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Extracellular zinc regulates contextual fear memory formation in male rats through MMP-BDNF-TrkB pathway in dorsal hippocampus and basolateral amygdala. Behav Brain Res 2023; 439:114230. [PMID: 36442645 DOI: 10.1016/j.bbr.2022.114230] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 11/26/2022]
Abstract
Large amount of zinc (100 µM even up to 300 µM) is released from the nerve terminals in response to high frequency neuronal stimulation in certain brain regions including hippocampus and amygdala. However, its precise pharmacological effect is poorly understood. Here, we investigated the role of extracellular zinc (endogenous zinc) and exogenous zinc in memory formation using contextual fear conditioning (CFC) model. Male Sprague Dawley rats were trained for fear conditioning followed by in vivo microdialysis for collection of microdialysate samples from CA1 and CA3 regions of hippocampus and basolateral amygdala (BLA). Extracellular zinc chelator CaEDTA, BDNF scavenger TrkB-Fc, exogenous 7,8-DHF and matrix metalloproteinases (MMP) inhibitor were infused into the CA1 and CA3 regions of hippocampus and BLA after CFC. Different doses of exogenous zinc hydroaspartate were administered intraperitoneally immediately after CFC. We found that CFC increased the level of extracellular zinc in the hippocampus and BLA. Infusing the CaEDTA, TrkB-Fc and MMP inhibitor into the CA1 and CA3 regions of hippocampus and BLA disrupted the fear memory formation. Furthermore, administration of TrKB agonist 7,8-DHF reversed the inhibitory effect of CaEDTA on fear memory formation, suggesting that extracellular zinc may regulate fear memory formation via the BDNF-TrKB pathway. We also found that high dose of exogenous zinc hydroaspartate supplementation increased extracellular zinc levels in brain and enhanced fear memory formation. Altogether, these findings indicate that extracellular zinc may participate in formation of contextual fear memory through MMP-BDNF-TrkB pathway in the hippocampus and BLA.
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Sikora J, Di Bisceglie Caballero S, Reiss D, Kieffer BL, Paoletti P, Jacob PY, Ouagazzal AM. Zn2+ inhibits spatial memory and hippocampal place cell representation through high-affinity binding to the NMDA receptor GluN2A subunit. iScience 2022; 25:105355. [DOI: 10.1016/j.isci.2022.105355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/11/2022] [Accepted: 10/11/2022] [Indexed: 10/31/2022] Open
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Takeda A. [Brain Function and Pathophysiology Focused on Zn 2+ Dynamics]. YAKUGAKU ZASSHI 2022; 142:855-866. [PMID: 35908946 DOI: 10.1248/yakushi.22-00074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The basal levels of intracellular Zn2+ and extracellular Zn2+ are in the range of ~100 pM and ~10 nM, respectively, in the brain. Extracellular Zn2+ dynamics is involved in both cognitive performance and neurodegeneration. The bidirectional actions are linked with extracellular glutamate and amyloid-β1-42 (Aβ1-42). Intracellular Zn2+ signaling via extracellular glutamate is required for learning and memory, while intracellular Zn2+ dysregulation induces cognitive decline. Furthermore, human Aβ1-42, a causative peptide in Alzheimer's disease pathogenesis captures extracellular Zn2+ and readily taken up into hippocampal neurons followed by intracellular Zn2+ dysregulation. Aβ1-42-mediated intracellular Zn2+ dysregulation is accelerated with aging, because extracellular Zn2+ is age-relatedly increased, resulting in Aβ1-42-induced cognitive decline and neurodegeneration with aging. On the other hand, metallothioneins, zinc-binding proteins can capture Zn2+ released from intracellular Zn-Aβ1-42 complexes and serve for intracellular Zn2+-buffering to maintain intracellular Zn2+ homeostasis. This review summarizes Zn2+ function and its neurotoxicity in the brain, and also the potential defense strategy via metallothioneins against Aβ1-42-induced pathogenesis.
