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Nakakubo S, Hiramatsu Y, Goto T, Kimura S, Narugami M, Nakajima M, Ueda Y, Shiraishi H, Manabe A, Sharmin D, Cook JM, Egawa K. Therapeutic effects of KRM-II-81, positive allosteric modulator for α2/3 subunit containing GABA A receptors, in a mouse model of Dravet syndrome. Front Pharmacol 2023; 14:1273633. [PMID: 37849734 PMCID: PMC10577232 DOI: 10.3389/fphar.2023.1273633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction: Dravet syndrome (DS) is an intractable epilepsy syndrome concomitant with neurodevelopmental disorder that begins in infancy. DS is dominantly caused by mutations in the SCN1A gene, which encodes the α subunit of a voltage-gated Na channel. Pre-synaptic inhibitory dysfunction is regarded as the pathophysiological mechanism, but an effective strategy for ameliorating seizures and behavioral problems is still under development. Here, we evaluated the effects of KRM-II-81, a newly developed positive allosteric modulator for α 2/3 subunit containing GABAA receptors (α2/3-GABAAR) in a mice model of DS both in vivo and at the neuronal level. Methods: We used knock-in mice carrying a heterozygous, clinically relevant SCN1A mutation (background strain: C57BL/6 J) as a model of the DS (Scn1a WT/A1783V mice), knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V). Seizure threshold and locomotor activity was evaluated by using the hyperthermia-induced seizure paradigm and open filed test, respectively. Anxiety-like behavior was assessed by avoidance of the center region in locomotor activity. We estimated a sedative effect by the total distance traveled in locomotor activity and grip strength. Inhibitory post synaptic currents (IPSCs) were recorded from a hippocampal CA1 pyramidal neuron in an acutely prepared brain slice. Results: KRM-II-81 significantly increased the seizure threshold of Scn1a WT/A1783V mice in a dose-dependent manner. A low dose of KRM-II-81 specifically improved anxiety-like behavior of Scn1a WT/A1783V mice. A sedative effect was induced by relatively high dose of KRM-II-81 in Scn1a WT/A1783V mice, the dose of which was not sedative for WT mice. KRM-II-81 potentiated IPSCs by increasing its decay time kinetics. This effect was more prominent in Scn1a WT/A1783V mice. Discussion: Higher activation of α2/3-GABAAR by KRM-II-81 suggests a compensatory modification of post synaptic inhibitory function against presynaptic inhibitory dysfunction in Scn1a WT/A1783V. The increased sensitivity for KRM-II-81 may be relevant to the distinct dose-dependent effect in each paradigm of Scn1a WT/A1783V mice. Conclusion: Selective activation for α2/3-GABAAR by KRM-II-81 could be potential therapeutic strategy for treating seizures and behavioral problems in DS.
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Affiliation(s)
- Sachiko Nakakubo
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yasuyoshi Hiramatsu
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Takeru Goto
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Syuhei Kimura
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Masashi Narugami
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Midori Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yuki Ueda
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Atsushi Manabe
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Dishary Sharmin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
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Wibawa P, Walterfang M, Malpas CB, Glikmann‐Johnston Y, Poudel G, Razi A, Hannan AJ, Velakoulis D, Georgiou‐Karistianis N. Selective perforant-pathway atrophy in Huntington disease: MRI analysis of hippocampal subfields. Eur J Neurol 2023; 30:2650-2660. [PMID: 37306313 PMCID: PMC10946817 DOI: 10.1111/ene.15918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 04/17/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
INTRODUCTION While individuals with Huntington disease (HD) show memory impairment that indicates hippocampal dysfunction, the available literature does not consistently identify structural evidence for involvement of the whole hippocampus but rather suggests that hippocampal atrophy may be confined to certain hippocampal subregions. METHODS We processed T1-weighted MRI from IMAGE-HD study using FreeSurfer 7.0 and compared the volumes of the hippocampal subfields among 36 early motor symptomatic (symp-HD), 40 pre-symptomatic (pre-HD), and 36 healthy control individuals across three timepoints over 36 months. RESULTS Mixed-model analyses revealed significantly lower subfield volumes in symp-HD, compared with pre-HD and control groups, in the subicular regions of the perforant-pathway: presubiculum, subiculum, dentate gyrus, tail, and right molecular layer. These adjoining subfields aggregated into a single principal component, which demonstrated an accelerated rate of atrophy in the symp-HD. Volumes between pre-HD and controls did not show any significant difference. In the combined HD groups, CAG repeat length and disease burden score were associated with presubiculum, molecular layer, tail, and perforant-pathway subfield volumes. Hippocampal left tail and perforant-pathway subfields were associated with motor onset in the pre-HD group. CONCLUSIONS Hippocampal subfields atrophy in early symptomatic HD affects key regions of the perforant-pathway, which may implicate the distinctive memory impairment at this stage of illness. Their volumetric associations with genetic and clinical markers suggest the selective susceptibility of these subfields to mutant Huntingtin and disease progression.
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Affiliation(s)
- Pierre Wibawa
- NeuropsychiatryRoyal Melbourne HospitalParkvilleVictoriaAustralia
- Melbourne Neuropsychiatry CenterUniversity of MelbourneParkvilleVictoriaAustralia
- School of Psychological Sciences and Turner Institute for Brain and Mental HealthMonash UniversityClaytonVictoriaAustralia
| | - Mark Walterfang
- NeuropsychiatryRoyal Melbourne HospitalParkvilleVictoriaAustralia
- Melbourne Neuropsychiatry CenterUniversity of MelbourneParkvilleVictoriaAustralia
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Charles B. Malpas
- NeuropsychiatryRoyal Melbourne HospitalParkvilleVictoriaAustralia
- Melbourne Neuropsychiatry CenterUniversity of MelbourneParkvilleVictoriaAustralia
| | - Yifat Glikmann‐Johnston
- School of Psychological Sciences and Turner Institute for Brain and Mental HealthMonash UniversityClaytonVictoriaAustralia
| | - Govinda Poudel
- Mary Mackillop Institute for Health ResearchAustralian Catholic UniversityFitzroyVictoriaAustralia
| | - Adeel Razi
- School of Psychological Sciences and Turner Institute for Brain and Mental HealthMonash UniversityClaytonVictoriaAustralia
| | - Anthony J. Hannan
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Dennis Velakoulis
- NeuropsychiatryRoyal Melbourne HospitalParkvilleVictoriaAustralia
- Melbourne Neuropsychiatry CenterUniversity of MelbourneParkvilleVictoriaAustralia
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Nellie Georgiou‐Karistianis
- School of Psychological Sciences and Turner Institute for Brain and Mental HealthMonash UniversityClaytonVictoriaAustralia
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Courtney CD, Pamukcu A, Chan CS. Cell and circuit complexity of the external globus pallidus. Nat Neurosci 2023; 26:1147-1159. [PMID: 37336974 DOI: 10.1038/s41593-023-01368-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/18/2023] [Indexed: 06/21/2023]
Abstract
The external globus pallidus (GPe) of the basal ganglia has been underappreciated owing to poor understanding of its cells and circuits. It was assumed that the GPe consisted of a homogeneous neuron population primarily serving as a 'relay station' for information flowing through the indirect basal ganglia pathway. However, the advent of advanced tools in rodent models has sparked a resurgence in interest in the GPe. Here, we review recent data that have unveiled the cell and circuit complexity of the GPe. These discoveries have revealed that the GPe does not conform to traditional views of the basal ganglia. In particular, recent evidence confirms that the afferent and efferent connections of the GPe span both the direct and the indirect pathways. Furthermore, the GPe displays broad interconnectivity beyond the basal ganglia, consistent with its emerging multifaceted roles in both motor and non-motor functions. In summary, recent data prompt new proposals for computational rules of the basal ganglia.
