.13246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 11/24/2022] Open
Abstract
Bipolar disorder is characterized by sleep dysregulation, suggesting a role for the reticular activating system (RAS). Postmortem studies showed increased expression of neuronal calcium sensor protein 1 (NCS-1) in the brains of some bipolar disorder patients, and reduced or aberrant gamma band activity is present in the same disorder. Lithium (Li+) has been shown to effectively treat the mood disturbances in bipolar disorder patients. We previously showed that NCS-1 at low levels increased, and at high levels decreased, gamma oscillations in RAS pedunculopontine neurons (PPN), and that Li+ decreased these oscillations. We previously described the effects of each agent on oscillations, G-protein mechanisms, and Ca2+ currents. However, we designed the present experiments to determine the nature of the interaction of NCS-1 and Li+ at physiological concentrations that would have an effect within minutes of application. As expected, Li+ decreased gamma oscillation amplitude, while NCS-1 increased the amplitude of gamma oscillations. We identified NCS-1 at 2 μmol/L as a concentration that increased gamma oscillations within 5-10 min, and Li+ at 10 μmol/L as a concentration that decreased gamma oscillations within 5 min. The combined application of NCS-1 and Li+ at these concentrations showed that Li+ reduced the effects of NCS-1 on oscillation amplitude within 5-10 min. These results demonstrate that at physiological levels, Li+ acts to reduce the effects of NCS-1 so that, given over expression of NCS-1, Li+ would have salutary effects.
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Affiliation(s)
- Stasia D'Onofrio
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - James Hyde
- Department of Psychiatry and Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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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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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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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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Baker JL, Ryou JW, Wei XF, Butson CR, Schiff ND, Purpura KP. Robust modulation of arousal regulation, performance, and frontostriatal activity through central thalamic deep brain stimulation in healthy nonhuman primates. J Neurophysiol 2016; 116:2383-2404. [PMID: 27582298 DOI: 10.1152/jn.01129.2015] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 08/08/2016] [Indexed: 11/22/2022] Open
Abstract
The central thalamus (CT) is a key component of the brain-wide network underlying arousal regulation and sensory-motor integration during wakefulness in the mammalian brain. Dysfunction of the CT, typically a result of severe brain injury (SBI), leads to long-lasting impairments in arousal regulation and subsequent deficits in cognition. Central thalamic deep brain stimulation (CT-DBS) is proposed as a therapy to reestablish and maintain arousal regulation to improve cognition in select SBI patients. However, a mechanistic understanding of CT-DBS and an optimal method of implementing this promising therapy are unknown. Here we demonstrate in two healthy nonhuman primates (NHPs), Macaca mulatta, that location-specific CT-DBS improves performance in visuomotor tasks and is associated with physiological effects consistent with enhancement of endogenous arousal. Specifically, CT-DBS within the lateral wing of the central lateral nucleus and the surrounding medial dorsal thalamic tegmental tract (DTTm) produces a rapid and robust modulation of performance and arousal, as measured by neuronal activity in the frontal cortex and striatum. Notably, the most robust and reliable behavioral and physiological responses resulted when we implemented a novel method of CT-DBS that orients and shapes the electric field within the DTTm using spatially separated DBS leads. Collectively, our results demonstrate that selective activation within the DTTm of the CT robustly regulates endogenous arousal and enhances cognitive performance in the intact NHP; these findings provide insights into the mechanism of CT-DBS and further support the development of CT-DBS as a therapy for reestablishing arousal regulation to support cognition in SBI patients.
