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Gopal N, Leitz J, Wang C, Esquivies L, Pfuetzner RA, Brunger AT. A new method for isolation and purification of fusion-competent inhibitory synaptic vesicles. Curr Res Physiol 2024; 7:100121. [PMID: 38572021 PMCID: PMC10990708 DOI: 10.1016/j.crphys.2024.100121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/18/2024] [Accepted: 02/16/2024] [Indexed: 04/05/2024] Open
Abstract
Synaptic vesicles specific to inhibitory GABA-releasing neurons are critical for regulating neuronal excitability. To study the specific molecular composition, architecture, and function of inhibitory synaptic vesicles, we have developed a new method to isolate and purify GABA synaptic vesicles from mouse brains. GABA synaptic vesicles were immunoisolated from mouse brain tissue using an engineered fragment antigen-binding region (Fab) against the vesicular GABA transporter (vGAT) and purified. Western blot analysis confirmed that the GABA synaptic vesicles were specifically enriched for vGAT and largely depleted of contaminants from other synaptic vesicle types, such as vesicular glutamate transporter (vGLUT1), and other cellular organelles. This degree of purity was achieved despite the relatively low abundance of vGAT vesicles compared to the total synaptic vesicle pool in mammalian brains. Cryo-electron microscopy images of these isolated GABA synaptic vesicles revealed intact morphology with circular shape and protruding proteinaceous densities. The GABA synaptic vesicles are functional, as assessed by a hybrid (ex vivo/in vitro) vesicle fusion assay, and they undergo synchronized fusion with synthetic plasma membrane mimic vesicles in response to Ca2+-triggering, but, as a negative control, not to Mg2+-triggering. Our immunoisolation method could also be applied to other types of vesicles.
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Affiliation(s)
- Nisha Gopal
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
| | - Jeremy Leitz
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
| | - Chuchu Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
| | - Luis Esquivies
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
| | - Richard A. Pfuetzner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
| | - Axel T. Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, USA
- Department of Structural Biology, Stanford University, Stanford, USA
- Department of Photon Science, Stanford University, Stanford, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, USA
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Ju P, Chen J, Ma L, Cheng Y, Liu J, Sun Y, Zhu C, Shen Z, Wang W, Peng Y, Ali U, Xu N, Chen J. Histone deacetylase 4 inhibition ameliorates the social deficits induced by Ephrin-B2 mutation. Prog Neuropsychopharmacol Biol Psychiatry 2023; 120:110622. [PMID: 36029930 DOI: 10.1016/j.pnpbp.2022.110622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 07/26/2022] [Accepted: 08/22/2022] [Indexed: 11/20/2022]
Abstract
Deterioration of inhibitory synapse may be an essential neurological basis underlying abnormal social behaviours. Manipulations that regulate GABAergic transmission are associated with improved behavioural phenotypes in sociability. The synaptic protein, Ephrin-B2 (EB2), plays an important role in the maintenance and reconfiguration of inhibitory synapses in the medial prefrontal cortex (mPFC). However, the inhibitory cell-type specific role of EB2 in the pathophysiology and treatment of social deficits remains unknown. As expected, we revealed that tdTomato-expressing cells were only found in GABAergic neurons instead of excitatory neurons in transgenic EB2-vGATCre mice. This result indicated that depletion of EB2 would occur in those neurons, which further contribute to social deficits. In addition, specific over-expression of mPFC EB2 restored the defective social behaviour abnormalities. These results suggest that the effect of EB2 on social deficits is anatomically and cell-type specific. More importantly, the global upregulation of HDAC4 expression was found in EB2-vGATCre mice. Significant subcellular nuclear shuttling of HDAC4 in vGAT+ neurons was examined and quantified, suggesting a role of nuclear HDAC4 in mediating the mechanism underlying EB2 impairment in vGAT+ neurons. Treatment with LMK235 led to a remarkable rescue of social deficits, thus our data revealed a new domain for the potential utility of HDAC targeting agents to treat social deficits. In conclusion, these results not only revealed a novel molecular mechanism underlying the pathophysiology of social deficits, but also suggested a potential intervention avenue for the treatment of social deficits.
