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Copenhaver AE, LeGates TA. Sex-Specific Mechanisms Underlie Long-Term Potentiation at Hippocampus→Medium Spiny Neuron Synapses in the Medial Shell of the Nucleus Accumbens. J Neurosci 2024; 44:e0100242024. [PMID: 38806250 PMCID: PMC11223474 DOI: 10.1523/jneurosci.0100-24.2024] [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: 01/15/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
Sex differences have complicated our understanding of the neurobiological basis of many behaviors that are key for survival. As such, continued elucidation of the similarities and differences between sexes is necessary to gain insight into brain function and vulnerability. The connection between the hippocampus (Hipp) and nucleus accumbens (NAc) is a crucial site where modulation of neuronal activity mediates reward-related behavior. Our previous work demonstrated that long-term potentiation (LTP) of Hipp→NAc synapses is rewarding, and mice can establish learned associations between LTP of these synapses and the contextual environment in which LTP occurred. Here, we investigated sex differences in the mechanisms underlying Hipp→NAc LTP using whole-cell electrophysiology and pharmacology. We observed similarities in basal synaptic strength between males and females and found that LTP occurs postsynaptically with similar magnitudes in both sexes. However, key sex differences emerged as LTP in males required NMDA receptors (NMDAR), whereas LTP in females utilized an NMDAR-independent mechanism involving L-type voltage-gated Ca2+ channels (VGCCs) and estrogen receptor α (ERα). We also uncovered sex-similar features as LTP in both sexes depended on CaMKII activity and occurred independently of dopamine-1 receptor (D1R) activation. Our results have elucidated sex-specific molecular mechanisms for LTP in an integral pathway that mediates reward-related behaviors, emphasizing the importance of considering sex as a variable in mechanistic studies. Continued characterization of sex-specific mechanisms underlying plasticity will offer novel insight into the neurophysiological basis of behavior, with significant implications for understanding how diverse processes mediate behavior and contribute to vulnerability to developing psychiatric disorders.
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Affiliation(s)
- Ashley E Copenhaver
- Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250
| | - Tara A LeGates
- Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Maryland 21201
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Li X, Feng R, Guo Z, Meng Y, Zou Y, Liao W, Peng Q, Zhong H, Zhao W. Direct investigations of the effects of nicardipine on calcium channels of astrocytes by Atomic Force Microscopy. Talanta 2024; 274:125947. [PMID: 38537353 DOI: 10.1016/j.talanta.2024.125947] [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: 10/01/2023] [Revised: 03/12/2024] [Accepted: 03/16/2024] [Indexed: 05/04/2024]
Abstract
Calcium channel blockers (CCB) of astrocytes can blockade the calcium ions entry through the voltage gated calcium channels (VGCC), and is widely used in the diseases related with VGCC of astrocytes. But many aspects of the interaction mechanisms between the CCB and VGCC of astrocytes still remain unclear due to the limited resolution of the approaches. Herein the effects of the nicardipine (a type of CCB) on VGCC of astrocytes were investigated at very high spatial, force and electrical resolution by multiple modes of Atomic Force Microscopy (AFM) directly. The results reveal that after the addition of nicardipine, the recognition signals of VGCC disappeared; the specific unbinding forces vanished; the conductivity of the astrocytes decreased (the current decreased about 2.9 pA and the capacitance was doubled); the surface potential of the astrocytes reduced about 14.2 mV. The results of electrical properties investigations are consistent with the simulation experiments. The relations between these biophysical and biochemical properties of VGCC have been discussed. All these demonstrate that the interactions between nicardipine and VGCC have been studied at nanometer spatial resolution, at picoNewton force resolution and very high electrical signal resolution (pA in current, pF in capacitance and 0.1 mV in surface potential) level. The approaches are considered to be high resolution and high sensitivity, and will be helpful and useful in the further investigations of the effects of other types of CCB on ion channels, and will also be helpful in the investigations of mechanisms and therapy of ion channelopathies.
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Affiliation(s)
- Xinyu Li
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Rongrong Feng
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Zeling Guo
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Yu Meng
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Yulan Zou
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Wenchao Liao
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Qianwei Peng
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Basic Medicine, Gannan Medical University, Ganzhou, 341000, People's Republic of China
| | - Haijian Zhong
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China.
| | - Weidong Zhao
- Key Laboratory of Biomaterials and Biofabrication in Tissue Engineering of Jiangxi Province, Gannan Medical University, Ganzhou, 341000, People's Republic of China; School of Medical Information Engineering, Gannan Medical University, Ganzhou, 341000, People's Republic of China; Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou, 341000, People's Republic of China.
