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Sengking J, Mahakkanukrauh P. The underlying mechanism of calcium toxicity-induced autophagic cell death and lysosomal degradation in early stage of cerebral ischemia. Anat Cell Biol 2024; 57:155-162. [PMID: 38680098 PMCID: PMC11184419 DOI: 10.5115/acb.24.003] [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: 01/05/2024] [Revised: 02/21/2024] [Accepted: 03/11/2024] [Indexed: 05/01/2024] Open
Abstract
Cerebral ischemia is the important cause of worldwide disability and mortality, that is one of the obstruction of blood vessels supplying to the brain. In early stage, glutamate excitotoxicity and high level of intracellular calcium (Ca2+) are the major processes which can promote many downstream signaling involving in neuronal death and brain tissue damaging. Moreover, autophagy, the reusing of damaged cell organelles, is affected in early ischemia. Under ischemic conditions, autophagy plays an important role to maintain energy of the brain and its function. In the other hand, over intracellular Ca2+ accumulation triggers excessive autophagic process and lysosomal degradation leading to autophagic process impairment which finally induce neuronal death. This article reviews the association between intracellular Ca2+ and autophagic process in acute stage of ischemic stroke.
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Affiliation(s)
- Jirakhamon Sengking
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pasuk Mahakkanukrauh
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Excellence in Osteology Research and Training Center (ORTC), Chaing Mai University, Chiang Mai, Thailand
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Qiu J, Yang Y, Liu J, Zhao W, Li Q, Zhu T, Liang P, Zhou C. The volatile anesthetic isoflurane differentially inhibits voltage-gated sodium channel currents between pyramidal and parvalbumin neurons in the prefrontal cortex. Front Neural Circuits 2023; 17:1185095. [PMID: 37396397 PMCID: PMC10311640 DOI: 10.3389/fncir.2023.1185095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/25/2023] [Indexed: 07/04/2023] Open
Abstract
Background How volatile anesthetics work remains poorly understood. Modulations of synaptic neurotransmission are the direct cellular mechanisms of volatile anesthetics in the central nervous system. Volatile anesthetics such as isoflurane may reduce neuronal interaction by differentially inhibiting neurotransmission between GABAergic and glutamatergic synapses. Presynaptic voltage-dependent sodium channels (Nav), which are strictly coupled with synaptic vesicle exocytosis, are inhibited by volatile anesthetics and may contribute to the selectivity of isoflurane between GABAergic and glutamatergic synapses. However, it is still unknown how isoflurane at clinical concentrations differentially modulates Nav currents between excitatory and inhibitory neurons at the tissue level. Methods In this study, an electrophysiological recording was applied in cortex slices to investigate the effects of isoflurane on Nav between parvalbumin (PV+) and pyramidal neurons in PV-cre-tdTomato and/or vglut2-cre-tdTomato mice. Results Isoflurane at clinically relevant concentrations produced a hyperpolarizing shift in the voltage-dependent inactivation and slowed the recovery time from the fast inactivation in both cellular subtypes. Since the voltage of half-maximal inactivation was significantly depolarized in PV+ neurons compared to that of pyramidal neurons, isoflurane inhibited the peak Nav currents in pyramidal neurons more potently than those of PV+ neurons (35.95 ± 13.32% vs. 19.24 ± 16.04%, P = 0.036 by the Mann-Whitney test). Conclusions Isoflurane differentially inhibits Nav currents between pyramidal and PV+ neurons in the prefrontal cortex, which may contribute to the preferential suppression of glutamate release over GABA release, resulting in the net depression of excitatory-inhibitory circuits in the prefrontal cortex.
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Affiliation(s)
- Jingxuan Qiu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Yaoxin Yang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wenling Zhao
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qian Li
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Peng Liang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
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Patch Clamp: The First Four Decades of a Technique That Revolutionized Electrophysiology and Beyond. Rev Physiol Biochem Pharmacol 2022; 186:1-28. [PMID: 35471741 DOI: 10.1007/112_2022_71] [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: 02/01/2023]
Abstract
Forty years ago, the introduction of a new electrophysiological technique, the patch clamp, revolutionized the fields of Cellular Physiology and Biophysics, providing for the first time the possibility of describing the behavior of a single protein, an ion-permeable channel of the cell plasma membrane, in its physiological environment. The new approach was actually much more potent and versatile than initially envisaged, and it has evolved into several different modalities that have radically changed our knowledge of how cells (not only the classical "electrically excitable "ones, such as nerves and muscles) use electrical signaling to modulate and organize their activity. This review aims at telling the history of the background from which the new technique evolved and at analyzing some of its more recent developments.