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Affiliation(s)
- Connor D Courtney
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Arin Pamukcu
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - C Savio Chan
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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Emerging Role of Neuron-Glia in Neurological Disorders: At a Glance. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3201644. [PMID: 36046684 PMCID: PMC9423989 DOI: 10.1155/2022/3201644] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/05/2022] [Indexed: 11/18/2022]
Abstract
Based on the diverse physiological influence, the impact of glial cells has become much more evident on neurological illnesses, resulting in the origins of many diseases appearing to be more convoluted than previously happened. Since neurological disorders are often random and unknown, hence the construction of animal models is difficult to build, representing a small fraction of people with a gene mutation. As a result, an immediate necessity is grown to work within in vitro techniques for examining these illnesses. As the scientific community recognizes cell-autonomous contributions to a variety of central nervous system illnesses, therapeutic techniques involving stem cells for treating neurological diseases are gaining traction. The use of stem cells derived from a variety of sources is increasingly being used to replace both neuronal and glial tissue. The brain's energy demands necessitate the reliance of neurons on glial cells in order for it to function properly. Furthermore, glial cells have diverse functions in terms of regulating their own metabolic activities, as well as collaborating with neurons via secreted signaling or guidance molecules, forming a complex network of neuron-glial connections in health and sickness. Emerging data reveals that metabolic changes in glial cells can cause morphological and functional changes in conjunction with neuronal dysfunction under disease situations, highlighting the importance of neuron-glia interactions in the pathophysiology of neurological illnesses. In this context, it is required to improve our understanding of disease mechanisms and create potential novel therapeutics. According to research, synaptic malfunction is one of the features of various mental diseases, and glial cells are acting as key ingredients not only in synapse formation, growth, and plasticity but also in neuroinflammation and synaptic homeostasis which creates critical physiological capacity in the focused sensory system. The goal of this review article is to elaborate state-of-the-art information on a few glial cell types situated in the central nervous system (CNS) and highlight their role in the onset and progression of neurological disorders.
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Diamond JM, Lopes MB, Elias WJ, Jansen LA. Gamma-Aminobutyric Acid A Receptor Subunit Expression and Cellular Localization in the Human Parkinsonian Globus Pallidus. World Neurosurg 2022; 165:e159-e168. [PMID: 35659589 DOI: 10.1016/j.wneu.2022.05.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND The gamma-aminobutyric acid A (GABAA) receptor is an important mediator of cellular signaling in the globus pallidus and might be implicated in the pathophysiology of Parkinson disease (PD). The goal of the present study was to characterize GABAA receptor subunit expression in the normal and parkinsonian human globus pallidus. METHODS Postmortem brain specimens were obtained from 8 patients with pathological evidence of PD at autopsy and from 4 control patients without such evidence. These tissues were exposed to primary antibodies directed against the α1 and α3 subunits of the GABAA receptor and were visualized and quantified using fluorescence microscopy. RESULTS No differences were found in the pallidal neuronal density in the control versus PD tissues. Projection neurons strongly expressed the α1, α3, and β2 GABAA receptor subunits. After normalizing the immunofluorescence intensities in the globus pallidus to those in the adjacent structures, no significant differences were found in GABAA receptor subunit expression in the globus pallidus between the PD specimens and the control specimens. CONCLUSIONS Compensatory changes in GABAA receptor α1 and α3 subunit expression in response to PD-related signaling abnormalities in the globus pallidus did not occur in our PD cohort.
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Affiliation(s)
- Joshua M Diamond
- Department of Neurological Surgery, University of Virginia Medical Center, Charlottesville, Virginia, USA
| | - M Beatriz Lopes
- Department of Pathology, University of Virginia Medical Center, Charlottesville, Virginia, USA
| | - W Jeff Elias
- Department of Neurological Surgery, University of Virginia Medical Center, Charlottesville, Virginia, USA.
| | - Laura A Jansen
- Department of Neurology, University of Virginia Medical Center, Charlottesville, Virginia, USA
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Ríos JL, Schinella GR, Moragrega I. Phenolics as GABA A Receptor Ligands: An Updated Review. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27061770. [PMID: 35335130 PMCID: PMC8953830 DOI: 10.3390/molecules27061770] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 11/16/2022]
Abstract
Natural products can act as potential GABA modulators, avoiding the undesirable effects of traditional pharmacology used for the inhibition of the central nervous system such as benzodiazepines (BZD). Phenolics, especially flavonoids and phlorotannins, have been considered as modulators of the BZD-site of GABAA receptors (GABAARs), with sedative, anxiolytic or anticonvulsant effects. However, the wide chemical structural variability of flavonoids shows their potential action at more than one additional binding site on GABAARs, which may act either negatively, positively, by neutralizing GABAARs, or directly as allosteric agonists. Therefore, the aim of the present review is to compile and discuss an update of the role of phenolics, namely as pharmacological targets involving dysfunctions of the GABA system, analyzing both their different compounds and their mechanism as GABAergic modulators. We focus this review on articles written in English since the year 2010 until the present. Of course, although more research would be necessary to fully establish the type specificity of phenolics and their pharmacological activity, the evidence supports their potential as GABAAR modulators, thereby favoring their inclusion in the development of new therapeutic targets based on natural products. Specifically, the data compiled in this review allows for the directing of future research towards ortho-dihydroxy diterpene galdosol, the flavonoids isoliquiritigenin (chalcone), rhusflavone and agathisflavone (biflavonoids), as well as the phlorotannins, dieckol and triphlorethol A. Clinically, flavonoids are the most interesting phenolics due to their potential as anticonvulsant and anxiolytic drugs, and phlorotannins are also of interest as sedative agents.
