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Özçete ÖD, Banerjee A, Kaeser PS. Mechanisms of neuromodulatory volume transmission. Mol Psychiatry 2024:10.1038/s41380-024-02608-3. [PMID: 38789677 DOI: 10.1038/s41380-024-02608-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/07/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024]
Abstract
A wealth of neuromodulatory transmitters regulate synaptic circuits in the brain. Their mode of signaling, often called volume transmission, differs from classical synaptic transmission in important ways. In synaptic transmission, vesicles rapidly fuse in response to action potentials and release their transmitter content. The transmitters are then sensed by nearby receptors on select target cells with minimal delay. Signal transmission is restricted to synaptic contacts and typically occurs within ~1 ms. Volume transmission doesn't rely on synaptic contact sites and is the main mode of monoamines and neuropeptides, important neuromodulators in the brain. It is less precise than synaptic transmission, and the underlying molecular mechanisms and spatiotemporal scales are often not well understood. Here, we review literature on mechanisms of volume transmission and raise scientific questions that should be addressed in the years ahead. We define five domains by which volume transmission systems can differ from synaptic transmission and from one another. These domains are (1) innervation patterns and firing properties, (2) transmitter synthesis and loading into different types of vesicles, (3) architecture and distribution of release sites, (4) transmitter diffusion, degradation, and reuptake, and (5) receptor types and their positioning on target cells. We discuss these five domains for dopamine, a well-studied monoamine, and then compare the literature on dopamine with that on norepinephrine and serotonin. We include assessments of neuropeptide signaling and of central acetylcholine transmission. Through this review, we provide a molecular and cellular framework for volume transmission. This mechanistic knowledge is essential to define how neuromodulatory systems control behavior in health and disease and to understand how they are modulated by medical treatments and by drugs of abuse.
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Affiliation(s)
- Özge D Özçete
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA.
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2
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Khamis H, Cohen O. Coupled action potential and calcium dynamics underlie robust spontaneous firing in dopaminergic neurons. Phys Biol 2024; 21:026005. [PMID: 38382117 DOI: 10.1088/1478-3975/ad2bd4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 02/21/2024] [Indexed: 02/23/2024]
Abstract
Dopaminergic neurons are specialized cells in the substantia nigra, tasked with dopamine secretion. This secretion relies on intracellular calcium signaling coupled to neuronal electrical activity. These neurons are known to display spontaneous calcium oscillationsin-vitroandin-vivo, even in synaptic isolation, controlling the basal dopamine levels. Here we outline a kinetic model for the ion exchange across the neuronal plasma membrane. Crucially, we relax the assumption of constant, cytoplasmic sodium and potassium concentration. We show that sodium-potassium dynamics are strongly coupled to calcium dynamics and are essential for the robustness of spontaneous firing frequency. The model predicts several regimes of electrical activity, including tonic and 'burst' oscillations, and predicts the switch between those in response to perturbations. 'Bursting' correlates with increased calcium amplitudes, while maintaining constant average, allowing for a vast change in the calcium signal responsible for dopamine secretion. All the above traits provide the flexibility to create rich action potential dynamics that are crucial for cellular function.
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Affiliation(s)
- Hadeel Khamis
- Gateway Institute for Brain Research, Fort Lauderdale, FL 33314, United States of America
| | - Ohad Cohen
- Gateway Institute for Brain Research, Fort Lauderdale, FL 33314, United States of America
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3
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Brimblecombe KR, Connor-Robson N, Bataille CJR, Roberts BM, Gracie C, O'Connor B, Te Water Naude R, Karthik G, Russell AJ, Wade-Martins R, Cragg SJ. Inhibition of striatal dopamine release by the L-type calcium channel inhibitor isradipine co-varies with risk factors for Parkinson's. Eur J Neurosci 2024; 59:1242-1259. [PMID: 37941514 DOI: 10.1111/ejn.16180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/25/2023] [Accepted: 10/14/2023] [Indexed: 11/10/2023]
Abstract
Ca2+ entry into nigrostriatal dopamine (DA) neurons and axons via L-type voltage-gated Ca2+ channels (LTCCs) contributes, respectively, to pacemaker activity and DA release and has long been thought to contribute to vulnerability to degeneration in Parkinson's disease. LTCC function is greater in DA axons and neurons from substantia nigra pars compacta than from ventral tegmental area, but this is not explained by channel expression level. We tested the hypothesis that LTCC control of DA release is governed rather by local mechanisms, focussing on candidate biological factors known to operate differently between types of DA neurons and/or be associated with their differing vulnerability to parkinsonism, including biological sex, α-synuclein, DA transporters (DATs) and calbindin-D28k (Calb1). We detected evoked DA release ex vivo in mouse striatal slices using fast-scan cyclic voltammetry and assessed LTCC support of DA release by detecting the inhibition of DA release by the LTCC inhibitors isradipine or CP8. Using genetic knockouts or pharmacological manipulations, we identified that striatal LTCC support of DA release depended on multiple intersecting factors, in a regionally and sexually divergent manner. LTCC function was promoted by factors associated with Parkinsonian risk, including male sex, α-synuclein, DAT and a dorsolateral co-ordinate, but limited by factors associated with protection, that is, female sex, glucocerebrosidase activity, Calb1 and ventromedial co-ordinate. Together, these data show that LTCC function in DA axons and isradipine effect are locally governed and suggest they vary in a manner that in turn might impact on, or reflect, the cellular stress that leads to parkinsonian degeneration.
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Affiliation(s)
- Katherine R Brimblecombe
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland, USA
| | - Natalie Connor-Robson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK
| | - Carole J R Bataille
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Bradley M Roberts
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK
| | - Caitlin Gracie
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Bethan O'Connor
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | - Gayathri Karthik
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Angela J Russell
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Richard Wade-Martins
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland, USA
| | - Stephanie J Cragg
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland, USA
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4
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Costas-Ferreira C, Silva ACDJ, Hage-Melim LIDS, Faro LRF. Role of voltage-dependent calcium channels on the striatal in vivo dopamine release induced by the organophosphorus pesticide glyphosate. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 104:104285. [PMID: 37783442 DOI: 10.1016/j.etap.2023.104285] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/25/2023] [Accepted: 09/29/2023] [Indexed: 10/04/2023]
Abstract
In the present study, we investigated the role of voltage-sensitive calcium channels (VSCCs) on the striatal dopamine release induced by the pesticide glyphosate (GLY) using selective VSCC inhibitors. The dopamine levels were measured by in vivo cerebral microdialysis coupled to HPLC-ED. Nicardipine (L-type VSCC antagonist) or ω-conotoxin MVIIC (non-selective P/Q-type antagonist) had no effect on dopamine release induced by 5 mM GLY. In contrast, flunarizine (T-type antagonist) or ω-conotoxin GVIA (neuronal N-type antagonist) significantly reduced GLY-stimulated dopamine release. These results suggest that GLY-induced dopamine release depends on extracellular calcium and its influx through the T- and N-type VSCCs. These findings were corroborated by molecular docking, which allowed us to establish a correlation between the effect of GLY on blocked VSCC with the observed dopamine release. We propose new molecular targets of GLY in the dorsal striatum, which could have important implications for the assessment of pesticide risks in non-target organisms.
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Affiliation(s)
- Carmen Costas-Ferreira
- Department of Functional Biology and Health sciences, Faculty of Biology, University of Vigo, Spain
| | | | | | - Lilian R Ferreira Faro
- Department of Functional Biology and Health sciences, Faculty of Biology, University of Vigo, Spain.
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5
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Dahimene S, Page KM, Nieto-Rostro M, Pratt WS, Dolphin AC. The Interplay Between Splicing of Two Exon Combinations Differentially Affects Membrane Targeting and Function of Human Ca V2.2. FUNCTION 2023; 5:zqad060. [PMID: 38020068 PMCID: PMC10666670 DOI: 10.1093/function/zqad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/16/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
N-type calcium channels (CaV2.2) are predominantly localized in presynaptic terminals, and are particularly important for pain transmission in the spinal cord. Furthermore, they have multiple isoforms, conferred by alternatively spliced or cassette exons, which are differentially expressed. Here, we have examined alternatively spliced exon47 variants that encode a long or short C-terminus in human CaV2.2. In the Ensembl database, all short exon47-containing transcripts were associated with the absence of exon18a, therefore, we also examined the effect of inclusion or absence of exon18a, combinatorially with the exon47 splice variants. We found that long exon47, only in the additional presence of exon18a, results in CaV2.2 currents that have a 3.6-fold greater maximum conductance than the other three combinations. In contrast, cell-surface expression of CaV2.2 in both tsA-201 cells and hippocampal neurons is increased ∼4-fold by long exon47, relative to short exon47, in either the presence or the absence of exon18a. This surprising discrepancy between trafficking and function indicates that cell-surface expression is enhanced by long exon47, independently of exon18a. However, in the presence of long exon47, exon18a mediates an additional permissive effect on CaV2.2 gating. We also investigated the single-nucleotide polymorphism in exon47 that has been linked to schizophrenia and Parkinson's disease, which we found is only non-synonymous in the short exon47 C-terminal isoform, resulting in two minor alleles. This study highlights the importance of investigating the combinatorial effects of exon inclusion, rather than each in isolation, in order to increase our understanding of calcium channel function.
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Affiliation(s)
- Shehrazade Dahimene
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Karen M Page
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Manuela Nieto-Rostro
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Wendy S Pratt
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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Skiteva O, Yao N, Mantas I, Zhang X, Perlmann T, Svenningsson P, Chergui K. Aberrant somatic calcium channel function in cNurr1 and LRRK2-G2019S mice. NPJ Parkinsons Dis 2023; 9:56. [PMID: 37029193 PMCID: PMC10082048 DOI: 10.1038/s41531-023-00500-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 03/23/2023] [Indexed: 04/09/2023] Open
Abstract
In Parkinson's disease (PD), axons of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) degenerate before their cell bodies. Calcium influx during pacemaker firing might contribute to neuronal loss, but it is not known if dysfunctions of voltage-gated calcium channels (VGCCs) occur in DA neurons somata and axon terminals. We investigated T-type and L-type VGCCs in SNc-DA neurons of two mouse models of PD: mice with a deletion of the Nurr1 gene in DA neurons from an adult age (cNurr1 mice), and mice bearing the G2019S mutation in the gene coding for LRRK2 (G2019S mice). Adult cNurr1 mice displayed motor and DA deficits, while middle-aged G2019S mice did not. The number and morphology of SNc-DA neurons, most of their intrinsic membrane properties and pacemaker firing were unaltered in cNurr1 and G2019S mice compared to their control and wild-type littermates. L-type VGCCs contributed to the pacemaker firing of SNc-DA neurons in G2019S mice, but not in control, wild-type, and cNurr1 mice. In cNurr1 mice, but not G2019S mice, the contribution of T-type VGCCs to the pacemaker firing of SNc-DA neurons was reduced, and somatic dopamine-D2 autoreceptors desensitized more. Altered contribution of L-type and T-type VGCCs to the pacemaker firing was not observed in the presence of a LRRK2 kinase inhibitor in G2019S mice, and in the presence of a flavonoid with antioxidant activity in G2019S and cNurr1 mice. The role of L-type and T-type VGCCs in controlling dopamine release from axon terminals in the striatum was unaltered in cNurr1 and G2019S mice. Our findings uncover opposite changes, linked to oxidative stress, in the function of two VGCCs in DA neurons somata, but not axon terminals, in two different experimental PD models.