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Affiliation(s)
- Atsushi Takeda
- School of Pharmaceutical Sciences, University of Shizuoka
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Sikora J, Kieffer BL, Paoletti P, Ouagazzal AM. Synaptic zinc contributes to motor and cognitive deficits in 6-hydroxydopamine mouse models of Parkinson's disease. Neurobiol Dis 2019; 134:104681. [PMID: 31759136 DOI: 10.1016/j.nbd.2019.104681] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/05/2019] [Accepted: 11/19/2019] [Indexed: 12/19/2022] Open
Abstract
Hyperactivity of glutamatergic corticostrial pathways is recognized as a key pathophysiological mechanism contributing to development of PD symptoms and dopaminergic neurotoxicity. Subset of corticostriatal projection neurons uses Zn2+ as a co-transmitter alongside glutamate, but the role of synaptically released Zn2+ in PD remains unexplored. We used genetically modified mice and pharmacological tools in combination with 6-hydroxydopamine (6-OHDA) lesion models of PD to investigate the contribution of synaptic zinc to disease associated behavioral deficits and neurodegeneration. Vesicular zinc transporter-3 (ZnT3) knockout mice lacking releasable Zn2+ were more resistant to locomotor deficit and memory impairment of nigrostriatal dopamine (DA) denervation compared to wildtype littermates. The loss of striatal dopaminergic fibers was comparable between genotypes, indicating that synaptically released Zn2+ contributes to behavioral deficits but not neurotoxic effects of 6-OHDA. To gain further insight into the mechanisms of Zn2+ actions, we used the extracellular Zn2+ chelator CaEDTA and knock-in mice lacking the high affinity Zn2+ inhibition of GluN2A-containing NMDA receptors (GluN2A-NMDARs). Acute chelation of extracellular Zn2+ in the striatum restored locomotor deficit of 6-OHDA lesion, confirming that synaptic Zn2+ suppresses locomotor behavior. Disruption of the Zn2+-GluN2A interaction had, on the other hand, no impact on locomotor deficit or neurotoxic effect of 6-OHDA. Collectively, these findings provide clear evidence for the implication of striatal synaptic Zn2+ in the pathophysiology of PD. They unveil that synaptic Zn2+ plays predominantly a detrimental role by promoting motor and cognitive deficits caused by nigrostriatal DA denervation, pointing towards new therapeutic interventions.
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Affiliation(s)
- Joanna Sikora
- Laboratoire de Neurosciences Cognitives, Aix-Marseille Univ, CNRS, LNC, UMR 7291, 13331 Marseille, France; Aix-marseille Université, Marseille, France
| | - Brigitte L Kieffer
- Douglas Research Center, Department of Psychiatry, McGill University, Montréal, Canada
| | - Pierre Paoletti
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, Paris, France
| | - Abdel-Mouttalib Ouagazzal
- Laboratoire de Neurosciences Cognitives, Aix-Marseille Univ, CNRS, LNC, UMR 7291, 13331 Marseille, France.
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Neely CLC, Lippi SLP, Lanzirotti A, Flinn JM. Localization of Free and Bound Metal Species through X-Ray Synchrotron Fluorescence Microscopy in the Rodent Brain and Their Relation to Behavior. Brain Sci 2019; 9:E74. [PMID: 30925761 PMCID: PMC6523809 DOI: 10.3390/brainsci9040074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/23/2019] [Accepted: 03/26/2019] [Indexed: 12/27/2022] Open
Abstract
Biometals in the brain, such as zinc, copper, and iron, are often discussed in cases of neurological disorders; however, these metals also have important regulatory functions and mediate cell signaling and plasticity. With the use of synchrotron X-ray fluorescence, our lab localized total, both bound and free, levels of zinc, copper, and iron in a cross section of one hemisphere of a rat brain, which also showed differing metal distributions in different regions within the hippocampus, the site in the brain known to be crucial for certain types of memory. This review discusses the several roles of these metals in brain regions with an emphasis on hippocampal cell signaling, based on spatial mapping obtained from X-ray fluorescence microscopy. We also discuss the localization of these metals and emphasize different cell types and receptors in regions with metal accumulation, as well as the potential relationship between this physiology and behavior.
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Affiliation(s)
- Caroline L C Neely
- Department of Psychology, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
| | - Stephen L P Lippi
- Department of Psychology & Sociology, Angelo State University, 2601 W. Avenue N, ASU Station #10907, San Angelo, TX 76909, USA.
| | - Antonio Lanzirotti
- Center for Advanced Radiation Sources, University of Chicago, 9700 South Cass Avenue, Argonne, IL 60439, USA.