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Fish KN, Rocco BR, Wilson JD, Lewis DA. Laminar-Specific Alterations in Calbindin-Positive Boutons in the Prefrontal Cortex of Subjects With Schizophrenia. Biol Psychiatry 2022:S0006-3223(22)01809-1. [PMID: 36868891 DOI: 10.1016/j.biopsych.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND Cognitive deficits in schizophrenia are associated with altered GABA (gamma-aminobutyric acid) neurotransmission in the prefrontal cortex (PFC). GABA neurotransmission requires GABA synthesis by 2 isoforms of glutamic acid decarboxylase (GAD65 and GAD67) and packaging by the vesicular GABA transporter (vGAT). Current postmortem findings suggest that GAD67 messenger RNA is lower in a subset of the calbindin-expressing (CB+) class of GABA neurons in schizophrenia. Hence, we assessed if CB+ GABA neuron boutons are affected in schizophrenia. METHODS For 20 matched pairs of subjects with schizophrenia and unaffected comparison subjects, PFC tissue sections were immunolabeled for vGAT, CB, GAD67, and GAD65. The density of CB+ GABA boutons and levels of the 4 proteins per bouton were quantified. RESULTS Some CB+ GABA boutons contained both GAD65 and GAD67 (GAD65+/GAD67+), whereas others contained only GAD65 (GAD65+) or GAD67 (GAD67+). In schizophrenia, vGAT+/CB+/GAD65+/GAD67+ bouton density was not altered, vGAT+/CB+/GAD65+ bouton density was 86% higher in layers 2/superficial 3 (L2/3s), and vGAT+/CB+/GAD67+ bouton density was 36% lower in L5-6. Bouton GAD levels were differentially altered across bouton types and layers. In schizophrenia, the sum of GAD65 and GAD67 levels in vGAT+/CB+/GAD65+/GAD67+ boutons was 36% lower in L6, GAD65 levels were 51% higher in vGAT+/CB+/GAD65+ boutons in L2, and GAD67 levels in vGAT+/CB+/GAD67+ boutons were 30% to 46% lower in L2/3s-6. CONCLUSIONS These findings indicate that schizophrenia-associated alterations in the strength of inhibition from CB+ GABA neurons in the PFC differ across cortical layers and bouton classes, suggesting complex contributions to PFC dysfunction and cognitive impairments in schizophrenia.
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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: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Blanco-Centurion C, Luo S, Vidal-Ortiz A, Swank C, Shiromani PJ. Activity of a subset of vesicular GABA-transporter neurons in the ventral zona incerta anticipates sleep onset. Sleep 2021; 44:6017820. [PMID: 33270105 DOI: 10.1093/sleep/zsaa268] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/01/2020] [Indexed: 01/03/2023] Open
Abstract
STUDY OBJECTIVES Sleep and wake are opposing behavioral states controlled by the activity of specific neurons that need to be located and mapped. To better understand how a waking brain falls asleep it is necessary to identify activity of individual phenotype-specific neurons, especially neurons that anticipate sleep onset. In freely behaving mice, we used microendoscopy to monitor calcium (Ca2+) fluorescence in individual hypothalamic neurons expressing the vesicular GABA transporter (vGAT), a validated marker of GABA neurons. METHODS vGAT-Cre mice (male = 3; female = 2) transfected with rAAV-FLEX-GCaMP6M in the lateral hypothalamus were imaged 30 days later during multiple episodes of waking (W), non-rapid-eye movement sleep (NREMS) or REMS (REMS). RESULTS 372 vGAT neurons were recorded in the zona incerta. 23.9% of the vGAT neurons showed maximal fluorescence during wake (classified as wake-max), 4% were NREM-max, 56.2% REM-max, 5.9% wake/REM max, while 9.9% were state-indifferent. In the NREM-max group, Ca2+ fluorescence began to increase before onset of NREM sleep, remained high throughout NREM sleep, and declined in REM sleep. CONCLUSIONS We found that 60.2% of the vGAT GABA neurons in the zona incerta had activity that was biased towards sleep (NREM and REMS). A subset of vGAT neurons (NREM-max) became active in advance of sleep onset and may induce sleep by inhibiting the activity of the arousal neurons. Abnormal activation of the NREM-max neurons may drive sleep attacks and hypersomnia.