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Affiliation(s)
- Olga Skiteva
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Ning Yao
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Ioannis Mantas
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Xiaoqun Zhang
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Thomas Perlmann
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Per Svenningsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Karima Chergui
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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7
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Mancini M, Natoli S, Gardoni F, Di Luca M, Pisani A. Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19. Int J Mol Sci 2023; 24:ijms24065618. [PMID: 36982693 PMCID: PMC10056044 DOI: 10.3390/ijms24065618] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson’s disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (α-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant α-syn metabolism.
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Affiliation(s)
- Maria Mancini
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Silvia Natoli
- Department of Clinical Science and Translational Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
- IRCCS Maugeri Pavia, 27100 Pavia, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan, 20133 Milan, Italy; (F.G.); (M.D.L.)
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan, 20133 Milan, Italy; (F.G.); (M.D.L.)
| | - Antonio Pisani
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
- Correspondence: ; Tel.: +39-0382-380-247
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8
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Kershberg L, Banerjee A, Kaeser PS. Protein composition of axonal dopamine release sites in the striatum. eLife 2022; 11:e83018. [PMID: 36579890 PMCID: PMC9937654 DOI: 10.7554/elife.83018] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 12/22/2022] [Indexed: 12/30/2022] Open
Abstract
Dopamine is an important modulator of cognition and movement. We recently found that evoked dopamine secretion is fast and relies on active zone-like release sites. Here, we used in vivo biotin identification (iBioID) proximity proteomics in mouse striatum to assess which proteins are present at these sites. Using three release site baits, we identified proteins that are enriched over the general dopamine axonal protein content, and they fell into several categories, including active zone, Ca2+ regulatory, and synaptic vesicle proteins. We also detected many proteins not previously associated with vesicular exocytosis. Knockout of the presynaptic organizer protein RIM strongly decreased the hit number obtained with iBioID, while Synaptotagmin-1 knockout did not. α-Synuclein, a protein linked to Parkinson's disease, was enriched at release sites, and its enrichment was lost in both tested mutants. We conclude that RIM organizes scaffolded dopamine release sites and provide a proteomic assessment of the composition of these sites.
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Affiliation(s)
- Lauren Kershberg
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Aditi Banerjee
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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9
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Role of voltage-sensitive Ca 2+ channels in the in vivo dopamine release induced by the organophosphorus pesticide glufosinate ammonium in rat striatum. Toxicol Lett 2022; 373:105-113. [PMID: 36427774 DOI: 10.1016/j.toxlet.2022.11.012] [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: 05/11/2022] [Revised: 10/05/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
The possible role of voltage-sensitive calcium channels (VSCC) activation in the glufosinate ammonium (GLA)-induced dopamine release was investigated using selective VSCC blockers and the dopamine levels were measured by HPLC from samples obtained by in vivo cerebral microdialysis. While pretreatment with 10 μM flunarizine (T-type VSCC antagonist) or nicardipine (L-type VSCC antagonist) had no statistically significant effect on dopamine release induced by 10 mM GLA, pretreatment with 100 μM of both antagonists, or 20 μM ω-conotoxin MVIIC (non-selective P/Q-type VSCC antagonist) significantly decreased the GLA-induced dopamine release over 72.2%, 73%, and 70.2%, respectively. Administration of the specific antagonist of neuronal N-type VSCCs, the ω-conotoxin GVIA (20 μM), produced an almost complete blockade of in vivo dopamine release induced by GLA. These results show that GLA-induced dopamine release could be produced by the activation of a wide range of striatal VSCC located at the synaptic terminals and axons of striatal dopaminergic neurons, especially N-type VSCC.
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10
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Everett AC, Graul BE, Ronström JW, Robinson JK, Watts DB, España RA, Siciliano CA, Yorgason JT. Effectiveness and Relationship between Biased and Unbiased Measures of Dopamine Release and Clearance. ACS Chem Neurosci 2022; 13:1534-1548. [PMID: 35482592 PMCID: PMC10763521 DOI: 10.1021/acschemneuro.2c00033] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Fast-scan cyclic voltammetry (FSCV) is an effective tool for measuring dopamine release and clearance throughout the brain, especially the striatum where dopamine terminals are abundant and signals are heavily regulated by release machinery and the dopamine transporter (DAT). Peak height measurement is perhaps the most common method for measuring dopamine release, but it is influenced by changes in clearance. Michaelis-Menten-based modeling has been a standard in measuring dopamine clearance, but it is problematic in that it requires experimenter fitted modeling subject to experimenter bias. This study presents the use of the first derivative (velocity) of evoked dopamine signals as an alternative approach for measuring and distinguishing dopamine release from clearance. Maximal upward velocity predicts reductions in dopamine peak height due to D2 and GABAB receptor stimulation and by alterations in calcium concentrations. The Michaelis-Menten maximal velocity (Vmax) measure, an approximation for DAT levels, predicts maximal downward velocity in slices and in vivo. Dopamine peak height and upward velocity were similar between wild-type and DAT knock-out (DATKO) mice. In contrast, downward velocity was lower and exponential decay (tau) was higher in DATKO mice, supporting the use of both measures for extreme changes in DAT activity. In slices, the competitive DAT inhibitors cocaine, PTT, and WF23 increased peak height and upward velocity differentially across increasing concentrations, with PTT and cocaine reducing these measures at high concentrations. Downward velocity and tau values decreased and increased respectively across concentrations, with greater potency and efficacy observed with WF23 and PTT. In vivo recordings demonstrated similar effects of WF23, PTT, and cocaine on measures of release and clearance. Tau was a more sensitive measure at low concentrations, supporting its use as a surrogate for the Michaelis-Menten measure of apparent affinity (Km). Together, these results inform on the use of these various measures for dopamine release and clearance.
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Affiliation(s)
- Anna C. Everett
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
| | - Ben E. Graul
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
| | - Joakim W. Ronström
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
| | - J. Kayden Robinson
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
| | - Daniel B. Watts
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
| | - Rodrigo A. España
- Drexel University, Department of Neurobiology & Anatomy, Philadelphia, PA 28619, USA
| | - Cody A. Siciliano
- Vanderbilt University, Center for Addiction Research, Nashville, TN 37203, USA
| | - Jordan T. Yorgason
- Brigham Young University, Department of Cellular Biology and Physiology, Provo, UT 84602, USA
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11
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Brundage JN, Mason CP, Wadsworth HA, Finuf CS, Nelson JJ, Ronström PJW, Jones SR, Siciliano CA, Steffensen SC, Yorgason JT. Regional and sex differences in spontaneous striatal dopamine transmission. J Neurochem 2022; 160:598-612. [PMID: 34265080 PMCID: PMC10044475 DOI: 10.1111/jnc.15473] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/10/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022]
Abstract
Striatal dopamine release is key for learning and motivation and is composed of subregions including the dorsal striatum (DS), nucleus accumbens core, and the nucleus accumbens shell. Spontaneously occurring dopamine release was compared across these subregions. Dopamine release/uptake dynamics differ across striatal subregions, with dopamine transient release amplitude and release frequency greatest in male mice, and the largest signals observed in the DS. Surprisingly, female mice exhibited little regional differences in dopamine release for DS and nucleus accumbens core regions, but lower release in the nucleus accumbens shell. Blocking voltage-gated K+ channel (Kv channels) with 4-aminopyridine enhanced dopamine detection without affecting reuptake. The 4-aminopyridine effects were greatest in ventral regions of female mice, suggesting regional differences in Kv channel expression. The dopamine transporter blocker cocaine also enhanced detection across subregions in both sexes, with greater overall increased release in females than males. Thus, sex differences in dopamine transmission are apparent and likely include differences in the Kv channel and dopamine transporter function. The lack of regional differences in dopamine release observed in females indicates differential regulation of spontaneous and evoked dopamine release.
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Affiliation(s)
| | - Colin P. Mason
- Neuroscience Center, Brigham Young University, Provo, UT, USA
| | | | - Chris S. Finuf
- Department of Psychology and Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Josh J. Nelson
- Neuroscience Center, Brigham Young University, Provo, UT, USA
| | | | - Sara R. Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, NC, USA
| | - Cody A. Siciliano
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN, USA
| | - Scott C. Steffensen
- Department of Psychology and Neuroscience Center, Brigham Young University, Provo, UT, USA
| | - Jordan T. Yorgason
- Neuroscience Center, Brigham Young University, Provo, UT, USA
- Department of Cellular Biology and Physiology, Brigham Young University, Provo, UT, USA
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12
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Banerjee A, Imig C, Balakrishnan K, Kershberg L, Lipstein N, Uronen RL, Wang J, Cai X, Benseler F, Rhee JS, Cooper BH, Liu C, Wojcik SM, Brose N, Kaeser PS. Molecular and functional architecture of striatal dopamine release sites. Neuron 2022; 110:248-265.e9. [PMID: 34767769 PMCID: PMC8859508 DOI: 10.1016/j.neuron.2021.10.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 09/22/2021] [Accepted: 10/19/2021] [Indexed: 01/21/2023]
Abstract
Despite the importance of dopamine for striatal circuit function, mechanistic understanding of dopamine transmission remains incomplete. We recently showed that dopamine secretion relies on the presynaptic scaffolding protein RIM, indicating that it occurs at active zone-like sites similar to classical synaptic vesicle exocytosis. Here, we establish using a systematic gene knockout approach that Munc13 and Liprin-α, active zone proteins for vesicle priming and release site organization, are important for dopamine secretion. Furthermore, RIM zinc finger and C2B domains, which bind to Munc13 and Liprin-α, respectively, are needed to restore dopamine release after RIM ablation. In contrast, and different from typical synapses, the active zone scaffolds RIM-BP and ELKS, and RIM domains that bind to them, are expendable. Hence, dopamine release necessitates priming and release site scaffolding by RIM, Munc13, and Liprin-α, but other active zone proteins are dispensable. Our work establishes that efficient release site architecture mediates fast dopamine exocytosis.
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Affiliation(s)
- Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | | | - Lauren Kershberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Noa Lipstein
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Riikka-Liisa Uronen
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jiexin Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Xintong Cai
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jeong Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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13
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Du Y, Lee YB, Graves SM. Chronic methamphetamine-induced neurodegeneration: Differential vulnerability of ventral tegmental area and substantia nigra pars compacta dopamine neurons. Neuropharmacology 2021; 200:108817. [PMID: 34610287 PMCID: PMC8556701 DOI: 10.1016/j.neuropharm.2021.108817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/17/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022]
Abstract
Methamphetamine (meth) increases monoamine oxidase (MAO)-dependent mitochondrial stress in substantia nigra pars compacta (SNc) axons; chronic administration produces SNc degeneration that is prevented by MAO inhibition suggesting that MAO-dependent axonal mitochondrial stress is a causal factor. To test whether meth similarly increases mitochondrial stress in ventral tegmental area (VTA) axons, we used a genetically encoded redox biosensor to assess mitochondrial stress ex vivo. Meth increased MAO-dependent mitochondrial stress in both SNc and VTA axons. However, despite having the same meth-induced stress as SNc neurons, VTA neurons were resistant to chronic meth-induced degeneration indicating that meth-induced MAO-dependent mitochondrial stress in axons was necessary but not sufficient for degeneration. To determine whether L-type Ca2+ channel-dependent stress differentiates SNc and VTA axons, as reported in the soma, the L-type Ca2+ channel activator Bay K8644 was used. Opening L-type Ca2+ channels increased axonal mitochondrial stress in SNc but not VTA axons. To first determine whether mitochondrial stress was necessary for SNc degeneration, mice were treated with the mitochondrial antioxidant mitoTEMPO. Chronic meth-induced SNc degeneration was prevented by mitoTEMPO thereby confirming the necessity of mitochondrial stress. Similar to results with the antioxidant, both MAO inhibition and L-type Ca2+ channel inhibition also prevented SNc degeneration. Taken together the presented data demonstrate that both MAO- and L-type Ca2+ channel-dependent mitochondrial stress is necessary for chronic meth-induced degeneration.