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Affiliation(s)
- José-Luis Ríos
- Departament de Farmacologia, Facultat de Farmàcia, Universitat de València, Av. Vicent Andrés Estellés s/n, Burjassot, 46100 Valencia, Spain
- Correspondence:
| | - Guillermo R. Schinella
- Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata BA1900, Argentina;
- Instituto de Ciencias de la Salud, UNAJ-CICPBA, Florencio Varela BA1888, Argentina
| | - Inés Moragrega
- Departament de Psicobiologia, Facultat de Psicologia, Universitat de València, Av. Blasco Ibáñez 21, 46010 Valencia, Spain;
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Bey K, Lippold JV, Aslan B, Hurlemann R, Ettinger U. Effects of lorazepam on prosaccades and saccadic adaptation. J Psychopharmacol 2021; 35:91-99. [PMID: 33274663 DOI: 10.1177/0269881120972424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Benzodiazepines have reliable adverse effects on saccadic eye movements, but the impact of sex as a potential modulator of these effects is less clear. A recent study reported stronger adverse effects on the spatial consistency of saccades in females, which may reflect sex differences in cerebellar mechanisms. AIMS We aimed to further examine the role of sex as a potential modulator of benzodiazepine effects by employing the saccadic adaptation paradigm, which is known to be sensitive to cerebellar functioning. METHODS A total of n=50 healthy adults performed a horizontal step prosaccade task and a saccadic adaptation task under 0.5 mg lorazepam, 1 mg lorazepam and placebo in a double-blind, within-subjects design. RESULTS In the prosaccade task, lorazepam had adverse effects on measures of peak velocity, latency and spatial consistency. The administration of 0.5 mg lorazepam led to significant reductions in gain-decrease adaptation, while a dose of 1 mg did not impair adaptation learning. Gain-increase adaptation was generally less pronounced, and unaffected by the drug. There were no significant drug×sex interactions in either task. CONCLUSIONS We conclude that a low dose of lorazepam impairs gain-decrease adaptation independent of sex. At higher doses, however, increasing fatigue may facilitate adaptation and thus counteract the adverse effects observed at lower doses. With regards to prosaccades, our findings confirm peak velocity as well as latency and spatial measures as sensitive biomarkers of GABAergic effects.
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Affiliation(s)
- Katharina Bey
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | | | - Behrem Aslan
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | - René Hurlemann
- Department of Psychiatry, University of Oldenburg, Bad Zwischenahn, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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Sperk G, Kirchmair E, Bakker J, Sieghart W, Drexel M, Kondova I. Immunohistochemical distribution of 10 GABA A receptor subunits in the forebrain of the rhesus monkey Macaca mulatta. J Comp Neurol 2020; 528:2551-2568. [PMID: 32220012 PMCID: PMC7496627 DOI: 10.1002/cne.24910] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 12/23/2022]
Abstract
GABAA receptors are composed of five subunits arranged around a central chloride channel. Their subunits originate from different genes or gene families. The majority of GABAA receptors in the mammalian brain consist of two α-, two β- and one γ- or δ-subunit. This subunit organization crucially determines the physiological and pharmacological properties of the GABAA receptors. Using immunohistochemistry, we investigated the distribution of 10 GABAA receptor subunits (α1, α2, α3, α4, α5, β1, β2, β3, γ2, and δ) in the fore brain of three female rhesus monkeys (Macaca mulatta). Within the cerebral cortex, subunits α1, α5, β2, β3, and γ2 were found in all layers, α2, α3, and β1 were more concentrated in the inner and outer layers. The caudate/putamen was rich in α1, α2, α5, all three β-subunits, γ2, and δ. Subunits α3 and α5 were more concentrated in the caudate than in the putamen. In contrast, α1, α2, β1, β2, γ2, and δ were highest in the pallidum. Most dorsal thalamic nuclei contained subunits α1, α2, α4, β2, β3, and γ2, whereas α1, α3, β1, and γ2 were most abundant in the reticular nucleus. Within the amygdala, subunits α1, α2, α5, β1, β3, γ2, and δ were concentrated in the cortical nucleus, whereas in the lateral and basolateral amygdala α1, α2, α5, β1, β3, and δ, and in the central amygdala α1, α2, β3, and γ2 were most abundant. Interestingly, subunit α3-IR outlined the intercalated nuclei of the amygdala. In the hippocampus, subunits α1, α2, α5, β2, β3, γ2, and δ were highly expressed in the dentate molecular layer, whereas α1, α2, α3, α5, β1, β2, β3, and γ2 were concentrated in sector CA1 and the subiculum. The distribution of GABAA receptor subunits in the rhesus monkey was highly heterogeneous indicating a high number of differently assembled receptors. In most areas investigated, notably in the striatum/pallidum, amygdaloid nuclei and in the hippocampus it was more diverse than in the rat and mouse indicating a more heterogeneous and less defined receptor assembly in the monkey than in rodent brain.
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Key Words
- GABAA receptor subunits
- RRID:AB_2108828
- ab GAD67, RRID:AB_2278725
- ab NeuN, RRID:AB_2278725
- ab α2, RRID:AB_2827793
- ab α3, RRID:AB_2827797
- ab α4, RRID:AB_2827798
- ab α5, RRID:AB_2827799
- ab β1, RRID:AB_2827800
- ab β2, RRID:AB_2827801
- ab β3, RRID:AB_2827802
- ab γ2, RRID:AB_2827803
- ab δ, RRID:AB_2827804
- amygdala
- antibody α1 (BD24)
- basal ganglia
- benzodiazepine
- goat biotinylated anti-rabbit ab, RRID:AB_2336810
- horse anti-mouse ab, RRID:AB_2336811
- immunohistochemistry
- monkey
- primate
- thalamus
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Affiliation(s)
- Günther Sperk
- Department of PharmacologyMedical University InnsbruckInnsbruckAustria
| | - Elke Kirchmair
- Department of PharmacologyMedical University InnsbruckInnsbruckAustria
| | - Jaco Bakker
- Division of Veterinary Care, Animal Science DepartmentBiomedical Primate Research CentreRijswijkThe Netherlands
| | - Werner Sieghart
- Department of Molecular Neurosciences, Center for Brain ResearchMedical University ViennaViennaAustria
| | - Meinrad Drexel
- Department of PharmacologyMedical University InnsbruckInnsbruckAustria
| | - Ivanela Kondova
- Division of Pathology and Microbiology, Animal Science DepartmentBiomedical Primate Research CentreRijswijkThe Netherlands
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Serrano-Regal MP, Bayón-Cordero L, Ordaz RP, Garay E, Limon A, Arellano RO, Matute C, Sánchez-Gómez MV. Expression and Function of GABA Receptors in Myelinating Cells. Front Cell Neurosci 2020; 14:256. [PMID: 32973453 PMCID: PMC7472887 DOI: 10.3389/fncel.2020.00256] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/24/2020] [Indexed: 01/14/2023] Open
Abstract
Myelin facilitates the fast transmission of nerve impulses and provides metabolic support to axons. Differentiation of oligodendrocyte progenitor cells (OPCs) and Schwann cell (SC) precursors is critical for myelination during development and myelin repair in demyelinating disorders. Myelination is tightly controlled by neuron-glia communication and requires the participation of a wide repertoire of signals, including neurotransmitters such as glutamate, ATP, adenosine, or γ-aminobutyric acid (GABA). GABA is the main inhibitory neurotransmitter in the central nervous system (CNS) and it is also present in the peripheral nervous system (PNS). The composition and function of GABA receptors (GABARs) are well studied in neurons, while their nature and role in glial cells are still incipient. Recent studies demonstrate that GABA-mediated signaling mechanisms play relevant roles in OPC and SC precursor development and function, and stand out the implication of GABARs in oligodendrocyte (OL) and SC maturation and myelination. In this review, we highlight the evidence supporting the novel role of GABA with an emphasis on the molecular identity of the receptors expressed in these glial cells and the possible signaling pathways involved in their actions. GABAergic signaling in myelinating cells may have potential implications for developing novel reparative therapies in demyelinating diseases.
