1
|
McKenna MC, Sonnewald U, Waageptersen HS, White HS. A tribute to Arne Schousboe's contributions to neurochemistry and his innovative and enduring research in GABA, glutamate, and brain energy metabolism. J Neurochem 2024. [PMID: 39183580 DOI: 10.1111/jnc.16207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/06/2024] [Accepted: 08/06/2024] [Indexed: 08/27/2024]
Abstract
This is a tribute to Arne Schousboe, Professor Emeritus at the University of Copenhagen, an eminent neurochemist and neuroscientist who was a leader in the fields of GABA, glutamate, and brain energy metabolism. Arne was known for his keen intellect, his wide-ranging expertise in neurochemistry and neuropharmacology of GABA and glutamate and brain energy metabolism. Arne was also known for his strong leadership, his warm and engaging personality and his enjoyment of fine wine and great food shared with friends, family, and colleagues. Sadly, Arne passed away on February 27, 2024, after a short illness. He is survived by his wife Inger Schousboe, his two children, and three wonderful grandchildren. His death is a tremendous loss to the neuroscience community. He will be greatly missed by his friends, family, and colleagues. Some of the highlights of Arne's career are described in this tribute.
Collapse
Affiliation(s)
- Mary C McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ursula Sonnewald
- Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - H Steve White
- Department of Pharmacy, University of Washington, Seattle, Washington, USA
| |
Collapse
|
2
|
Pan TY, Pan YJ, Tsai SJ, Tsai CW, Yang FY. Focused Ultrasound Stimulates the Prefrontal Cortex and Prevents MK-801-Induced Psychiatric Symptoms of Schizophrenia in Rats. Schizophr Bull 2024; 50:120-131. [PMID: 37301986 PMCID: PMC10754174 DOI: 10.1093/schbul/sbad078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND HYPOTHESIS Treatment of schizophrenia remains a major challenge. Recent studies have focused on glutamatergic signaling hypoactivity through N-methyl-D-aspartate (NMDA) receptors. Low-intensity pulsed ultrasound (LIPUS) improves behavioral deficits and ameliorates neuropathology in dizocilpine (MK-801)-treated rats. The aim of this study was to investigate the efficacy of LIPUS against psychiatric symptoms and anxiety-like behaviors. STUDY DESIGN Rats assigned to 4 groups were pretreated with or without LIPUS for 5 days. The open field and prepulse inhibition tests were performed after saline or MK-801 (0.3 mg/kg) administration. Then, the neuroprotective effects of LIPUS on the MK-801-treated rats were evaluated using western blotting and immunohistochemical staining. STUDY RESULTS LIPUS stimulation of the prefrontal cortex (PFC) prevented deficits in locomotor activity and sensorimotor gating and improved anxiety-like behavior. MK-801 downregulated the expression of NR1, the NMDA receptor, in rat medial PFC (mPFC). NR1 expression was significantly higher in animals receiving LIPUS pretreatment compared to those receiving only MK-801. In contrast, a significant increase in c-Fos-positive cells in the mPFC and ventral tegmental area was observed in the MK-801-treated rats compared to those receiving only saline; this change was suppressed by pretreatment with LIPUS. CONCLUSIONS This study provides new evidence for the role of LIPUS stimulation in regulating the NMDA receptor and modulating c-Fos activity, which makes it a potentially valuable antipsychotic treatment for schizophrenia.
Collapse
Affiliation(s)
- Tsung-Yu Pan
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Ju Pan
- Department of Psychiatry, Far Eastern Memorial Hospital, New Taipei City, Taiwan
- Institute of Public Health, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Shih-Jen Tsai
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
- Division of Psychiatry, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Che-Wen Tsai
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Feng-Yi Yang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| |
Collapse
|
3
|
Koh W, Kwak H, Cheong E, Lee CJ. GABA tone regulation and its cognitive functions in the brain. Nat Rev Neurosci 2023; 24:523-539. [PMID: 37495761 DOI: 10.1038/s41583-023-00724-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2023] [Indexed: 07/28/2023]
Abstract
γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter released at GABAergic synapses, mediating fast-acting phasic inhibition. Emerging lines of evidence unequivocally indicate that a small amount of extracellular GABA - GABA tone - exists in the brain and induces a tonic GABA current that controls neuronal activity on a slow timescale relative to that of phasic inhibition. Surprisingly, studies indicate that glial cells that synthesize GABA, such as astrocytes, release GABA through non-vesicular mechanisms, such as channel-mediated release, and thereby act as the source of GABA tone in the brain. In this Review, we first provide an overview of major advances in our understanding of the cell-specific molecular and cellular mechanisms of GABA synthesis, release and clearance that regulate GABA tone in various brain regions. We next examine the diverse ways in which the tonic GABA current regulates synaptic transmission and synaptic plasticity through extrasynaptic GABAA-receptor-mediated mechanisms. Last, we discuss the physiological mechanisms through which tonic inhibition modulates cognitive function on a slow timescale. In this Review, we emphasize that the cognitive functions of tonic GABA current extend beyond mere inhibition, laying a foundation for future research on the physiological and pathophysiological roles of GABA tone regulation in normal and abnormal psychiatric conditions.
Collapse
Affiliation(s)
- Wuhyun Koh
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, South Korea
| | - Hankyul Kwak
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea.
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, South Korea.
| |
Collapse
|
4
|
Purushotham SS, Buskila Y. Astrocytic modulation of neuronal signalling. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1205544. [PMID: 37332623 PMCID: PMC10269688 DOI: 10.3389/fnetp.2023.1205544] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/18/2023] [Indexed: 06/20/2023]
Abstract
Neuronal signalling is a key element in neuronal communication and is essential for the proper functioning of the CNS. Astrocytes, the most prominent glia in the brain play a key role in modulating neuronal signalling at the molecular, synaptic, cellular, and network levels. Over the past few decades, our knowledge about astrocytes and their functioning has evolved from considering them as merely a brain glue that provides structural support to neurons, to key communication elements. Astrocytes can regulate the activity of neurons by controlling the concentrations of ions and neurotransmitters in the extracellular milieu, as well as releasing chemicals and gliotransmitters that modulate neuronal activity. The aim of this review is to summarise the main processes through which astrocytes are modulating brain function. We will systematically distinguish between direct and indirect pathways in which astrocytes affect neuronal signalling at all levels. Lastly, we will summarize pathological conditions that arise once these signalling pathways are impaired focusing on neurodegeneration.
Collapse
Affiliation(s)
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- The MARCS Institute, Western Sydney University, Campbelltown, NSW, Australia
| |
Collapse
|
5
|
Hartmann J, Henschel N, Bartmann K, Dönmez A, Brockerhoff G, Koch K, Fritsche E. Molecular and Functional Characterization of Different BrainSphere Models for Use in Neurotoxicity Testing on Microelectrode Arrays. Cells 2023; 12:cells12091270. [PMID: 37174670 PMCID: PMC10177384 DOI: 10.3390/cells12091270] [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: 03/13/2023] [Revised: 04/14/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
The currently accepted methods for neurotoxicity (NT) testing rely on animal studies. However, high costs and low testing throughput hinder their application for large numbers of chemicals. To overcome these limitations, in vitro methods are currently being developed based on human-induced pluripotent stem cells (hiPSC) that allow higher testing throughput at lower costs. We applied six different protocols to generate 3D BrainSphere models for acute NT evaluation. These include three different media for 2D neural induction and two media for subsequent 3D differentiation resulting in self-organized, organotypic neuron/astrocyte microtissues. All induction protocols yielded nearly 100% NESTIN-positive hiPSC-derived neural progenitor cells (hiNPCs), though with different gene expression profiles concerning regional patterning. Moreover, gene expression and immunocytochemistry analyses revealed that the choice of media determines neural differentiation patterns. On the functional level, BrainSpheres exhibited different levels of electrical activity on microelectrode arrays (MEA). Spike sorting allowed BrainSphere functional characterization with the mixed cultures consisting of GABAergic, glutamatergic, dopaminergic, serotonergic, and cholinergic neurons. A test method for acute NT testing, the human multi-neurotransmitter receptor (hMNR) assay, was proposed to apply such MEA-based spike sorting. These models are promising tools not only in toxicology but also for drug development and disease modeling.
Collapse
Affiliation(s)
- Julia Hartmann
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
| | - Noah Henschel
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
| | - Kristina Bartmann
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
- DNTOX GmbH, Gurlittstraße 53, 40223 Düsseldorf, Germany
| | - Arif Dönmez
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
- DNTOX GmbH, Gurlittstraße 53, 40223 Düsseldorf, Germany
| | - Gabriele Brockerhoff
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
| | - Katharina Koch
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
- DNTOX GmbH, Gurlittstraße 53, 40223 Düsseldorf, Germany
| | - Ellen Fritsche
- IUF-Leibniz-Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Duesseldorf, Germany
- DNTOX GmbH, Gurlittstraße 53, 40223 Düsseldorf, Germany
- Medical Faculty, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| |
Collapse
|
6
|
Akyuz E, Celik BR, Aslan FS, Sahin H, Angelopoulou E. Exploring the Role of Neurotransmitters in Multiple Sclerosis: An Expanded Review. ACS Chem Neurosci 2023; 14:527-553. [PMID: 36724132 DOI: 10.1021/acschemneuro.2c00589] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system (CNS). Although emerging evidence has shown that changes in neurotransmitter levels in the synaptic gap may contribute to the pathophysiology of MS, their specific role has not been elucidated yet. In this review, we aim to analyze preclinical and clinical evidence on the structural and functional changes in neurotransmitters in MS and critically discuss their potential role in MS pathophysiology. Preclinical studies have demonstrated that alterations in glutamate metabolism may contribute to MS pathophysiology, by causing excitotoxic neuronal damage. Dysregulated interaction between glutamate and GABA results in synaptic loss. The GABAergic system also plays an important role, by regulating the activity and plasticity of neural networks. Targeting GABAergic/glutamatergic transmission may be effective in fatigue and cognitive impairment in MS. Acetylcholine (ACh) and dopamine can also affect the T-mediated inflammatory responses, thereby being implicated in MS-related neuroinflammation. Also, melatonin might affect the frequency of relapses in MS, by regulating the sleep-wake cycle. Increased levels of nitric oxide in inflammatory lesions of MS patients may be also associated with axonal neuronal degeneration. Therefore, neurotransmitter imbalance may be critically implicated in MS pathophysiology, and future studies are needed for our deeper understanding of their role in MS.