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Maiorov SA, Laryushkin DP, Kritskaya KA, Zinchenko VP, Gaidin SG, Kosenkov AM. The Role of Ion Channels and Intracellular Signaling Cascades in the Inhibitory Action of WIN 55,212-2 upon Hyperexcitation. Brain Sci 2024; 14:668. [PMID: 39061409 PMCID: PMC11274798 DOI: 10.3390/brainsci14070668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/19/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024] Open
Abstract
Gi-coupled receptors, particularly cannabinoid receptors (CBRs), are considered perspective targets for treating brain pathologies, including epilepsy. However, the precise mechanism of the anticonvulsant effect of the CBR agonists remains unknown. We have found that WIN 55,212-2 (a CBR agonist) suppresses the synchronous oscillations of the intracellular concentration of Ca2+ ions (epileptiform activity) induced in the neurons of rat hippocampal neuron-glial cultures by bicuculline or NH4Cl. As we have demonstrated, the WIN 55,212-2 effect is mediated by CB1R receptors. The agonist suppresses Ca2+ inflow mediated by the voltage-gated calcium channels but does not alter the inflow mediated by NMDA, AMPA, and kainate receptors. We have also found that phospholipase C (PLC), protein kinase C (PKC), and G-protein-coupled inwardly rectifying K+ channels (GIRK channels) are involved in the molecular mechanism underlying the inhibitory action of CB1R activation against epileptiform activity. Thus, our results demonstrate that the antiepileptic action of CB1R agonists is mediated by different intracellular signaling cascades, including non-canonical PLC/PKC-associated pathways.
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Affiliation(s)
| | | | | | | | - Sergei G. Gaidin
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia (A.M.K.)
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Ali NH, Al-Kuraishy HM, Al-Gareeb AI, Alnaaim SA, Hetta HF, Saad HM, Batiha GES. A Mutual Nexus Between Epilepsy and α-Synuclein: A Puzzle Pathway. Mol Neurobiol 2024:10.1007/s12035-024-04204-6. [PMID: 38703341 DOI: 10.1007/s12035-024-04204-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 04/12/2024] [Indexed: 05/06/2024]
Abstract
Alpha-synuclein (α-Syn) is a specific neuronal protein that regulates neurotransmitter release and trafficking of synaptic vesicles. Exosome-associated α-Syn which is specific to the central nervous system (CNS) is involved in the pathogenesis of epilepsy. Therefore, this review aimed to elucidate the possible link between α-Syn and epilepsy, and how it affects the pathophysiology of epilepsy. A neurodegenerative protein such as α-Syn is implicated in the pathogenesis of epilepsy. Evidence from preclinical and clinical studies revealed that upregulation of α-Syn induces progressive neuronal dysfunctions through induction of oxidative stress, neuroinflammation, and inhibition of autophagy in a vicious cycle with subsequent development of severe epilepsy. In addition, accumulation of α-Syn in epilepsy could be secondary to the different cellular alterations including oxidative stress, neuroinflammation, reduction of brain-derived neurotrophic factor (BDNF) and progranulin (PGN), and failure of the autophagy pathway. However, the mechanism of α-Syn-induced-epileptogenesis is not well elucidated. Therefore, α-Syn could be a secondary consequence of epilepsy. Preclinical and clinical studies are warranted to confirm this causal relationship.
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Affiliation(s)
- Naif H Ali
- Department of Internal Medicine, Medical College, Najran University, Najran, Kingdom of Saudi Arabia
| | - Hayder M Al-Kuraishy
- Department of Clinical Pharmacology and Medicine, College of Medicine, Mustansiriyah University, M.B.Ch.B, FRCP, P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Jabir Ibn Hayyan Medical University, Al-Ameer Qu, P.O. Box 13, Kufa, Najaf, Iraq
| | - Saud A Alnaaim
- Clinical Neurosciences Department, College of Medicine, King Faisal University, Hofuf, Saudi Arabia
| | - Helal F Hetta
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, 71515, Egypt
| | - Hebatallah M Saad
- Department of Pathology, Faculty of Veterinary Medicine, Matrouh University, Matrouh, 51744, Egypt.
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, AlBeheira, Egypt.