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Affiliation(s)
- Yijuan Du
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - You Bin Lee
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Steven M Graves
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA.
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14
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Daniel NH, Aravind A, Thakur P. Are ion channels potential therapeutic targets for Parkinson's disease? Neurotoxicology 2021; 87:243-257. [PMID: 34699791 DOI: 10.1016/j.neuro.2021.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 01/31/2023]
Abstract
Parkinson's disease (PD) is primarily associated with the progressive neurodegeneration of the dopaminergic neurons in the substantia nigra region of the brain. The resulting motor symptoms are managed with the help of dopamine replacement therapies. However, these therapeutics do not prevent the neurodegeneration underlying the disease and therefore lose their effectiveness in managing disease symptoms over time. Thus, there is an urgent need to develop newer therapeutics for the benefit of patients. The release of dopamine and the firing activity of substantia nigra neurons is regulated by several ion channels that act in concert. Dysregulations of these channels cause the aberrant movement of various ions in the intracellular milieu. This eventually leads to disruption of intracellular signalling cascades, alterations in cellular homeostasis, and bioenergetic deficits. Therefore, ion channels play a central role in driving the high vulnerability of dopaminergic neurons to degenerate during PD. Targeting ion channels offers an attractive mechanistic strategy to combat the process of neurodegeneration. In this review, we highlight the evidence pointing to the role of various ion channels in driving the PD processes. In addition, we also discuss the various drugs or compounds that target the ion channels and have shown neuroprotective potential in the in-vitro and in-vivo models of PD. We also discuss the current clinical status of various drugs targeting the ion channels in the context of PD.
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Affiliation(s)
- Neha Hanna Daniel
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Ananya Aravind
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Poonam Thakur
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India.
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15
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Erhardt B, Marcora MS, Frenkel L, Bochicchio PA, Bodin DH, Silva BA, Farías MI, Allo MÁ, Höcht C, Ferrari CC, Pitossi FJ, Leal MC. Plasma membrane calcium ATPase downregulation in dopaminergic neurons alters cellular physiology and motor behaviour in Drosophila melanogaster. Eur J Neurosci 2021; 54:5915-5931. [PMID: 34312939 DOI: 10.1111/ejn.15401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/14/2021] [Accepted: 07/22/2021] [Indexed: 11/29/2022]
Abstract
The accumulation of Ca2+ and its subsequent increase in oxidative stress is proposed to be involved in selective dysfunctionality of dopaminergic neurons, the main cell type affected in Parkinson's disease. To test the in vivo impact of Ca2+ increment in dopaminergic neurons physiology, we downregulated the plasma membrane Ca2+ ATPase (PMCA), a pump that extrudes cytosolic Ca2+ , by expressing PMCARNAi in Drosophila melanogaster dopaminergic neurons. In these animals, we observed major locomotor alterations paralleled to higher cytosolic Ca2+ and increased levels of oxidative stress in mitochondria. Interestingly, although no overt degeneration of dopaminergic neurons was observed, evidences of neuronal dysfunctionality were detected such as increases in presynaptic vesicles in dopaminergic neurons and in the levels of dopamine in the brain, as well as presence of toxic effects when PMCA was downregulated in the eye. Moreover, reduced PMCA levels were found in a Drosophila model of Parkinson's disease, Parkin knock-out, expanding the functional relevance of PMCA reduction to other Parkinson's disease-related models. In all, we have generated a new model to study motor abnormalities caused by increments in Ca2+ that lead to augmented oxidative stress in a dopaminergic environment, added to a rise in synaptic vesicles and dopamine levels.
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Affiliation(s)
- Brenda Erhardt
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
| | - María Silvina Marcora
- Instituto de Química y Fisicoquímica Biológicas (IQUIFIB)-CONICET, Buenos Aires, Argentina
| | - Lía Frenkel
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Pablo Alejandro Bochicchio
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Diego Hernán Bodin
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Berenice Anabel Silva
- Fundación Instituto Leloir, Buenos Aires, Argentina.,Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB)-CONICET, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - María Isabel Farías
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Miguel Ángel Allo
- Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Christian Höcht
- Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carina Cintia Ferrari
- Fundación Instituto Leloir, Buenos Aires, Argentina.,Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB)-CONICET, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Fernando Juan Pitossi
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
| | - María Celeste Leal
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Fundación Instituto Leloir, Buenos Aires, Argentina
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16
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Liu C, Goel P, Kaeser PS. Spatial and temporal scales of dopamine transmission. Nat Rev Neurosci 2021; 22:345-358. [PMID: 33837376 PMCID: PMC8220193 DOI: 10.1038/s41583-021-00455-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2021] [Indexed: 02/02/2023]
Abstract
Dopamine is a prototypical neuromodulator that controls circuit function through G protein-coupled receptor signalling. Neuromodulators are volume transmitters, with release followed by diffusion for widespread receptor activation on many target cells. Yet, we are only beginning to understand the specific organization of dopamine transmission in space and time. Although some roles of dopamine are mediated by slow and diffuse signalling, recent studies suggest that certain dopamine functions necessitate spatiotemporal precision. Here, we review the literature describing dopamine signalling in the striatum, including its release mechanisms and receptor organization. We then propose the domain-overlap model, in which release and receptors are arranged relative to one another in micrometre-scale structures. This architecture is different from both point-to-point synaptic transmission and the widespread organization that is often proposed for neuromodulation. It enables the activation of receptor subsets that are within micrometre-scale domains of release sites during baseline activity and broader receptor activation with domain overlap when firing is synchronized across dopamine neuron populations. This signalling structure, together with the properties of dopamine release, may explain how switches in firing modes support broad and dynamic roles for dopamine and may lead to distinct pathway modulation.
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Affiliation(s)
- Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pragya Goel
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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17
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Downs AM, Fan X, Kadakia RF, Donsante Y, Jinnah HA, Hess EJ. Cell-intrinsic effects of TorsinA(ΔE) disrupt dopamine release in a mouse model of TOR1A dystonia. Neurobiol Dis 2021; 155:105369. [PMID: 33894367 DOI: 10.1016/j.nbd.2021.105369] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/29/2021] [Accepted: 04/19/2021] [Indexed: 11/19/2022] Open
Abstract
TOR1A-associated dystonia, otherwise known as DYT1 dystonia, is an inherited dystonia caused by a three base-pair deletion in the TOR1A gene (TOR1AΔE). Although the mechanisms underlying the dystonic movements are largely unknown, abnormalities in striatal dopamine and acetylcholine neurotransmission are consistently implicated whereby dopamine release is reduced while cholinergic tone is increased. Because striatal cholinergic neurotransmission mediates dopamine release, it is not known if the dopamine release deficit is mediated indirectly by abnormal acetylcholine neurotransmission or if Tor1a(ΔE) acts directly within dopaminergic neurons to attenuate release. To dissect the microcircuit that governs the deficit in dopamine release, we conditionally expressed Tor1a(ΔE) in either dopamine neurons or cholinergic interneurons in mice and assessed striatal dopamine release using ex vivo fast scan cyclic voltammetry or dopamine efflux using in vivo microdialysis. Conditional expression of Tor1a(ΔE) in cholinergic neurons did not affect striatal dopamine release. In contrast, conditional expression of Tor1a(ΔE) in dopamine neurons reduced dopamine release to 50% of normal, which is comparable to the deficit in Tor1a+/ΔE knockin mice that express the mutation ubiquitously. Despite the deficit in dopamine release, we found that the Tor1a(ΔE) mutation does not cause obvious nerve terminal dysfunction as other presynaptic mechanisms, including electrical excitability, vesicle recycling/refilling, Ca2+ signaling, D2 dopamine autoreceptor function and GABAB receptor function, are intact. Although the mechanistic link between Tor1a(ΔE) and dopamine release is unclear, these results clearly demonstrate that the defect in dopamine release is caused by the action of the Tor1a(ΔE) mutation within dopamine neurons.
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Affiliation(s)
- Anthony M Downs
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Xueliang Fan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Radhika F Kadakia
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - Yuping Donsante
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA
| | - H A Jinnah
- Department of Neurology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA; Department of Human Genetics, Emory University School of Medicine, 101 Woodruff Circle, WMB 6300, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, 101 Woodruff Circle, WMB 6300, Atlanta, GA 30322, USA
| | - Ellen J Hess
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA; Department of Neurology, Emory University School of Medicine, 101 Woodruff Circle, WMB 6304, Atlanta, GA 30322, USA.
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18
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Ortner NJ. Voltage-Gated Ca 2+ Channels in Dopaminergic Substantia Nigra Neurons: Therapeutic Targets for Neuroprotection in Parkinson's Disease? Front Synaptic Neurosci 2021; 13:636103. [PMID: 33716705 PMCID: PMC7952618 DOI: 10.3389/fnsyn.2021.636103] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/25/2021] [Indexed: 12/21/2022] Open
Abstract
The loss of dopamine (DA)-producing neurons in the substantia nigra pars compacta (SN) underlies the core motor symptoms of the progressive movement disorder Parkinson's disease (PD). To date, no treatment to prevent or slow SN DA neurodegeneration exists; thus, the identification of the underlying factors contributing to the high vulnerability of these neurons represents the basis for the development of novel therapies. Disrupted Ca2+ homeostasis and mitochondrial dysfunction seem to be key players in the pathophysiology of PD. The autonomous pacemaker activity of SN DA neurons, in combination with low cytosolic Ca2+ buffering, leads to large somatodendritic fluctuations of intracellular Ca2+ levels that are linked to elevated mitochondrial oxidant stress. L-type voltage-gated Ca2+ channels (LTCCs) contribute to these Ca2+ oscillations in dendrites, and LTCC inhibition was beneficial in cellular and in vivo animal models of PD. However, in a recently completed phase 3 clinical trial, the dihydropyridine (DHP) LTCC inhibitor isradipine failed to slow disease progression in early PD patients, questioning the feasibility of DHPs for PD therapy. Novel evidence also suggests that R- and T-type Ca2+ channels (RTCCs and TTCCs, respectively) represent potential PD drug targets. This short review aims to (re)evaluate the therapeutic potential of LTCC, RTCC, and TTCC inhibition in light of novel preclinical and clinical data and the feasibility of available Ca2+ channel blockers to modify PD disease progression. I also summarize their cell-specific roles for SN DA neuron function and describe how their gating properties allow activity (and thus their contribution to stressful Ca2+ oscillations) during pacemaking.