Collapse
Affiliation(s)
- Enes Akyuz
- Department of Biophysics, International School of Medicine, University of Health Sciences, Istanbul, Turkey, 34668
| | - Betul Rana Celik
- Hamidiye School of Medicine, University of Health Sciences, Istanbul, Turkey, 34668
| | - Feyza Sule Aslan
- Hamidiye International School of Medicine, University of Health Sciences, Istanbul, Turkey, 34668
| | - Humeyra Sahin
- School of Medicine, Bezmialem Vakif University, Istanbul, Turkey, 34093
| | - Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens, Greece, 115 27
| |
Collapse
|
7
|
Kang W, Ju C, Joo J, Lee J, Shon YM, Park SM. Closed-loop direct control of seizure focus in a rodent model of temporal lobe epilepsy via localized electric fields applied sequentially. Nat Commun 2022; 13:7805. [PMID: 36528681 PMCID: PMC9759546 DOI: 10.1038/s41467-022-35540-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Direct electrical stimulation of the seizure focus can achieve the early termination of epileptic oscillations. However, direct intervention of the hippocampus, the most prevalent seizure focus in temporal lobe epilepsy is thought to be not practicable due to its large size and elongated shape. Here, in a rat model, we report a sequential narrow-field stimulation method for terminating seizures, while focusing stimulus energy at the spatially extensive hippocampal structure. The effects and regional specificity of this method were demonstrated via electrophysiological and biological responses. Our proposed modality demonstrates spatiotemporal preciseness and selectiveness for modulating the pathological target region which may have potential for further investigation as a therapeutic approach.
Collapse
Affiliation(s)
- Wonok Kang
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Chanyang Ju
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Jaesoon Joo
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea
| | - Jiho Lee
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Young-Min Shon
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea ,grid.264381.a0000 0001 2181 989XDepartment of Neurology, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 Republic of Korea
| | - Sung-Min Park
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Electrical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.15444.300000 0004 0470 5454Institute of Convergence Science, Yonsei University, Seoul, 03722 Republic of Korea
| |
Collapse
|
8
|
Feleke R, Jazayeri D, Abouzeid M, Powell KL, Srivastava PK, O’Brien TJ, Jones NC, Johnson MR. Integrative genomics reveals pathogenic mediator of valproate-induced neurodevelopmental disability. Brain 2022; 145:3832-3842. [PMID: 36071595 PMCID: PMC9679160 DOI: 10.1093/brain/awac296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/22/2022] [Accepted: 08/03/2022] [Indexed: 11/13/2022] Open
Abstract
Prenatal exposure to the anti-seizure medication sodium valproate (VPA) is associated with an increased risk of adverse postnatal neurodevelopmental outcomes, including lowered intellectual ability, autism spectrum disorder and attention-deficit hyperactivity disorder. In this study, we aimed to clarify the molecular mechanisms underpinning the neurodevelopmental consequences of gestational VPA exposure using integrative genomics. We assessed the effect of gestational VPA on foetal brain gene expression using a validated rat model of valproate teratogenicity that mimics the human scenario of chronic oral valproate treatment during pregnancy at doses that are therapeutically relevant to the treatment of epilepsy. Two different rat strains were studied-inbred Genetic Absence Epilepsy Rats from Strasbourg, a model of genetic generalized epilepsy, and inbred non-epileptic control rats. Female rats were fed standard chow or VPA mixed in standard chow for 2 weeks prior to conception and then mated with same-strain males. In the VPA-exposed rats maternal oral treatment was continued throughout pregnancy. Foetuses were extracted via C-section on gestational Day 21 (1 day prior to birth) and foetal brains were snap-frozen and genome-wide gene expression data generated. We found that gestational VPA exposure via chronic maternal oral dosing was associated with substantial drug-induced differential gene expression in the pup brains, including dysregulated splicing, and observed that this occurred in the absence of evidence for significant neuronal gain or loss. The functional consequences of VPA-induced gene expression were explored using pathway analysis and integration with genetic risk data for psychiatric disease and behavioural traits. The set of genes downregulated by VPA in the pup brains were significantly enriched for pathways related to neurodevelopment and synaptic function and significantly enriched for heritability to human intelligence, schizophrenia and bipolar disorder. Our results provide a mechanistic link between chronic foetal VPA exposure and neurodevelopmental disability mediated by VPA-induced transcriptional dysregulation.
Collapse
Affiliation(s)
| | | | - Maya Abouzeid
- Department of Brain Sciences, Imperial College London, London, UK
| | - Kim L Powell
- The Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia,Department of Neuroscience, The Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia
| | | | | | | | - Michael R Johnson
- Correspondence to: Professor Michael R. Johnson Department of Brain Sciences Imperial College London Room E419 Burlington Danes Building 160 Du Cane Road, London W12 0NN, UK E-mail:
| |
Collapse
|
9
|
Ragan CM, Ahmed EI, Vitale EM, Linning-Duffy K, Miller-Smith SM, Maguire J, Lonstein JS. Postpartum State, but Not Maternal Caregiving or Level of Anxiety, Increases Medial Prefrontal Cortex GAD65 and vGAT in Female Rats. Front Glob Womens Health 2022; 2:746518. [PMID: 35211693 PMCID: PMC8861351 DOI: 10.3389/fgwh.2021.746518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/27/2021] [Indexed: 11/13/2022] Open
Abstract
Upregulation of the inhibitory neurotransmitter, GABA, is involved in many of the behavioral differences between postpartum and nulliparous female rodents. This is evidenced by studies showing that pharmacological blockade of GABAergic activity impairs maternal caregiving and postpartum affective behaviors. However, the influence of motherhood on the capacity for GABA synthesis or release in the medial prefrontal cortex (mPFC; brain region involved in many social and affective behaviors) is not well-understood. Western blotting was used to compare postpartum and nulliparous rats in protein levels of the 65-kD isoform of glutamic acid decarboxylase (GAD65; synthesizes most GABA released from terminals) and vesicular GABA transporter (vGAT; accumulates GABA into synaptic vesicles for release) in the mPFC. We found that postpartum mothers had higher GAD65 and vGAT compared to virgins, but such differences were not found between maternally sensitized and non-sensitized virgins, indicating that reproduction rather than just the display of maternal caregiving is required. To test whether GAD65 and vGAT levels in the mPFC were more specifically related to anxiety-related behavior within postpartum mothers, we selected 8 low-anxiety and 8 high-anxiety dams based on their time spent in the open arms of an elevated plus maze on postpartum day 7. There were no significant differences between the anxiety groups in either GAD65 or vGAT levels. These data further indicate that frontal cortical GABA is affected by female reproduction and more likely contributes to differences in the display of socioemotional behaviors across, but not within, female reproductive state.
Collapse
Affiliation(s)
- Christina M. Ragan
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
- School of Biology and Undergraduate Neuroscience Program, Georgia Institute of Technology, Atlanta, GA, United States
| | - Eman I. Ahmed
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Erika M. Vitale
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
| | | | - Stephanie M. Miller-Smith
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Jamie Maguire
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Joseph S. Lonstein
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
- Behavioral Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Joseph S. Lonstein
| |
Collapse
|
10
|
Fish KN, Rocco BR, DeDionisio AM, Dienel SJ, Sweet RA, Lewis DA. Altered Parvalbumin Basket Cell Terminals in the Cortical Visuospatial Working Memory Network in Schizophrenia. Biol Psychiatry 2021; 90:47-57. [PMID: 33892915 PMCID: PMC8243491 DOI: 10.1016/j.biopsych.2021.02.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/21/2021] [Accepted: 02/11/2021] [Indexed: 12/28/2022]
Abstract
BACKGROUND Visuospatial working memory (vsWM), which is commonly impaired in schizophrenia, involves information processing across the primary visual cortex, association visual cortex, posterior parietal cortex, and dorsolateral prefrontal cortex (DLPFC). Within these regions, vsWM requires inhibition from parvalbumin-expressing basket cells (PVBCs). Here, we analyzed indices of PVBC axon terminals across regions of the vsWM network in schizophrenia. METHODS For 20 matched pairs of subjects with schizophrenia and unaffected comparison subjects, tissue sections from the primary visual cortex, association visual cortex, posterior parietal cortex, and DLPFC were immunolabeled for PV, the 65- and 67-kDa isoforms of glutamic acid decarboxylase (GAD65 and GAD67) that synthesize GABA (gamma-aminobutyric acid), and the vesicular GABA transporter. The density of PVBC terminals and of protein levels per terminal was quantified in layer 3 of each cortical region using fluorescence confocal microscopy. RESULTS In comparison subjects, all measures, except for GAD65 levels, exhibited a caudal-to-rostral decline across the vsWM network. In subjects with schizophrenia, the density of detectable PVBC terminals was significantly lower in all regions except the DLPFC, whereas PVBC terminal levels of PV, GAD67, and GAD65 proteins were lower in all regions. A composite measure of inhibitory strength was lower in subjects with schizophrenia, although the magnitude of the diagnosis effect was greater in the primary visual, association visual, and posterior parietal cortices than in the DLPFC. CONCLUSIONS In schizophrenia, alterations in PVBC terminals across the vsWM network suggest the presence of a shared substrate for cortical dysfunction during vsWM tasks. However, regional differences in the magnitude of the disease effect on an index of PVBC inhibitory strength suggest region-specific alterations in information processing during vsWM tasks.
Collapse
Affiliation(s)
- Kenneth N Fish
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania.
| | - Brad R Rocco
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adam M DeDionisio
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Samuel J Dienel
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert A Sweet
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| |
Collapse
|
11
|
Wang X, Hu Y, Liu W, Ma Y, Chen X, Xue T, Cui D. Molecular Basis of GABA Hypofunction in Adolescent Schizophrenia-Like Animals. Neural Plast 2021; 2021:9983438. [PMID: 33936193 PMCID: PMC8062182 DOI: 10.1155/2021/9983438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/22/2021] [Accepted: 03/30/2021] [Indexed: 01/11/2023] Open
Abstract
Schizophrenia is a neurodevelopmental disorder that NMDA receptor (NMDAR) hypofunction appears centrally involved. Schizophrenia typically emerges in adolescence or early adulthood. Electrophysiological and several neurochemical changes have linked the GABA deficits to abnormal behaviors induced by NMDAR hypofunction. However, few studies have systematically investigated the molecular basis of GABA deficits, especially during adolescence. To address this issue, we transiently administrated MK-801 to mice on PND 10, which exhibited schizophrenia-relevant deficits in adolescence. Slice recording showed reduced GABA transmission and PVI+ hypofunction, indicating GABAergic hypofunction. Cortical proteomic evaluation combined with analysis of single cell data from the Allen Brain showed that various metabolic processes were enriched in top ranks and differentially altered in excitatory neurons, GABAergic interneurons, and glial cells. Notably, the GABA-related amino acid metabolic process was disturbed in both astrocytes and interneurons, in which we found a downregulated set of GABA-related proteins (GAD65, SYNPR, DBI, GAT3, SN1, and CPT1A). They synergistically regulate GABA synthesis, release, reuptake, and replenishment. Their downregulation indicates impaired GABA cycle and homeostasis regulated by interneuron-astrocyte communication in adolescence. Our findings on molecular basis of GABA deficits could provide potential drug targets of GABAergic rescue for early prevention and intervention.