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Affiliation(s)
- Mari Paz Serrano-Regal
- Laboratory of Neurobiology, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
| | - Laura Bayón-Cordero
- Laboratory of Neurobiology, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
| | - Rainald Pablo Ordaz
- Laboratorio de Neurofisiología Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Mexico
| | - Edith Garay
- Laboratorio de Neurofisiología Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Mexico
| | - Agenor Limon
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, United States
| | - Rogelio O. Arellano
- Laboratorio de Neurofisiología Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Mexico
| | - Carlos Matute
- Laboratory of Neurobiology, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
| | - María Victoria Sánchez-Gómez
- Laboratory of Neurobiology, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neurosciences, University of the Basque Country (UPV/EHU), Leioa, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
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GABA ARα2 is Decreased in the Axon Initial Segment of Pyramidal Cells in Specific Areas of the Prefrontal Cortex in Autism. Neuroscience 2020; 437:76-86. [PMID: 32335215 DOI: 10.1016/j.neuroscience.2020.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/13/2020] [Accepted: 04/16/2020] [Indexed: 12/20/2022]
Abstract
Some forms of Autism Spectrum Disorder, a neurodevelopmental syndrome characterized by impaired communication and social skills as well as repetitive behaviors, are purportedly associated with dysregulation of the excitation/inhibition balance in the cerebral cortex. Through human postmortem tissue analysis, we previously found a significant decrease in the number of a gamma-aminobutyric acid (GABA)ergic interneuron subtype, the chandelier (Ch) cell, in the prefrontal cortex of subjects with autism. Ch cells exclusively target the axon initial segment (AIS) of excitatory pyramidal (Pyr) neurons, and a single Ch cell forms synapses on hundreds of Pyr cells, indicating a possible role in maintaining electrical balance. Thus, we herein investigated this crucial link between Ch and Pyr cells in the anatomy of autism neuropathology by examining GABA receptor protein expression in the Pyr cell AIS in subjects with autism. We collected tissue from the prefrontal cortex (Brodmann Areas (BA) 9, 46, and 47) of 20 subjects with autism and 20 age- and sex-matched control subjects. Immunohistochemical staining with antibodies against the GABAA receptor subunit α2 (GABAARα2) - the subunit most prevalent in the Pyr cell AIS - revealed a significantly decreased GABAARα2 protein in the Pyr cell AIS in supragranular layers of prefrontal cortical areas BA9 and BA47 in autism. Downregulated GABAARα2 protein in the Pyr cell AIS may result from decreased GABA synthesis in the prefrontal cortex of subjects with autism, and thereby contribute to an excitation/inhibition imbalance. Our findings support the potential for GABA receptor agonists asa therapeutic tool for autism.
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Henssen D, Giesen E, van der Heiden M, Kerperien M, Lange S, van Cappellen van Walsum AM, Kurt E, van Dongen R, Schutter D, Vissers K. A systematic review of the proposed mechanisms underpinning pain relief by primary motor cortex stimulation in animals. Neurosci Lett 2020; 719:134489. [DOI: 10.1016/j.neulet.2019.134489] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/28/2019] [Accepted: 09/09/2019] [Indexed: 01/23/2023]
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12
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TGF-β/Smad3 Signalling Modulates GABA Neurotransmission: Implications in Parkinson's Disease. Int J Mol Sci 2020; 21:ijms21020590. [PMID: 31963327 PMCID: PMC7013528 DOI: 10.3390/ijms21020590] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
γ-Aminobutiryc acid (GABA) is found extensively in different brain nuclei, including parts involved in Parkinson’s disease (PD), such as the basal ganglia and hippocampus. In PD and in different models of the disorder, an increase in GABA neurotransmission is observed and may promote bradykinesia or L-Dopa-induced side-effects. In addition, proteins involved in GABAA receptor (GABAAR) trafficking, such as GABARAP, Trak1 or PAELR, may participate in the aetiology of the disease. TGF-β/Smad3 signalling has been associated with several pathological features of PD, such as dopaminergic neurodegeneration; reduction of dopaminergic axons and dendrites; and α-synuclein aggregation. Moreover, TGF-β/Smad3 intracellular signalling was recently shown to modulate GABA neurotransmission in the context of parkinsonism and cognitive alterations. This review provides a summary of GABA neurotransmission and TGF-β signalling; their implications in PD; and the regulation of GABA neurotransmission by TGF-β/Smad3. There appear to be new possibilities to develop therapeutic approaches for the treatment of PD using GABA modulators.
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13
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Chazalon M, Paredes-Rodriguez E, Morin S, Martinez A, Cristóvão-Ferreira S, Vaz S, Sebastiao A, Panatier A, Boué-Grabot E, Miguelez C, Baufreton J. GAT-3 Dysfunction Generates Tonic Inhibition in External Globus Pallidus Neurons in Parkinsonian Rodents. Cell Rep 2019; 23:1678-1690. [PMID: 29742425 DOI: 10.1016/j.celrep.2018.04.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/08/2018] [Accepted: 04/02/2018] [Indexed: 12/26/2022] Open
Abstract
The external globus pallidus (GP) is a key GABAergic hub in the basal ganglia (BG) circuitry, a neuronal network involved in motor control. In Parkinson's disease (PD), the rate and pattern of activity of GP neurons are profoundly altered and contribute to the motor symptoms of the disease. In rodent models of PD, the striato-pallidal pathway is hyperactive, and extracellular GABA concentrations are abnormally elevated in the GP, supporting the hypothesis of an alteration of neuronal and/or glial clearance of GABA. Here, we discovered the existence of persistent GABAergic tonic inhibition in GP neurons of dopamine-depleted (DD) rodent models. We showed that glial GAT-3 transporters are downregulated while neuronal GAT-1 function remains normal in DD rodents. Finally, we showed that blocking GAT-3 activity in vivo alters the motor coordination of control rodents, suggesting that GABAergic tonic inhibition in the GP contributes to the pathophysiology of PD.
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Affiliation(s)
- Marine Chazalon
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France
| | | | - Stéphanie Morin
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France
| | - Audrey Martinez
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France
| | - Sofia Cristóvão-Ferreira
- Institute of Pharmacology and Neurosciences, Faculty of Medicine, and Unit of Neuroscience, Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal
| | - Sandra Vaz
- Institute of Pharmacology and Neurosciences, Faculty of Medicine, and Unit of Neuroscience, Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal
| | - Ana Sebastiao
- Institute of Pharmacology and Neurosciences, Faculty of Medicine, and Unit of Neuroscience, Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal
| | - Aude Panatier
- INSERM U1215, Neurocentre Magendie, 33000 Bordeaux, France; Université de Bordeaux, 33000 Bordeaux, France
| | - Eric Boué-Grabot
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France
| | - Cristina Miguelez
- Department of Pharmacology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Jérôme Baufreton
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33000 Bordeaux, France.