| | - Jane M Flinn
- Department of Psychology, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
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Adrenergic β receptor activation in the basolateral amygdala, which is intracellular Zn 2+-dependent, rescues amyloid β 1-42-induced attenuation of dentate gyrus LTP. Neurochem Int 2018; 120:43-48. [PMID: 30030113 DOI: 10.1016/j.neuint.2018.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/27/2018] [Accepted: 07/16/2018] [Indexed: 01/01/2023]
Abstract
On the basis of the evidence that the basolateral amygdala (BLA) modulates hippocampal memory processes via synaptic plasticity, here we report that adrenergic β receptor activation in the BLA rescues amyloid β1-42 (Aβ1-42)-induced attenuation of long-term potentiation (LTP) at perforant pathway-dentate granule cell (DGC) synapses. When 500 μM isoproterenol (2 μl), an adrenergic β receptor agonist, was injected into the BLA 20 min before LTP induction, LTP was enhanced. Isoproterenol-mediated enhancement of LTP was blocked by co-injection with 100 μM ZnAF-2DA, an intracellular Zn2+ chelator, suggesting that intracellular Zn2+ is required for the intracellular signaling cascade after adrenergic β receptor activation in the BLA. Aβ1-42-induced attenuation of LTP, which was induced by Aβ1-42 injection into the dentate gyrus 60 min before LTP induction, was rescued by isoproterenol injection into the BLA 20 min before LTP induction, but not by 500 μM phenylephrine (2 μl), an adrenergic α1 receptor agonist, injection into the BLA, which did not enhance LTP unlike the case of isoproterenol injection. Interestingly, Aβ1-42-induced attenuation of LTP was also rescued by 100 μM isoproterenol injection into the BLA 20 min before LTP induction, which did not enhance LTP. The present study demonstrates that adrenergic β receptor activation in the BLA, which is linked with intracellular Zn2+ signaling, rescues Aβ1-42-induced attenuation of dentate gyrus LTP. It is likely that adrenergic β receptor activation in the BLA is a strategy for rescuing Aβ1-42-induced cognitive decline that is associated with hippocampal synaptic plasticity.
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Signaling by Synaptic Zinc is Required for Whisker-Mediated, Fine Texture Discrimination. Neuroscience 2017; 369:242-247. [PMID: 29158108 DOI: 10.1016/j.neuroscience.2017.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 01/08/2023]
Abstract
Zinc-containing terminals are found throughout the neocortex, concentrated predominantly in layers II/III, V, and VI. Synaptic zinc is a potent neurotransmitter/modulator and, therefore, may mediate inter- or intra-cortical integration of sensory information. We have previously shown that levels of synaptic zinc are rapidly modulated in somatosensory (barrel) cortex, in an experience- and activity-dependent manner. Zinc transporter 3 (ZnT3) knockout (KO) mice lack synaptic zinc and provide us with a good model to examine the contribution of synaptic zinc to barrel cortex-dependent behavior. In the present study, we show that ZnT3 KO mice display a marked decrease in acuity for whisker-dependent texture discrimination. ZnT3 KO mice were not able to discriminate between textures having an average particle diameter less than 300 μm while control mice were able to discriminate between textures having particle diameters separated by as little as 25 μm. This loss of texture discrimination acuity in ZnT3 KO mice was whisker-dependent and was observed in young (2 months-of-age) and older mice (12 months-of-age). These results show that zincergic signaling is necessary for the normal integration of somatosensory information.
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Blakemore LJ, Trombley PQ. Zinc as a Neuromodulator in the Central Nervous System with a Focus on the Olfactory Bulb. Front Cell Neurosci 2017; 11:297. [PMID: 29033788 PMCID: PMC5627021 DOI: 10.3389/fncel.2017.00297] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
The olfactory bulb (OB) is central to the sense of smell, as it is the site of the first synaptic relay involved in the processing of odor information. Odor sensations are first transduced by olfactory sensory neurons (OSNs) before being transmitted, by way of the OB, to higher olfactory centers that mediate olfactory discrimination and perception. Zinc is a common trace element, and it is highly concentrated in the synaptic vesicles of subsets of glutamatergic neurons in some brain regions including the hippocampus and OB. In addition, zinc is contained in the synaptic vesicles of some glycinergic and GABAergic neurons. Thus, zinc released from synaptic vesicles is available to modulate synaptic transmission mediated by excitatory (e.g., N-methyl-D aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)) and inhibitory (e.g., gamma-aminobutyric acid (GABA), glycine) amino acid receptors. Furthermore, extracellular zinc can alter the excitability of neurons through effects on a variety of voltage-gated ion channels. Consistent with the notion that zinc acts as a regulator of neuronal activity, we and others have shown zinc modulation (inhibition and/or potentiation) of amino acid receptors and voltage-gated ion channels expressed by OB neurons. This review summarizes the locations and release of vesicular zinc in the central nervous system (CNS), including in the OB. It also summarizes the effects of zinc on various amino acid receptors and ion channels involved in regulating synaptic transmission and neuronal excitability, with a special emphasis on the actions of zinc as a neuromodulator in the OB. An understanding of how neuroactive substances such as zinc modulate receptors and ion channels expressed by OB neurons will increase our understanding of the roles that synaptic circuits in the OB play in odor information processing and transmission.