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Affiliation(s)
- Jonathan L Baker
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York;
| | - Jae-Wook Ryou
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
| | - Xuefeng F Wei
- College of New Jersey, Department of Biomedical Engineering, Ewing Township, New Jersey; and
| | - Christopher R Butson
- University of Utah, Scientific Computing & Imaging (SCI) Institute, Department of Bioengineering, Salt Lake City, Utah
| | - Nicholas D Schiff
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
| | - Keith P Purpura
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
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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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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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Sitti I, Acar G, Zisakis AK, Özdemir M, Acar F, Burchiel KJ. Effect of Subthalamic Nucleus Stimulation on Pedunculopontine Nucleus Neural Activity. Stereotact Funct Neurosurg 2016; 94:54-9. [PMID: 26977617 DOI: 10.1159/000442892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 11/30/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND The pedunculopontine nucleus has recently been proposed as an alternative target for deep brain stimulation for the treatment of medically intractable Parkinson's disease. The suggested indication for pedunculopontine nucleus deep brain stimulation is severe and medically intractable axial symptoms such as gait and postural impairment. OBJECTIVE Our goal in this study was to describe the effects of subthalamic nucleus stimulation on pedunculopontine nucleus electrophysiological activity. METHODS Fourteen male Wistar rats were divided into a sham stimulation group and an experimental group. In both groups, electrodes were implanted bilaterally into the subthalamic nucleus and into the right pedunculopontine nucleus. Microelectrode recordings were carried out in both groups prior to and during subthalamic nucleus stimulation. RESULTS Subthalamic nucleus stimulation produced no clear inhibition of neuronal firing in the pedunculopontine nucleus. However, we found that stimulation of the subthalamic nucleus at 60 Hz produces some entrainment of pedunculopontine nucleus neuronal firing and a shift of subthalamic nucleus firing patterns to more tonic and random patterns. These results are consistent with the effects of deep brain stimulation on neuronal activity in the subthalamic nucleus and globus pallidus internus. CONCLUSION The result of this study provides additional evidence to improve our understanding of the mechanism of subthalamic nucleus-deep brain stimulation, and its physiological consequences.
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Affiliation(s)
- Ilkay Sitti
- Department of Neurosurgery, Faculty of Medicine, Pamukkale University, Denizli, Turkey
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D'Onofrio S, Urbano FJ, Messias E, Garcia-Rill E. Lithium decreases the effects of neuronal calcium sensor protein 1 in pedunculopontine neurons. Physiol Rep 2016; 4:e12740. [PMID: 27033453 PMCID: PMC4814880 DOI: 10.14814/phy2.12740] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/20/2016] [Accepted: 02/24/2016] [Indexed: 12/21/2022] Open
Abstract
Human postmortem studies reported increased expression of neuronal calcium sensor protein 1 (NCS-1) in the brains of some bipolar disorder patients, and reduced or aberrant gamma band activity is present in the same disorder. Bipolar disorder is characterized by sleep dysregulation, suggesting a role for the reticular activating system (RAS). Lithium (Li(+)) has been shown to effectively treat the mood disturbances in bipolar disorder patients and was proposed to act by inhibiting the interaction betweenNCS-1 and inositol 1,4,5-triphosphate receptor protein (InsP3R).NCS-1 is known to enhance the activity of InsP3R, and of Ca(2+)-mediated gamma oscillatory activity in the pedunculopontine nucleus (PPN), part of theRAS This study aimed to determine the nature of some of the intracellular mechanisms of Li(+)on ratPPNcells and to identify the interaction between Li(+)andNCS-1. Since Li(+)has been shown to act by inhibiting the enhancing effects ofNCS-1, we tested the hypothesis that Li(+)would reduced the effects of overexpression ofNCS-1 and prevent the downregulation of gamma band activity. Li(+)decreased gamma oscillation frequency and amplitude by downregulating Ca(2+)channel activity, whereasNCS-1 reduced the effect of Li(+)on Ca(2+)currents. These effects were mediated by a G-protein overinhibition of Ca(2+)currents. These results suggest that Li(+)affected intracellular pathways involving the activation of voltage-gated Ca(2+)channels mediated by an intracellular mechanism involving voltage-dependent activation of G proteins, thereby normalizing gamma band oscillations mediated by P/Q-type calcium channels modulated byNCS-1.