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Affiliation(s)
- Nadine J. Ortner
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
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19
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Zachry JE, Nolan SO, Brady LJ, Kelly SJ, Siciliano CA, Calipari ES. Sex differences in dopamine release regulation in the striatum. Neuropsychopharmacology 2021; 46:491-499. [PMID: 33318634 PMCID: PMC8027008 DOI: 10.1038/s41386-020-00915-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 01/05/2023]
Abstract
The mesolimbic dopamine system-which originates in the ventral tegmental area and projects to the striatum-has been shown to be involved in the expression of sex-specific behavior and is thought to be a critical mediator of many psychiatric diseases. While substantial work has focused on sex differences in the anatomy of dopamine neurons and relative dopamine levels between males and females, an important characteristic of dopamine release from axon terminals in the striatum is that it is rapidly modulated by local regulatory mechanisms independent of somatic activity. These processes can occur via homosynaptic mechanisms-such as presynaptic dopamine autoreceptors and dopamine transporters-as well as heterosynaptic mechanisms, such as retrograde signaling from postsynaptic cholinergic and GABAergic systems, among others. These regulators serve as potential targets for the expression of sex differences in dopamine regulation in both ovarian hormone-dependent and independent fashions. This review describes how sex differences in microcircuit regulatory mechanisms can alter dopamine dynamics between males and females. We then describe what is known about the hormonal mechanisms controlling/regulating these processes. Finally, we highlight the missing gaps in our knowledge of these systems in females. Together, a more comprehensive and mechanistic understanding of how sex differences in dopamine function manifest will be particularly important in developing evidence-based therapeutics that target this system and show efficacy in both sexes.
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Affiliation(s)
- Jennifer E. Zachry
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Suzanne O. Nolan
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Lillian J. Brady
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Shannon J. Kelly
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Cody A. Siciliano
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232 USA
| | - Erin S. Calipari
- grid.152326.10000 0001 2264 7217Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232 USA ,grid.152326.10000 0001 2264 7217Department of Psychiatry and Behavioral Sciences, Vanderbilt University, Nashville, TN 37232 USA
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20
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Blazon M, LaCarubba B, Bunda A, Czepiel N, Mallat S, Londrigan L, Andrade A. N-type calcium channels control GABAergic transmission in brain areas related to fear and anxiety. OBM NEUROBIOLOGY 2021; 5:10.21926/obm.neurobiol.2101083. [PMID: 33521586 PMCID: PMC7845927 DOI: 10.21926/obm.neurobiol.2101083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
N-type (CaV2.2) calcium channels are key for action potential-evoked transmitter release in the peripheral and central nervous system. Previous studies have highlighted the functional relevance of N-type calcium channels at both the peripheral and central level. In the periphery, the N-type calcium channels regulate nociceptive and sympathetic responses. At the central level, N-type calcium channels have been linked to aggression, hyperlocomotion, and anxiety. Among the areas of the brain that are involved in anxiety are the basolateral amygdala, medial prefrontal cortex, and ventral hippocampus. These three areas share similar characteristics in their neuronal circuitry, where pyramidal projection neurons are under the inhibitory control of a wide array of interneurons including those that express the peptide cholecystokinin. This type of interneuron is well-known to rely on N-type calcium channels to release GABA in the hippocampus, however, whether these channels control GABA release from cholecystokinin-expressing interneurons in the basolateral amygdala and medial prefrontal cortex is not known. Here, using mouse models to genetically label cholecystokinin-expressing interneurons and electrophysiology, we found that in the basolateral amygdala, N-type calcium channels control ~50% of GABA release from these neurons onto pyramidal cells. By contrast, in the medial prefrontal cortex N-type calcium channels are functionally absent in synapses of cholecystokinin-expressing interneurons, but control ~40% of GABA release from other types of interneurons. Our findings provide insights into the precise localization of N-type calcium channels in interneurons of brain areas related to anxiety.
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Affiliation(s)
- Maxwell Blazon
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Brianna LaCarubba
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Alexandra Bunda
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Natalie Czepiel
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Shayna Mallat
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Laura Londrigan
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Arturo Andrade
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
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21
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Evolution of in vivo dopamine monitoring techniques. Pharmacol Biochem Behav 2020; 200:173078. [PMID: 33278398 DOI: 10.1016/j.pbb.2020.173078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/06/2020] [Accepted: 11/18/2020] [Indexed: 01/01/2023]
Abstract
The brain dopamine system is central to numerous behavioral processes, including movement, learning, and motivation. Accordingly, disruptions of this neural system underlie numerous neurological and psychiatric disorders. Current understanding of how dopamine neurotransmission contributes to behavior and its dysfunction has been driven by technological advancements that permit spatiotemporally-defined measurements of dopaminergic signaling in behaving animals. In this review, we will discuss the evolution of in vivo neural monitoring technologies for measuring dopamine neuron function. We focus on the dopamine system for two reasons: (1) the central role of dopamine neurotransmission in normal behavior and disease, and (2) dopamine neuron measurements have long been at the forefront of in vivo neural monitoring technologies. We will provide a brief overview of standard techniques for monitoring dopamine function, including electrophysiology, microdialysis, and voltammetry. Then, we will discuss recent advancements in optical technologies using genetically-encoded fluorescent proteins (GEFPs), including a critical evaluation of their advantages and limitations.
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22
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Hirano AA, Vuong HE, Kornmann HL, Schietroma C, Stella SL, Barnes S, Brecha NC. Vesicular Release of GABA by Mammalian Horizontal Cells Mediates Inhibitory Output to Photoreceptors. Front Cell Neurosci 2020; 14:600777. [PMID: 33335476 PMCID: PMC7735995 DOI: 10.3389/fncel.2020.600777] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
Feedback inhibition by horizontal cells regulates rod and cone photoreceptor calcium channels that control their release of the neurotransmitter glutamate. This inhibition contributes to synaptic gain control and the formation of the center-surround antagonistic receptive fields passed on to all downstream neurons, which is important for contrast sensitivity and color opponency in vision. In contrast to the plasmalemmal GABA transporter found in non-mammalian horizontal cells, there is evidence that the mechanism by which mammalian horizontal cells inhibit photoreceptors involves the vesicular release of the inhibitory neurotransmitter GABA. Historically, inconsistent findings of GABA and its biosynthetic enzyme, L-glutamate decarboxylase (GAD) in horizontal cells, and the apparent lack of surround response block by GABAergic agents diminished support for GABA's role in feedback inhibition. However, the immunolocalization of the vesicular GABA transporter (VGAT) in the dendritic and axonal endings of horizontal cells that innervate photoreceptor terminals suggested GABA was released via vesicular exocytosis. To test the idea that GABA is released from vesicles, we localized GABA and GAD, multiple SNARE complex proteins, synaptic vesicle proteins, and Cav channels that mediate exocytosis to horizontal cell dendritic tips and axonal terminals. To address the perceived relative paucity of synaptic vesicles in horizontal cell endings, we used conical electron tomography on mouse and guinea pig retinas that revealed small, clear-core vesicles, along with a few clathrin-coated vesicles and endosomes in horizontal cell processes within photoreceptor terminals. Some small-diameter vesicles were adjacent to the plasma membrane and plasma membrane specializations. To assess vesicular release, a functional assay involving incubation of retinal slices in luminal VGAT-C antibodies demonstrated vesicles fused with the membrane in a depolarization- and calcium-dependent manner, and these labeled vesicles can fuse multiple times. Finally, targeted elimination of VGAT in horizontal cells resulted in a loss of tonic, autaptic GABA currents, and of inhibitory feedback modulation of the cone photoreceptor Cai, consistent with the elimination of GABA release from horizontal cell endings. These results in mammalian retina identify the central role of vesicular release of GABA from horizontal cells in the feedback inhibition of photoreceptors.
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Affiliation(s)
- Arlene A. Hirano
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Helen E. Vuong
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Helen L. Kornmann
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cataldo Schietroma
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Salvatore L. Stella
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Steven Barnes
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Doheny Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Nicholas C. Brecha
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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23
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Roberts BM, Doig NM, Brimblecombe KR, Lopes EF, Siddorn RE, Threlfell S, Connor-Robson N, Bengoa-Vergniory N, Pasternack N, Wade-Martins R, Magill PJ, Cragg SJ. GABA uptake transporters support dopamine release in dorsal striatum with maladaptive downregulation in a parkinsonism model. Nat Commun 2020; 11:4958. [PMID: 33009395 PMCID: PMC7532441 DOI: 10.1038/s41467-020-18247-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 08/13/2020] [Indexed: 12/31/2022] Open
Abstract
Striatal dopamine (DA) is critical for action and learning. Recent data show that DA release is under tonic inhibition by striatal GABA. Ambient striatal GABA tone on striatal projection neurons can be determined by plasma membrane GABA uptake transporters (GATs) located on astrocytes and neurons. However, whether striatal GATs and astrocytes determine DA output are unknown. We reveal that DA release in mouse dorsolateral striatum, but not nucleus accumbens core, is governed by GAT-1 and GAT-3. These GATs are partly localized to astrocytes, and are enriched in dorsolateral striatum compared to accumbens core. In a mouse model of early parkinsonism, GATs are downregulated, tonic GABAergic inhibition of DA release augmented, and nigrostriatal GABA co-release attenuated. These data define previously unappreciated and important roles for GATs and astrocytes in supporting DA release in striatum, and reveal a maladaptive plasticity in early parkinsonism that impairs DA output in vulnerable striatal regions. GABA transporters expressed in the striatum may affect behaviour. Here the authors investigate the contribution of GABA transporters on astrocytes to the regulation of dopamine release in the striatum, and show decreased expression of GAT-1 and GAT-3 in a mouse model of Parkinsonism.
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Affiliation(s)
- Bradley M Roberts
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK. .,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK.
| | - Natalie M Doig
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3TH, UK
| | - Katherine R Brimblecombe
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK
| | - Emanuel F Lopes
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Ruth E Siddorn
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Sarah Threlfell
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK
| | - Natalie Connor-Robson
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK
| | - Nora Bengoa-Vergniory
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK
| | - Nicholas Pasternack
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Richard Wade-Martins
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK
| | - Peter J Magill
- Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK.,Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3TH, UK
| | - Stephanie J Cragg
- Centre for Integrative Neuroscience, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK. .,Oxford Parkinson's Disease Centre, University of Oxford, Oxford, OX1 3PT, UK.
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24
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Kramer PF, Twedell EL, Shin JH, Zhang R, Khaliq ZM. Axonal mechanisms mediating γ-aminobutyric acid receptor type A (GABA-A) inhibition of striatal dopamine release. eLife 2020; 9:e55729. [PMID: 32870779 PMCID: PMC7462615 DOI: 10.7554/elife.55729] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/15/2020] [Indexed: 01/03/2023] Open
Abstract
Axons of dopaminergic neurons innervate the striatum where they contribute to movement and reinforcement learning. Past work has shown that striatal GABA tonically inhibits dopamine release, but whether GABA-A receptors directly modulate transmission or act indirectly through circuit elements is unresolved. Here, we use whole-cell and perforated-patch recordings to test for GABA-A receptors on the main dopaminergic neuron axons and branching processes within the striatum of adult mice. Application of GABA depolarized axons, but also decreased the amplitude of axonal spikes, limited propagation and reduced striatal dopamine release. The mechanism of inhibition involved sodium channel inactivation and shunting. Lastly, we show the positive allosteric modulator diazepam enhanced GABA-A currents on dopaminergic axons and directly inhibited release, but also likely acts by reducing excitation from cholinergic interneurons. Thus, we reveal the mechanisms of GABA-A receptor modulation of dopamine release and provide new insights into the actions of benzodiazepines within the striatum.