Collapse
Affiliation(s)
- Xiaodan Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
- Department of Neurology & Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Hu
- Shenzhi Department of the Fourth Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Wenxin Liu
- College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Yuanyuan Ma
- Shenzhi Department of the Fourth Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Xi Chen
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
| | - Ting Xue
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
| | - Donghong Cui
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
- Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
12
|
Integrative opioid-GABAergic neuronal mechanisms regulating dopamine efflux in the nucleus accumbens of freely moving animals. Pharmacol Rep 2021; 73:971-983. [PMID: 33743175 DOI: 10.1007/s43440-021-00249-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/26/2021] [Accepted: 03/11/2021] [Indexed: 01/14/2023]
Abstract
The nucleus accumbens (NAc) is a terminal region of mesocorticolimbic dopamine (DA) neuronal projections from the ventral tegmental area. Accumbal DA release is integrated by afferents from other brain regions and by interneurons, which involve a diversity of neurotransmitters and neuropeptides. These integrative processes, implicated in the pathobiology of neuropsychiatric disorders, are mediated via receptor subtypes whose relative roles in the regulation of accumbal DA release are poorly understood. Such complex interactions are exemplified by how selective activation of opioid receptor subtypes enhances accumbal DA efflux in a manner that is modulated by changes in neural activity through GABA receptor subtypes. This review delineates the roles of GABAA and GABAB receptors in GABAergic neural mechanisms in NAc that participate in delta- and mu-opioid receptor-mediated increases in accumbal DA efflux in freely moving rats, focusing on studies using in vivo brain microdialysis. First, we consider how endogenous GABA exerts inhibition of accumbal DA efflux through GABA receptor subtypes. We also consider possible intra-neuronal source of the endogenous GABA that inhibits accumbal DA efflux. As NAc contains GABAergic neurons that express delta- or mu-opioid receptors, inhibition of accumbal GABAergic neurons is a candidate for mediating delta- or mu-opioid receptor-mediated increases in accumbal DA efflux. Therefore, we provide a detailed analysis of the effects of GABA receptor subtype ligands on delta- and mu-opioid receptor-mediated accumbal DA efflux. Finally, we present an integrative model to explain the mechanisms of interaction among delta- and mu-opioid receptors, GABAergic neurons and DAergic neurons in NAc.
Collapse
|
13
|
Chen SG, Tsai CH, Lin CJ, Lee CC, Yu HY, Hsieh TH, Liu HL. Transcranial focused ultrasound pulsation suppresses pentylenetetrazol induced epilepsy in vivo. Brain Stimul 2019; 13:35-46. [PMID: 31575487 DOI: 10.1016/j.brs.2019.09.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 09/04/2019] [Accepted: 09/23/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Epilepsy is a neurological disorder characterized by abnormal neuron discharge, and one-third of epilepsy patients suffer from drug-resistant epilepsy (DRE). The current management for DRE includes epileptogenic lesion resection, disconnection, and neuromodulation. Neuromodulation is achieved through invasive electrical stimulus including deep brain stimulation, vagus nerve stimulation, or responsive neurostimulation (RNS). As an alternative therapy, transcranial focused ultrasound (FUS) can transcranially and non-invasively modulate neuron activity. OBJECTIVE This study seeks to verify the use of FUS pulsations to suppress spikes in an acute epileptic small-animal model, and to investigate possible biological mechanisms by which FUS pulsations interfere with epileptic neuronal activity. METHODS The study used a total of 76 Sprague-Dawley rats. For the epilepsy model, rats were administered pentylenetetrazol (PTZ) to induce acute epileptic-like abnormal neuron discharges, followed by FUS exposure. Various ultrasound parameters were set to test the epilepsy-suppressing effect, while concurrently monitoring and analyzing electroencephalogram (EEG) signals. Animal behavior was monitored and histological examinations were conducted to evaluate the hazard posed by ultrasound exposure and the expression of neuronal activity markers. Western blotting was used to evaluate the correlation between FUS-induced epileptic suppression and the PI3K-mTOR signaling pathway. RESULTS We observed that FUS pulsations effectively suppressed epileptic activity and observed EEG spectrum oscillations; the spike-suppressing effect depended on the selection of ultrasound parameters and highly correlated with FUS exposure level. Expression level changes of c-Fos and GAD65 were confirmed in the cortex and hippocampus, indicating that FUS pulsations deactivated excitatory cells and activated GABAergic terminals. No tissue damage, inflammatory response, or behavioral abnormalities were observed in rats treated with FUS under these exposure parameters. We also found that the FUS pulsations down-regulated the S6 phosphorylation and decreased pAKT expression. CONCLUSION Our results suggest that pulsed FUS exposure effectively suppresses epileptic spikes in an acute epilepsy animal model, and finds that ultrasound pulsation interferes with neuronal activity and affects the PTZ-induced PI3K-Akt-mTOR pathway, which might help explain the mechanism underlying ultrasound-related epileptic spike control.
Collapse
Affiliation(s)
- Sin-Guang Chen
- Department of Electrical Engineering, Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan; Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Chih-Hung Tsai
- Department of Electrical Engineering, Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Chia-Jung Lin
- Department of Electrical Engineering, Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Cheng-Chia Lee
- Department of Neurosurgery, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine and Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Hsiang-Yu Yu
- School of Medicine and Brain Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Tsung-Hsun Hsieh
- School of Physical Therapy and Graduate Institute of Rehabilitation Science, Chang Gung University, Taoyuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan.
| | - Hao-Li Liu
- Department of Electrical Engineering, Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
| |
Collapse
|
14
|
Pinellia Total Alkaloids Modulate the GABAergic System in Hippocampal Formation on Pilocarpine-Induced Epileptic Rats. Chin J Integr Med 2019; 26:138-145. [DOI: 10.1007/s11655-019-2944-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2019] [Indexed: 01/13/2023]
|
15
|
Metabolism and metabolomics of opiates: A long way of forensic implications to unravel. J Forensic Leg Med 2019; 61:128-140. [DOI: 10.1016/j.jflm.2018.12.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 12/15/2018] [Accepted: 12/17/2018] [Indexed: 12/27/2022]
|
16
|
Mayorquin LC, Rodriguez AV, Sutachan JJ, Albarracín SL. Connexin-Mediated Functional and Metabolic Coupling Between Astrocytes and Neurons. Front Mol Neurosci 2018; 11:118. [PMID: 29695954 PMCID: PMC5905222 DOI: 10.3389/fnmol.2018.00118] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/27/2018] [Indexed: 01/24/2023] Open
Abstract
The central nervous system (CNS) requires sophisticated regulation of neuronal activity. This modulation is partly accomplished by non-neuronal cells, characterized by the presence of transmembrane gap junctions (GJs) and hemichannels (HCs). This allows small molecule diffusion to guarantee neuronal synaptic activity and plasticity. Astrocytes are metabolically and functionally coupled to neurons by the uptake, binding and recycling of neurotransmitters. In addition, astrocytes release metabolites, such as glutamate, glutamine, D-serine, adenosine triphosphate (ATP) and lactate, regulating synaptic activity and plasticity by pre- and postsynaptic mechanisms. Uncoupling neuroglial communication leads to alterations in synaptic transmission that can be detrimental to neuronal circuit function and behavior. Therefore, understanding the pathways and mechanisms involved in this intercellular communication is fundamental for the search of new targets that can be used for several neurological disease treatments. This review will focus on molecular mechanisms mediating physiological and pathological coupling between astrocytes and neurons through GJs and HCs.
Collapse
Affiliation(s)
- Lady C Mayorquin
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Andrea V Rodriguez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Jhon-Jairo Sutachan
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Sonia L Albarracín
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| |
Collapse
|
17
|
Enhanced susceptibility to stress and seizures in GAD65 deficient mice. PLoS One 2018; 13:e0191794. [PMID: 29377906 PMCID: PMC5788371 DOI: 10.1371/journal.pone.0191794] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/11/2018] [Indexed: 12/23/2022] Open
Abstract
Reduced gamma-aminobutyric acid (GABA) inhibition has been implicated in both anxiety and epilepsy. GAD65-/- (NOD/LtJ) mice have significantly decreased basal GABA levels in the brain and a lowered threshold for seizure generation. One fifth of GAD65 -/- mice experienced stress-induced seizures upon exposure to an open field at 4 weeks of age. In each successive week until 8 weeks of age, the latency to seizures decreased with prior seizure experience. 100% of GAD65-/- mice exhibited stress-induced seizures by the end of 8 weeks. GAD65-/- mice also exhibited marked impairment in open field exploratory behavior and deficits in spatial learning acquisition on a Barnes maze. Anxiety-like behavior in an open field was observed prior to seizure onset and was predictive of subsequent seizures. Immunohistochemical characterization of interneuron subtypes in GAD65-/- mice showed a selective decrease in GABA and neuropeptide Y (NPY) levels and no change in calbindin (CLB) or calretinin (CLR) immunoreactivity in the hippocampus. Stem cells from the medial ganglionic eminence (MGE) were injected into the hippocampal hilus to restore GABAergic interneurons. One week after transplantation, MGE-transplanted mice demonstrated significant seizure resistance compared to sham surgical controls. The percent area of GFP+ MGE graft in the hippocampus correlated significantly with the increase in seizure latency. Our data indicate that impaired GABAergic neurotransmission can cause anxiety-like behavior and stress-induced seizures that can be rescued by MGE stem cell transplantation.
Collapse
|
18
|
Xu J, Zheng X, Cheng KK, Chang X, Shen G, Liu M, Wang Y, Shen J, Zhang Y, He Q, Dong J, Yang Z. NMR-based metabolomics Reveals Alterations of Electro-acupuncture Stimulations on Chronic Atrophic Gastritis Rats. Sci Rep 2017; 7:45580. [PMID: 28358020 PMCID: PMC5372362 DOI: 10.1038/srep45580] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/28/2017] [Indexed: 12/15/2022] Open
Abstract
Chronic atrophic gastritis (CAG) is a common gastrointestinal disease which has been considered as precancerous lesions of gastric carcinoma. Previously, electro-acupuncture stimulation has been shown to be effective in ameliorating symptoms of CAG. However the underlying mechanism of this beneficial treatment is yet to be established. In the present study, an integrated histopathological examination along with molecular biological assay, as well as 1H NMR analysis of multiple biological samples (urine, serum, stomach, cortex and medulla) were employed to systematically assess the pathology of CAG and therapeutic effect of electro-acupuncture stimulation at Sibai (ST 2), Liangmen (ST 21), and Zusanli (ST 36) acupoints located in the stomach meridian using a rat model of CAG. The current results showed that CAG caused comprehensive metabolic alterations including the TCA cycle, glycolysis, membrane metabolism and catabolism, gut microbiota-related metabolism. On the other hand, electro-acupuncture treatment was found able to normalize a number of CAG-induced metabolomics changes by alleviating membrane catabolism, restoring function of neurotransmitter in brain and partially reverse the CAG-induced perturbation in gut microbiota metabolism. These findings provided new insights into the biochemistry of CAG and mechanism of the therapeutic effect of electro-acupuncture stimulations.