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Affiliation(s)
- Laura J Blakemore
- Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Department of Biological Science, Florida State UniversityTallahassee, FL, United States
| | - Paul Q Trombley
- Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Department of Biological Science, Florida State UniversityTallahassee, FL, United States
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Fujise Y, Kubota M, Suzuki M, Tamano H, Takeda A. Blockade of intracellular Zn 2+ signaling in the basolateral amygdala affects object recognition memory via attenuation of dentate gyrus LTP. Neurochem Int 2017; 108:1-6. [DOI: 10.1016/j.neuint.2017.01.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/18/2017] [Accepted: 01/24/2017] [Indexed: 12/01/2022]
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Supplementation with zinc in rats enhances memory and reverses an age-dependent increase in plasma copper. Behav Brain Res 2017; 333:179-183. [PMID: 28693861 DOI: 10.1016/j.bbr.2017.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/26/2022]
Abstract
Zinc and copper are essential trace elements. Dyshomeostasis in these two metals has been observed in Alzheimer's disease, which causes profound cognitive impairment. Insulin therapy has been shown to enhance cognitive performance; however, recent data suggest that this effect may be at least in part due to the inclusion of zinc in the insulin formulation used. Zinc plays a key role in regulation of neuronal glutamate signaling, suggesting a possible link between zinc and memory processes. Consistent with this, zinc deficiency causes cognitive impairments in children. The effect of zinc supplementation on short- and long-term recognition memory, and on spatial working memory, was explored in young and adult male Sprague Dawley rats. After behavioral testing, hippocampal and plasma zinc and copper were measured. Age increased hippocampal zinc and copper, as well as plasma copper, and decreased plasma zinc. An interaction between age and treatment affecting plasma copper was also found, with zinc supplementation reversing elevated plasma copper concentration in adult rats. Zinc supplementation enhanced cognitive performance across tasks. These data support zinc as a plausible therapeutic intervention to ameliorate cognitive impairment in disorders characterized by alterations in zinc and copper, such as Alzheimer's disease.
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A high fat diet-induced decrease in hippocampal newly-born neurons of male mice is exacerbated by mild psychological stress using a Communication Box. J Affect Disord 2017; 209:209-216. [PMID: 27930914 DOI: 10.1016/j.jad.2016.11.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/26/2016] [Accepted: 11/15/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND Obese persons have a higher incidence of depression than healthy-weight persons. Several studies indicated that the exposure to a high fat diet (HFD) results in a decrease in hippocampal neurogenesis, which leads to higher stress response and stress-induced depression. Although stress is a risk factor for obesity and depression, no studies to date have investigated the effect of stress on the hippocampal neurogenesis of HFD-induced obese animals. The aim of this study was to elucidate whether or not obese HFD-fed mice are vulnerable to stress-induced depression by investigating hippocampal neurogenesis. METHODS Sixty-four male ICR mice (four weeks of age) were fed a control (N=24) or 45%HFD (N=40) for seven weeks. Of the HFD-fed group, twenty-four mice met the criteria for "diet-induced obesity". The animals were then exposed to three consecutive days of psychological stress using a Communication Box. Half were sacrificed to evaluate the physiological changes, and the other half were perfused to quantify hippocampal neuroblasts/immature neurons by the estimation of doublecortin-immunopositive cells. RESULTS In the HFD-fed mice, psychological stress resulted in increases in caloric intake and visceral adipose tissue and a significant decrease in doublecortin-positive cells in the dentate gyrus; however, no such differences were found in the control diet-fed group. Limitations Further study using other neurogenic markers to assess the stage-specific changes in hippocampal neurogenesis will be required CONCLUSIONS: Our findings suggest that an HFD-induced decrease in hippocampal newly-born neurons leads to stress vulnerability, which may contribute to a high risk of stress-induced depression for obese persons.