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14
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Kwakowsky A, Calvo-Flores Guzmán B, Pandya M, Turner C, Waldvogel HJ, Faull RL. GABA A receptor subunit expression changes in the human Alzheimer's disease hippocampus, subiculum, entorhinal cortex and superior temporal gyrus. J Neurochem 2019; 145:374-392. [PMID: 29485232 DOI: 10.1111/jnc.14325] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/17/2018] [Accepted: 02/12/2018] [Indexed: 12/14/2022]
Abstract
Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABA type A receptors (GABAA Rs) are severely affected in Alzheimer's disease (AD). However, the distribution and subunit composition of GABAA Rs in the AD brain are not well understood. This is the first comprehensive study to show brain region- and cell layer-specific alterations in the expression of the GABAA R subunits α1-3, α5, β1-3 and γ2 in the human AD hippocampus, entorhinal cortex and superior temporal gyrus. In late-stage AD tissue samples using immunohistochemistry we found significant alteration of all investigated GABAA Rs subunits except for α3 and β1 that were well preserved. The most prominent changes include an increase in GABAA R α1 expression associated with AD in all layers of the CA3 region, in the stratum (str.) granulare and hilus of the dentate gyrus. We found a significant increase in GABAA R α2 expression in the str. oriens of the CA1-3, str. radiatum of the CA2,3 and decrease in the str. pyramidale of the CA1 region in AD cases. In AD there was a significant increase in GABAA R α5 subunit expression in str. pyramidale, str. oriens of the CA1 region and decrease in the superior temporal gyrus. We also found a significant decrease in the GABAA R β3 subunit immunoreactivity in the str. oriens of the CA2, str. granulare and str. moleculare of the dentate gyrus. In conclusion, these findings indicate that the expression of the GABAA R subunits shows brain region- and layer-specific alterations in AD, and these changes could significantly influence and alter GABAA R function in the disease. Cover Image for this issue: doi: 10.1111/jnc.14179.
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Affiliation(s)
- Andrea Kwakowsky
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Beatriz Calvo-Flores Guzmán
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Madhavi Pandya
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Clinton Turner
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Department of Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Henry J Waldvogel
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Richard L Faull
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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15
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Silva AR, Grosso C, Delerue-Matos C, Rocha JM. Comprehensive review on the interaction between natural compounds and brain receptors: Benefits and toxicity. Eur J Med Chem 2019; 174:87-115. [PMID: 31029947 DOI: 10.1016/j.ejmech.2019.04.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 02/06/2023]
Abstract
Given their therapeutic activity, natural products have been used in traditional medicines throughout the centuries. The growing interest of the scientific community in phytopharmaceuticals, and more recently in marine products, has resulted in a significant number of research efforts towards understanding their effect in the treatment of neurodegenerative diseases, such as Alzheimer's (AD), Parkinson (PD) and Huntington (HD). Several studies have shown that many of the primary and secondary metabolites of plants, marine organisms and others, have high affinities for various brain receptors and may play a crucial role in the treatment of diseases affecting the central nervous system (CNS) in mammalians. Actually, such compounds may act on the brain receptors either by agonism, antagonism, allosteric modulation or other type of activity aimed at enhancing a certain effect. The current manuscript comprehensively reviews the state of the art on the interactions between natural compounds and brain receptors. This information is of foremost importance when it is intended to investigate and develop cutting-edge drugs, more effective and with alternative mechanisms of action to the conventional drugs presently used for the treatment of neurodegenerative diseases. Thus, we reviewed the effect of 173 natural products on neurotransmitter receptors, diabetes related receptors, neurotrophic factor related receptors, immune system related receptors, oxidative stress related receptors, transcription factors regulating gene expression related receptors and blood-brain barrier receptors.
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Affiliation(s)
- Ana R Silva
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology (DB), University of Minho (UM), Campus Gualtar, P-4710-057, Braga, Portugal
| | - Clara Grosso
- REQUIMTE/LAQV, Instituto Superior de Engenharia do Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, P-4249-015, Porto, Portugal.
| | - Cristina Delerue-Matos
- REQUIMTE/LAQV, Instituto Superior de Engenharia do Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, P-4249-015, Porto, Portugal
| | - João M Rocha
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology (DB), University of Minho (UM), Campus Gualtar, P-4710-057, Braga, Portugal; REQUIMTE/LAQV, Grupo de investigação de Química Orgânica Aplicada (QUINOA), Laboratório de polifenóis alimentares, Departamento de Química e Bioquímica (DQB), Faculdade de Ciências da Universidade do Porto (FCUP), Rua do Campo Alegre, s/n, P-4169-007, Porto, Portugal
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16
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Perez-Rosello T, Gelman S, Tombaugh G, Cachope R, Beaumont V, Surmeier DJ. Enhanced striatopallidal gamma-aminobutyric acid (GABA) A receptor transmission in mouse models of huntington's disease. Mov Disord 2019; 34:684-696. [PMID: 30726572 DOI: 10.1002/mds.27622] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/20/2018] [Accepted: 01/03/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is caused by a CAG repeat expansion in the huntingtin gene. This mutation leads to progressive dysfunction that is largely attributable to dysfunction of the striatum. The earliest signs of striatal pathology in HD are found in indirect pathway gamma-Aminobutyric acid (GABA)-ergic spiny projection neurons that innervate the external segment of the globus pallidus (GPe). What is less clear is whether the synaptic coupling of spiny projection neurons with GPe neurons changes in HD. OBJECTIVES The principal goal of this study was to determine whether striatopallidal synaptic transmission was altered in 2 mouse models of HD. METHODS Striatopallidal synaptic transmission was studied using electrophysiological and optogenetic approaches in ex vivo brain slices from 2 HD models: Q175 heterozygous (het) and R6/2 mice. RESULTS Striatopallidal synaptic transmission increased in strength with the progression of behavioral deficits in Q175 and R6/2 mice. The alteration in synaptic transmission was evident in both prototypical and arkypallidal GPe neurons. This change did not appear attributable to an increase in the probability of GABA release but, rather, to an enhancement in the postsynaptic response to GABA released at synaptic sites. This alteration significantly increased the ability of striatopallidal axon terminals to pause ongoing GPe activity. CONCLUSIONS In 2 mouse models of HD, striatopallidal synaptic transmission increased in parallel with the progression of behavioral deficits. This adaptation could compensate in part for the concomitant deficit in the ability of corticostriatal signals to activate spiny projection neurons and pause GPe activity. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Tamara Perez-Rosello
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | | | - Roger Cachope
- CHDI Management/CHDI Foundation, California, Los Angeles, USA
| | - Vahri Beaumont
- CHDI Management/CHDI Foundation, California, Los Angeles, USA
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Hsu YT, Chang YG, Chern Y. Insights into GABA Aergic system alteration in Huntington's disease. Open Biol 2018; 8:rsob.180165. [PMID: 30518638 PMCID: PMC6303784 DOI: 10.1098/rsob.180165] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 10/30/2018] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disease that is characterized by a triad of motor, psychiatric and cognitive impairments. There is still no effective therapy to delay or halt the disease progress. The striatum and cortex are two particularly affected brain regions that exhibit dense reciprocal excitatory glutamate and inhibitory gamma-amino butyric acid (GABA) connections. Imbalance between excitatory and inhibitory signalling is known to greatly affect motor and cognitive processes. Emerging evidence supports the hypothesis that disrupted GABAergic circuits underlie HD pathogenesis. In the present review, we focused on the multiple defects recently found in the GABAergic inhibitory system, including altered GABA level and synthesis, abnormal subunit composition and distribution of GABAA receptors and aberrant GABAA receptor-mediated signalling. In particular, the important role of cation–chloride cotransporters (i.e. NKCC1 and KCC2) is discussed. Recent studies also suggest that neuroinflammation contributes significantly to the abnormal GABAergic inhibition in HD. Thus, GABAA receptors and cation–chloride cotransporters are potential therapeutic targets for HD. Given the limited availability of therapeutic treatments for HD, a better understanding of GABAergic dysfunction in HD could provide novel therapeutic opportunities.