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Affiliation(s)
- Stasia D'Onofrio
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Francisco J Urbano
- IFIBYNE-CONICET-UBA, University of Buenos Aires, Buenos Aires, Argentina
| | - Erick Messias
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas Department of Psychiatry, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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Garcia-Rill E, Virmani T, Hyde J, D’Onofrio S, Mahaffey S. Arousal and the control of perception and movement. CURRENT TRENDS IN NEUROLOGY 2016; 10:53-64. [PMID: 28690375 PMCID: PMC5501251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recent discoveries on the nature of the activity generated by the reticular activating system (RAS) suggest that arousal is much more involved in perception and movement than previously thought. The RAS is not simply an amorphous, unspecific region but rather a distinct group of nuclei with specific cell and transmitter types that control waking and modulate such processes as perception and movement. Thus, disturbances in the RAS will affect a number of neurological disorders. The discovery of gamma band activity in the RAS determined that high threshold calcium channels are responsible for generating gamma band activity in the RAS. Results showing that waking is mediated by CaMKII modulation of P/Q-type channels and REM sleep is modulated by cAMP/PK modulation of N-type channels points to different intracellular pathways influencing each state. Few studies address these important breakthroughs. Novel findings also show that the same primate RAS neurons exhibiting activity in relation to arousal are also involved in locomotion. Moreover, deep brain stimulation of this region, specifically the pedunculopontine nucleus (PPN DBS), in Parkinson's disease has salutary effects on movement, sleep, and cognition. Gamma oscillations appear to participate in sensory perception, problem solving, and memory, and coherence at these frequencies may occur at cortical or thalamocortical levels. However, rather than participating in the temporal binding of sensory events, gamma band activity generated in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking, and relay such activation to the cortex. Continuous sensory input will thus induce gamma band activity in the RAS to participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our perceptions and actions. Such a role has received little attention but promises to help understand and treat a number of neurological disorders.
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Affiliation(s)
- E. Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - T. Virmani
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR
| | - J.R. Hyde
- Department of Psychiatry and Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA
| | - S. D’Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
| | - S. Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR
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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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Garcia-Rill E, Luster B, D’Onofrio S, Mahaffey S, Bisagno V, Urbano FJ. Pedunculopontine arousal system physiology - Deep brain stimulation (DBS). Sleep Sci 2015; 8:153-61. [PMID: 26779322 PMCID: PMC4688589 DOI: 10.1016/j.slsci.2015.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/03/2015] [Accepted: 09/05/2015] [Indexed: 12/19/2022] Open
Abstract
This review describes the wake/sleep symptoms present in Parkinson׳s disease, and the role of the pedunculopontine nucleus in these symptoms. The physiology of PPN cells is important not only because it is a major element of the reticular activating system, but also because it is a novel target for deep brain stimulation in the treatment of gait and postural deficits in Parkinson׳s disease. A greater understanding of the physiology of the target nuclei within the brainstem and basal ganglia, amassed over the past decades, has enabled increasingly better patient outcomes from deep brain stimulation for movement disorders.
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Key Words
- Basal forebrain
- Calcium channels
- DBS, deep brain stimulation
- EEG, electroencephalogram
- Gamma band activity
- LC, locus coeruleus
- Lateral hypothalamus
- Orexin
- PD, Parkinson׳s disease
- PGO, ponto-geniculo-occipital
- PPN, pedunculopontine nucleus
- RAS, reticular activating system
- REM, rapid eye movement
- SN, substantia nigra
- STN, subthalamic nucleus
- SubCD, subcoeruleus nucleus dorsalis
- Tuberomammillary
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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
| | - Stasia D’Onofrio
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Susan Mahaffey
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Veronica Bisagno
- IFIBYNE-CONICET and ININFA-CONICET, University of Buenos Aires, Argentina
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Urbano FJ, Bisagno V, González B, Celeste Rivero-Echeto M, Muñiz JA, Luster B, D'Onofrio S, Mahaffey S, Garcia-Rill E. Pedunculopontine arousal system physiology-Effects of psychostimulant abuse. ACTA ACUST UNITED AC 2015; 8:162-8. [PMID: 26779323 PMCID: PMC4688579 DOI: 10.1016/j.slsci.2015.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 09/21/2015] [Accepted: 09/25/2015] [Indexed: 01/26/2023]
Abstract
This review describes the interactions between the pedunculopontine nucleus (PPN), the ventral tegmental area (VTA), and the thalamocortical system. Experiments using modulators of cholinergic receptors in the PPN clarified its role on psychostimulant-induced locomotion. PPN activation was found to be involved in the animal’s voluntary search for psychostimulants. Every PPN neuron is known to generate gamma band oscillations. Voltage-gated calcium channels are key elements in the generation and maintenance of gamma band activity of PPN neurons. Calcium channels are also key elements mediating psychostimulant-induced alterations in the thalamic targets of PPN output. Thus, the PPN is a key substrate for maintaining arousal and REM sleep, but also in modulating psychostimulant self-administration.