Collapse
Affiliation(s)
- Jingjing Xu
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Xujuan Zheng
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Kian-Kai Cheng
- Department of Bioprocess &Polymer Engineering, Innovative Centre in Agritechnology, University Teknologi Malaysia, Johor 81310, Malaysia
| | - Xiaorong Chang
- College of Acupuncture and Moxibustion, Hunan University of Chinese Medicine, Changsha 410007, China
| | - Guiping Shen
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Mi Liu
- College of Acupuncture and Moxibustion, Hunan University of Chinese Medicine, Changsha 410007, China
| | - Yadong Wang
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Jiacheng Shen
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Yuan Zhang
- College of Acupuncture and Moxibustion, Hunan University of Chinese Medicine, Changsha 410007, China
| | - Qida He
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Jiyang Dong
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| | - Zongbao Yang
- Department of Electronic Science, and Department of Traditional Chinese Medicine, Xiamen University, Xiamen 361005, China
| |
Collapse
|
19
|
Davis KN, Tao R, Li C, Gao Y, Gondré-Lewis MC, Lipska BK, Shin JH, Xie B, Ye T, Weinberger DR, Kleinman JE, Hyde TM. GAD2 Alternative Transcripts in the Human Prefrontal Cortex, and in Schizophrenia and Affective Disorders. PLoS One 2016; 11:e0148558. [PMID: 26848839 PMCID: PMC4744057 DOI: 10.1371/journal.pone.0148558] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/19/2016] [Indexed: 01/04/2023] Open
Abstract
Genetic variation and early adverse environmental events work together to increase risk for schizophrenia. γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in adult mammalian brain, plays a major role in normal brain development, and has been strongly implicated in the pathobiology of schizophrenia. GABA synthesis is controlled by two glutamic acid decarboxylase (GAD) genes, GAD1 and GAD2, both of which produce a number of alternative transcripts. Genetic variants in the GAD1 gene are associated with increased risk for schizophrenia, and reduced expression of its major transcript in the human dorsolateral prefrontal cortex (DLPFC). No consistent changes in GAD2 expression have been found in brains from patients with schizophrenia. In this work, with the use of RNA sequencing and PCR technologies, we confirmed and tracked the expression of an alternative truncated transcript of GAD2 (ENST00000428517) in human control DLPFC homogenates across lifespan besides the well-known full length transcript of GAD2. In addition, using quantitative RT-PCR, expression of GAD2 full length and truncated transcripts were measured in the DLPFC of patients with schizophrenia, bipolar disorder and major depression. The expression of GAD2 full length transcript is decreased in the DLPFC of schizophrenia and bipolar disorder patients, while GAD2 truncated transcript is increased in bipolar disorder patients but decreased in schizophrenia patients. Moreover, the patients with schizophrenia with completed suicide or positive nicotine exposure showed significantly higher expression of GAD2 full length transcript. Alternative transcripts of GAD2 may be important in the growth and development of GABA-synthesizing neurons as well as abnormal GABA signaling in the DLPFC of patients with schizophrenia and affective disorders.
Collapse
Affiliation(s)
- Kasey N. Davis
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892–1385, United States of America
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
- Laboratory for Neurodevelopment, Department of Anatomy, Howard University College of Medicine, Washington D.C., 20059, United States of America
| | - Ran Tao
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Chao Li
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Yuan Gao
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Marjorie C. Gondré-Lewis
- Laboratory for Neurodevelopment, Department of Anatomy, Howard University College of Medicine, Washington D.C., 20059, United States of America
| | - Barbara K. Lipska
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892–1385, United States of America
| | - Joo Heon Shin
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Bin Xie
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Tianzhang Ye
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Daniel R. Weinberger
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
- Department of Psychiatry and Behavior Sciences, and Neurology, Johns Hopkins University School of Medicine, Johns Hopkins University Medical Campus, Baltimore, Maryland, 21205, United States of America
- Departments of Neuroscience and the Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Joel E. Kleinman
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
| | - Thomas M. Hyde
- The Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, United States of America
- Department of Psychiatry and Behavior Sciences, and Neurology, Johns Hopkins University School of Medicine, Johns Hopkins University Medical Campus, Baltimore, Maryland, 21205, United States of America
- * E-mail:
| |
Collapse
|
20
|
Kim J, Son Y, Kim J, Lee S, Kang S, Park K, Kim SH, Kim JC, Kim J, Takayama C, Im HI, Yang M, Shin T, Moon C. Developmental and degenerative modulation of GABAergic transmission in the mouse hippocampus. Int J Dev Neurosci 2015; 47:320-32. [PMID: 26394279 DOI: 10.1016/j.ijdevneu.2015.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/05/2015] [Accepted: 08/21/2015] [Indexed: 11/30/2022] Open
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter involved in synaptic plasticity. GABAergic transmission is also implicated in developmental and degenerative processes in the brain. The goal of the present study was to understand the developmental and degenerative regulation of GABAergic transmission in the mouse hippocampus by examining changes in GABA receptor subunit mRNA levels and GABA-related protein expression during postnatal development of the hippocampus and trimethyltin (TMT)-induced neurodegeneration in the juvenile (postnatal day [PD] 24) and adult hippocampus (PD 56). During postnatal development, the mRNA levels of GABA A receptor (GABAAR) subunits, including α1, α4, β1, β2, and δ; GABA B receptor (GABABR) subunit 2; and the expression of GABA-related proteins, including glutamic acid decarboxylase, vesicular GABA transporter (VGAT), and potassium chloride cotransporter 2 increased gradually in the mouse hippocampus. The results of seizure scoring and histopathological findings in the hippocampus revealed a more pronounced response to the same administered TMT dose in juvenile mice, compared with that in adult mice. The mRNA levels of most GABA receptor subunits in the juvenile hippocampus, excluding GABAAR subunit β3, were dynamically altered after TMT treatment. The mRNA levels of GABAAR subunits γ2 and δ decreased significantly in the adult hippocampus following TMT treatment, whereas the level of GABABR subunit 1 mRNA increased significantly. Among the GABA-related proteins, only VGAT decreased significantly in the juvenile and adult mouse hippocampus after TMT treatment. In conclusion, regulation of GABAergic signaling in the mouse hippocampus may be related to maturation of the central nervous system and the degree of neurodegeneration during postnatal development and TMT-induced neurodegeneration in the experimental animals.
Collapse
Affiliation(s)
- Jinwook Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Yeonghoon Son
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Juhwan Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea; Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea
| | - Sueun Lee
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Sohi Kang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Kyunghwan Park
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Jeongtae Kim
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Heh-In Im
- Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea
| | - Miyoung Yang
- Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, South Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690-756, South Korea.
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea.
| |
Collapse
|
21
|
Prager EM, Bergstrom HC, Wynn GH, Braga MFM. The basolateral amygdala γ-aminobutyric acidergic system in health and disease. J Neurosci Res 2015; 94:548-67. [PMID: 26586374 DOI: 10.1002/jnr.23690] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 10/01/2015] [Accepted: 10/18/2015] [Indexed: 01/13/2023]
Abstract
The brain comprises an excitatory/inhibitory neuronal network that maintains a finely tuned balance of activity critical for normal functioning. Excitatory activity in the basolateral amygdala (BLA), a brain region that plays a central role in emotion and motivational processing, is tightly regulated by a relatively small population of γ-aminobutyric acid (GABA) inhibitory neurons. Disruption in GABAergic inhibition in the BLA can occur when there is a loss of local GABAergic interneurons, an alteration in GABAA receptor activation, or a dysregulation of mechanisms that modulate BLA GABAergic inhibition. Disruptions in GABAergic control of the BLA emerge during development, in aging populations, or after trauma, ultimately resulting in hyperexcitability. BLA hyperexcitability manifests behaviorally as an increase in anxiety, emotional dysregulation, or development of seizure activity. This Review discusses the anatomy, development, and physiology of the GABAergic system in the BLA and circuits that modulate GABAergic inhibition, including the dopaminergic, serotonergic, noradrenergic, and cholinergic systems. We highlight how alterations in various neurotransmitter receptors, including the acid-sensing ion channel 1a, cannabinoid receptor 1, and glutamate receptor subtypes, expressed on BLA interneurons, modulate GABAergic transmission and how defects of these systems affect inhibitory tonus within the BLA. Finally, we discuss alterations in the BLA GABAergic system in neurodevelopmental (autism/fragile X syndrome) and neurodegenerative (Alzheimer's disease) diseases and after the development of epilepsy, anxiety, and traumatic brain injury. A more complete understanding of the intrinsic excitatory/inhibitory circuit balance of the amygdala and how imbalances in inhibitory control contribute to excessive BLA excitability will guide the development of novel therapeutic approaches in neuropsychiatric diseases.
Collapse
Affiliation(s)
- Eric M Prager
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services, University of the Health Sciences, Bethesda, Maryland
| | | | - Gary H Wynn
- Center for the Study of Traumatic Stress, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland.,Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland.,Program in Neuroscience, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Maria F M Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services, University of the Health Sciences, Bethesda, Maryland.,Center for the Study of Traumatic Stress, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland.,Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland.,Program in Neuroscience, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| |
Collapse
|
22
|
Müller I, Çalışkan G, Stork O. The GAD65 knock out mouse - a model for GABAergic processes in fear- and stress-induced psychopathology. GENES BRAIN AND BEHAVIOR 2015; 14:37-45. [PMID: 25470336 DOI: 10.1111/gbb.12188] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 12/16/2022]
Abstract
The γ-amino butyric acid (GABA) synthetic enzyme glutamic acid decarboxylase (GAD)65 is critically involved in the activity-dependent regulation of GABAergic inhibition in the central nervous system. It is also required for the maturation of the GABAergic system during adolescence, a phase that is critical for the development of several neuropsychiatric diseases. Mice bearing a null mutation of the GAD65 gene develop hyperexcitability of the amygdala and hippocampus, and a phenotype of increased anxiety and pathological fear memory reminiscent of posttraumatic stress disorder. Although genetic association of GAD65 in human has not yet been reported, these findings are in line with observations of reduced GABAergic function in these brain regions of anxiety disorder patients. The particular value of GAD65(-/-) mice thus lies in modeling the effects of reduced GABAergic function in the mature nervous system. The expression of GAD65 and a second GAD isozyme, GAD67, are differentially regulated in response to stress in limbic brain areas suggesting that by controlling GABAergic inhibition these enzymes determine the vulnerability for the development of pathological anxiety and other stress-induced phenotypes. In fact, we could recently show that GAD65 haplodeficiency, which results in delayed postnatal increase of GABA levels, provides resilience to juvenile-stress-induced anxiety to GAD65(+/-) mice thus foiling the increased fear and anxiety in homozygous GAD65(-/-) mice.