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Pavlowsky A, Wallace E, Fenton AA, Alarcon JM. Persistent modifications of hippocampal synaptic function during remote spatial memory. Neurobiol Learn Mem 2017; 138:182-197. [PMID: 27568918 PMCID: PMC5326703 DOI: 10.1016/j.nlm.2016.08.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 12/30/2022]
Abstract
A widely accepted notion for a process underlying memory formation is that learning changes the efficacy of synapses by the mechanism of synaptic plasticity. While there is compelling evidence of changes in synaptic efficacy observed after learning, demonstration of persistent synaptic changes accompanying memory has been elusive. We report that acquisition of a hippocampus and long-term potentiation dependent place memory persistently changes the function of CA1 synapses. Using extracellular recordings we measured CA3-CA1 and EC-CA1 synaptic responses and found robust changes in the CA3-CA1 pathway after memory training. Crucially, these changes in synaptic function lasted at least a month and coincided with the persistence of long-term place memories; the changes were only observed in animals that expressed robust memory, and not in animals with poor memory recall. Interestingly, our findings were observed at the level of populations of synapses; suggesting that memory formation recruits widespread synaptic circuits and persistently reorganizes their function to store information.
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Affiliation(s)
- Alice Pavlowsky
- Department of Pathology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Neural and Behavioral, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - Emma Wallace
- Graduate Program in Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - André A Fenton
- The Robert F. Furchgott Center for Neural and Behavioral, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Department of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
| | - Juan Marcos Alarcon
- Department of Pathology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Neural and Behavioral, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
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Takeda A, Tamano H. Insight into cognitive decline from Zn 2+ dynamics through extracellular signaling of glutamate and glucocorticoids. Arch Biochem Biophys 2016; 611:93-99. [DOI: 10.1016/j.abb.2016.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 02/06/2023]
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LC–MS/MS assay of ropinirole in rat biological matrices: elimination of lysoglycerophosphocholines-based matrix effect. Bioanalysis 2016; 8:1823-35. [DOI: 10.4155/bio-2016-0087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: To adequately support PK evaluation of ropinirole in rats following intranasal administration, it was desirable to determine ropinirole concentrations in rat plasma, brain homogenate and microdialysate. Results & methodology: A robust LC–MS/MS method has been developed for the determination of ropinirole in biological samples. Liquid–liquid extraction using ethyl acetate eliminated matrix effect due to significantly reduced levels of lysoglycerophosphocholines. The assay was fully validated with dynamic ranges of 0.01–20 ng/ml for plasma and brain homogenate samples and 0.1–200 ng/ml for microdialysate samples. Conclusion: The proposed method was accurate and precise for the quantification of ropinirole in biological samples and was successfully applied to a microdialysis study of ropinirole in rats.
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Takeda A, Tamano H. Significance of the degree of synaptic Zn2+ signaling in cognition. Biometals 2015; 29:177-85. [DOI: 10.1007/s10534-015-9907-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 11/24/2022]
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Takeda A, Fujii H, Minamino T, Tamano H. Intracellular Zn(2+) signaling in cognition. J Neurosci Res 2014; 92:819-24. [PMID: 24723300 DOI: 10.1002/jnr.23385] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/30/2014] [Accepted: 02/21/2014] [Indexed: 12/22/2022]
Abstract
Brain zinc homeostasis is strictly controlled under healthy conditions, indicating the importance of zinc for physiological function in the brain. A part of zinc in the brain exists in the synaptic vesicles, is released from a subclass of glutamatergic neurons (i.e., zincergic neurons), and serves as a signal factor (Zn(2+) signal) in the intracellular (cytosol) compartment as well as in the extracellular compartment. Zn(2+) signaling is dynamically linked to glutamate signaling and may be involved in synaptic plasticity, such as long-term potentiaion and cognitive activity. In zincergic synapses, intracellular Zn(2+) signaling in the postsynaptic neurons, which is linked to Zn(2+) release from zincergic neuron terminals, plays a role in cognitive activity. When nonzincergic synapses participate in cognition, on the other hand, it is possible that intracellular Zn(2+) signaling, which is due mainly to Zn(2+) release from the internal stores and/or metallothioneins, also is involved in cognitive activity, because zinc-dependent system such as zinc-binding proteins is usually required for cognitive process. Intracellular Zn(2+) dynamics may be modified via an endocrine system activity, glucocorticoid secretion in both zincergic and nonzincergic neurons, which is linked to a long-lasting change in synaptic efficacy. On the basis of the evidence of cognitive decline caused by the lack and/or the blockade of synaptic Zn(2+) signaling, this article summarizes the involvement of intracellular Zn(2+) signaling in zincergic synapses in cognition and a hypothetical involvement of that in nonzincergic synapses.