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Affiliation(s)
- Paul F Kramer
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Emily L Twedell
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Jung Hoon Shin
- Laboratory on Neurobiology of Compulsive Behaviors, National Institute of Alcohol Abuse and Alcoholism, National Institutes of HealthBethesdaUnited States
| | - Renshu Zhang
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Zayd M Khaliq
- Cellular Neurophysiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
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25
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Nolan SO, Zachry JE, Johnson AR, Brady LJ, Siciliano CA, Calipari ES. Direct dopamine terminal regulation by local striatal microcircuitry. J Neurochem 2020; 155:475-493. [PMID: 32356315 DOI: 10.1111/jnc.15034] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 02/06/2023]
Abstract
Regulation of axonal dopamine release by local microcircuitry is at the hub of several biological processes that govern the timing and magnitude of signaling events in reward-related brain regions. An important characteristic of dopamine release from axon terminals in the striatum is that it is rapidly modulated by local regulatory mechanisms. These processes can occur via homosynaptic mechanisms-such as presynaptic dopamine autoreceptors and dopamine transporters - as well heterosynaptic mechanisms such as retrograde signaling from postsynaptic cholinergic and dynorphin systems, among others. Additionally, modulation of dopamine release via diffusible messengers, such as nitric oxide and hydrogen peroxide, allows for various metabolic factors to quickly and efficiently regulate dopamine release and subsequent signaling. Here we review how these mechanisms work in concert to influence the timing and magnitude of striatal dopamine signaling, independent of action potential activity at the level of dopaminergic cell bodies in the midbrain, thereby providing a parallel pathway by which dopamine can be modulated. Understanding the complexities of local regulation of dopamine signaling is required for building comprehensive frameworks of how activity throughout the dopamine system is integrated to drive signaling and control behavior.
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Affiliation(s)
- Suzanne O Nolan
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Jennifer E Zachry
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Amy R Johnson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Lillian J Brady
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Cody A Siciliano
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN TN, USA
| | - Erin S Calipari
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Department of Psychiatry and Behavioral Sciences, Vanderbilt University, Nashville, TN, USA
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26
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Banerjee A, Lee J, Nemcova P, Liu C, Kaeser PS. Synaptotagmin-1 is the Ca 2+ sensor for fast striatal dopamine release. eLife 2020; 9:58359. [PMID: 32490813 PMCID: PMC7319770 DOI: 10.7554/elife.58359] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/02/2020] [Indexed: 11/13/2022] Open
Abstract
Dopamine powerfully controls neural circuits through neuromodulation. In the vertebrate striatum, dopamine adjusts cellular functions to regulate behaviors across broad time scales, but how the dopamine secretory system is built to support fast and slow neuromodulation is not known. Here, we set out to identify Ca2+-triggering mechanisms for dopamine release. We find that synchronous dopamine secretion is abolished in acute brain slices of conditional knockout mice in which Synaptotagmin-1 is removed from dopamine neurons. This indicates that Synaptotagmin-1 is the Ca2+ sensor for fast dopamine release. Remarkably, dopamine release induced by strong depolarization and asynchronous release during stimulus trains are unaffected by Synaptotagmin-1 knockout. Microdialysis further reveals that these modes and action potential-independent release provide significant amounts of extracellular dopamine in vivo. We propose that the molecular machinery for dopamine secretion has evolved to support fast and slow signaling modes, with fast release requiring the Ca2+ sensor Synaptotagmin-1.
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Affiliation(s)
- Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Jinoh Lee
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Paulina Nemcova
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, United States
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27
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Yorgason JT, Hedges DM, Obray JD, Jang EY, Bills KB, Woodbury M, Williams B, Parsons MJ, Andres MA, Steffensen SC. Methamphetamine increases dopamine release in the nucleus accumbens through calcium-dependent processes. Psychopharmacology (Berl) 2020; 237:1317-1330. [PMID: 31965252 PMCID: PMC7196509 DOI: 10.1007/s00213-020-05459-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/10/2020] [Indexed: 11/28/2022]
Abstract
RATIONALE Methamphetamine (METH) enhances exocytotic dopamine (DA) signals and induces DA transporter (DAT)-mediated efflux in brain striatal regions such as the nucleus accumbens (NAc). Blocking sigma receptors prevents METH-induced DA increases. Sigma receptor activation induces Ca2+ release from intracellular stores, which may be responsible for METH-induced DA increases. OBJECTIVES The role of intracellular and extracellular Ca2+ in METH-induced DA increases and associated behavior was tested. METHODS METH-induced Ca2+ release was measured in hNPC-derived DA cells using ratiometric Ca2+ imaging. In mouse brain slices, fast-scan cyclic voltammetry was used to measure METH effects on two measures of dopamine: electrically stimulated and DAT-mediated efflux. Intracellular and extracellular Ca2+ was removed through pharmacological blockade of Ca2+ permeable channels (Cd2+ and IP3 sensitive channels), intracellular Ca2+ chelation (BAPTA-AM), or non-inclusion (zero Ca2+). Lastly, METH effects on dopamine-mediated locomotor behavior were tested in rats. Rats received intra-NAc injections of ACSF or 2-aminoethoxydiphenyl borate (2-APB; IP3 receptor blocker) and intraperitoneal METH (5 mg/kg) to test the role of intracellular Ca2+ release in DA-mediated behaviors. RESULTS Reducing Ca2+ extracellular levels and Ca2+ release from intracellular stores prevented intracellular Ca2+ release. Intracellular Ca2+ chelation and blocking intracellular Ca2+ release reduced METH effects on voltammetric measures of dopamine. Blocking intracellular Ca2+ release via 2-APB resulted in increased METH-induced circling behavior. CONCLUSIONS METH induces NAc DA release through intracellular Ca2+ activity. Blocking intracellular Ca2+ release prevents METH effects on DA signals and related behavior.
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Affiliation(s)
- Jordan T. Yorgason
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - David M. Hedges
- Brigham Young University, Department of Chemistry and Biochemistry; Provo, Utah
| | - J. Daniel Obray
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - Eun Young Jang
- Research Center for Safety Pharmacology, Korea Institute of Toxicology; Daejeon, South Korea
| | - Kyle B. Bills
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - Mark Woodbury
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - Ben Williams
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - Mandy J. Parsons
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah
| | - Marilou A. Andres
- University of Hawaii at Manoa, Pacific Biosciences Research Center; Honolulu, Hawaii
| | - Scott C. Steffensen
- Brigham Young University, Department of Psychology/Neuroscience; Provo, Utah,Corresponding Author: Scott C. Steffensen, 1050 SWKT, Brigham Young University, Provo UT, 84602, Tel: 801-422-9499, Fax: 801-422-0602,
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28
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Lahiri AK, Bevan MD. Dopaminergic Transmission Rapidly and Persistently Enhances Excitability of D1 Receptor-Expressing Striatal Projection Neurons. Neuron 2020; 106:277-290.e6. [PMID: 32075716 PMCID: PMC7182485 DOI: 10.1016/j.neuron.2020.01.028] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/26/2019] [Accepted: 01/22/2020] [Indexed: 12/13/2022]
Abstract
Substantia nigra dopamine neurons have been implicated in the initiation and invigoration of movement, presumably through their modulation of striatal projection neuron (SPN) activity. However, the impact of native dopaminergic transmission on SPN excitability has not been directly demonstrated. Using perforated patch-clamp recording, we found that optogenetic stimulation of nigrostriatal dopamine axons rapidly and persistently elevated the excitability of D1 receptor-expressing SPNs (D1-SPNs). The evoked firing of D1-SPNs increased within hundreds of milliseconds of stimulation and remained elevated for ≥ 10 min. Consistent with the negative modulation of depolarization- and Ca2+-activated K+ currents, dopaminergic transmission accelerated subthreshold depolarization in response to current injection, reduced the latency to fire, and transiently diminished action potential afterhyperpolarization. Persistent modulation was protein kinase A dependent and associated with a reduction in action potential threshold. Together, these data demonstrate that dopaminergic transmission potently increases D1-SPN excitability with a time course that could support subsecond and sustained behavioral control.
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Affiliation(s)
- Asha K Lahiri
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mark D Bevan
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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29
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Lenahan C, Sanghavi R, Huang L, Zhang JH. Rhodopsin: A Potential Biomarker for Neurodegenerative Diseases. Front Neurosci 2020; 14:326. [PMID: 32351353 PMCID: PMC7175229 DOI: 10.3389/fnins.2020.00326] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 03/19/2020] [Indexed: 12/12/2022] Open
Abstract
Retinal alterations have recently been associated with numerous neurodegenerative diseases. Rhodopsin is a G-protein coupled receptor found in the rod cells of the retina. As a biomarker associated with retinal thinning and degeneration, it bears potential in the early detection and monitoring of several neurodegenerative diseases. In this review article, we summarize the findings of correlations between rhodopsin and several neurodegenerative disorders as well as the potential of a novel technique, cSLO, in the quantification of rhodopsin.
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Affiliation(s)
- Cameron Lenahan
- Burrell College of Osteopathic Medicine, Las Cruces, NM, United States.,Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - Rajvee Sanghavi
- Burrell College of Osteopathic Medicine, Las Cruces, NM, United States
| | - Lei Huang
- Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, United States.,Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA, United States.,Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - John H Zhang
- Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, United States.,Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA, United States.,Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, United States.,Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda, CA, United States
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30
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Benkert J, Hess S, Roy S, Beccano-Kelly D, Wiederspohn N, Duda J, Simons C, Patil K, Gaifullina A, Mannal N, Dragicevic E, Spaich D, Müller S, Nemeth J, Hollmann H, Deuter N, Mousba Y, Kubisch C, Poetschke C, Striessnig J, Pongs O, Schneider T, Wade-Martins R, Patel S, Parlato R, Frank T, Kloppenburg P, Liss B. Cav2.3 channels contribute to dopaminergic neuron loss in a model of Parkinson's disease. Nat Commun 2019; 10:5094. [PMID: 31704946 PMCID: PMC6841684 DOI: 10.1038/s41467-019-12834-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 09/27/2019] [Indexed: 12/21/2022] Open
Abstract
Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkinson's disease. The mechanisms underlying this age-dependent and region-selective neurodegeneration remain unclear. Here we identify Cav2.3 channels as regulators of nigral neuronal viability. Cav2.3 transcripts were more abundant than other voltage-gated Ca2+ channels in mouse nigral neurons and upregulated during aging. Plasmalemmal Cav2.3 protein was higher than in dopaminergic neurons of the ventral tegmental area, which do not degenerate in Parkinson's disease. Cav2.3 knockout reduced activity-associated nigral somatic Ca2+ signals and Ca2+-dependent after-hyperpolarizations, and afforded full protection from degeneration in vivo in a neurotoxin Parkinson's mouse model. Cav2.3 deficiency upregulated transcripts for NCS-1, a Ca2+-binding protein implicated in neuroprotection. Conversely, NCS-1 knockout exacerbated nigral neurodegeneration and downregulated Cav2.3. Moreover, NCS-1 levels were reduced in a human iPSC-model of familial Parkinson's. Thus, Cav2.3 and NCS-1 may constitute potential therapeutic targets for combatting Ca2+-dependent neurodegeneration in Parkinson's disease.