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Affiliation(s)
- Carlos Blanco-Centurion
- Laboratory of Sleep Medicine and Chronobiology, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
| | - SiWei Luo
- Laboratory of Sleep Medicine and Chronobiology, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
| | | | - Colby Swank
- Laboratory of Sleep Medicine and Chronobiology, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
| | - Priyattam J Shiromani
- Laboratory of Sleep Medicine and Chronobiology, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC.,Ralph H. Johnson VA Medical Center, Charleston, SC
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An H, Koh W, Kang S, Nam MH, Lee CJ. Differential Proximity of Perisynaptic Astrocytic Best1 at the Excitatory and Inhibitory Tripartite Synapses in APP/PS1 and MAOB-KO Mice Revealed by Lattice Structured Illumination Microscopy. Exp Neurobiol 2021; 30:213-221. [PMID: 34132201 PMCID: PMC8278139 DOI: 10.5607/en21015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 05/28/2021] [Accepted: 05/30/2021] [Indexed: 12/19/2022] Open
Abstract
Bestrophin-1 (Best1) is a GABA- and glutamate-permeable, Ca2+-activated Cl- channel, which is mainly expressed in astrocytes and localized at the microdomain or perisynaptic junction of the tripartite synapse. Distribution of Best1 is dramatically changed in pathological conditions such as Alzheimer's disease. However, it is still unknown whether Best1 is located at the glutamatergic or GABAergic tripartite synapses. Here, we utilized the Lattice structured illumination microscopy (Lattice SIM) to visualize Best1 expression at the perisynaptic junctions of the tripartite synapses in CA1 of mouse hippocampus. We performed co-labeling with antibodies against 1) Best1 and vesicular glutamate transporter-2 (vGLUT2) or 2) Best1 and vesicular GABA transporter (vGAT) to measure the proximity of Best1-containing perisynapse to glutamatergic or GABAergic presynapse, respectively. In addition, we examined two transgenic mouse lines of 1) APP/PS1 mouse showing high astrocytic MAOB activity and cytosolic GABA and 2) MAOB-KO mouse showing low astrocytic GABA. Lattice SIM images were further processed by Imaris, which allowed 3D-rendering and spot identification. We found that astrocytic Best1 was distributed closer to the glutamatergic synapses than GABAergic synapses in the wild-type mice. In APP/PS1 mice, Best1 distribution was significantly changed by moving away from the glutamatergic synapses while moving closer to the GABAergic synapses. On the contrary, in MAOB-KO mice, the Best1 distribution was dramatically changed by moving closer to the glutamatergic synapses and moving far away from the GABAergic synapses. Our findings propose that the proximity of Best1-containing perisynapses to presynapses dynamically changes according to the level of astrocytic cytosolic GABA.
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Affiliation(s)
- Heeyoung An
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - Wuhyun Koh
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - SeungHee Kang
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - Min-Ho Nam
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
- Department of KHU-KIST Convergence Science and Technology, Kyung Hee University, Seoul 02453, Korea
| | - C. Justin Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
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Handara G, Kröger S. Alternative Splicing and the Intracellular Domain Mediate TM-agrin's Ability to Differentially Regulate the Density of Excitatory and Inhibitory Synapse-like Specializations in Developing CNS Neurons. Neuroscience 2019; 419:60-71. [PMID: 31672640 DOI: 10.1016/j.neuroscience.2019.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 01/26/2023]
Abstract
Agrin is a multi-domain protein best known for its essential function during formation of the neuromuscular junction. Alternative mRNA splicing at sites named y and z in the C-terminal part of agrin regulates its interaction with a receptor complex consisting of the agrin-binding low-density lipoprotein receptor-related protein 4 (Lrp4) and the muscle-specific kinase (MuSK). Isoforms with inserts at both splice sites bind to Lrp4, activate MuSK and are synaptogenic at the neuromuscular junction. Agrin is also expressed as a transmembrane protein in the central nervous system (CNS) but its function during interneuronal synapse formation is unclear. Recently we demonstrated that transfection of a full-length cDNA coding for transmembrane agrin (TM-agrin) in cultured embryonic cortical neurons induced an Lrp4-dependent but MuSK-independent increase in dendritic glutamatergic synapses and an Lrp4- and MuSK-independent reduction of inhibitory synapses. Here we show that presynaptic specializations were similarly affected by TM-agrin overexpression. In addition, we mapped the regions within TM-agrin responsible for TM-agrin's effects on dendritic aggregates of synapse-associated proteins. We show that the presence of a four amino acid insert at splice site y is essential for the increase in the density of puncta containing the postsynaptic density protein 95 kDa. This effect was independent of splice site z. The reduction of the gephyrin puncta density was independent of the entire extracellular part of TM-agrin but required a highly conserved serine residue in the intracellular domain of TM-agrin. These results provide further evidence for a function of TM-agrin during CNS synaptogenesis and demonstrate that different domains and alternative splicing of TM-agrin differentially affect excitatory and inhibitory synapse formation in cultured embryonic CNS neurons.