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Low LE, Wang Q, Chen Y, Lin P, Yang S, Gong L, Lee J, Siva SP, Goh BH, Li F, Ling D. Microenvironment-tailored nanoassemblies for the diagnosis and therapy of neurodegenerative diseases. NANOSCALE 2021; 13:10197-10238. [PMID: 34027535 DOI: 10.1039/d1nr02127c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Neurodegenerative disorder is an illness involving neural dysfunction/death attributed to complex pathological processes, which eventually lead to the mortality of the host. It is generally recognized through features such as mitochondrial dysfunction, protein aggregation, oxidative stress, metal ions dyshomeostasis, membrane potential change, neuroinflammation and neurotransmitter impairment. The aforementioned neuronal dysregulations result in the formation of a complex neurodegenerative microenvironment (NME), and may interact with each other, hindering the performance of therapeutics for neurodegenerative disease (ND). Recently, smart nanoassemblies prepared from functional nanoparticles, which possess the ability to interfere with different NME factors, have shown great promise to enhance the diagnostic and therapeutic efficacy of NDs. Herein, this review highlights the recent advances of stimuli-responsive nanoassemblies that can effectively combat the NME for the management of ND. The first section outlined the NME properties and their interrelations that are exploitable for nanoscale targeting. The discussion is then extended to the controlled assembly of functional nanoparticles for the construction of stimuli-responsive nanoassemblies. Further, the applications of stimuli-responsive nanoassemblies for the enhanced diagnosis and therapy of ND are introduced. Finally, perspectives on the future development of NME-tailored nanomedicines are given.
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Affiliation(s)
- Liang Ee Low
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Biofunctional Molecule Exploratory (BMEX) Research Group, School of Pharmacy, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Qiyue Wang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Ying Chen
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Peihua Lin
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Shengfei Yang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Linji Gong
- National Center for Translational Medicine, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jiyoung Lee
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China.
| | - Sangeetaprivya P Siva
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Bey-Hing Goh
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Biofunctional Molecule Exploratory (BMEX) Research Group, School of Pharmacy, Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Fangyuan Li
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Daishun Ling
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China. and Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China and National Center for Translational Medicine, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China and Key Laboratory of Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, 310027, P. R. China
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Raastad M. The Slow Depolarization Following Individual Spikes in Thin, Unmyelinated Axons in Mammalian Cortex. Front Cell Neurosci 2019; 13:203. [PMID: 31156391 PMCID: PMC6532452 DOI: 10.3389/fncel.2019.00203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/23/2019] [Indexed: 11/13/2022] Open
Abstract
An important goal in neuroscience is to understand how neuronal excitability is controlled. Therefore, Gardner-Medwin's 1972 discovery, that cerebellar parallel fibers were more excitable up to 100 ms after individual action potentials, could have had great impact. If this long-lasting effect were due to intrinsic membrane mechanisms causing a depolarizing after-potential (DAP) this was an important finding. However, that hypothesis met resistance because the use of K+ sensitive electrodes showed that synchronous activation, as commonly used in excitability tests, increased extracellular K+ concentration sufficiently to explain much of the hyperexcitability. It is still controversial because intra-axonal recordings, which could have settled the debate, have not been made from parallel fibers or other axons of similar calibers. If it had not been for the fact that such thin axons are, by far, the most common axon type in cortical areas and control almost all glutamate release, it would be tempting to ignore them until an appropriate intra-axonal recording technique is invented. I will go through the literature that, taken together, supports the hypothesis that a DAP is an intrinsic membrane mechanism in cerebellar parallel fibers and hippocampal Schaffer collaterals. It is most likely due to a well-controlled process that stops the fast repolarization at a membrane potential positive to resting membrane potential, leaving the membrane more excitable for ~100 ms during a slow, passive discharge of the membrane capacitance. The DAP helps reduce failures but can also cause uncontrolled bursting if it is not properly controlled. The voltage at which the fast repolarization stops, and the DAP starts, is close the activation range of both Na+ and Ca2+ voltage activated channels and is therefore essential for neuronal function.
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Affiliation(s)
- Morten Raastad
- Department of Physiology, School of Medicine, Emory University, Atlanta, GA, United States
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Zhou C, Johnson KW, Herold KF, Hemmings HC. Differential Inhibition of Neuronal Sodium Channel Subtypes by the General Anesthetic Isoflurane. J Pharmacol Exp Ther 2019; 369:200-211. [PMID: 30792243 DOI: 10.1124/jpet.118.254938] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/19/2019] [Indexed: 02/05/2023] Open
Abstract
Volatile anesthetics depress neurotransmitter release in a brain region- and neurotransmitter-selective manner by unclear mechanisms. Voltage-gated sodium channels (Navs), which are coupled to synaptic vesicle exocytosis, are inhibited by volatile anesthetics through reduction of peak current and modulation of gating. Subtype-selective effects of anesthetics on Nav might contribute to observed neurotransmitter-selective anesthetic effects on release. We analyzed anesthetic effects on Na+ currents mediated by the principal neuronal Nav subtypes Nav1.1, Nav1.2, and Nav1.6 heterologously expressed in ND7/23 neuroblastoma cells using whole-cell patch-clamp electrophysiology. Isoflurane at clinically relevant concentrations induced a hyperpolarizing shift in the voltage dependence of steady-state inactivation and slowed recovery from fast inactivation in all three Nav subtypes, with the voltage of half-maximal steady-state inactivation significantly more positive for Nav1.1 (-49.7 ± 3.9 mV) than for Nav1.2 (-57.5 ± 1.2 mV) or Nav1.6 (-58.0 ± 3.8 mV). Isoflurane significantly inhibited peak Na+ current (I Na) in a voltage-dependent manner: at a physiologically relevant holding potential of -70 mV, isoflurane inhibited peak I Na of Nav1.2 (16.5% ± 5.5%) and Nav1.6 (18.0% ± 7.8%), but not of Nav1.1 (1.2% ± 0.8%). Since Nav subtypes are differentially expressed both between neuronal types and within neurons, greater inhibition of Nav1.2 and Nav1.6 compared with Nav1.1 could contribute to neurotransmitter-selective effects of isoflurane on synaptic transmission.