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Affiliation(s)
- Julia Benkert
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Simon Hess
- Institute for Zoology, Biocenter, CECAD, University of Cologne, Cologne, Germany
| | - Shoumik Roy
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Dayne Beccano-Kelly
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Johanna Duda
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Carsten Simons
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Komal Patil
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | | | - Nadja Mannal
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Elena Dragicevic
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Desirée Spaich
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Sonja Müller
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Julia Nemeth
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Helene Hollmann
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Nora Deuter
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Yassine Mousba
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Joerg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Olaf Pongs
- Institute of Physiology, CIPMM, University of the Saarland, Homburg, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Sandip Patel
- Department of Cell and Developmental Biology, UCL, London, UK
| | - Rosanna Parlato
- Institute of Applied Physiology, University of Ulm, Ulm, Germany
| | - Tobias Frank
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Peter Kloppenburg
- Institute for Zoology, Biocenter, CECAD, University of Cologne, Cologne, Germany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, Germany.
- New College, University of Oxford, Oxford, UK.
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31
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Selective vulnerability in α-synucleinopathies. Acta Neuropathol 2019; 138:681-704. [PMID: 31006067 PMCID: PMC6800835 DOI: 10.1007/s00401-019-02010-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/13/2019] [Accepted: 04/05/2019] [Indexed: 12/11/2022]
Abstract
Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy are neurodegenerative disorders resulting in progressive motor/cognitive deficits among other symptoms. They are characterised by stereotypical brain cell loss accompanied by the formation of proteinaceous aggregations of the protein α-synuclein (α-syn), being, therefore, termed α-synucleinopathies. Although the presence of α-syn inclusions is a common hallmark of these disorders, the exact nature of the deposited protein is specific to each disease. Different neuroanatomical regions and cellular populations manifest a differential vulnerability to the appearance of protein deposits, cell dysfunction, and cell death, leading to phenotypic diversity. The present review describes the multiple factors that contribute to the selective vulnerability in α-synucleinopathies. We explore the intrinsic cellular properties in the affected regions, including the physiological and pathophysiological roles of endogenous α-syn, the metabolic and genetic build-up of the cells and their connectivity. These factors converge with the variability of the α-syn conformational strains and their spreading capacity to dictate the phenotypic diversity and regional vulnerability of each disease. Finally, we describe the exogenous and environmental factors that potentially contribute by igniting and modulating the differential pathology in α-synucleinopathies. In conclusion, we think that it is the confluence of this disruption of the cellular metabolic state and α-syn structural equilibrium through the anatomical connectivity which appears to initiate cascades of pathological processes triggered by genetic, environmental, or stochastic events that result in the "death by a thousand cuts" profile of α-synucleinopathies.
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32
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Plasticity in striatal dopamine release is governed by release-independent depression and the dopamine transporter. Nat Commun 2019; 10:4263. [PMID: 31537790 PMCID: PMC6753151 DOI: 10.1038/s41467-019-12264-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 08/13/2019] [Indexed: 01/19/2023] Open
Abstract
Mesostriatal dopaminergic neurons possess extensively branched axonal arbours. Whether action potentials are converted to dopamine output in the striatum will be influenced dynamically and critically by axonal properties and mechanisms that are poorly understood. Here, we address the roles for mechanisms governing release probability and axonal activity in determining short‐term plasticity of dopamine release, using fast‐scan cyclic voltammetry in the ex vivo mouse striatum. We show that brief short‐term facilitation and longer short term depression are only weakly dependent on the level of initial release, i.e. are release insensitive. Rather, short-term plasticity is strongly determined by mechanisms which govern axonal activation, including K+‐gated excitability and the dopamine transporter, particularly in the dorsal striatum. We identify the dopamine transporter as a master regulator of dopamine short‐term plasticity, governing the balance between release‐dependent and independent mechanisms that also show region‐specific gating. Dopamine release in the striatum has important roles in action selection and in disorders such as Parkinson’s disease. The authors here show that short-term plasticity of dopamine release is strongly determined by axonal activation and dopamine transporters.
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33
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Brimblecombe KR, Vietti-Michelina S, Platt NJ, Kastli R, Hnieno A, Gracie CJ, Cragg SJ. Calbindin-D28K Limits Dopamine Release in Ventral but Not Dorsal Striatum by Regulating Ca 2+ Availability and Dopamine Transporter Function. ACS Chem Neurosci 2019; 10:3419-3426. [PMID: 31361457 PMCID: PMC6706870 DOI: 10.1021/acschemneuro.9b00325] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
![]()
The
calcium-binding protein calbindin-D28K, or calb1, is expressed
at higher levels by dopamine (DA) neurons originating in the ventral
tegmental area (VTA) than in the adjacent substantia nigra pars compacta
(SNc). Calb1 has received attention for a potential role in neuroprotection
in Parkinson’s disease. The underlying physiological roles
for calb1 are incompletely understood. We used cre-loxP technology
to knock down calb1 in mouse DA neurons to test whether calb1 governs
axonal release of DA in the striatum, detected using fast-scan cyclic
voltammetry ex vivo. In the ventral but not dorsal striatum, calb1
knockdown elevated DA release and modified the spatiotemporal coupling
of Ca2+ entry to DA release. Furthermore, calb1 knockdown
enhanced DA uptake but attenuated the impact of DA transporter (DAT)
inhibition by cocaine on underlying DA release. These data reveal
that calb1 acts through a range of mechanisms underpinning both DA
release and uptake to limit DA transmission in the ventral but not
dorsal striatum.
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Affiliation(s)
- Katherine R. Brimblecombe
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Stefania Vietti-Michelina
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Nicola J. Platt
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Rahel Kastli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Ahmad Hnieno
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Caitlin J. Gracie
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Stephanie J. Cragg
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
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34
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Liu C, Kaeser PS. Mechanisms and regulation of dopamine release. Curr Opin Neurobiol 2019; 57:46-53. [PMID: 30769276 PMCID: PMC6629510 DOI: 10.1016/j.conb.2019.01.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 01/17/2023]
Abstract
Dopamine controls motor functions, motivation, and reward-related learning through G-protein coupled receptor signaling. The current working model is that upon release, dopamine diffuses to influence many target cells via wide-spread receptors. Recent studies, however, suggest that dopamine release is fast and generates small signaling hotspots. In this review, we summarize progress on the understanding of the dopamine release apparatus and evaluate how its properties may shape dopamine signaling during firing. We discuss how mechanisms of regulation may act through this machinery and propose that striatal architecture for dopamine signaling may have evolved to support rapid dopamine coding.
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Affiliation(s)
- Changliang Liu
- Department of Neurobiology, Harvard Medical School, United States
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, United States.
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35
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Bunda A, LaCarubba B, Akiki M, Andrade A. Tissue- and cell-specific expression of a splice variant in the II-III cytoplasmic loop of Cacna1b. FEBS Open Bio 2019; 9:1603-1616. [PMID: 31314171 PMCID: PMC6722902 DOI: 10.1002/2211-5463.12701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/19/2019] [Accepted: 07/15/2019] [Indexed: 11/25/2022] Open
Abstract
Presynaptic CaV2.2 (N‐type) channels are fundamental for transmitter release across the nervous system. The gene encoding CaV2.2 channels, Cacna1b, contains alternatively spliced exons that result in functionally distinct splice variants (e18a, e24a, e31a, and 37a/37b). Alternative splicing of the cassette exon 18a generates two mRNA transcripts (+e18a‐Cacna1b and ∆e18a‐Cacna1b). In this study, using novel mouse genetic models and in situ hybridization (BaseScope™), we confirmed that +e18a‐Cacna1b splice variants are expressed in monoaminergic regions of the midbrain. We expanded these studies and identified +e18a‐Cacna1b mRNA in deep cerebellar cells and spinal cord motor neurons. Furthermore, we determined that +e18a‐Cacna1b is enriched in cholecystokinin‐expressing interneurons. Our results provide key information to understand cell‐specific functions of CaV2.2 channels.
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Affiliation(s)
- Alexandra Bunda
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Brianna LaCarubba
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Marie Akiki
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
| | - Arturo Andrade
- Department of Biological SciencesUniversity of New HampshireDurhamNHUSA
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36
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Andrade A, Brennecke A, Mallat S, Brown J, Gomez-Rivadeneira J, Czepiel N, Londrigan L. Genetic Associations between Voltage-Gated Calcium Channels and Psychiatric Disorders. Int J Mol Sci 2019; 20:E3537. [PMID: 31331039 PMCID: PMC6679227 DOI: 10.3390/ijms20143537] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/12/2019] [Accepted: 07/13/2019] [Indexed: 12/23/2022] Open
Abstract
Psychiatric disorders are mental, behavioral or emotional disorders. These conditions are prevalent, one in four adults suffer from any type of psychiatric disorders world-wide. It has always been observed that psychiatric disorders have a genetic component, however, new methods to sequence full genomes of large cohorts have identified with high precision genetic risk loci for these conditions. Psychiatric disorders include, but are not limited to, bipolar disorder, schizophrenia, autism spectrum disorder, anxiety disorders, major depressive disorder, and attention-deficit and hyperactivity disorder. Several risk loci for psychiatric disorders fall within genes that encode for voltage-gated calcium channels (CaVs). Calcium entering through CaVs is crucial for multiple neuronal processes. In this review, we will summarize recent findings that link CaVs and their auxiliary subunits to psychiatric disorders. First, we will provide a general overview of CaVs structure, classification, function, expression and pharmacology. Next, we will summarize tools to study risk loci associated with psychiatric disorders. We will examine functional studies of risk variations in CaV genes when available. Finally, we will review pharmacological evidence of the use of CaV modulators to treat psychiatric disorders. Our review will be of interest for those studying pathophysiological aspects of CaVs.
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Affiliation(s)
- Arturo Andrade
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
| | - Ashton Brennecke
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Shayna Mallat
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Julian Brown
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | | | - Natalie Czepiel
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Laura Londrigan
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
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Effects of local activation and blockade of dopamine D4 receptors in the spiking activity of the reticular thalamic nucleus in normal and in ipsilateral dopamine-depleted rats. Brain Res 2019; 1712:34-46. [DOI: 10.1016/j.brainres.2019.01.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/08/2019] [Accepted: 01/30/2019] [Indexed: 01/01/2023]
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38
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Silm K, Yang J, Marcott PF, Asensio CS, Eriksen J, Guthrie DA, Newman AH, Ford CP, Edwards RH. Synaptic Vesicle Recycling Pathway Determines Neurotransmitter Content and Release Properties. Neuron 2019; 102:786-800.e5. [PMID: 31003725 PMCID: PMC6541489 DOI: 10.1016/j.neuron.2019.03.031] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 01/28/2019] [Accepted: 03/19/2019] [Indexed: 01/03/2023]
Abstract
In contrast to temporal coding by synaptically acting neurotransmitters such as glutamate, neuromodulators such as monoamines signal changes in firing rate. The two modes of signaling have been thought to reflect differences in release by different cells. We now find that midbrain dopamine neurons release glutamate and dopamine with different properties that reflect storage in different synaptic vesicles. The vesicles differ in release probability, coupling to presynaptic Ca2+ channels and frequency dependence. Although previous work has attributed variation in these properties to differences in location or cytoskeletal association of synaptic vesicles, the release of different transmitters shows that intrinsic differences in vesicle identity drive different modes of release. Indeed, dopamine but not glutamate vesicles depend on the adaptor protein AP-3, revealing an unrecognized linkage between the pathway of synaptic vesicle recycling and the properties of exocytosis. Storage of the two transmitters in different vesicles enables the transmission of distinct signals.