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Affiliation(s)
- Gerry Handara
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152 Planegg-Martinsried, Germany; Institute for Stem Cell Research, German Research Center for Environmental Health, Helmholtz Centre Munich, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Stephan Kröger
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152 Planegg-Martinsried, Germany.
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Testa G, Mainardi M, Olimpico F, Pancrazi L, Cattaneo A, Caleo M, Costa M. A triheptanoin-supplemented diet rescues hippocampal hyperexcitability and seizure susceptibility in FoxG1 +/- mice. Neuropharmacology 2019; 148:305-310. [PMID: 30639390 DOI: 10.1016/j.neuropharm.2019.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/11/2018] [Accepted: 01/08/2019] [Indexed: 12/27/2022]
Abstract
The Forkhead Box G1 (FOXG1) gene encodes a transcription factor with an essential role in mammalian telencephalon development. FOXG1-related disorders, caused by deletions, intragenic mutations or duplications, are usually associated with severe intellectual disability, autistic features, and, in 87% of subjects, epileptiform manifestations. In a subset of patients with FoxG1 mutations, seizures remain intractable, prompting the need for novel therapeutic options. To address this issue, we took advantage of a haploinsufficient animal model, the FoxG1+/- mouse. In vivo electrophysiological analyses of FoxG1+/- mice detected hippocampal hyperexcitability, which turned into overt seizures upon delivery of the proconvulsant kainic acid, as confirmed by behavioral observations. These alterations were associated with decreased expression of the chloride transporter KCC2. Next, we tested whether a triheptanoin-based anaplerotic diet could have an impact on the pathological phenotype of FoxG1+/- mice. This manipulation abated altered neural activity and normalized enhanced susceptibility to proconvulsant-induced seizures, in addition to rescuing altered expression of KCC2 and increasing the levels of the GABA transporter vGAT. In conclusion, our data show that FoxG1 haploinsufficiency causes dysfunction of hippocampal circuits and increases the susceptibility to a proconvulsant insult, and that these alterations are rescued by triheptanoin dietary treatment.
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Affiliation(s)
- Giovanna Testa
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy
| | - Marco Mainardi
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy; Institute of Neuroscience, Italian National Research Council (CNR), Via Moruzzi, 1, 56124, Pisa, Italy.
| | - Francesco Olimpico
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy
| | - Laura Pancrazi
- Institute of Neuroscience, Italian National Research Council (CNR), Via Moruzzi, 1, 56124, Pisa, Italy
| | - Antonino Cattaneo
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy
| | - Matteo Caleo
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy; Institute of Neuroscience, Italian National Research Council (CNR), Via Moruzzi, 1, 56124, Pisa, Italy
| | - Mario Costa
- Laboratory of Biology "Bio@SNS", Scuola Normale Superiore, Piazza dei Cavalieri, 7, 56124, Pisa, Italy; Institute of Neuroscience, Italian National Research Council (CNR), Via Moruzzi, 1, 56124, Pisa, Italy.