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Affiliation(s)
- Francisco J Urbano
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Verónica Bisagno
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Argentina
| | - Betina González
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Argentina
| | | | - Javier A Muñiz
- IFIBYNE-CONICET, ININFA-CONICET, University of Buenos Aires, Argentina
| | - Brennon Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Stasia D'Onofrio
- 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
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Garcia-Rill E, Luster B, D’Onofrio S, Mahaffey S. Arousal, motor control, and parkinson's disease. Transl Neurosci 2015; 6:198-207. [PMID: 27747095 PMCID: PMC4936629 DOI: 10.1515/tnsci-2015-0021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/30/2015] [Indexed: 11/22/2022] Open
Abstract
This review highlights the most important discovery in the reticular activating system (RAS) in the last 10 years, the manifestation of gamma (γ) band activity in cells of the RAS, especially in the pedunculopontine nucleus (PPN), which is in charge of the high frequency states of waking and rapid eye movement sleep. This discovery is critical to understanding the modulation of movement by the RAS and how it sets the background over which we generate voluntary and triggered movements. The presence of γ band activity in the RAS is proposed to participate in the process of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. Early findings using stimulation of this region to induce arousal, and also to elicit stepping, are placed in this context. This finding also helps explain the novel use of PPN deep brain stimulation for the treatment of Parkinson's disease, although considerable work remains to be done.
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Affiliation(s)
- E. Garcia-Rill
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - B. Luster
- Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - S. D’Onofrio
- 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
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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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Ishibashi M, Gumenchuk I, Kang B, Steger C, Lynn E, Molina NE, Eisenberg LM, Leonard CS. Orexin Receptor Activation Generates Gamma Band Input to Cholinergic and Serotonergic Arousal System Neurons and Drives an Intrinsic Ca(2+)-Dependent Resonance in LDT and PPT Cholinergic Neurons. Front Neurol 2015; 6:120. [PMID: 26082752 PMCID: PMC4451588 DOI: 10.3389/fneur.2015.00120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/11/2015] [Indexed: 01/29/2023] Open
Abstract
A hallmark of the waking state is a shift in EEG power to higher frequencies with epochs of synchronized intracortical gamma activity (30-60 Hz) - a process associated with high-level cognitive functions. The ascending arousal system, including cholinergic laterodorsal (LDT) and pedunculopontine (PPT) tegmental neurons and serotonergic dorsal raphe (DR) neurons, promotes this state. Recently, this system has been proposed as a gamma wave generator, in part, because some neurons produce high-threshold, Ca(2+)-dependent oscillations at gamma frequencies. However, it is not known whether arousal-related inputs to these neurons generate such oscillations, or whether such oscillations are ever transmitted to neuronal targets. Since key arousal input arises from hypothalamic orexin (hypocretin) neurons, we investigated whether the unusually noisy, depolarizing orexin current could provide significant gamma input to cholinergic and serotonergic neurons, and whether such input could drive Ca(2+)-dependent oscillations. Whole-cell recordings in brain slices were obtained from mice expressing Cre-induced fluorescence in cholinergic LDT and PPT, and serotonergic DR neurons. After first quantifying reporter expression accuracy in cholinergic and serotonergic neurons, we found that the orexin current produced significant high frequency, including gamma, input to both cholinergic and serotonergic neurons. Then, by using a dynamic clamp, we found that adding a noisy orexin conductance to cholinergic neurons induced a Ca(2+)-dependent resonance that peaked in the theta and alpha frequency range (4-14 Hz) and extended up to 100 Hz. We propose that this orexin current noise and the Ca(2+) dependent resonance work synergistically to boost the encoding of high-frequency synaptic inputs into action potentials and to help ensure cholinergic neurons fire during EEG activation. This activity could reinforce thalamocortical states supporting arousal, REM sleep, and intracortical gamma.