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Affiliation(s)
- Kätlin Silm
- Departments of Neurology and Physiology, Graduate Programs in Neuroscience and Cell Biology, Kavli Institute for Fundamental Neuroscience, Weill Institute for the Neurosciences, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Jing Yang
- Departments of Neurology and Physiology, Graduate Programs in Neuroscience and Cell Biology, Kavli Institute for Fundamental Neuroscience, Weill Institute for the Neurosciences, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Pamela F Marcott
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Cedric S Asensio
- Departments of Neurology and Physiology, Graduate Programs in Neuroscience and Cell Biology, Kavli Institute for Fundamental Neuroscience, Weill Institute for the Neurosciences, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Jacob Eriksen
- Departments of Neurology and Physiology, Graduate Programs in Neuroscience and Cell Biology, Kavli Institute for Fundamental Neuroscience, Weill Institute for the Neurosciences, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Daryl A Guthrie
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program, Baltimore, MD 21224, USA
| | - Amy H Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institutes of Drug Abuse - Intramural Research Program, Baltimore, MD 21224, USA
| | - Christopher P Ford
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert H Edwards
- Departments of Neurology and Physiology, Graduate Programs in Neuroscience and Cell Biology, Kavli Institute for Fundamental Neuroscience, Weill Institute for the Neurosciences, UCSF School of Medicine, San Francisco, CA 94143, USA.
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Sgobio C, Sun L, Ding J, Herms J, Lovinger DM, Cai H. Unbalanced calcium channel activity underlies selective vulnerability of nigrostriatal dopaminergic terminals in Parkinsonian mice. Sci Rep 2019; 9:4857. [PMID: 30890737 PMCID: PMC6425036 DOI: 10.1038/s41598-019-41091-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 02/18/2019] [Indexed: 11/23/2022] Open
Abstract
Dopamine (DA) release in striatum is functionally segregated across a dorsolateral/ventromedial axis. Interestingly, nigrostriatal DA signaling disruption in Parkinson's disease (PD) preferentially affects the dorsolateral striatum. The relationship between afferent presynaptic calcium transients (PreCaTs) in DA terminals and DA release in dorsolateral (Caudato-Putamen, DLS) and ventromedial (Nucleus Accumbens Shell, VS) striatal subregions was examined by ex vivo real-time dual-recording in conditional transgenic mice expressing the calcium indicator protein GCaMP3. In DLS, minimal increases in cytosolic calcium trigger steep DA release while PreCaTs and DA release in VS both were proportional to the number of pulses in burst stimulation. Co-expressing α-synuclein with the Parkinson's disease (PD)-associated A53T mutation and GCaMP3 in midbrain DA neurons revealed augmented cytosolic steady state and activity-dependent intra-terminal calcium levels preferentially in DLS, as well as hyperactivation and enhanced expression of N-type calcium channels. Thus, unbalanced calcium channel activity is a presynaptic mechanism to consider in the multifaceted pathogenic pathways of progressive neurodegeneration.
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Affiliation(s)
- Carmelo Sgobio
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
- Translational research division, German Center for Neurodegenerative Diseases (DZNE), Munich, 81377, Germany
| | - Lixin Sun
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jinhui Ding
- Computational Biology Group, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jochen Herms
- Translational research division, German Center for Neurodegenerative Diseases (DZNE), Munich, 81377, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität München, Munich, 81377, Germany
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Section on Synaptic Pharmacology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, 20852, USA.
| | - Huaibin Cai
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA.
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Dopamine Release Dynamics in the Tuberoinfundibular Dopamine System. J Neurosci 2019; 39:4009-4022. [PMID: 30782976 DOI: 10.1523/jneurosci.2339-18.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/06/2019] [Accepted: 01/09/2019] [Indexed: 11/21/2022] Open
Abstract
The relationship between neuronal impulse activity and neurotransmitter release remains elusive. This issue is especially poorly understood in the neuroendocrine system, with its particular demands on periodically voluminous release of neurohormones at the interface of axon terminals and vasculature. A shortage of techniques with sufficient temporal resolution has hindered real-time monitoring of the secretion of the peptides that dominate among the neurohormones. The lactotropic axis provides an important exception in neurochemical identity, however, as pituitary prolactin secretion is primarily under monoaminergic control, via tuberoinfundibular dopamine (TIDA) neurons projecting to the median eminence (ME). Here, we combined electrical or optogenetic stimulation and fast-scan cyclic voltammetry to address dopamine release dynamics in the male mouse TIDA system. Imposing different discharge frequencies during brief (3 s) stimulation of TIDA terminals in the ME revealed that dopamine output is maximal at 10 Hz, which was found to parallel the TIDA neuron action potential frequency distribution during phasic discharge. Over more sustained stimulation periods (150 s), maximal output occurred at 5 Hz, similar to the average action potential firing frequency of tonically active TIDA neurons. Application of the dopamine transporter blocker, methylphenidate, significantly increased dopamine levels in the ME, supporting a functional role of the transporter at the neurons' terminals. Lastly, TIDA neuron stimulation at the cell body yielded perisomatic release of dopamine, which may contribute to an ultrafast negative feedback mechanism to constrain TIDA electrical activity. Together, these data shed light on how spiking patterns in the neuroendocrine system translate to vesicular release toward the pituitary and identify how dopamine dynamics are controlled in the TIDA system at different cellular compartments.SIGNIFICANCE STATEMENT A central question in neuroscience is the complex relationship between neuronal discharge activity and transmitter release. By combining optogenetic stimulation and voltammetry, we address this issue in dopamine neurons of the neuroendocrine system, which faces particular spatiotemporal demands on exocytotic release; large amounts of neurohormone need to be secreted into the portal capillaries with precise timing to adapt to physiological requirements. Our data show that release is maximal around the neurons' default firing frequency. We further provide support for functional dopamine transport at the neurovascular terminals, shedding light on a long-standing controversy about the existence of neuroendocrine transmitter reuptake. Finally, we show that dopamine release occurs also at the somatodendritic level, providing a substrate for an ultrashort autoregulatory feedback loop.
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Liss B, Striessnig J. The Potential of L-Type Calcium Channels as a Drug Target for Neuroprotective Therapy in Parkinson's Disease. Annu Rev Pharmacol Toxicol 2019; 59:263-289. [PMID: 30625283 DOI: 10.1146/annurev-pharmtox-010818-021214] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The motor symptoms of Parkinson's disease (PD) mainly arise from degeneration of dopamine neurons within the substantia nigra. As no disease-modifying PD therapies are available, and side effects limit long-term benefits of current symptomatic therapies, novel treatment approaches are needed. The ongoing phase III clinical study STEADY-PD is investigating the potential of the dihydropyridine isradipine, an L-type Ca2+ channel (LTCC) blocker, for neuroprotective PD therapy. Here we review the clinical and preclinical rationale for this trial and discuss potential reasons for the ambiguous outcomes of in vivo animal model studies that address PD-protective dihydropyridine effects. We summarize current views about the roles of Cav1.2 and Cav1.3 LTCC isoforms for substantia nigra neuron function, and their high vulnerability to degenerative stressors, and for PD pathophysiology. We discuss different dihydropyridine sensitivities of LTCC isoforms in view of their potential as drug targets for PD neuroprotection, and we conclude by considering how these aspects could guide further drug development.
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Affiliation(s)
- Birgit Liss
- Institut für Angewandte Physiologie, Universität Ulm, 89081 Ulm, Germany;
| | - Jörg Striessnig
- Abteilung Pharmakologie und Toxikologie, Institut für Pharmazie, and Center for Molecular Biosciences Innsbruck, Universität Innsbruck, A-6020 Innsbruck, Austria;
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42
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Surmeier DJ. Determinants of dopaminergic neuron loss in Parkinson's disease. FEBS J 2018; 285:3657-3668. [PMID: 30028088 DOI: 10.1111/febs.14607] [Citation(s) in RCA: 235] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/20/2018] [Accepted: 07/18/2018] [Indexed: 12/11/2022]
Abstract
The cardinal motor symptoms of Parkinson's disease (PD) are caused by the death of dopaminergic neurons in the substantia nigra pars compacta (SNc). Alpha-synuclein (aSYN) pathology and mitochondrial dysfunction have been implicated in PD pathogenesis, but until recently it was unclear why SNc dopaminergic neurons should be particularly vulnerable to these two types of insult. In this brief review, the evidence that SNc dopaminergic neurons have an anatomical, physiological, and biochemical phenotype that predisposes them to mitochondrial dysfunction and synuclein pathology is summarized. The recognition that certain traits may predispose neurons to PD-linked pathology creates translational opportunities for slowing or stopping disease progression.
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Affiliation(s)
- Dalton James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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43
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Faro LRF, Alfonso M, Ferreira VM, Durán R. Role of voltage-gated calcium channels on striatal dopamine release induced by inorganic mercury in freely moving rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 59:13-16. [PMID: 29482112 DOI: 10.1016/j.etap.2018.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 01/29/2018] [Accepted: 02/10/2018] [Indexed: 06/08/2023]
Abstract
The possible role of voltage-sensitive calcium channels (VSCC) activation on the HgCl2-induced dopamine release was investigated using selective VSCC blockers and the dopamine levels were measured by HPLC from samples obtained by in vivo brain microdialysis. Infusion of HgCl2 in nicardipine (10 or 100 μM) or flunaricine (10 μM) pretreated animals had no significant effect on dopamine release induced by HgCl2. Pretreatment with 100 μM flunaricine, 20 μM ω-conotoxin MVIIC, or ω-conotoxin GVIA significantly decreased the HgCl2-induced dopamine release over 61%, 88%, and 99%, respectively. HgCl2-induced dopamine release could be produced, at least in part, by activation of VSCC at dopaminergic terminals, especially N- and P/Q-type.
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Affiliation(s)
| | - Miguel Alfonso
- Department of Functional Biology and Health Sciences, University of Vigo, Spain
| | | | - Rafael Durán
- Department of Functional Biology and Health Sciences, University of Vigo, Spain
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44
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Liu C, Kershberg L, Wang J, Schneeberger S, Kaeser PS. Dopamine Secretion Is Mediated by Sparse Active Zone-like Release Sites. Cell 2018; 172:706-718.e15. [PMID: 29398114 DOI: 10.1016/j.cell.2018.01.008] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 11/15/2017] [Accepted: 01/04/2018] [Indexed: 10/18/2022]
Abstract
Dopamine controls essential brain functions through volume transmission. Different from fast synaptic transmission, where neurotransmitter release and receptor activation are tightly coupled by an active zone, dopamine transmission is widespread and may not necessitate these organized release sites. Here, we determine whether striatal dopamine secretion employs specialized machinery for release. Using super resolution microscopy, we identified co-clustering of the active zone scaffolding proteins bassoon, RIM and ELKS in ∼30% of dopamine varicosities. Conditional RIM knockout disrupted this scaffold and, unexpectedly, abolished dopamine release, while ELKS knockout had no effect. Optogenetic experiments revealed that dopamine release was fast and had a high release probability, indicating the presence of protein scaffolds for coupling Ca2+ influx to vesicle fusion. Hence, dopamine secretion is mediated by sparse, mechanistically specialized active zone-like release sites. This architecture supports spatially and temporally precise coding for dopamine and provides molecular machinery for regulation.