Collapse
Affiliation(s)
- Iris Müller
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | | | | |
Collapse
|
23
|
Hertz L, Chen Y, Waagepetersen HS. Effects of ketone bodies in Alzheimer's disease in relation to neural hypometabolism, β-amyloid toxicity, and astrocyte function. J Neurochem 2015; 134:7-20. [PMID: 25832906 DOI: 10.1111/jnc.13107] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 03/22/2015] [Accepted: 03/24/2015] [Indexed: 12/11/2022]
Abstract
Diet supplementation with ketone bodies (acetoacetate and β-hydroxybuturate) or medium-length fatty acids generating ketone bodies has consistently been found to cause modest improvement of mental function in Alzheimer's patients. It was suggested that the therapeutic effect might be more pronounced if treatment was begun at a pre-clinical stage of the disease instead of well after its manifestation. The pre-clinical stage is characterized by decade-long glucose hypometabolism in brain, but ketone body metabolism is intact even initially after disease manifestation. One reason for the impaired glucose metabolism may be early destruction of the noradrenergic brain stem nucleus, locus coeruleus, which stimulates glucose metabolism, at least in astrocytes. These glial cells are essential in Alzheimer pathogenesis. The β-amyloid peptide Aβ interferes with their cholinergic innervation, which impairs synaptic function because of diminished astrocytic glutamate release. Aβ also reduces glucose metabolism and causes hyperexcitability. Ketone bodies are similarly used against seizures, but the effectively used concentrations are so high that they must interfere with glucose metabolism and de novo synthesis of neurotransmitter glutamate, reducing neuronal glutamatergic signaling. The lower ketone body concentrations used in Alzheimer's disease may owe their effect to support of energy metabolism, but might also inhibit release of gliotransmitter glutamate. Alzheimer's disease is a panglial-neuronal disorder with long-standing brain hypometabolism, aberrations in both neuronal and astrocytic glucose metabolism, inflammation, hyperexcitability, and dementia. Relatively low doses of β-hydroxybutyrate can have an ameliorating effect on cognitive function. This could be because of metabolic supplementation or inhibition of Aβ-induced release of glutamate as gliotransmitter, which is likely to reduce hyperexcitability and inflammation. The therapeutic β-hydroxybutyrate doses are too low to reduce neuronally released glutamate.
Collapse
Affiliation(s)
- Leif Hertz
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Ye Chen
- Henry M. Jackson Foundation, Bethesda, Maryland, USA
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
24
|
Lower glutamic acid decarboxylase 65-kDa isoform messenger RNA and protein levels in the prefrontal cortex in schizoaffective disorder but not schizophrenia. Biol Psychiatry 2015; 77:167-76. [PMID: 24993056 PMCID: PMC4247819 DOI: 10.1016/j.biopsych.2014.05.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/13/2014] [Accepted: 05/21/2014] [Indexed: 01/27/2023]
Abstract
BACKGROUND Altered gamma-aminobutyric acid (GABA) signaling in the prefrontal cortex (PFC) has been associated with cognitive dysfunction in patients with schizophrenia and schizoaffective disorder. Levels of the GABA-synthesizing enzyme glutamic acid decarboxylase 67-kDa isoform (GAD67) in the PFC have been consistently reported to be lower in patients with these disorders, but the status of the second GABA-synthesizing enzyme, glutamic acid decarboxylase 65-kDa isoform (GAD65), remains unclear. METHODS GAD65 messenger RNA (mRNA) levels were quantified in PFC area 9 by quantitative polymerase chain reaction from 62 subjects with schizophrenia or schizoaffective disorder and 62 matched healthy comparison subjects. In a subset of subject pairs, GAD65 relative protein levels were quantified by confocal immunofluorescence microscopy. RESULTS Mean GAD65 mRNA levels were 13.6% lower in subjects with schizoaffective disorder but did not differ in subjects with schizophrenia relative to their matched healthy comparison subjects. In the subjects with schizoaffective disorder, mean GAD65 protein levels were 19.4% lower and were correlated with GAD65 mRNA levels. Lower GAD65 mRNA and protein levels within subjects with schizoaffective disorder were not attributable to factors commonly comorbid with the diagnosis. CONCLUSIONS In concert with previous studies, these findings suggest that schizoaffective disorder is associated with lower levels of both GAD65 and GAD67 mRNA and protein in the PFC, whereas subjects with schizophrenia have lower mean levels of only GAD67 mRNA and protein. Because cognitive function is generally better preserved in patients with schizoaffective disorder relative to patients with schizophrenia, these findings may support an interpretation that GAD65 downregulation provides a homeostatic response complementary to GAD67 downregulation that serves to reduce inhibition in the face of lower PFC network activity.
Collapse
|
25
|
Jiang P, Zhang LH, Cai HL, Li HD, Liu YP, Tang MM, Dang RL, Zhu WY, Xue Y, He X. Neurochemical effects of chronic administration of calcitriol in rats. Nutrients 2014; 6:6048-59. [PMID: 25533012 PMCID: PMC4277014 DOI: 10.3390/nu6126048] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/12/2014] [Accepted: 12/16/2014] [Indexed: 01/09/2023] Open
Abstract
Despite accumulating data showing the various neurological actions of vitamin D (VD), its effects on brain neurochemistry are still far from fully understood. To further investigate the neurochemical influence of VD, we assessed neurotransmitter systems in the brain of rats following 6-week calcitriol (1,25-dihydroxyvitamin D) administration (50 ng/kg/day or 100 ng/kg/day). Both the two doses of calcitriol enhanced VDR protein level without affecting serum calcium and phosphate status. Rats treated with calcitriol, especially with the higher dose, exhibited elevated γ-aminobutyric acid (GABA) status. Correspondingly, the mRNA expression of glutamate decarboxylase (GAD) 67 was increased. 100 ng/kg of calcitriol administration also increased glutamate and glutamine levels in the prefrontal cortex, but did not alter glutamine synthetase (GS) expression. Additionally, calcitriol treatment promoted tyrosine hydroxylase (TH) and tryptophan hydroxylase 2 (TPH2) expression without changing dopamine and serotonin status. However, the concentrations of the metabolites of dopamine and serotonin were increased and the drug use also resulted in a significant rise of monoamine oxidase A (MAOA) expression, which might be responsible to maintain the homeostasis of dopaminergic and serotonergic neurotransmission. Collectively, the present study firstly showed the effects of calcitriol in the major neurotransmitter systems, providing new evidence for the role of VD in brain function.
Collapse
Affiliation(s)
- Pei Jiang
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Li-Hong Zhang
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Hua-Lin Cai
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Huan-De Li
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Yi-Ping Liu
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Mi-Mi Tang
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Rui-Li Dang
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Wen-Ye Zhu
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Ying Xue
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Xin He
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| |
Collapse
|
26
|
Walls AB, Eyjolfsson EM, Schousboe A, Sonnewald U, Waagepetersen HS. A subconvulsive dose of kainate selectively compromises astrocytic metabolism in the mouse brain in vivo. J Cereb Blood Flow Metab 2014; 34:1340-6. [PMID: 24824917 PMCID: PMC4126094 DOI: 10.1038/jcbfm.2014.88] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/09/2014] [Accepted: 04/16/2014] [Indexed: 11/09/2022]
Abstract
Despite the well-established use of kainate as a model for seizure activity and temporal lobe epilepsy, most studies have been performed at doses giving rise to general limbic seizures and have mainly focused on neuronal function. Little is known about the effect of lower doses of kainate on cerebral metabolism and particularly that associated with astrocytes. We investigated astrocytic and neuronal metabolism in the cerebral cortex of adult mice after treatment with saline (controls), a subconvulsive or a mildly convulsive dose of kainate. A combination of [1,2-(13)C]acetate and [1-(13)C]glucose was injected and subsequent nuclear magnetic resonance spectroscopy of cortical extracts was employed to distinctively map astrocytic and neuronal metabolism. The subconvulsive dose of kainate led to an instantaneous increase in the cortical lactate content, a subsequent reduction in the amount of [4,5-(13)C]glutamine and an increase in the calculated astrocytic TCA cycle activity. In contrast, the convulsive dose led to decrements in the cortical content and (13)C labeling of glutamate, glutamine, GABA, and aspartate. Evidence is provided that astrocytic metabolism is affected by a subconvulsive dose of kainate, whereas a higher dose is required to affect neuronal metabolism. The cerebral glycogen content was dose-dependently reduced by kainate supporting a role for glycogen during seizure activity.
Collapse
Affiliation(s)
- Anne B Walls
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elvar M Eyjolfsson
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ursula Sonnewald
- Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
27
|
Wang X, Gao F, Zhu J, Guo E, Song X, Wang S, Zhan RZ. Immunofluorescently labeling glutamic acid decarboxylase 65 coupled with confocal imaging for identifying GABAergic somata in the rat dentate gyrus-A comparison with labeling glutamic acid decarboxylase 67. J Chem Neuroanat 2014; 61-62:51-63. [PMID: 25058170 DOI: 10.1016/j.jchemneu.2014.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 07/11/2014] [Accepted: 07/12/2014] [Indexed: 01/23/2023]
Abstract
As γ-aminobutyric acid (GABA) is synthesized by two isoforms of glutamic acid decarboxylase (GAD), namely, GAD65 and GAD67, immunohistochemically targeting either isoform of GAD is theoretically useful for identifying GABAergic cell bodies. In practice, targeting GAD67 remains to be a popular choice. However, identifying GABAergic cell bodies with GAD67 immunoreactivity in the hippocampal dentate gyrus, especially in the hilus, is not without pitfalls. In the present study, we compared the characteristics of GAD65 immunoreactivity to GAD67 immunoreactivity in the rat dentate gyrus and examined perikaryal expression of GAD65 in four neurochemically prevalent subgroups of interneurons in the hilus. Experiments were done in normal adult Sprague-Dawley rats and GAD67-GFP knock-in mice. Horizontal hippocampal slices cut from the ventral portion of hippocampi were immunofluorescently stained and scanned using a confocal microscope. Immunoreactivity for both GAD67 and GAD65 was visible throughout the dentate gyrus. Perikaryal GAD67 immunoreactivity was denser but variable in terms of distribution pattern and intensity among cells whereas perikaryal GAD65 immunoreactivity displayed similar distribution pattern and staining intensity. Among different layers of the dentate gyrus, GAD67 immunoreactivity was densest in the hilus despite GAD65 immunoreactivity being more intense in the granule cell layer. Co-localization experiments showed that GAD65, but not GAD67, was expressed in all hilar calretinin (CR)-, neuronal nitric oxide synthase (nNOS)-, parvalbumin (PV)- or somatostatin (SOM)-positive somata. Labeling CR, nNOS, PV, and SOM in sections obtained from GAD67-GFP knock-in mice revealed that a large portion of SOM-positive cells had weak GFP expression. In addition, double labeling of GAD65/GABA and GAD67/GABA showed that nearly all of GABA-immunoreactive cells had perikaryal GAD65 expression whereas more than one-tenth of GABA-immunoreactive cells lacked perikaryal GAD67 immunoreactivity. Inhibition of axonal transport with colchicine dramatically improved perikaryal GAD65 immunoreactivity in GABAergic cells without significant augmentation to be seen in granule cells. Double labeling GAD65 and GAD67 in the sections obtained from colchicine-pretreated animals confirmed that a portion of GAD65-immunoreactive cells had weak or even no GAD67 immunoreactivity. We conclude that for confocal imaging, immunofluorescently labeling GAD65 for identifying GABAergic somata in the hilus of the dentate gyrus has advantages over labeling GAD67 in terms of easier recognition of perikaryal labeling and more consistent expression in GABAergic somata. Inhibition of axonal transport with colchicine further improves perikaryal GAD65 labeling, making GABAergic cells more distinguishable.