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Copenhaver AE, LeGates TA. Sex-specific mechanisms underlie long-term potentiation at hippocampus-nucleus accumbens synapses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575709. [PMID: 38293132 PMCID: PMC10827060 DOI: 10.1101/2024.01.15.575709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Sex differences have complicated our understanding of the neurobiological basis of many behaviors that are key for survival. As such, continued elucidation of the similarities and differences between sexes is necessary in order to gain insight into brain function and vulnerability. The connection between the hippocampus (Hipp) and nucleus accumbens (NAc) is a crucial site where modulation of neuronal activity mediates reward-related behavior. Our previous work demonstrated that long-term potentiation (LTP) of Hipp-NAc synapses is rewarding, and that mice can make learned associations between LTP of these synapses and the contextual environment in which LTP occurred. Here, we investigate sex differences in the mechanisms underlying Hipp-NAc LTP using whole-cell electrophysiology and pharmacology. We found that males and females display similar magnitudes of Hipp-NAc LTP which occurs postsynaptically. However, LTP in females requires L-type voltage-gated Ca 2+ channels (VGCC) for postsynaptic Ca 2+ influx, while males rely on NMDA receptors (NMDAR). Additionally, females require estrogen receptor α (ERα) activity for LTP while males do not. These differential mechanisms converge as LTP in both sexes depends on CAMKII activity and occurs independently of dopamine-1 receptor (D1R) activation. Our results have elucidated sex-specific molecular mechanisms for LTP in an integral excitatory pathway that mediates reward-related behaviors, emphasizing the importance of considering sex as a variable in mechanistic studies. Continued characterization of sex-specific mechanisms underlying plasticity will offer novel insight into the neurophysiological basis of behavior, with significant implications for understanding how diverse processes mediate behavior and contribute to vulnerability to developing psychiatric disorders. SIGNIFICANCE STATEMENT Strengthening of Hipp-NAc synapses drives reward-related behaviors. Male and female mice have similar magnitudes of long-term potentiation (LTP) and both sexes have a predicted postsynaptic locus of plasticity. Despite these similarities, we illustrate here that sex-specific molecular mechanisms are used to elicit LTP. Given the bidirectional relationship between Hipp-NAc synaptic strength in mediating reward-related behaviors, the use of distinct molecular mechanisms may explain sex differences observed in stress susceptibility or response to rewarding stimuli. Discovery and characterization of convergent sex differences provides mechanistic insight into the sex-specific function of Hipp-NAc circuitry and has widespread implications for circuits mediating learning and reward-related behavior.
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Song X, Li D, Gan L, Xiong X, Nie A, Zhao H, Hu Y, Li G, Guo J. Intravenous Injection of Na Ions Aggravates Ang II-Induced Hypertension-Related Vascular Endothelial Injury by Increasing Transmembrane Osmotic Pressure. Int J Nanomedicine 2023; 18:7505-7521. [PMID: 38106448 PMCID: PMC10723192 DOI: 10.2147/ijn.s435144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/03/2023] [Indexed: 12/19/2023] Open
Abstract
Introduction Extracellular protein nanoparticles (PNs) and ions perform synergistical functions in the control of transmembrane osmotic pressure (OP) under isotonic conditions. Intravenous injection may disrupt the ion balance and alter PN levels in blood plasma, changing transmembrane OP and damaging vascular endothelial cells. Methods Na ions were injected into AngII-induced HUVECs to simulate cell injury in vitro, and tail vein infusion of Na ions into hypertensive rats was performed to assess vascular damage. Optical measurements using an intermediate filament (IF) tension probe were conducted to detect indicators related to transmembrane OP. Immunofluorescence, Western blotting and small interfering RNA (siRNA) transfection were employed to investigate inflammasomes and the relationship between Abl2 and inflammation. Results Electrolyte injections with sodium ions (but not glucose and hydroxyethyl starch) induced the production of ASC and NLRP3 inflammasomes in Ang II-induced HUVECs; this in turn resulted in the disorder of calcium signals, and changes in transmembrane OP and cell permeability. Moreover, injection of Na ions into Ang II-induced HUVECs activated the mechanosensitive protein Abl2, involved in inflammation-induced transmembrane OP changes. A drug combination was identified that could induce OP recovery and block hyperpermeability induced by cytoplasmic inflammatory corpuscles in vivo and in vitro. Conclusion Changes in extracellular PNs and ions following chemical stimuli (Ang II) participate in the regulation of transmembrane OP. Furthermore, injection of Na ions causes vascular endothelial injury in Ang II-induced cells in vitro and hypertension rats in vivo, suggesting it is not safe for hypertensive patients, and we propose a new drug combination as a solution.