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Affiliation(s)
- Atsushi Takeda
- Department of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan; Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
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Takeda A, Tamano H. Cognitive decline due to excess synaptic Zn(2+) signaling in the hippocampus. Front Aging Neurosci 2014; 6:26. [PMID: 24578691 PMCID: PMC3936311 DOI: 10.3389/fnagi.2014.00026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/13/2014] [Indexed: 12/02/2022] Open
Abstract
Zinc is an essential component of physiological brain function. Vesicular zinc is released from glutamatergic (zincergic) neuron terminals and serves as a signal factor (Zn2+ signal) in both the intracellular (cytosol) compartment and the extracellular compartment. Synaptic Zn2+ signaling is dynamically linked to neurotransmission and is involved in processes of synaptic plasticity such as long-term potentiation and cognitive activity. On the other hand, the activity of the hypothalamic–pituitary–adrenal (HPA) axis, i.e., glucocorticoid secretion, which can potentiate glutamatergic neuron activity, is linked to cognitive function. HPA axis activity modifies synaptic Zn2+ dynamics at zincergic synapses. An increase in HPA axis activity, which occurs after exposure to stress, may induce excess intracellular Zn2+ signaling in the hippocampus, followed by hippocampus-dependent memory deficit. Excessive excitation of zincergic neurons in the hippocampus can contribute to cognitive decline under stressful and/or pathological conditions. This paper provides an overview of the ``Hypothesis and Theory'' of Zn2+-mediated modification of cognitive activity.
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Affiliation(s)
- Atsushi Takeda
- Department of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka Shizuoka, Japan
| | - Haruna Tamano
- Department of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizuoka Shizuoka, Japan
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Takeda A, Nakamura M, Fujii H, Tamano H. Synaptic Zn2+ homeostasis and its significance. Metallomics 2013; 5:417-23. [DOI: 10.1039/c3mt20269k] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Sgarzi M, Lombardo M, Trombini C, Zaccheroni N, Farruggia G, Merolle L, Sargenti A, Iotti S, Marraccini C, Prodi L. Expanding the targets of the diaza-18-crown-6 hydroxyquinoline derivatives family to Zn(II) ions for intracellular sensing. Supramol Chem 2013. [DOI: 10.1080/10610278.2012.745545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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deCampo D, Fudge J. Where and what is the paralaminar nucleus? A review on a unique and frequently overlooked area of the primate amygdala. Neurosci Biobehav Rev 2012; 36:520-35. [PMID: 21906624 PMCID: PMC3221880 DOI: 10.1016/j.neubiorev.2011.08.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 07/25/2011] [Accepted: 08/18/2011] [Indexed: 12/16/2022]
Abstract
The primate amygdala is composed of multiple subnuclei that play distinct roles in amygdala function. While some nuclei have been areas of focused investigation, others remain virtually unknown. One of the more obscure regions of the amygdala is the paralaminar nucleus (PL). The PL in humans and non-human primates is relatively expanded compared to lower species. Long considered to be part of the basal nucleus, the PL has several interesting features that make it unique. These features include a dense concentration of small cells, high concentrations of receptors for corticotropin releasing hormone and benzodiazepines, and dense innervation of serotonergic fibers. More recently, high concentrations of immature-appearing cells have been noted in the primate PL, suggesting special mechanisms of neural plasticity. Following a brief overview of amygdala structure and function, this review will provide an introduction to the history, embryology, anatomical connectivity, immunohistochemical and cytoarchitectural properties of the PL. Our conclusion is that the PL is a unique subregion of the amygdala that may yield important clues about the normal growth and function of the amygdala, particularly in higher species.