Collapse
Affiliation(s)
- Xiaochen Wang
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Fei Gao
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Jianchun Zhu
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Enpu Guo
- Division of General Surgery, The Second Affiliated Hospital, Shandong University of Traditional Chinese Medicine, China
| | - Xueying Song
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Shuanglian Wang
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Ren-Zhi Zhan
- Department of Physiology, Shandong University School of Medicine, Jinan, China.
| |
Collapse
|
28
|
Lo-Castro A, Curatolo P. Epilepsy associated with autism and attention deficit hyperactivity disorder: is there a genetic link? Brain Dev 2014; 36:185-93. [PMID: 23726375 DOI: 10.1016/j.braindev.2013.04.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/28/2013] [Accepted: 04/30/2013] [Indexed: 12/26/2022]
Abstract
Autism Spectrum Disorders (ASDs) and Attention Deficit and Hyperactivity Disorder (ADHD) are the most common comorbid conditions associated with childhood epilepsy. The co-occurrence of an epilepsy/autism phenotype or an epilepsy/ADHD phenotype has a complex and heterogeneous pathogenesis, resulting from several altered neurobiological mechanisms involved in early brain development, and influencing synaptic plasticity, neurotransmission and functional connectivity. Rare clinically relevant chromosomal aberrations, in addition to environmental factors, may confer an increased risk for ASDs/ADHD comorbid with epilepsy. The majority of the candidate genes are involved in synaptic formation/remodeling/maintenance (NRX1, CNTN4, DCLK2, CNTNAP2, TRIM32, ASTN2, CTNTN5, SYN1), neurotransmission (SYNGAP1, GABRG1, CHRNA7), or DNA methylation/chromatin remodeling (MBD5). Two genetic disorders, such as Tuberous sclerosis and Fragile X syndrome may serve as models for understanding the common pathogenic pathways leading to ASDs and ADHD comorbidities in children with epilepsy, offering the potential for new biologically focused treatment options.
Collapse
Affiliation(s)
- Adriana Lo-Castro
- Neuroscience Department, Pediatric Neurology and Psychiatry Unit, Tor Vergata University of Rome, Italy.
| | - Paolo Curatolo
- Neuroscience Department, Pediatric Neurology and Psychiatry Unit, Tor Vergata University of Rome, Italy
| |
Collapse
|
29
|
Carver CM, Reddy DS. Neurosteroid interactions with synaptic and extrasynaptic GABA(A) receptors: regulation of subunit plasticity, phasic and tonic inhibition, and neuronal network excitability. Psychopharmacology (Berl) 2013; 230:151-88. [PMID: 24071826 PMCID: PMC3832254 DOI: 10.1007/s00213-013-3276-5] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/29/2013] [Indexed: 12/25/2022]
Abstract
RATIONALE Neurosteroids are steroids synthesized within the brain with rapid effects on neuronal excitability. Allopregnanolone, allotetrahydrodeoxycorticosterone, and androstanediol are three widely explored prototype endogenous neurosteroids. They have very different targets and functions compared to conventional steroid hormones. Neuronal γ-aminobutyric acid (GABA) type A (GABA(A)) receptors are one of the prime molecular targets of neurosteroids. OBJECTIVE This review provides a critical appraisal of recent advances in the pharmacology of endogenous neurosteroids that interact with GABA(A) receptors in the brain. Neurosteroids possess distinct, characteristic effects on the membrane potential and current conductance of the neuron, mainly via potentiation of GABA(A) receptors at low concentrations and direct activation of receptor chloride channel at higher concentrations. The GABA(A) receptor mediates two types of inhibition, now characterized as synaptic (phasic) and extrasynaptic (tonic) inhibition. Synaptic release of GABA results in the activation of low-affinity γ2-containing synaptic receptors, while high-affinity δ-containing extrasynaptic receptors are persistently activated by the ambient GABA present in the extracellular fluid. Neurosteroids are potent positive allosteric modulators of synaptic and extrasynaptic GABA(A) receptors and therefore enhance both phasic and tonic inhibition. Tonic inhibition is specifically more sensitive to neurosteroids. The resulting tonic conductance generates a form of shunting inhibition that controls neuronal network excitability, seizure susceptibility, and behavior. CONCLUSION The growing understanding of the mechanisms of neurosteroid regulation of the structure and function of the synaptic and extrasynaptic GABA(A) receptors provides many opportunities to create improved therapies for sleep, anxiety, stress, epilepsy, and other neuropsychiatric conditions.
Collapse
Affiliation(s)
- Chase Matthew Carver
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, 2008 Medical Research and Education Building, 8447 State Highway 47, Bryan, TX, 77807-3260, USA
| | | |
Collapse
|
30
|
Tomiyama K, Kato R, Hara Y, Kobayashi M, Mishina M, Yanagawa Y, Kinsella A, Koshikawa N, Waddington J. Phenotypic characterization of orofacial movement topography in mutants with disruption of amino acid mechanisms: Glutamate N2A/B/D [GluRε1/2/4] subtypes and the GABA synthesizing enzyme GAD65. Neuroscience 2013; 250:743-54. [DOI: 10.1016/j.neuroscience.2013.07.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 07/02/2013] [Accepted: 07/16/2013] [Indexed: 01/29/2023]
|
31
|
Leke R, Silveira TR, Escobar TDC, Schousboe A. Expression of Glutamate Decarboxylase (GAD) mRNA in the brain of bile duct ligated rats serving as a model of hepatic encephalopathy. Neurochem Res 2013; 39:605-11. [PMID: 23904086 DOI: 10.1007/s11064-013-1116-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 07/17/2013] [Accepted: 07/22/2013] [Indexed: 12/14/2022]
Abstract
Hepatic encephalopathy (HE) is a neurologic disorder that involves different pathophysiological mechanisms, including disturbances in the GABAergic neurotransmitter system. Albeit an overall increase in the level of neurotransmitter GABA has not been found in HE, alterations in GABA receptors and metabolism have been described. Moreover, it has been reported that bile duct ligated (BDL) rats, an animal model for the study of HE, exhibited an altered GABA biosynthesis involving preferentially the tricarboxylic (TCA) cycle. In this context it should be noted that the GABA synthesizing enzyme glutamate decarboxylase (GAD) is expressed in the brain in two isoforms GAD67 and GAD65, GAD65 being related to the synthesis of GABA that occurs via the TCA cycle and coupled to the vesicular pool of the neurotransmitter. The aim of the present study was to investigate whether changes in mRNA expression of GAD67 and GAD65 were related to the altered GABA biosynthesis previously observed. To study this, cerebral cortices and hippocampi were dissected from control and BDL rats, total mRNA was isolated and cDNA was synthesized by reverse transcription reaction. Subsequently samples were analyzed for gene expression of GAD67 and GAD65 by qPCR multiplex assay, using GAPDH as endogenous control. No changes in GAD67 and GAD65 mRNA expression between control and BDL rats either in cerebral cortex or in hippocampus were observed indicating that the HE condition did not lead to changes in GAD mRNA expression. However, other regulatory mechanism might be affecting GAD activity and to clarify this additional studies need to be conducted.
Collapse
Affiliation(s)
- Renata Leke
- Experimental Hepatology and Gastroenterology Laboratory, Research Center of Hospital de Clínicas de Porto Alegre, Avenida Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-903, Brazil,
| | | | | | | |
Collapse
|
32
|
Enoch MA, Baghal B, Yuan Q, Goldman D. A factor analysis of global GABAergic gene expression in human brain identifies specificity in response to chronic alcohol and cocaine exposure. PLoS One 2013; 8:e64014. [PMID: 23717525 PMCID: PMC3661725 DOI: 10.1371/journal.pone.0064014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/07/2013] [Indexed: 12/15/2022] Open
Abstract
Although expression patterns of GABAergic genes in rodent brain have largely been elucidated, no comprehensive studies have been performed in human brain. The purpose of this study was to identify global patterns of GABAergic gene expression in healthy adults, including trans and cis effects in the GABAA gene clusters, before determining the effects of chronic alcohol and cocaine exposure on gene expression in the hippocampus. RNA-Seq data from ‘BrainSpan’ was obtained across 16 brain regions from postmortem samples from nine adults. A factor analysis was performed on global expression of 21 GABAergic pathway genes. Factor specificity for response to chronic alcohol/cocaine exposure was subsequently determined from the analysis of RNA-Seq data from postmortem hippocampus of eight alcoholics, eight cocaine addicts and eight controls. Six gene expression factors were identified. Most genes loaded (≥0.5) onto one factor; six genes loaded onto two. The largest factor (0.30 variance) included the chromosome 5 gene cluster that encodes the most common GABAA receptor, α1β2γ2, and genes encoding the α3β3γ2 receptor. Genes within this factor were largely unresponsive to chronic alcohol/cocaine exposure. In contrast, the chromosome 4 gene cluster factor (0.14 variance) encoding the α2β1γ1 receptor was influenced by chronic alcohol/cocaine exposure. Two other factors (0.17 and 0.06 variance) showed expression changes in alcoholics/cocaine addicts; these factors included genes involved in GABA synthesis and synaptic transport. Finally there were two factors that included genes with exceptionally low (0.10 variance) and high (0.09 variance) expression in the cerebellum; the former factor was unaffected by alcohol/cocaine exposure. This study has shown that there appears to be specificity of GABAergic gene groups, defined by covariation in expression, for response to chronic alcohol/cocaine exposure. These findings might have implications for combating stress-related craving and relapse.
Collapse
Affiliation(s)
- Mary-Anne Enoch
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA.
| | | | | | | |
Collapse
|
33
|
Frisch C, Malter MP, Elger CE, Helmstaedter C. Neuropsychological course of voltage-gated potassium channel and glutamic acid decarboxylase antibody related limbic encephalitis. Eur J Neurol 2013; 20:1297-304. [PMID: 23678940 DOI: 10.1111/ene.12186] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/08/2013] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE Autoantibodies (abs) to glutamic acid decarboxylase (GAD) and to voltage-gated potassium channels (VGKC) induce distinct courses of limbic encephalitis, related to MRI findings, seizure outcome and cognition. METHODS A detailed analysis of the cognitive course of the two forms is presented, spanning a median time interval of 28 months, including parameters of attention, learning and memory in 15 VGKC-ab-positive and 16 GAD-ab-positive patients. RESULTS In both groups, the initially significantly impaired attention performance recovered to a putatively premorbid level. In VGKC patients the partially severely impaired learning and memory performance improved under treatment but remained subnormal at last follow-up. By contrast, GAD-ab-positive patients had initially less impaired learning and memory scores but did not show an improvement under treatment. CONCLUSIONS The results provide evidence of distinct relations between inductive processes and cognitive outcome in VGKC-ab-positive and GAD-ab-positive subforms of limbic encephalitis, which possibly depend on differences in pathogenic molecular mechanisms and affected cerebral loci.