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Affiliation(s)
- Xianrui Song
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Danyang Li
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Lingling Gan
- Experiment Center for Science and Technology, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Xiyu Xiong
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Aobo Nie
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Huanhuan Zhao
- Basic Medical Experiment Center, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Yunfeng Hu
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
| | - Guangming Li
- Department of Anesthesiology, Huaian First People’s Hospital, Nanjing Medical University, Huaian, Jiangsu, 223001, People’s Republic of China
| | - Jun Guo
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, People’s Republic of China
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Laryushkin DP, Maiorov SA, Zinchenko VP, Mal'tseva VN, Gaidin SG, Kosenkov AM. Of the Mechanisms of Paroxysmal Depolarization Shifts: Generation and Maintenance of Bicuculline-Induced Paroxysmal Activity in Rat Hippocampal Cell Cultures. Int J Mol Sci 2023; 24:10991. [PMID: 37446169 DOI: 10.3390/ijms241310991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Abnormal depolarization of neuronal membranes called paroxysmal depolarization shift (PDS) represents a cellular correlate of interictal spikes. The mechanisms underlying the generation of PDSs or PDS clusters remain obscure. This study aimed to investigate the role of ionotropic glutamate receptors (iGluRs) in the generation of PDS and dependence of the PDS pattern on neuronal membrane potential. We have shown that significant depolarization or hyperpolarization (by more than ±50 mV) of a single neuron does not change the number of individual PDSs in the cluster, indicating the involvement of an external stimulus in PDS induction. Based on this data, we have suggested reliable protocols for stimulating single PDS or PDS clusters. Furthermore, we have found that AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors are necessary for PDS generation since AMPAR antagonist NBQX completely suppresses bicuculline-induced paroxysmal activity. In turn, antagonists of NMDA (N-methyl-D-aspartate) and kainate receptors (D-AP5 and UBP310, respectively) caused a decrease in the amplitude of the first action potential in PDSs and in the amplitude of the oscillations of intracellular Ca2+ concentration occurring alongside the PDS cluster generation. The effects of the NMDAR (NMDA receptor) and KAR (kainate receptor) antagonists indicate that these receptors are involved only in the modulation of paroxysmal activity. We have also shown that agonists of some Gi-coupled receptors, such as A1 adenosine (A1Rs) or cannabinoid receptors (CBRs) (N6-cyclohexyladenosine and WIN 55,212-2, respectively), completely suppressed PDS generation, while the A1R agonist even prevented it. We hypothesized that the dynamics of extracellular glutamate concentration govern paroxysmal activity. Fine-tuning of neuronal activity via action on Gi-coupled receptors or iGluRs paves the way for the development of new approaches for epilepsy pharmacotherapy.
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Affiliation(s)
- Denis P Laryushkin
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Sergei A Maiorov
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Valery P Zinchenko
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Valentina N Mal'tseva
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Sergei G Gaidin
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Artem M Kosenkov
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
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8
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Gaidin SG, Maiorov SA, Laryushkin DP, Zinchenko VP, Kosenkov AM. A novel approach for vital visualization and studying of neurons containing Ca 2+ -permeable AMPA receptors. J Neurochem 2023; 164:583-597. [PMID: 36415923 DOI: 10.1111/jnc.15729] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 10/19/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022]
Abstract
Calcium-permeable AMPA receptors (CP-AMPARs) play a pivotal role in brain functioning in health and disease. They are involved in synaptic plasticity, synaptogenesis, and neuronal circuits development. However, the functions of neurons expressing CP-AMPARs and their role in the modulation of network activity remain elusive since reliable and accurate visualization methods are absent. Here we developed an approach allowing the vital identification of neurons containing CP-AMPARs. The proposed method relies on evaluating Ca2+ influx in neurons during activation of AMPARs in the presence of NMDAR and KAR antagonists, and blockers of voltage-gated Ca2+ channels. Using this method, we studied the properties of CP-AMPARs-containing neurons. We showed that the overwhelming majority of neurons containing CP-AMPARs are GABAergic, and they are distinguished by higher amplitudes of the calcium responses to applications of the agonists. Furthermore, about 30% of CP-AMPARs-containing neurons demonstrate the presence of GluK1-containing KARs. Although CP-AMPARs-containing neurons are characterized by more significant Ca2+ influx during the activation of AMPARs than other neurons, AMPAR-mediated Na+ influx is similar in these two groups. We revealed that neurons containing CP-AMPARs demonstrate weak GABA(A)R-mediated inhibition because of the low percentage of GABAergic synapses on the soma of these cells. However, our data show that weak GABA(A)R-mediated inhibition is inherent to all GABAergic neurons in the culture and cannot be considered a unique feature of CP-AMPARs-containing neurons. We believe that the suggested approach will help to understand the role of CP-AMPARs in the mammalian nervous system in more detail.