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Affiliation(s)
- Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Lauren Kershberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jiexin Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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Melchior JR, Jones SR. Chronic ethanol exposure increases inhibition of optically targeted phasic dopamine release in the nucleus accumbens core and medial shell ex vivo. Mol Cell Neurosci 2017; 85:93-104. [PMID: 28942046 PMCID: PMC5698100 DOI: 10.1016/j.mcn.2017.09.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/08/2017] [Accepted: 09/18/2017] [Indexed: 01/07/2023] Open
Abstract
Dopamine signaling encodes reward learning and motivated behavior through modulation of synaptic signaling in the nucleus accumbens, and aberrations in these processes are thought to underlie obsessive behaviors associated with alcohol abuse. The nucleus accumbens is divided into core and shell sub-regions with overlapping but also divergent contributions to behavior. Here we optogenetically targeted dopamine projections to the accumbens allowing us to isolate stimulation of dopamine terminals ex vivo. We applied 5 pulse (phasic) light stimulations to probe intrinsic differences in dopamine release parameters across regions. Also, we exposed animals to 4weeks of chronic intermittent ethanol vapor and measured phasic release. We found that initial release probability, uptake rate and autoreceptor inhibition were greater in the accumbens core compared to the shell, yet the shell showed greater phasic release ratios. Following chronic ethanol, uptake rates were increased in the core but not the shell, suggesting region-specific neuronal adaptations. Conversely, kappa opioid receptor function was upregulated in both regions to a similar extent, suggesting a local mechanism of kappa opioid receptor regulation that is generalized across the nucleus accumbens. These data suggest that dopamine axons in the nucleus accumbens core and shell display differences in intrinsic release parameters, and that ethanol-induced adaptations to dopamine neuron terminal fields may not be homogeneous. Also, chronic ethanol exposure induces an upregulation in kappa opioid receptor function, providing a mechanism for potential over-inhibition of accumbens dopamine signaling which may negatively impact downstream synaptic function and ultimately bias choice towards previously reinforced alcohol use behaviors.
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Affiliation(s)
- James R Melchior
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
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46
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Winland CD, Welsh N, Sepulveda-Rodriguez A, Vicini S, Maguire-Zeiss KA. Inflammation alters AMPA-stimulated calcium responses in dorsal striatal D2 but not D1 spiny projection neurons. Eur J Neurosci 2017; 46:2519-2533. [PMID: 28921719 PMCID: PMC5673553 DOI: 10.1111/ejn.13711] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 12/22/2022]
Abstract
Neuroinflammation precedes neuronal loss in striatal neurodegenerative diseases and can be exacerbated by the release of proinflammatory molecules by microglia. These molecules can affect trafficking of AMPARs. The preferential trafficking of calcium-permeable versus impermeable AMPARs can result in disruptions of [Ca2+ ]i and alter cellular functions. In striatal neurodegenerative diseases, changes in [Ca2+ ]i and L-type voltage-gated calcium channels (VGCCs) have been reported. Therefore, this study sought to determine whether a proinflammatory environment alters AMPA-stimulated [Ca2+ ]i through calcium-permeable AMPARs and/or L-type VGCCs in dopamine-2- and dopamine-1-expressing striatal spiny projection neurons (D2 and D1 SPNs) in the dorsal striatum. Mice expressing the calcium indicator protein, GCaMP in D2 or D1 SPNs, were utilized for calcium imaging. Microglial activation was assessed by morphology analyses. To induce inflammation, acute mouse striatal slices were incubated with lipopolysaccharide (LPS). Here we report that LPS treatment potentiated AMPA responses only in D2 SPNs. When a nonspecific VGCC blocker was included, we observed a decrease of AMPA-stimulated calcium fluorescence in D2 but not D1 SPNs. The remaining agonist-induced [Ca2+ ]i was mediated by calcium-permeable AMPARs because the responses were completely blocked by a selective calcium-permeable AMPAR antagonist. We used isradipine, the highly selective L-type VGCC antagonist to determine the role of L-type VGCCs in SPNs treated with LPS. Isradipine decreased AMPA-stimulated responses selectively in D2 SPNs after LPS treatment. Our findings suggest that dorsal striatal D2 SPNs are specifically targeted in proinflammatory conditions and that L-type VGCCs and calcium-permeable AMPARs are important mediators of this effect.
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MESH Headings
- Animals
- CX3C Chemokine Receptor 1/genetics
- CX3C Chemokine Receptor 1/metabolism
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/metabolism
- Cations, Divalent/metabolism
- Corpus Striatum/drug effects
- Corpus Striatum/metabolism
- Corpus Striatum/pathology
- Dopaminergic Neurons/drug effects
- Dopaminergic Neurons/metabolism
- Dopaminergic Neurons/pathology
- Female
- Inflammation/metabolism
- Inflammation/pathology
- Lipopolysaccharides
- Male
- Mice, Inbred C57BL
- Mice, Transgenic
- Microglia/drug effects
- Microglia/metabolism
- Microglia/pathology
- Receptors, AMPA/antagonists & inhibitors
- Receptors, AMPA/metabolism
- Receptors, Dopamine D1/genetics
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Tissue Culture Techniques
- alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/metabolism
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Affiliation(s)
- Carissa D. Winland
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
- Department of Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
| | - Nora Welsh
- Department of Biology, Georgetown University, Washington, D.C. 20007 USA
| | - Alberto Sepulveda-Rodriguez
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, D.C. 20007 USA
| | - Stefano Vicini
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, D.C. 20007 USA
| | - Kathleen A. Maguire-Zeiss
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
- Department of Neuroscience, Georgetown University Medical Center, Washington, D.C. 20007 USA
- Department of Biology, Georgetown University, Washington, D.C. 20007 USA
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47
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Parkinson's Disease Is Not Simply a Prion Disorder. J Neurosci 2017; 37:9799-9807. [PMID: 29021297 DOI: 10.1523/jneurosci.1787-16.2017] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/09/2017] [Accepted: 06/17/2017] [Indexed: 12/31/2022] Open
Abstract
The notion that prion-like spreading of misfolded α-synuclein (α-SYN) causes Parkinson's disease (PD) has received a great deal of attention. Although attractive in its simplicity, the hypothesis is difficult to reconcile with postmortem analysis of human brains and connectome-mapping studies. An alternative hypothesis is that PD pathology is governed by regional or cell-autonomous factors. Although these factors provide an explanation for the pattern of neuronal loss in PD, they do not readily explain the apparently staged distribution of Lewy pathology in many PD brains, the feature of the disease that initially motivated the spreading hypothesis by Braak and colleagues. While each hypothesis alone has its shortcomings, a synthesis of the two can explain much of what we know about the etiopathology of PD.Dual Perspectives Companion Paper: Prying into the Prion Hypothesis for Parkinson's Disease, by Patrik Brundin and Ronald Melki.
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Surmeier DJ, Halliday GM, Simuni T. Calcium, mitochondrial dysfunction and slowing the progression of Parkinson's disease. Exp Neurol 2017; 298:202-209. [PMID: 28780195 DOI: 10.1016/j.expneurol.2017.08.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 07/25/2017] [Accepted: 08/01/2017] [Indexed: 12/20/2022]
Abstract
Parkinson's disease is characterized by progressively distributed Lewy pathology and neurodegeneration. The motor symptoms of clinical Parkinson's disease (cPD) are unequivocally linked to the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). Several features of these neurons appear to make them selectively vulnerable to factors thought to cause cPD, like aging, genetic mutations and environmental toxins. Among these features, Ca2+ entry through Cav1 channels is particularly amenable to pharmacotherapy in early stage cPD patients. This review outlines the linkage between these channels, mitochondrial oxidant stress and cPD pathogenesis. It also summarizes considerations that went into the design and execution of the ongoing Phase 3 clinical trial with an inhibitor of these channels - isradipine.
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Affiliation(s)
- D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Glenda M Halliday
- Brain and Mind Centre, Sydney Medical School, University of Sydney, 2006, Australia; School of Medical Sciences, University of New South Wales, Neuroscience Research Australia, Sydney 2052, Australia
| | - Tanya Simuni
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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α6β2 subunit containing nicotinic acetylcholine receptors exert opposing actions on rapid dopamine signaling in the nucleus accumbens of rats with high-versus low-response to novelty. Neuropharmacology 2017; 126:281-291. [PMID: 28666811 DOI: 10.1016/j.neuropharm.2017.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 06/07/2017] [Accepted: 06/26/2017] [Indexed: 11/22/2022]
Abstract
Determining neurobiological factors that contribute to individual variance in drug addiction vulnerability allows for identification of at-risk populations, use of preventative measures and personalized medicine in the treatment of substance use disorders. Rodents that exhibit high locomotor activity when exploring an inescapable novel environment (high-responder; HR) are more susceptible to the reinforcing effects of many abused compounds, including nicotine, as compared to animals that exhibit low locomotor activity (low-responder; LR). Given that nicotinic acetylcholine receptor (nAChR) modulation of reward-related dopamine signaling at accumbal dopamine terminals is critical for the acquisition of drug self-administration, we hypothesized that nAChR modulation of dopamine release would be predicted by an animal's novelty response. Using voltammetry in the nucleus accumbens core of rats, we found that nicotine produced opposite effects in HR and LR animals on stimulation frequencies that model phasic dopamine release, whereby release magnitude was either augmented or attenuated, respectively. Further, nicotine suppressed dopamine release elected by stimulation frequencies that model tonic release in LR animals, but had no effect in HR animals. The differential effects of nicotine were likely due to desensitization of nAChRs, since the nAChR antagonists mecamylamine (non-selective, 2 μM), dihydro-beta-erythroidine (β2-selective, 500 nM), and α-conotoxin MII [H9A; L15A] (α6-selective, 100 nM) produced effects similar to nicotine. Moreover, dihydro-beta-erythroidine failed to show differential effects in HR and LR rats when applied after α-conotoxin MII [H9A; L15A], suggesting a critical role of α6β2 compared non α6-containing nAChRs in the differential effects observed in these phenotypes. These results delineate a potential mechanism for individual variability in behavioral sensitivity to nicotine.
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Surmeier DJ, Obeso JA, Halliday GM. Selective neuronal vulnerability in Parkinson disease. Nat Rev Neurosci 2017; 18:101-113. [PMID: 28104909 DOI: 10.1038/nrn.2016.178] [Citation(s) in RCA: 623] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Intracellular α-synuclein (α-syn)-rich protein aggregates called Lewy pathology (LP) and neuronal death are commonly found in the brains of patients with clinical Parkinson disease (cPD). It is widely believed that LP appears early in the disease and spreads in synaptically coupled brain networks, driving neuronal dysfunction and death. However, post-mortem analysis of human brains and connectome-mapping studies show that the pattern of LP in cPD is not consistent with this simple model, arguing that, if LP propagates in cPD, it must be gated by cell- or region-autonomous mechanisms. Moreover, the correlation between LP and neuronal death is weak. In this Review, we briefly discuss the evidence for and against the spreading LP model, as well as evidence that cell-autonomous factors govern both α-syn pathology and neuronal death.
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Affiliation(s)
- D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - José A Obeso
- Centro Integral de Neurociencias A.C. (CINAC), HM Puerta del Sur, Hospitales de Madrid, Mostoles and CEU San Pablo University, 28938 Madrid, Spain.,Network Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), Instituto Carlos III, 28031 Madrid, Spain
| | - Glenda M Halliday
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, Sydney 2006, Australia.,School of Medical Sciences, University of New South Wales and Neuroscience Research Australia, Sydney 2052, Australia
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