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Jin T, Wang R, Peng S, Liu X, Zhang H, He X, Teng W, Teng X. Developmental Hypothyroidism Influences the Development of the Entorhinal-Dentate Gyrus Pathway of Rat Offspring. Endocrinol Metab (Seoul) 2022; 37:290-302. [PMID: 35390249 PMCID: PMC9081305 DOI: 10.3803/enm.2021.1343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/21/2022] [Accepted: 02/10/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Developmental hypothyroidism impairs learning and memory in offspring, which depend on extensive neuronal circuits in the entorhinal cortex, together with the hippocampus and neocortex. The entorhinal-dentate gyrus pathway is the main entrance of memory circuits. We investigated whether developmental hypothyroidism impaired the morphological development of the entorhinal-dentate gyrus pathway. METHODS We examined the structure and function of the entorhinal-dentate gyrus pathway in response to developmental hypothyroidism induced using 2-mercapto-1-methylimidazole. RESULTS 1,1´-Dioctadecyl-3,3,3´,3´-tetramethylindocarbocyanine perchlorate tract tracing indicated that entorhinal axons showed delayed growth in reaching the outer molecular layer of the dentate gyrus at postnatal days 2 and 4 in hypothyroid conditions. The proportion of fibers in the outer molecular layer was significantly smaller in the hypothyroid group than in the euthyroid group at postnatal day 4. At postnatal day 10, the pathway showed a layer-specific distribution in the outer molecular layer, similar to the euthyroid group. However, the projected area of entorhinal axons was smaller in the hypothyroid group than in the euthyroid group. An electrophysiological examination showed that hypothyroidism impaired the long-term potentiation of the perforant and the cornu ammonis 3-cornu ammonis 1 pathways. Many repulsive axon guidance molecules were involved in the formation of the entorhinaldentate gyrus pathway. The hypothyroid group had higher levels of erythropoietin-producing hepatocyte ligand A3 and semaphorin 3A than the euthyroid group. CONCLUSION We demonstrated that developmental hypothyroidism might influence the development of the entorhinal-dentate gyrus pathway, contributing to impaired long-term potentiation. These findings improve our understanding of neural mechanisms for memory function.
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Affiliation(s)
- Ting Jin
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ranran Wang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
- Department of Endocrinology, Chifeng College Affiliated Hospital, Chifeng, China
| | - Shiqiao Peng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Xin Liu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Hanyi Zhang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Xue He
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Weiping Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Xiaochun Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, National Health Commission Key Laboratory of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, China
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Hu Y, Guo TC, Zhang XY, Tian J, Lu YS. Paired associative stimulation improves synaptic plasticity and functional outcomes after cerebral ischemia. Neural Regen Res 2019; 14:1968-1976. [PMID: 31290455 PMCID: PMC6676880 DOI: 10.4103/1673-5374.259618] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Paired associative stimulation is a relatively new non-invasive brain stimulation technique that combines transcranial magnetic stimulation and peripheral nerve stimulation. The effects of paired associative stimulation on the excitability of the cerebral cortex can vary according to the time interval between the transcranial magnetic stimulation and peripheral nerve stimulation. We established a model of cerebral ischemia in rats via transient middle cerebral artery occlusion. We administered paired associative stimulation with a frequency of 0.05 Hz 90 times over 4 weeks. We then evaluated spatial learning and memory using the Morris water maze. Changes in the cerebral ultra-structure and synaptic plasticity were assessed via transmission electron microscopy and a 64-channel multi-electrode array. We measured mRNA and protein expression levels of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 in the hippocampus using a real-time polymerase chain reaction and western blot assay. Paired associative stimulation treatment significantly improved learning and memory in rats subjected to cerebral ischemia. The ultra-structures of synapses in the CA1 area of the hippocampus in rats subjected to cerebral ischemia were restored by paired associative stimulation. Long-term potentiation at synapses in the CA3 and CA1 regions of the hippocampus was enhanced as well. The protein and mRNA expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 increased after paired associative stimulation treatment. These data indicate that paired associative stimulation can protect cognition after cerebral ischemia. The observed effect may be mediated by increases in the mRNA and protein expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1, and by enhanced synaptic plasticity in the CA1 area of the hippocampus. The animal experiments were approved by the Animal Ethics Committee of Tongji Medical College, Huazhong University of Science & Technology, China (approval No. TJ-A20151102) on July 11, 2015.