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Affiliation(s)
- Cheng Zhou
- Departments of Anesthesiology (C.Z., K.W.J., K.F.H., H.C.H.) and Pharmacology (H.C.H.), Weill Cornell Medicine, New York, New York; and Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China (C.Z.)
| | - Kenneth W Johnson
- Departments of Anesthesiology (C.Z., K.W.J., K.F.H., H.C.H.) and Pharmacology (H.C.H.), Weill Cornell Medicine, New York, New York; and Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China (C.Z.)
| | - Karl F Herold
- Departments of Anesthesiology (C.Z., K.W.J., K.F.H., H.C.H.) and Pharmacology (H.C.H.), Weill Cornell Medicine, New York, New York; and Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China (C.Z.)
| | - Hugh C Hemmings
- Departments of Anesthesiology (C.Z., K.W.J., K.F.H., H.C.H.) and Pharmacology (H.C.H.), Weill Cornell Medicine, New York, New York; and Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China (C.Z.)
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Sodium Channel-Dependent and -Independent Mechanisms Underlying Axonal Afterdepolarization at Mouse Hippocampal Mossy Fibers. eNeuro 2018; 5:eN-NWR-0254-18. [PMID: 30225345 PMCID: PMC6140107 DOI: 10.1523/eneuro.0254-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 11/21/2022] Open
Abstract
Action potentials propagating along axons are often followed by prolonged afterdepolarization (ADP) lasting for several tens of milliseconds. Axonal ADP is thought to be an important factor in modulating the fidelity of spike propagation during repetitive firings. However, the mechanism as well as the functional significance of axonal ADP remain unclear, partly due to inaccessibility to small structures of axon for direct electrophysiological recordings. Here, we examined the ionic and electrical mechanisms underlying axonal ADP using whole-bouton recording from mossy fiber terminals in mice hippocampal slices. ADP following axonal action potentials was strongly enhanced by focal application of veratridine, an inhibitor of Na+ channel inactivation. In contrast, tetrodotoxin (TTX) partly suppressed ADP, suggesting that a Na+ channel–dependent component is involved in axonal ADP. The remaining TTX-resistant Na+ channel–independent component represents slow capacitive discharge reflecting the shape and electrical properties of the axonal membrane. We also addressed the functional impact of axonal ADP on presynaptic function. In paired-pulse stimuli, we found that axonal ADP minimally affected the peak height of subsequent action potentials, although the rising phase of action potentials was slightly slowed, possibly due to steady-state inactivation of Na+ channels by prolonged depolarization. Voltage clamp analysis of Ca2+ current elicited by action potential waveform commands revealed that axonal ADP assists short-term facilitation of Ca2+ entry into the presynaptic terminals. Taken together, these data show that axonal ADP maintains reliable firing during repetitive stimuli and plays important roles in the fine-tuning of short-term plasticity of transmitter release by modulating Ca2+ entry into presynaptic terminals.
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Resistance to action potential depression of a rat axon terminal in vivo. Proc Natl Acad Sci U S A 2017; 114:4249-4254. [PMID: 28373550 DOI: 10.1073/pnas.1619433114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The shape of the presynaptic action potential (AP) has a strong impact on neurotransmitter release. Because of the small size of most terminals in the central nervous system, little is known about the regulation of their AP shape during natural firing patterns in vivo. The calyx of Held is a giant axosomatic terminal in the auditory brainstem, whose biophysical properties have been well studied in slices. Here, we made whole-cell recordings from calyceal terminals in newborn rat pups. The calyx showed a characteristic burst firing pattern, which has previously been shown to originate from the cochlea. Surprisingly, even for frequencies over 200 Hz, the AP showed little or no depression. Current injections showed that the rate of rise of the AP depended strongly on its onset potential, and that the membrane potential after the AP (Vafter) was close to the value at which no depression would occur during high-frequency activity. Immunolabeling revealed that Nav1.6 is already present at the calyx shortly after its formation, which was in line with the fast recovery from AP depression that we observed in slice recordings. Our findings thus indicate that fast recovery from depression and an inter-AP membrane potential that minimizes changes on the next AP in vivo, together enable high timing precision of the calyx of Held already shortly after its formation.
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