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Affiliation(s)
- Yi-Ting Hsu
- PhD Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan, Republic of China.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan, Republic of China
| | - Ya-Gin Chang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, Republic of China.,Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan, Republic of China
| | - Yijuang Chern
- PhD Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan, Republic of China .,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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18
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Palomero-Gallagher N, Zilles K. Cyto- and receptor architectonic mapping of the human brain. HANDBOOK OF CLINICAL NEUROLOGY 2018; 150:355-387. [PMID: 29496153 DOI: 10.1016/b978-0-444-63639-3.00024-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mapping of the human brain is more than the generation of an atlas-based parcellation of brain regions using histologic or histochemical criteria. It is the attempt to provide a topographically informed model of the structural and functional organization of the brain. To achieve this goal a multimodal atlas of the detailed microscopic and neurochemical structure of the brain must be registered to a stereotaxic reference space or brain, which also serves as reference for topographic assignment of functional data, e.g., functional magnet resonance imaging, electroencephalography, or magnetoencephalography, as well as metabolic imaging, e.g., positron emission tomography. Although classic maps remain pioneering steps, they do not match recent concepts of the functional organization in many regions, and suffer from methodic drawbacks. This chapter provides a summary of the recent status of human brain mapping, which is based on multimodal approaches integrating results of quantitative cyto- and receptor architectonic studies with focus on the cerebral cortex in a widely used reference brain. Descriptions of the methods for observer-independent and statistically testable cytoarchitectonic parcellations, quantitative multireceptor mapping, and registration to the reference brain, including the concept of probability maps and a toolbox for using the maps in functional neuroimaging studies, are provided.
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Affiliation(s)
- Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH, Aachen, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH, Aachen, Germany; JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich, Germany.
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19
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You C, Vandegrift B, Brodie MS. Ethanol actions on the ventral tegmental area: novel potential targets on reward pathway neurons. Psychopharmacology (Berl) 2018; 235:1711-1726. [PMID: 29549390 PMCID: PMC5949141 DOI: 10.1007/s00213-018-4875-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/06/2018] [Indexed: 12/14/2022]
Abstract
The ventral tegmental area (VTA) evaluates salience of environmental stimuli and provides dopaminergic innervation to many brain areas affected by acute and chronic ethanol exposure. While primarily associated with rewarding and reinforcing stimuli, recent evidence indicates a role for the VTA in aversion as well. Ethanol actions in the VTA may trigger neuroadaptation resulting in reduction of the aversive responses to alcohol and a relative increase in the rewarding responses. In searching for effective pharmacotherapies for the treatment of alcohol abuse and alcoholism, recognition of this imbalance may reveal novel strategies. In addition to conventional receptor/ion channel pharmacotherapies, epigenetic factors that control neuroadaptation to chronic ethanol treatment can be targeted as an avenue for development of therapeutic approaches to restore the balance. Furthermore, when exploring therapies to address reward/aversion imbalance in the action of alcohol in the VTA, sex differences have to be taken into account to ensure effective treatment for both men and women. These principles apply to a VTA-centric approach to therapies, but should hold true when thinking about the overall approach in the development of neuroactive drugs to treat alcohol use disorders. Although the functions of the VTA itself are complex, it is a useful model system to evaluate the reward/aversion imbalance that occurs with ethanol exposure and could be used to provide new leads in the efforts to develop novel drugs to treat alcoholism.
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Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Bertha Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA.
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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20
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Striatal Direct and Indirect Pathway Output Structures Are Differentially Altered in Mouse Models of Huntington's Disease. J Neurosci 2018; 38:4678-4694. [PMID: 29691329 DOI: 10.1523/jneurosci.0434-18.2018] [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] [Received: 02/15/2018] [Revised: 04/02/2018] [Accepted: 04/18/2018] [Indexed: 11/21/2022] Open
Abstract
The present study examined synaptic communication between direct and indirect output pathway striatal medium-sized spiny neurons (MSNs) and their target structures, the substantia nigra pars reticulata (SNr) and the external globus pallidus (GPe) in two mouse models of Huntington's disease (HD). Cre recombination, optogenetics, and whole-cell patch-clamp recordings were used to determine alterations in intrinsic and synaptic properties of SNr and GPe neurons from both male and female symptomatic R6/2 (>60 d) and presymptomatic (2 months) or symptomatic (10-12 months) YAC128 mice. Cell membrane capacitance was decreased, whereas input resistance was increased in SNr neurons from R6/2, but not YAC128 mice. The amplitude of GABAergic responses evoked by optogenetic stimulation of direct pathway terminals was reduced in SNr neurons of symptomatic mice of both models. A decrease in spontaneous GABA synaptic activity, in particular large-amplitude events, in SNr neurons also was observed. Passive membrane properties of GPe neurons were not different between R6/2 or YAC128 mice and their control littermates. Similarly, the amplitude of GABA responses evoked by activation of indirect pathway MSN terminals and the frequency of spontaneous GABA synaptic activity were similar in HD and control animals. In contrast, the decay time of the evoked GABA response was significantly longer in cells from HD mice. Interestingly, activation of indirect pathway MSNs within the striatum evoked larger-amplitude responses in direct pathway MSNs. Together, these results demonstrate differential alterations in responses evoked by direct and indirect pathway terminals in SNr and GPe leading to striatal output imbalance and motor dysfunction.SIGNIFICANCE STATEMENT Previous work on Huntington's disease (HD) focused on striatal medium-sized spiny neurons (MSNs) almost exclusively. Little is known about the effects that alterations in the striatum have on output structures of the direct and indirect pathways, the substantia nigra pars reticulata (SNr) and the external segment of the globus pallidus (GPe), respectively. We combined electrophysiological and optogenetic methods to examine responses evoked by selective activation of terminals of direct and indirect pathway MSNs in SNr and GPe neurons in two mouse models of HD. We show a differential disruption of synaptic communication between the direct and indirect output pathways of the striatum with their target regions leading to an imbalance of striatal output, which will contribute to motor dysfunction.