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Affiliation(s)
- Sergei G Gaidin
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Sergei A Maiorov
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Denis P Laryushkin
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Valery P Zinchenko
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Artem M Kosenkov
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
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9
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Sanchez GM, Incedal TC, Prada J, O'Callaghan P, Dyachok O, Echeverry S, Dumral Ö, Nguyen PM, Xie B, Barg S, Kreuger J, Dandekar T, Idevall-Hagren O. The β-cell primary cilium is an autonomous Ca2+ compartment for paracrine GABA signaling. J Cell Biol 2023; 222:213674. [PMID: 36350286 DOI: 10.1083/jcb.202108101] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/11/2022] [Accepted: 10/12/2022] [Indexed: 11/11/2022] Open
Abstract
The primary cilium is an organelle present in most adult mammalian cells that is considered as an antenna for sensing the local microenvironment. Here, we use intact mouse pancreatic islets of Langerhans to investigate signaling properties of the primary cilium in insulin-secreting β-cells. We find that GABAB1 receptors are strongly enriched at the base of the cilium, but are mobilized to more distal locations upon agonist binding. Using cilia-targeted Ca2+ indicators, we find that activation of GABAB1 receptors induces selective Ca2+ influx into primary cilia through a mechanism that requires voltage-dependent Ca2+ channel activation. Islet β-cells utilize cytosolic Ca2+ increases as the main trigger for insulin secretion, yet we find that increases in cytosolic Ca2+ fail to propagate into the cilium, and that this isolation is largely due to enhanced Ca2+ extrusion in the cilium. Our work reveals local GABA action on primary cilia that involves Ca2+ influx and depends on restricted Ca2+ diffusion between the cilium and cytosol.
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Affiliation(s)
| | | | - Juan Prada
- Department of Bioinformatics, University of Würzburg, Würzburg, Germany
| | - Paul O'Callaghan
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Oleg Dyachok
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | - Özge Dumral
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Phuoc My Nguyen
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Beichen Xie
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Johan Kreuger
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Thomas Dandekar
- Department of Bioinformatics, University of Würzburg, Würzburg, Germany
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Zhukov VV, Saphonov MV. Calcium Component of the Retinal Light Response in the Snail Lymnaea stagnalis: a Pharmacological and Ultrastructural Study. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022030036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Martini M, Rispoli G. Cation Permeability of Voltage-Gated Hair Cell Ca 2+ Channels of the Vertebrate Labyrinth. Int J Mol Sci 2022; 23:ijms23073786. [PMID: 35409146 PMCID: PMC8998708 DOI: 10.3390/ijms23073786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 02/05/2023] Open
Abstract
Some hearing, vestibular, and vision disorders are imputable to voltage-gated Ca2+ channels of the sensory cells. These channels convey a large Ca2+ influx despite extracellular Na+ being 70-fold more concentrated than Ca2+; such high selectivity is lost in low Ca2+, and Na+ can permeate. Since the permeation properties and molecular identity of sensory Ca2+ channels are debated, in this paper, we examine the Na+ current flowing through the L- and R-type Ca2+ channels of labyrinth hair cells. Ion currents and cytosolic free Ca2+ concentrations were simultaneously monitored in whole-cell recording synchronous to fast fluorescence imaging. L-type and R-type channels were present with different densities at selected sites. In 10 nM Ca2+, the activation and deactivation time constants of the L-type Na+ current were accelerated and its maximal amplitude increased by 6-fold compared to physiological Ca2+. The deactivation of the R-type Na+ current was not accelerated, and its current amplitude increased by 2.3-fold in low Ca2+; moreover, it was partially blocked by nifedipine in a voltage- and time-dependent manner. In conclusion, L channel gating is affected by the ion species permeating the channel, and its selectivity filter binds Ca2+ more strongly than that of R channel; furthermore, external Ca2+ prevents nifedipine from perturbing the R selectivity filter.
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