Collapse
Affiliation(s)
- C Frisch
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.
| | | | | | | |
Collapse
|
34
|
Local MEG networks: the missing link between protein expression and epilepsy in glioma patients? Neuroimage 2013; 75:195-203. [PMID: 23507380 DOI: 10.1016/j.neuroimage.2013.02.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/28/2013] [Accepted: 02/27/2013] [Indexed: 01/21/2023] Open
Abstract
Connectivity and network analysis in neuroscience has been applied to multiple spatial scales, but the links between these different scales have rarely been investigated. In tumor-related epilepsy, altered network topology is related to behavior, but the molecular basis of these observations is unknown. We elucidate the associations between microscopic features of brain tumors, local network topology, and functional patient status. We hypothesize that expression of proteins related to tumor-related epilepsy is directly correlated with network characteristics of the tumor area. Glioma patients underwent magnetoencephalography, and functional network topology of the tumor area was used to predict tissue protein expression patterns of tumor tissue collected during neurosurgery. Protein expression and network topology were interdependent; in particular between-module connectivity was selectively associated with two epilepsy-related proteins. Total number of seizures was related to both the role of the tumor area in the functional network and to protein expression. Importantly, classification of protein expression was predicted by between-module connectivity with up to 100% accuracy. Thus, network topology may serve as an intermediate level between molecular features of tumor tissue and symptomatology in brain tumor patients, and can potentially be used as a non-invasive marker for microscopic tissue characteristics.
Collapse
|
35
|
Ornithine decarboxylase and glutamate decarboxylase 65 as prognostic markers of gallbladder malignancy: a clinicopathological study in benign and malignant lesions of the gallbladder. Mol Med Rep 2012; 7:413-8. [PMID: 23152127 DOI: 10.3892/mmr.2012.1178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/31/2012] [Indexed: 12/16/2022] Open
Abstract
Ornithine decarboxylase (ODC) plays a critical role in cell proliferation and is overexpressed in a variety of cancers. Furthermore, γ-aminobutyric acid (GABA) content and glutamate decarboxylase (GAD) activity are increased in neoplastic tissues in colon and breast cancer. However, few studies have examined these molecules in gallbladder cancer specimens. We observed the expression levels of ODC and GAD65 in benign and malignant lesions of the gallbladder and investigated their clinicopathological significance for the first time. The expression levels of ODC and GAD65 in specimens from gallbladder adenocarcinoma (n=108), peritumoral tissues (n=46), adenomatous polyps (n=15) and chronic cholecystitis (n=35) were detected using immunohistochemical methods. Kaplan-Meier survival and Cox regression analyses were carried out to explore the clinical and pathological correlations. The levels of positive staining of ODC and GAD65 were significantly higher in gallbladder adenocarcinoma than in peritumoral tissues, adenomatous polyps and chronic cholecystitis. The Kaplan‑Meier survival analysis and Cox regression analysis showed that the expression of ODC and GAD65 correlated significantly with the one-year survival rate and the mean survival time of the patients postoperatively. We conclude that the overexpression of ODC and GAD65 are significant in the carcinogenesis and progression of gallbladder adenocarcinoma. They may be important biological markers for the evaluation of biological behaviors and the prognosis of gallbladder adenocarcinoma.
Collapse
|
36
|
Hansen N, Grünewald B, Weishaupt A, Colaço MN, Toyka KV, Sommer C, Geis C. Human Stiff person syndrome IgG-containing high-titer anti-GAD65 autoantibodies induce motor dysfunction in rats. Exp Neurol 2012; 239:202-9. [PMID: 23099416 DOI: 10.1016/j.expneurol.2012.10.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/11/2012] [Accepted: 10/16/2012] [Indexed: 11/16/2022]
Abstract
Stiff person syndrome (SPS) is an autoimmune CNS disorder characterized by muscle rigidity, spasms and anxiety. The majority of patients have high-titer autoantibodies (ab) against glutamate decarboxylase (GAD65). A pathogenic role of SPS-associated IgG with ab against GAD65 has been shown for anxiety-like behavior but not for the core motor signs. We repetitively injected the purified IgG fraction of an SPS patient with severe motor impairment but without anxious comorbidity containing high titers of anti-GAD65 ab (SPS-IgG) into the lateral ventricle (i.c.v.) or intrathecally (i.th.) at the spinal level in experimental rats. We analyzed the effects on motor and anxiety-like behavior. Non-SPS human IgG fractions served as controls. Animals injected i.c.v. with SPS-IgG showed stiffness-like behavior with impaired walking ability and reduced grip strength of the upper limbs as well as postural and sensorimotor dysfunction. Testing for anxiety-like behavior revealed no significant differences between SPS and control IgG-treated rats. IgG deposits were found only in rats treated with SPS-IgG and were localized predominantly in CNS structures involved in motor control including globus pallidus, internal capsule, striatum and anterior thalamus. Double immunofluorescence staining revealed that predominantly GABAergic interneurons were positive for i.c.v. injected SPS-IgG. Rats injected i.th. with SPS-IgG did not present obvious motor symptoms and had a normal synaptic transmission at the spinal level. We conclude that SPS-like motor dysfunction can be induced in rats by passive transfer of IgG from an SPS-patient with high titer of anti-GAD65 ab. GABAergic dysfunction in supraspinal motor pathways rather than in the spinal cord may lead to motor deficits observed in the rats contrasting observations made in SPS with amphiphysin antibodies.
Collapse
Affiliation(s)
- Niels Hansen
- Department of Neurology, University of Würzburg, Josef-Schneider Strasse 11, 97080 Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|
37
|
Singh S, Raina V, Chavali PL, Dubash T, Kadreppa S, Parab P, Chattopadhyay S. Regulation of GAD65 expression by SMAR1 and p53 upon Streptozotocin treatment. BMC Mol Biol 2012; 13:28. [PMID: 22978699 PMCID: PMC3459802 DOI: 10.1186/1471-2199-13-28] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 09/07/2012] [Indexed: 12/03/2022] Open
Abstract
Background GAD65 (Glutamic acid decarboxylase 65 KDa isoform) is one of the most important auto-antigens involved in Type 1 diabetes induction. Although it serves as one of the first injury markers of β-islets, the mechanisms governing GAD65 expression remain poorly understood. Since the regulation of GAD65 is crucial for the proper functioning of insulin secreting cells, we investigated the stress induced regulation of GAD65 transcription. Results The present study shows that SMAR1 regulates GAD65 expression at the transcription level. Using a novel protein-DNA pull-down assay, we show that SMAR1 binding is very specific to GAD65 promoter but not to the other isoform, GAD67. We show that Streptozotocin (STZ) mediated DNA damage leads to upregulation of SMAR1 and p53 expression, resulting in elevated levels of GAD65, in both cell lines as well as mouse β-islets. SMAR1 and p53 act synergistically to up-regulate GAD65 expression upon STZ treatment. Conclusion We propose a novel mechanism of GAD65 regulation by synergistic activities of SMAR1 and p53.
Collapse
Affiliation(s)
- Sandeep Singh
- Centre for Human Genetics, School of Health Sciences, Central University of Punjab, Bathinda 151001, India.
| | | | | | | | | | | | | |
Collapse
|
38
|
Lange SC, Bak LK, Waagepetersen HS, Schousboe A, Norenberg MD. Primary cultures of astrocytes: their value in understanding astrocytes in health and disease. Neurochem Res 2012; 37:2569-88. [PMID: 22926576 DOI: 10.1007/s11064-012-0868-0] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/01/2012] [Accepted: 08/01/2012] [Indexed: 12/26/2022]
Abstract
During the past few decades of astrocyte research it has become increasingly clear that astrocytes have taken a central position in all central nervous system activities. Much of our new understanding of astrocytes has been derived from studies conducted with primary cultures of astrocytes. Such cultures have been an invaluable tool for studying roles of astrocytes in physiological and pathological states. Many central astrocytic functions in metabolism, amino acid neurotransmission and calcium signaling were discovered using this tissue culture preparation and most of these observations were subsequently found in vivo. Nevertheless, primary cultures of astrocytes are an in vitro model that does not fully mimic the complex events occurring in vivo. Here we present an overview of the numerous contributions generated by the use of primary astrocyte cultures to uncover the diverse functions of astrocytes. Many of these discoveries would not have been possible to achieve without the use of astrocyte cultures. Additionally, we address and discuss the concerns that have been raised regarding the use of primary cultures of astrocytes as an experimental model system.
Collapse
Affiliation(s)
- Sofie C Lange
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
39
|
Deng Y, Bu Q, Hu Z, Deng P, Yan G, Duan J, Hu C, Zhou J, Shao X, Zhao J, Li Y, Zhu R, Zhao Y, Cen X. (1) H-nuclear magnetic resonance-based metabonomic analysis of brain in rhesus monkeys with morphine treatment and withdrawal intervention. J Neurosci Res 2012; 90:2154-62. [PMID: 22847893 DOI: 10.1002/jnr.23109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/23/2012] [Accepted: 06/06/2012] [Indexed: 02/05/2023]
Abstract
Comprehensive cerebral metabolites involved in morphine dependence have not been well explored. To gain a better understanding of morphine dependence and withdrawal therapy in a model highly related to humans, metabolic changes in brain hippocampus and prefrontal cortex (PFC) of rhesus monkeys were measured by (1) H-nuclear magnetic resonance spectroscopy, coupled with partial least squares and orthogonal signal correction analysis. The results showed that concentrations of myoinositol (M-Ins) and taurine were significantly reduced, whereas lactic acid was increased in hippocampus and PFC of morphine-dependent monkeys. Phosphocholine and creatine increased in PFC but decreased in hippocampus after chronic treatment of morphine. Moreover, N-acetyl aspartate (NAA), γ-aminobutyric acid, glutamate, glutathione, methionine, and homocysteic acid also changed in these brain regions. These results suggest that chronic morphine exposure causes profound disturbances of neurotransmitters, membrane, and energy metabolism in the brain. Notably, morphine-induced dysregulations in NAA, creatine, lactic acid, taurine, M-Ins, and phosphocholine were clearly reversed after intervention with methadone or clonidine. Our study highlights the potential of metabolic profiling to enhance our understanding of metabolite alteration and neurobiological actions associated with morphine addiction and withdrawal therapy in primates.