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21
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Rosas-Arellano A, Tejeda-Guzmán C, Lorca-Ponce E, Palma-Tirado L, Mantellero CA, Rojas P, Missirlis F, Castro MA. Huntington's disease leads to decrease of GABA-A tonic subunits in the D2 neostriatal pathway and their relocalization into the synaptic cleft. Neurobiol Dis 2018; 110:142-153. [DOI: 10.1016/j.nbd.2017.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/12/2017] [Accepted: 11/27/2017] [Indexed: 01/24/2023] Open
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22
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Rosas-Arellano A, Estrada-Mondragón A, Mantellero CA, Tejeda-Guzmán C, Castro MA. The adjustment of γ-aminobutyric acid A tonic subunits in Huntington's disease: from transcription to translation to synaptic levels into the neostriatum. Neural Regen Res 2018; 13:584-590. [PMID: 29722299 PMCID: PMC5950657 DOI: 10.4103/1673-5374.230270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
γ-Aminobutyric acid (GABA), plays a key role in all stages of life, also is considered the main inhibitory neurotransmitter. GABA activates two kind of membrane receptors known as GABAA and GABAB, the first one is responsible to render tonic inhibition by pentameric receptors containing α4−6, β3, δ, or ρ1−3 subunits, they are located at perisynaptic and/or in extrasynaptic regions. The biophysical properties of GABAA tonic inhibition have been related with cellular protection against excitotoxic injury and cell death in presence of excessive excitation. On this basis, GABAA tonic inhibition has been proposed as a potential target for therapeutic intervention of Huntington's disease. Huntington's disease is a neurodegenerative disorder caused by a genetic mutation of the huntingtin protein. For experimental studies of Huntington's disease mouse models have been developed, such as R6/1, R6/2, HdhQ92, HdhQ150, as well as YAC128. In all of them, some key experimental reports are focused on neostriatum. The neostriatum is considered as the most important connection between cerebral cortex and basal ganglia structures, its cytology display two pathways called direct and indirect constituted by medium sized spiny neurons expressing dopamine D1 and D2 receptors respectively, they display strong expression of many types of GABAA receptors, including tonic subunits. The studies about of GABAA tonic subunits and Huntington's disease into the neostriatum are rising in recent years, suggesting interesting changes in their expression and localization which can be used as a strategy to delay the cellular damage caused by the imbalance between excitation and inhibition, a hallmark of Huntington's disease.
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Affiliation(s)
- Abraham Rosas-Arellano
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile; Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile; Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav del IPN, Ciudad de México, México
| | | | - Carola A Mantellero
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago de Chile, Chile
| | - Carlos Tejeda-Guzmán
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav del IPN, Ciudad de México, México
| | - Maite A Castro
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias; Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
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23
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Hsu YT, Chang YG, Chang CP, Siew JJ, Chen HM, Tsai CH, Chern Y. Altered behavioral responses to gamma-aminobutyric acid pharmacological agents in a mouse model of Huntington's disease. Mov Disord 2017; 32:1600-1609. [PMID: 28782830 DOI: 10.1002/mds.27107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 06/21/2017] [Accepted: 06/23/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Disruptions in gamma-aminobutyric (GABA) acid signaling are believed to be involved in Huntington's disease pathogenesis, but the regulation of GABAergic signaling remains elusive. Here we evaluated GABAergic signaling by examining the function of GABAergic drugs in Huntington's disease and the expression of GABAergic molecules using mouse models and human brain tissues from Huntington's disease. METHODS We treated wild-type and R6/2 mice (a transgenic Huntington's disease mouse model) acutely with vehicle, diazepam, or gaboxadol (drugs that selectively target synaptic or extrasynaptic GABAA receptors) and monitored their locomotor activity. The expression levels of GABAA receptors and a major neuron-specific chloride extruder (potassium-chloride cotransporter-2) were analyzed by real-time quantitative polymerase chain reaction, Western blot, and immunocytochemistry. RESULTS The R6/2 mice were less sensitive to the sedative effects of both drugs, suggesting reduced function of GABAA receptors. Consistently, the expression levels of α1/α2 and δ subunits were lower in the cortex and striatum of R6/2 mice. Similar results were also found in 2 other mouse models of Huntington's disease and in Huntington's disease patients. Moreover, the interaction and expression levels of potassium-chloride cotransporter-2 and its activator (brain-type creatine kinase) were decreased in Huntington's disease neurons. These findings collectively suggest impaired chloride homeostasis, which further dampens GABAA receptor-mediated inhibitory signaling in Huntington's disease brains. CONCLUSIONS The dysregulated GABAergic responses and altered expression levels of GABAA receptors and potassium-chloride cotransporter-2 in Huntington's disease mice appear to be authentic and may contribute to the clinical manifestations of Huntington's disease patients. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Yi-Ting Hsu
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan
| | - Ya-Gin Chang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Ching-Pang Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jian-Jing Siew
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hui-Mei Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chon-Haw Tsai
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan
| | - Yijuang Chern
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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Developmental alterations in Huntington's disease neural cells and pharmacological rescue in cells and mice. Nat Neurosci 2017; 20:648-660. [PMID: 28319609 PMCID: PMC5610046 DOI: 10.1038/nn.4532] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/23/2017] [Indexed: 12/11/2022]
Abstract
Neural cultures derived from Huntington's disease (HD) patient-derived induced pluripotent stem cells were used for 'omics' analyses to identify mechanisms underlying neurodegeneration. RNA-seq analysis identified genes in glutamate and GABA signaling, axonal guidance and calcium influx whose expression was decreased in HD cultures. One-third of gene changes were in pathways regulating neuronal development and maturation. When mapped to stages of mouse striatal development, the profiles aligned with earlier embryonic stages of neuronal differentiation. We observed a strong correlation between HD-related histone marks, gene expression and unique peak profiles associated with dysregulated genes, suggesting a coordinated epigenetic program. Treatment with isoxazole-9, which targets key dysregulated pathways, led to amelioration of expanded polyglutamine repeat-associated phenotypes in neural cells and of cognitive impairment and synaptic pathology in HD model R6/2 mice. These data suggest that mutant huntingtin impairs neurodevelopmental pathways that could disrupt synaptic homeostasis and increase vulnerability to the pathologic consequence of expanded polyglutamine repeats over time.