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Fish KN, Rocco BR, Lewis DA. Laminar Distribution of Subsets of GABAergic Axon Terminals in Human Prefrontal Cortex. Front Neuroanat 2018; 12:9. [PMID: 29503610 PMCID: PMC5820353 DOI: 10.3389/fnana.2018.00009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/24/2018] [Indexed: 01/01/2023] Open
Abstract
In human prefrontal cortex (PFC), ~85% of γ-aminobutyric acid (GABA)-expressing neurons can be subdivided into non-overlapping groups by the presence of calbindin (CB), calretinin (CR) or parvalbumin (PV). Substantial research has focused on the differences in the laminar locations of the cells bodies of these neurons, with limited attention to the distribution of their axon terminals, their sites of action. We previously reported that in non-human primates subtypes of these cells are distinguishable by differences in terminal protein levels of the GABA synthesizing enzymes glutamic acid decarboxylase 65 (GAD65) and GAD67. Here we used multi-label fluorescence microscopy in human PFC to assess: (1) the laminar distributions of axon terminals containing CB, CR, or PV; and (2) the relative protein levels of GAD65, GAD67 and vesicular GABA transporter (vGAT) in CB, CR and PV terminals. The densities of the different CB, CR and PV terminal subpopulations differed across layers of the PFC. PV terminals comprised two subsets based on the presence of only GAD67 (GAD67+) or both GADs (GAD65/GAD67+), whereas CB and CR terminals comprised three subsets (GAD65+, GAD67+, or GAD65/GAD67+). The densities of the different CB, CR and PV GAD terminal subpopulations also differed across layers. Finally, within each of the three calcium-binding protein subpopulations intra-terminal protein levels of GAD and vGAT differed by GAD subpopulation. These findings are discussed in the context of the laminar distributions of CB, CR and PV cell bodies and the synaptic targets of their axons.
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Affiliation(s)
- Kenneth N Fish
- Western Psychiatric Institute and Clinic, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Brad R Rocco
- Western Psychiatric Institute and Clinic, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - David A Lewis
- Western Psychiatric Institute and Clinic, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.,Department of Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Rocco BR, DeDionisio AM, Lewis DA, Fish KN. Alterations in a Unique Class of Cortical Chandelier Cell Axon Cartridges in Schizophrenia. Biol Psychiatry 2017; 82:40-48. [PMID: 27884423 PMCID: PMC5374057 DOI: 10.1016/j.biopsych.2016.09.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 09/24/2016] [Accepted: 09/28/2016] [Indexed: 12/28/2022]
Abstract
BACKGROUND The axons of chandelier cells (ChCs) target the axon initial segment of pyramidal neurons, forming an array of boutons termed a cartridge. In schizophrenia, the density of cartridges detectable by gamma-aminobutyric acid (GABA) membrane transporter 1 immunoreactivity is lower, whereas the density of axon initial segments detectable by immunoreactivity for the α2 subunit of the GABAA receptor is higher in layers 2/superficial 3 of the prefrontal cortex. These findings were interpreted as compensatory responses to lower GABA levels in ChCs. However, we recently found that in schizophrenia, ChC cartridge boutons contain normal levels of the 67 kDa isoform of glutamic acid decarboxylase (GAD67) protein, the enzyme responsible for GABA synthesis in these boutons. To understand these findings we quantified the densities of ChC cartridges immunoreactive for vesicular GABA transporter (vGAT+), which is present in all cartridge boutons, and the subset of cartridges that contain calbindin (CB+). METHODS Prefrontal cortex tissue sections from 20 matched pairs of schizophrenia and unaffected comparison subjects were immunolabeled for vGAT, GAD67, and CB. RESULTS The mean density of vGAT+/CB+ cartridges was 2.7-fold higher, exclusively in layer 2 of schizophrenia subjects, whereas the density of vGAT+/CB- cartridges did not differ between subject groups. Neither vGAT, CB, or GAD67 protein levels per ChC bouton nor the number of boutons per cartridge differed between subject groups. CONCLUSIONS Our findings of a greater density of CB+ ChC cartridges in prefrontal cortex layer 2 from schizophrenia subjects suggests that the normal developmental pruning of these cartridges is blunted in the illness.