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Affiliation(s)
- Masaru Ishibashi
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Iryna Gumenchuk
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Bryan Kang
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Catherine Steger
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Elizabeth Lynn
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Nancy E Molina
- Department of Physiology, New York Medical College , Valhalla, NY , USA
| | - Leonard M Eisenberg
- Department of Physiology, New York Medical College , Valhalla, NY , USA ; Department of Medicine, New York Medical College , Valhalla, NY , USA
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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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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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Garcia-Rill E, Hyde J, Kezunovic N, Urbano FJ, Petersen E. The physiology of the pedunculopontine nucleus: implications for deep brain stimulation. J Neural Transm (Vienna) 2015; 122:225-35. [PMID: 24880787 PMCID: PMC4484763 DOI: 10.1007/s00702-014-1243-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/09/2014] [Indexed: 01/07/2023]
Abstract
This brief review resolves a number of persistent conflicts regarding the location and characteristics of the mesencephalic locomotor region, which has in the past been described as not locomotion-specific and is more likely the pedunculopontine nucleus (PPN). The parameters of stimulation used to elicit changes in posture and locomotion we now know are ideally suited to match the intrinsic membrane properties of PPN neurons. The physiology of these cells is important not only because it is a major element of the reticular activating system, but also because it is a novel target for the treatment of gait and postural deficits in Parkinson's disease (PD). The discussion explains many of the effects reported following deep brain stimulation (DBS) of the PPN by different groups and provides guidelines for the determination of long-term assessment and effects of PPN DBS. A greater understanding of the physiology of the target nuclei within the brainstem and basal ganglia, amassed over the past decades, has enabled increasingly better patient outcomes from DBS for movement disorders. Despite these improvements, there remains a great opportunity for further understanding of the mechanisms through which DBS has its effects and for further development of appropriate technology to effect these treatments. We review the scientific basis for one of the newest targets, the PPN, in the treatment of PD and other movement disorders, and address the needs for further investigation.
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Affiliation(s)
- E Garcia-Rill
- Department of Neurobiology and Developmental Sciences, Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Slot 847, 4301 West Markham St, Little Rock, AR, 72205, USA,
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50
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Altered activity in the central medial thalamus precedes changes in the neocortex during transitions into both sleep and propofol anesthesia. J Neurosci 2015; 34:13326-35. [PMID: 25274812 DOI: 10.1523/jneurosci.1519-14.2014] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
How general anesthetics cause loss of consciousness is unknown. Some evidence points toward effects on the neocortex causing "top-down" inhibition, whereas other findings suggest that these drugs act via subcortical mechanisms, possibly selectively stimulating networks promoting natural sleep. To determine whether some neuronal circuits are affected before others, we used Morlet wavelet analysis to obtain high temporal resolution in the time-varying power spectra of local field potentials recorded simultaneously in discrete brain regions at natural sleep onset and during anesthetic-induced loss of righting reflex in rats. Although we observed changes in the local field potentials that were anesthetic-specific, there were some common changes in high-frequency (20-40 Hz) oscillations (reductions in frequency and increases in power) that could be detected at, or before, sleep onset and anesthetic-induced loss of righting reflex. For propofol and natural sleep, these changes occur first in the thalamus before changes could be detected in the neocortex. With dexmedetomidine, the changes occurred simultaneously in the thalamus and neocortex. In addition, the phase relationships between the low-frequency (1-4 Hz) oscillations in thalamic nuclei and neocortical areas are essentially the same for natural sleep and following dexmedetomidine administration, but a sudden change in phase, attributable to an effect in the central medial thalamus, occurs at the point of dexmedetomidine loss of righting reflex. Our data are consistent with the central medial thalamus acting as a key hub through which general anesthesia and natural sleep are initiated.
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