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Jucaite A, Cselényi Z, Lappalainen J, McCarthy DJ, Lee CM, Nyberg S, Varnäs K, Stenkrona P, Halldin C, Cross A, Farde L. GABA A receptor occupancy by subtype selective GABA Aα2,3 modulators: PET studies in humans. Psychopharmacology (Berl) 2017; 234:707-716. [PMID: 28013354 PMCID: PMC5263201 DOI: 10.1007/s00213-016-4506-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/08/2016] [Indexed: 01/04/2023]
Abstract
RATIONALE Sedation, dependence, and abuse liability limit the use of non-selective γ-aminobutyric acid (GABAA) receptor positive modulators for the treatment of anxiety. AZD7325 and AZD6280 are novel, subtype-selective GABAAα2,3 receptor positive modulators with limited sedative effects. OBJECTIVES The current study aimed to confirm target engagement at GABAA receptors by AZD7325 and AZD6280 in humans and to determine the relationship between exposure, GABAA receptor occupancy, and tolerability. METHOD Two PET studies, using high-resolution research tomography (HRRT) and the radioligand [11C]flumazenil, were performed in 12 subjects at baseline and after administration of single oral doses of AZD7325 (0.2 to 30 mg) and AZD6280 (5 to 40 mg). PET images were analyzed using a simplified reference tissue model, and regional binding potentials (BPND) were obtained. The relationship between plasma concentration of AZD7325 or AZD6280 and GABAA receptor occupancy was described by hyperbolic function, and K i,plasma (plasma concentration required for 50% receptor occupancy) was estimated. Assessments of safety and tolerability included recording of adverse events, vital signs, electrocardiogram, and laboratory tests. RESULTS The [11C]flumazenil binding was reduced in a dose-dependent, saturable manner by both agents. Maximum receptor occupancy could be reached for both compounds without causing sedation or cognitive impairment. The K i,plasma estimates for AZD7325 and AZD6280 were 15 and 440 nmol/l, respectively. CONCLUSION High GABAA receptor occupancy by AZD7325 and AZD6280 could be reached without clear sedative effects.
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Affiliation(s)
- Aurelija Jucaite
- Department of Clinical Neuroscience, AstraZeneca PET Center, Karolinska Institutet, R5:02, SE-17176, Stockholm, Sweden. .,Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden.
| | - Zsolt Cselényi
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, AstraZeneca PET Center, Karolinska Institutet, R5:02, SE-17176 Stockholm, Sweden ,0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden
| | - Jaakko Lappalainen
- AstraZeneca Neuroscience Innovative Medicines, Cambridge, MA USA ,Marinus Pharmaceuticals, Radnor, PA USA
| | - Dennis J. McCarthy
- 0000 0001 1519 6403grid.418151.8AstraZeneca R&D, Södertälje, Sweden ,Independent Consultant, Newark, DE USA
| | - Chi-Ming Lee
- 0000 0001 1519 6403grid.418151.8AstraZeneca R&D, Södertälje, Sweden ,Ever East Consultants Limited, Hong Kong, People’s Republic of China
| | - Svante Nyberg
- 0000 0001 1519 6403grid.418151.8AstraZeneca R&D, Södertälje, Sweden ,0000 0000 9241 5705grid.24381.3cDepartment of Psychiatry, Karolinska University Hospital (Huddinge), Stockholm, Sweden
| | - Katarina Varnäs
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden
| | - Per Stenkrona
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden
| | - Christer Halldin
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden
| | - Alan Cross
- AstraZeneca Neuroscience Innovative Medicines, Cambridge, MA USA
| | - Lars Farde
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, AstraZeneca PET Center, Karolinska Institutet, R5:02, SE-17176 Stockholm, Sweden ,0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, PET Centre, Karolinska Institutet, Stockholm, Sweden
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26
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Histological Underpinnings of Grey Matter Changes in Fibromyalgia Investigated Using Multimodal Brain Imaging. J Neurosci 2016; 37:1090-1101. [PMID: 27986927 DOI: 10.1523/jneurosci.2619-16.2016] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/24/2016] [Accepted: 12/05/2016] [Indexed: 12/14/2022] Open
Abstract
Chronic pain patients present with cortical gray matter alterations, observed with anatomical magnetic resonance (MR) imaging. Reduced regional gray matter volumes are often interpreted to reflect neurodegeneration, but studies investigating the cellular origin of gray matter changes are lacking. We used multimodal imaging to compare 26 postmenopausal women with fibromyalgia with 25 healthy controls (age range: 50-75 years) to test whether regional gray matter volume decreases in chronic pain are associated with compromised neuronal integrity. Regional gray matter decreases were largely explained by T1 relaxation times in gray matter, a surrogate measure of water content, and not to any substantial degree by GABAA receptor concentration, an indirect marker of neuronal integrity measured with [18F] flumazenil PET. In addition, the MR spectroscopy marker of neuronal viability, N-acetylaspartate, did not differ between patients and controls. These findings suggest that decreased gray matter volumes are not explained by compromised neuronal integrity. Alternatively, a decrease in neuronal matter could be compensated for by an upregulation of GABAA receptors. The relation between regional gray matter and T1 relaxation times suggests decreased tissue water content underlying regional gray matter decreases. In contrast, regional gray matter increases were explained by GABAA receptor concentration in addition to T1 relaxation times, indicating perhaps increased neuronal matter or GABAA receptor upregulation and inflammatory edema. By providing information on the histological origins of cerebral gray matter alterations in fibromyalgia, this study advances the understanding of the neurobiology of chronic widespread pain. SIGNIFICANCE STATEMENT Regional gray matter alterations in chronic pain, as detected with voxel-based morphometry of anatomical magnetic resonance images, are commonly interpreted to reflect neurodegeneration, but this assumption has not been tested. We found decreased gray matter in fibromyalgia to be associated with T1 relaxation times, a surrogate marker of water content, but not with GABAA receptor concentration, a surrogate of neuronal integrity. In contrast, regional gray matter increases were partly explained by GABAA receptor concentration, indicating some form of neuronal plasticity. The study emphasizes that voxel-based morphometry is an exploratory measure, demonstrating the need to investigate the histological origin of gray matter alterations for every distinct clinical entity, and advances the understanding of the neurobiology of chronic (widespread) pain.
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Hegeman DJ, Hong ES, Hernández VM, Chan CS. The external globus pallidus: progress and perspectives. Eur J Neurosci 2016; 43:1239-65. [PMID: 26841063 PMCID: PMC4874844 DOI: 10.1111/ejn.13196] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/20/2016] [Accepted: 01/27/2016] [Indexed: 12/12/2022]
Abstract
The external globus pallidus (GPe) of the basal ganglia is in a unique and powerful position to influence processing of motor information by virtue of its widespread projections to all basal ganglia nuclei. Despite the clinical importance of the GPe in common motor disorders such as Parkinson's disease, there is only limited information about its cellular composition and organizational principles. In this review, recent advances in the understanding of the diversity in the molecular profile, anatomy, physiology and corresponding behaviour during movement of GPe neurons are described. Importantly, this study attempts to build consensus and highlight commonalities of the cellular classification based on existing but contentious literature. Additionally, an analysis of the literature concerning the intricate reciprocal loops formed between the GPe and major synaptic partners, including both the striatum and the subthalamic nucleus, is provided. In conclusion, the GPe has emerged as a crucial node in the basal ganglia macrocircuit. While subtleties in the cellular makeup and synaptic connection of the GPe create new challenges, modern research tools have shown promise in untangling such complexity, and will provide better understanding of the roles of the GPe in encoding movements and their associated pathologies.
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Affiliation(s)
- Daniel J Hegeman
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Ellie S Hong
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Vivian M Hernández
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - C Savio Chan
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
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