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Affiliation(s)
- Brad R Rocco
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Adam M DeDionisio
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Kenneth N Fish
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
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Li X, Wang Z, Tan L, Wang Y, Lu C, Chen R, Zhang S, Gao Y, Liu Y, Yin Y, Liu X, Liu E, Yang Y, Hu Y, Xu Z, Xu F, Wang J, Liu GP, Wang JZ. Correcting miR92a- vGAT-Mediated GABAergic Dysfunctions Rescues Human Tau-Induced Anxiety in Mice. Mol Ther 2017; 25:140-152. [PMID: 28129110 DOI: 10.1016/j.ymthe.2016.10.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 10/10/2016] [Accepted: 10/11/2016] [Indexed: 01/30/2023] Open
Abstract
Patients with Alzheimer's disease (AD) commonly show anxiety behaviors, but the molecular mechanisms are not clear and no efficient intervention exists. Here, we found that overexpression of human wild-type, full-length tau (termed htau) in hippocampus significantly decreased the extracellular γ-aminobutyric acid (GABA) level with inhibition of γ oscillation and the evoked inhibitory postsynaptic potential (eIPSP). With tau accumulation, the mice show age-dependent anxiety behaviors. Among the factors responsible for GABA synthesis, release, uptake, and transport, we found that accumulation of htau selectively suppressed expression of the intracellular vesicular GABA transporter (vGAT). Tau accumulation increased miR92a, which targeted vGAT mRNA 3' UTR and inhibited vGAT translation. Importantly, we found that upregulating GABA tones by intraperitoneal injection of midazolam (a GABA agonist), ChR2-mediated photostimulating and overexpressing vGAT, or blocking miR92a by using specific antagomir or inhibitor efficiently rescued the htau-induced GABAergic dysfunctions with attenuation of anxiety. Finally, we also demonstrated that vGAT level decreased while the miR92a increased in the AD brains. These findings demonstrate that the AD-like tau accumulation induces anxiety through disrupting miR92a-vGAT-GABA signaling, which reveals molecular mechanisms underlying the anxiety behavior in AD patients and potentially leads to the development of new therapeutics for tauopathies.
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Affiliation(s)
- Xiaoguang Li
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhihao Wang
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lu Tan
- Key Laboratory for Molecular Diagnosis of Hubei Province, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China
| | - Yali Wang
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Physiology Department, Henan Provincial Key Laboratory for Brain Research, Xinxiang Medical University, Xinxiang 453000, China
| | - Chengbiao Lu
- Physiology Department, Henan Provincial Key Laboratory for Brain Research, Xinxiang Medical University, Xinxiang 453000, China
| | - Rongxiang Chen
- State Key Laboratory for Magnet Resonance and Atom and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academia of Science, Wuhan 430071, China
| | - Shujuan Zhang
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yuan Gao
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yanchao Liu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yaling Yin
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xinghua Liu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Enjie Liu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ying Yang
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yu Hu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhipeng Xu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Fuqiang Xu
- State Key Laboratory for Magnet Resonance and Atom and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academia of Science, Wuhan 430071, China
| | - Jie Wang
- State Key Laboratory for Magnet Resonance and Atom and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academia of Science, Wuhan 430071, China
| | - Gong-Ping Liu
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine and Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
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Rocco BR, Lewis DA, Fish KN. Markedly Lower Glutamic Acid Decarboxylase 67 Protein Levels in a Subset of Boutons in Schizophrenia. Biol Psychiatry 2016; 79:1006-15. [PMID: 26364548 DOI: 10.1016/j.biopsych.2015.07.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/14/2015] [Accepted: 07/22/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Convergent findings indicate that cortical gamma-aminobutyric acid (GABA)ergic circuitry is altered in schizophrenia. Postmortem studies have consistently found lower levels of glutamic acid decarboxylase 67 (GAD67) messenger RNA (mRNA) in the prefrontal cortex (PFC) of subjects with schizophrenia. At the cellular level, the density of GABA neurons with detectable levels of GAD67 mRNA is ~30% lower across cortical layers. Knowing how this transcript deficit translates to GAD67 protein levels in axonal boutons is important for understanding the impact it might have on GABA synthesis. In addition, because reductions in GAD67 expression before, but not after, the maturation of GABAergic boutons results in a lower density of GABAergic boutons in mouse cortical cultures, knowing if GABAergic bouton density is altered in schizophrenia would provide insight into the timing of the GAD67 deficit. METHODS PFC tissue sections from 20 matched pairs of schizophrenia and comparison subjects were immunolabeled for the vesicular GABA transporter (vGAT) and GAD67. RESULTS vGAT+ bouton density did not differ between subject groups, consistent with findings that vGAT mRNA levels are unaltered in the illness and confirming that the number of cortical GABAergic boutons is not lower in schizophrenia. In contrast, in schizophrenia subjects, the proportion of vGAT+ boutons with detectable GAD67 levels (vGAT+/GAD67+ boutons) was 16% lower and mean GAD67 levels were 14% lower in the remaining vGAT+/GAD67+ boutons. CONCLUSIONS Our findings suggest that GABA production is markedly reduced in a subset of boutons in the PFC of schizophrenia subjects and that this reduction likely occurs after the maturation of GABAergic boutons.