Collapse
Affiliation(s)
- Yi Deng
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Buddhala C, Suarez M, Modi J, Prentice H, Ma Z, Tao R, Wu JY. Calpain cleavage of brain glutamic acid decarboxylase 65 is pathological and impairs GABA neurotransmission. PLoS One 2012; 7:e33002. [PMID: 22427928 PMCID: PMC3299728 DOI: 10.1371/journal.pone.0033002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 02/02/2012] [Indexed: 11/19/2022] Open
Abstract
Previously, we have shown that the GABA synthesizing enzyme, L-glutamic acid decarboxylase 65 (GAD65) is cleaved to form its truncated form (tGAD65) which is 2-3 times more active than the full length form (fGAD65). The enzyme responsible for cleavage was later identified as calpain. Calpain is known to cleave its substrates either under a transient physiological stimulus or upon a sustained pathological insult. However, the precise role of calpain cleavage of fGAD65 is poorly understood. In this communication, we examined the cleavage of fGAD65 under diverse pathological conditions including rats under ischemia/reperfusion insult as well as rat brain synaptosomes and primary neuronal cultures subjected to excessive stimulation with high concentration of KCl. We have shown that the formation of tGAD65 progressively increases with increasing stimulus concentration both in rat brain synaptosomes and primary rat embryo cultures. More importantly, direct cleavage of synaptic vesicle - associated fGAD65 by calpain was demonstrated and the resulting tGAD65 bearing the active site of the enzyme was detached from the synaptic vesicles. Vesicular GABA transport of the newly synthesized GABA was found to be reduced in calpain treated SVs. Furthermore, we also observed that the levels of tGAD65 in the focal cerebral ischemic rat brain tissue increased corresponding to the elevation of local glutamate as indicated by microdialysis. Moreover, the levels of tGAD65 was also proportional to the degree of cell death when the primary neuronal cultures were exposed to high KCl. Based on these observations, we conclude that calpain-mediated cleavage of fGAD65 is pathological, presumably due to decrease in the activity of synaptic vesicle - associated fGAD65 resulting in a decrease in the GABA synthesis - packaging coupling process leading to reduced GABA neurotransmission.
Collapse
Affiliation(s)
- Chandana Buddhala
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Marjorie Suarez
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Jigar Modi
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Howard Prentice
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Zhiyuan Ma
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Rui Tao
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| | - Jang Yen Wu
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, United States of America,
| |
Collapse
|
41
|
Hu Z, Deng Y, Hu C, Deng P, Bu Q, Yan G, Zhou J, Shao X, Zhao J, Li Y, Zhu R, Xu Y, Zhao Y, Cen X. ¹H NMR-based metabonomic analysis of brain in rats of morphine dependence and withdrawal intervention. Behav Brain Res 2012; 231:11-9. [PMID: 22391120 DOI: 10.1016/j.bbr.2012.02.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 02/13/2012] [Accepted: 02/17/2012] [Indexed: 02/05/2023]
Abstract
Metabolic consequences of morphine dependence and withdrawal intervention have not been well explored. In the present study, the metabolic changes in brain hippocampus, nucleus accumbens (NAc), prefrontal cortex (PFC) and striatum of rats with morphine dependence and withdrawal intervention were explored by using ¹H nuclear magnetic resonance coupled with principal component analysis, partial least squares and orthogonal signal correction analysis. We found that the concentrations of neurotransmitters including glutamate, glutamine and gamma-aminobutyric acid changed differentially in hippocampus, NAc, PFC and striatum after repeated morphine treatment. Significant changes were also found in a number of cerebral metabolites including N-acetyl aspartate (NAA), lactic acid, creatine, myo-inositol and taurine. These findings indicate the profound disturbances of energy metabolism, amino acid metabolism and neurotransmitters caused by chronic morphine treatment. Interestingly, morphine-induced changes in lactic acid, creatine and NAA were clearly reversed by intervention of methadone or clonidine. Our study provides a comprehensive understanding of the metabolic alteration associated with morphine addiction and withdrawal therapy, which may help to develop new pharmacotherapies.
Collapse
Affiliation(s)
- Zhengtao Hu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Rowley NM, Madsen KK, Schousboe A, Steve White H. Glutamate and GABA synthesis, release, transport and metabolism as targets for seizure control. Neurochem Int 2012; 61:546-58. [PMID: 22365921 DOI: 10.1016/j.neuint.2012.02.013] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 02/09/2012] [Indexed: 11/17/2022]
Abstract
The synthesis, release, reuptake, and metabolism of the excitatory and inhibitory neurotransmitters glutamate and GABA, respectively, are tightly controlled. Given the role that these two neurotransmitters play in normal and abnormal neurotransmission, it is important to consider the processes whereby they are regulated. This brief review is focused entirely on the metabolic aspects of glutamate and GABA synthesis and neurotransmission. It describes in limited detail the synthesis, release, reuptake, metabolism, cellular compartmentation and pharmacology of the glutamatergic and GABAergic synapse. This review also provides a summary and brief description of the pathologic and phenotypic features of the various genetic animal models that have been developed in an effort to provide a greater understanding of the role that each of the aforementioned metabolic processes plays in controlling excitatory and inhibitory neurotransmission and how their use will hopefully facilitate the development of safer and more efficacious therapies for the treatment of epilepsy and other neurological disorders.
Collapse
Affiliation(s)
- Nicole M Rowley
- Department of Pharmacology and Toxicology, Anticonvulsant Drug Development Program, University of Utah, 417 Wakara Way, Suite 3211, Salt Lake City, UT 84108, USA
| | | | | | | |
Collapse
|
43
|
Saigusa T, Aono Y, Sekino R, Uchida T, Takada K, Oi Y, Koshikawa N, Cools AR. In vivo neurochemical evidence that newly synthesised GABA activates GABA(B), but not GABA(A), receptors on dopaminergic nerve endings in the nucleus accumbens of freely moving rats. Neuropharmacology 2011; 62:907-13. [PMID: 21964521 DOI: 10.1016/j.neuropharm.2011.09.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 08/19/2011] [Accepted: 09/16/2011] [Indexed: 01/13/2023]
Abstract
GABA released from accumbal GABAergic interneurons plays an inhibitory role in the regulation of dopamine efflux through GABA(B) and GABA(A) receptors located on accumbal dopaminergic nerve endings. The cytosolic newly synthesised GABA alters vesicular GABA levels and, accordingly, the amount of GABA released from the neuron. Therefore, we hypothesised that glutamic acid decarboxylase (GAD) which generates GABA in accumbal GABAergic neurons, at least partly determines the GABA receptor subtype-mediated GABAergic tonus. To (in)validate this hypothesis, in vivo microdialysis was used to study the effects of an intra-accumbal infusion of the GAD inhibitor l-allylglycine (allylglycine) on the accumbal dopamine efflux of freely moving rats. The intra-accumbal infusion of allylglycine (50.0, 250.0 and 500.0 nmol) dose-dependently increased the accumbal dopamine levels. The co-administration of tetrodotoxin (720 pmol) suppressed the allylglycine (500.0 nmol)-induced dopamine efflux. The intra-accumbal infusion of GABA(B) receptor agonist baclofen (2.5 and 5.0 nmol) inhibited the allylglycine (500.0 nmol)-induced dopamine efflux. The baclofen's effects were counteracted by GABA(B) receptor antagonist saclofen (10.0 nmol). Neither GABA(A) receptor agonist (muscimol: 25.0 and 250.0 pmol) nor antagonist (bicuculline: 50.0 pmol) altered the allylglycine (250.0 and 500.0 nmol)-induced dopamine efflux. The present study provides in vivo neurochemical evidence that newly synthesised GABA that exerts an inhibitory tonus on the accumbal dopaminergic activity, acts at the level of GABA(B) receptors, but not GABA(A) receptors. The present study also shows that there is an allylglycine-insensitive GABA pool that release GABA exerting an inhibitory control of the accumbal dopaminergic activity, at the level of GABA(A) receptors. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
Collapse
Affiliation(s)
- Tadashi Saigusa
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Altered GABA signaling in early life epilepsies. Neural Plast 2011; 2011:527605. [PMID: 21826277 PMCID: PMC3150203 DOI: 10.1155/2011/527605] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 05/04/2011] [Accepted: 05/27/2011] [Indexed: 01/13/2023] Open
Abstract
The incidence of seizures is particularly high in the early ages of life. The immaturity of inhibitory systems, such as GABA, during normal brain development and its further dysregulation under pathological conditions that predispose to seizures have been speculated to play a major role in facilitating seizures. Seizures can further impair or disrupt GABAA signaling by reshuffling the subunit composition of its receptors or causing aberrant reappearance of depolarizing or hyperpolarizing GABAA receptor currents. Such effects may not result in epileptogenesis as frequently as they do in adults. Given the central role of GABAA signaling in brain function and development, perturbation of its physiological role may interfere with neuronal morphology, differentiation, and connectivity, manifesting as cognitive or neurodevelopmental deficits. The current GABAergic antiepileptic drugs, while often effective for adults, are not always capable of stopping seizures and preventing their sequelae in neonates. Recent studies have explored the therapeutic potential of chloride cotransporter inhibitors, such as bumetanide, as adjunctive therapies of neonatal seizures. However, more needs to be known so as to develop therapies capable of stopping seizures while preserving the age- and sex-appropriate development of the brain.
Collapse
|
45
|
Leke R, Bak LK, Iversen P, Sørensen M, Keiding S, Vilstrup H, Ott P, Portela LV, Schousboe A, Waagepetersen HS. Synthesis of neurotransmitter GABA via the neuronal tricarboxylic acid cycle is elevated in rats with liver cirrhosis consistent with a high GABAergic tone in chronic hepatic encephalopathy. J Neurochem 2011; 117:824-32. [PMID: 21395584 DOI: 10.1111/j.1471-4159.2011.07244.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Hepatic encephalopathy (HE) is a neuropsychiatric complication to liver disease. It is known that ammonia plays a role in the pathogenesis of HE and disturbances in the GABAergic system have been related to HE. Synthesis of GABA occurs by decarboxylation of glutamate formed by deamidation of astrocyte-derived glutamine. It is known that a fraction of glutamate is decarboxylated directly to GABA (referred to as the direct pathway) and that a fraction undergoes transamination with formation of alpha-ketoglutarate. The latter fraction is cycled through the neuronal tricarboxylic acid cycle, an energy-generating pathway, prior to being employed for GABA synthesis (the indirect pathway). We have previously shown that ammonia induces an elevation of the neuronal tricarboxylic acid cycle activity. Thus, the aims of the present study were to determine if increased levels of ammonia increase GABA synthesis via the indirect pathway in a rat model of HE induced by bile-duct ligation and in co-cultures of neurons and astrocytes exposed to ammonia. Employing (13) C-labeled precursors and subsequent analysis by mass spectrometry, we demonstrated that more GABA was synthesized via the indirect pathway in bile duct-ligated rats and in co-cultures subjected to elevated ammonia levels. Since the indirect pathway is associated with synthesis of vesicular GABA, this might explain the increased GABAergic tone in HE.
Collapse
Affiliation(s)
- Renata Leke
- PET Centre, Department of Medicine V, Aarhus University Hospital, Aarhus, Denmark
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Regulation of Orofacial Movement: Amino Acid Mechanisms and Mutant Models. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011. [DOI: 10.1016/b978-0-12-385198-7.00003-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
|