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Affiliation(s)
| | - Julie Fudge
- Department of Neurobiology and Anatomy
- Department of Psychiatry
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Sindreu C, Storm DR. Modulation of neuronal signal transduction and memory formation by synaptic zinc. Front Behav Neurosci 2011; 5:68. [PMID: 22084630 PMCID: PMC3211062 DOI: 10.3389/fnbeh.2011.00068] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 10/03/2011] [Indexed: 12/31/2022] Open
Abstract
The physiological role of synaptic zinc has remained largely enigmatic since its initial detection in hippocampal mossy fibers over 50 years ago. The past few years have witnessed a number of studies highlighting the ability of zinc ions to regulate ion channels and intracellular signaling pathways implicated in neuroplasticity, and others that shed some light on the elusive role of synaptic zinc in learning and memory. Recent behavioral studies using knock-out mice for the synapse-specific zinc transporter ZnT-3 indicate that vesicular zinc is required for the formation of memories dependent on the hippocampus and the amygdala, two brain centers that are prominently innervated by zinc-rich fibers. A common theme emerging from this research is the activity-dependent regulation of the Erk1/2 mitogen-activated-protein kinase pathway by synaptic zinc through diverse mechanisms in neurons. Here we discuss current knowledge on how synaptic zinc may play a role in cognition through its impact on neuronal signaling.
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Affiliation(s)
- Carlos Sindreu
- Department of Pharmacology, University of Washington Seattle, WA, USA
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Takeda A, Tamano H. Zinc signaling through glucocorticoid and glutamate signaling in stressful circumstances. J Neurosci Res 2011; 88:3002-10. [PMID: 20568287 DOI: 10.1002/jnr.22456] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Humans and animals are constantly exposed to environmental stress. The hypothalamic-pituitary-adrenal (HPA) axis responds to stress, followed by glucocorticoid secretion from the adrenal glands. This response serves to maintain homeostasis in the living body through energy mobilization or to restore it. The brain is an important target for glucocorticoids. The hippocampus participates in the regulation of the HPA axis. Stress activates glutamatergic neurons in the hippocampus, and serious stress induces dyshomeostasis of extracellular glutamate. This dyshomeostasis, which is potentiated by glucocorticoids, modifies cognitive and emotional behavior. On the other hand, zinc is necessary for glucocorticoid signaling and is released from glutamatergic (zincergic) neurons to modulate synaptic glutamate signaling. Stress also induces dyshomeostasis of extracellular zinc, which may be linked to dyshomeostasis of extracellular glutamate. Thus, glucocorticoid signaling might also contribute to dyshomeostasis of extracellular zinc. It is likely that zinc signaling participates in cognitive and emotional behavior through glucocorticoid and glutamate signaling under stressful circumstances. This Mini-Review analyzes the relationship among signals of glucocorticoid, glutamate, and zinc under stressful circumstances to elucidate the significance of the zinc signaling in response to stress.
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Affiliation(s)
- Atsushi Takeda
- Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
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Fukada T, Yamasaki S, Nishida K, Murakami M, Hirano T. Zinc homeostasis and signaling in health and diseases: Zinc signaling. J Biol Inorg Chem 2011; 16:1123-34. [PMID: 21660546 PMCID: PMC3176402 DOI: 10.1007/s00775-011-0797-4] [Citation(s) in RCA: 396] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 05/09/2011] [Indexed: 11/26/2022]
Abstract
The essential trace element zinc (Zn) is widely required in cellular functions, and abnormal Zn homeostasis causes a variety of health problems that include growth retardation, immunodeficiency, hypogonadism, and neuronal and sensory dysfunctions. Zn homeostasis is regulated through Zn transporters, permeable channels, and metallothioneins. Recent studies highlight Zn's dynamic activity and its role as a signaling mediator. Zn acts as an intracellular signaling molecule, capable of communicating between cells, converting extracellular stimuli to intracellular signals, and controlling intracellular events. We have proposed that intracellular Zn signaling falls into two classes, early and late Zn signaling. This review addresses recent findings regarding Zn signaling and its role in physiological processes and pathogenesis.
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Affiliation(s)
- Toshiyuki Fukada
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Laboratory of Allergy and Immunology, Graduate School of Medicine, Osaka University, Osaka, 565-0871 Japan
| | - Satoru Yamasaki
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
| | - Keigo Nishida
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Immune System, Cooperation Program, Graduate School of Frontier Biosciences, Osaka University, Osaka, 565-0871 Japan
| | - Masaaki Murakami
- Laboratories of Developmental Immunology, JST-CREST, Graduate School of Frontier Biosciences, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Osaka, 565-0871 Japan
| | - Toshio Hirano
- Laboratory for Cytokine Signaling, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045 Japan
- Laboratories of Developmental Immunology, JST-CREST, Graduate School of Frontier Biosciences, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Osaka, 565-0871 Japan
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