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Mainardi M, Di Garbo A, Caleo M, Berardi N, Sale A, Maffei L. Environmental enrichment strengthens corticocortical interactions and reduces amyloid-β oligomers in aged mice. Front Aging Neurosci 2014; 6:1. [PMID: 24478697 PMCID: PMC3899529 DOI: 10.3389/fnagi.2014.00001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 01/03/2014] [Indexed: 11/13/2022] Open
Abstract
Brain aging is characterized by global changes which are thought to underlie age-related cognitive decline. These include variations in brain activity and the progressive increase in the concentration of soluble amyloid-β (Aβ) oligomers, directly impairing synaptic function and plasticity even in the absence of any neurodegenerative disorder. Considering the high social impact of the decline in brain performance associated to aging, there is an urgent need to better understand how it can be prevented or contrasted. Lifestyle components, such as social interaction, motor exercise and cognitive activity, are thought to modulate brain physiology and its susceptibility to age-related pathologies. However, the precise functional and molecular factors that respond to environmental stimuli and might mediate their protective action again pathological aging still need to be clearly identified. To address this issue, we exploited environmental enrichment (EE), a reliable model for studying the effect of experience on the brain based on the enhancement of cognitive, social and motor experience, in aged wild-type mice. We analyzed the functional consequences of EE on aged brain physiology by performing in vivo local field potential (LFP) recordings with chronic implants. In addition, we also investigated changes induced by EE on molecular markers of neural plasticity and on the levels of soluble Aβ oligomers. We report that EE induced profound changes in the activity of the primary visual and auditory cortices and in their functional interaction. At the molecular level, EE enhanced plasticity by an upward shift of the cortical excitation/inhibition balance. In addition, EE reduced brain Aβ oligomers and increased synthesis of the Aβ-degrading enzyme neprilysin. Our findings strengthen the potential of EE procedures as a non-invasive paradigm for counteracting brain aging processes.
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Affiliation(s)
- Marco Mainardi
- Neuroscience Institute of the National Research Council Pisa, Italy
| | - Angelo Di Garbo
- Biophysics Institute of the National Research Council Pisa, Italy
| | - Matteo Caleo
- Neuroscience Institute of the National Research Council Pisa, Italy
| | - Nicoletta Berardi
- Neuroscience Institute of the National Research Council Pisa, Italy ; Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence Florence, Italy
| | - Alessandro Sale
- Neuroscience Institute of the National Research Council Pisa, Italy
| | - Lamberto Maffei
- Neuroscience Institute of the National Research Council Pisa, Italy ; Accademia dei Lincei Roma, Italy
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Sgadò P, Genovesi S, Kalinovsky A, Zunino G, Macchi F, Allegra M, Murenu E, Provenzano G, Tripathi PP, Casarosa S, Joyner AL, Bozzi Y. Loss of GABAergic neurons in the hippocampus and cerebral cortex of Engrailed-2 null mutant mice: implications for autism spectrum disorders. Exp Neurol 2013; 247:496-505. [PMID: 23360806 DOI: 10.1016/j.expneurol.2013.01.021] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/11/2012] [Accepted: 01/18/2013] [Indexed: 11/24/2022]
Abstract
The homeobox-containing transcription factor Engrailed-2 (En2) is involved in patterning and neuronal differentiation of the midbrain/hindbrain region, where it is prominently expressed. En2 mRNA is also expressed in the adult mouse hippocampus and cerebral cortex, indicating that it might also function in these brain areas. Genome-wide association studies revealed that En2 is a candidate gene for autism spectrum disorders (ASD), and mice devoid of its expression (En2(-/-) mice) display anatomical, behavioral and clinical "autistic-like" features. Since reduced GABAergic inhibition has been proposed as a possible pathogenic mechanism of ASD, we hypothesized that the phenotype of En2(-/-) mice might include defective GABAergic innervation in the forebrain. Here we show that the Engrailed proteins are present in postnatal GABAergic neurons of the mouse hippocampus and cerebral cortex, and adult En2(-/-) mice show reduced expression of GABAergic marker mRNAs in these areas. In addition, reduction in parvalbumin (PV), somatostatin (SOM) and neuropeptide Y (NPY) expressing interneurons is detected in the hippocampus and cerebral cortex of adult En2(-/-) mice. Our results raise the possibility of a link between altered function of En2, anatomical deficits of GABAergic forebrain neurons and the pathogenesis of ASD.
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