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Affiliation(s)
- Yan Hu
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology; Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Tie-Cheng Guo
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei Province, China
| | - Xiang-Yu Zhang
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei Province; Department of Rehabilitation Medicine, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Jun Tian
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China
| | - Yin-Shan Lu
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei Province, China
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The "curved lead pathway" method to enable a single lead to reach any two intracranial targets. Sci Rep 2017; 7:40533. [PMID: 28074898 PMCID: PMC5225435 DOI: 10.1038/srep40533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/07/2016] [Indexed: 12/23/2022] Open
Abstract
Deep brain stimulation is an effective way to treat movement disorders, and a powerful research tool for exploring brain functions. This report proposes a “curved lead pathway” method for lead implantation, such that a single lead can reach in sequence to any two intracranial targets. A new type of stereotaxic system for implanting a curved lead to the brain of human/primates was designed, the auxiliary device needed for this method to be used in rat/mouse was fabricated and verified in rat, and the Excel algorithm used for automatically calculating the necessary parameters was implemented. This “curved lead pathway” method of lead implantation may complement the current method, make lead implantation for multiple targets more convenient, and expand the experimental techniques of brain function research.
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BDNF-dependent plasticity induced by peripheral inflammation in the primary sensory and the cingulate cortex triggers cold allodynia and reveals a major role for endogenous BDNF as a tuner of the affective aspect of pain. J Neurosci 2015; 34:14739-51. [PMID: 25355226 DOI: 10.1523/jneurosci.0860-14.2014] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Painful experiences are multilayered, composed of sensory, affective, cognitive and behavioral facets. Whereas it is well accepted that the development of chronic pain is due to maladaptive neuronal changes, the underlying molecular mechanisms, their relationship to the different pain modalities, and indeed the localization of these changes are still unknown. Brain-derived neurotrophic factor (BDNF) is an activity-dependent neuromodulator in the adult brain, which enhances neuronal excitability. In the spinal cord, BDNF underlies the development and maintenance of inflammatory and neuropathic pain. Here, we hypothesized that BDNF could be a trigger of some of these plastic changes. Our results demonstrate that BDNF is upregulated in the anterior cingulate cortex (ACC) and the primary sensory cortex (S1) in rats with inflammatory pain. Injections of recombinant BDNF (into the ACC) or a viral vector synthesizing BDNF (into the ACC or S1) triggered both neuronal hyperexcitability, as shown by elevated long-term potentiation, and sustained pain hypersensitivity. Finally, pharmacological blockade of BDNF-tropomyosin receptor kinase B (TrkB) signaling in the ACC, through local injection of cyclotraxin-B (a novel, highly potent, and selective TrkB antagonist) prevented neuronal hyperexcitability, the emergence of cold hypersensitivity, and passive avoidance behavior. These findings show that BDNF-dependent neuronal plasticity in the ACC, a structure known to be involved in the affective-emotional aspect of pain, is a key mechanism in the development and maintenance of the emotional aspect of chronic pain.
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Ajetunmobi A, Prina-Mello A, Volkov Y, Corvin A, Tropea D. Nanotechnologies for the study of the central nervous system. Prog Neurobiol 2014; 123:18-36. [PMID: 25291406 DOI: 10.1016/j.pneurobio.2014.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 12/16/2022]
Abstract
The impact of central nervous system (CNS) disorders on the human population is significant, contributing almost €800 billion in annual European healthcare costs. These disorders not only have a disabling social impact but also a crippling economic drain on resources. Developing novel therapeutic strategies for these disorders requires a better understanding of events that underlie mechanisms of neural circuit physiology. Studying the relationship between genetic expression, synapse development and circuit physiology in CNS function is a challenging task, involving simultaneous analysis of multiple parameters and the convergence of several disciplines and technological approaches. However, current gold-standard techniques used to study the CNS have limitations that pose unique challenges to furthering our understanding of functional CNS development. The recent advancement in nanotechnologies for biomedical applications has seen the emergence of nanoscience as a key enabling technology for delivering a translational bridge between basic and clinical research. In particular, the development of neuroimaging and electrophysiology tools to identify the aetiology and progression of CNS disorders have led to new insights in our understanding of CNS physiology and the development of novel diagnostic modalities for therapeutic intervention. This review focuses on the latest applications of these nanotechnologies for investigating CNS function and the improved diagnosis of CNS disorders.
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Affiliation(s)
- A Ajetunmobi
- Department of Clinical Medicine, Institute of Molecular Medicine, St. James' Hospital, Trinity College Dublin, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Ireland
| | - A Prina-Mello
- Department of Clinical Medicine, Institute of Molecular Medicine, St. James' Hospital, Trinity College Dublin, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Ireland.
| | - Y Volkov
- Department of Clinical Medicine, Institute of Molecular Medicine, St. James' Hospital, Trinity College Dublin, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Ireland
| | - A Corvin
- Department of Psychiatry, Institute of Molecular Medicine, St. James' Hospital, Trinity College Dublin, Ireland
| | - D Tropea
- Department of Psychiatry, Institute of Molecular Medicine, St. James' Hospital, Trinity College Dublin, Ireland.
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Luo C, Kuner T, Kuner R. Synaptic plasticity in pathological pain. Trends Neurosci 2014; 37:343-55. [DOI: 10.1016/j.tins.2014.04.002] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/31/2014] [Accepted: 04/09/2014] [Indexed: 02/06/2023]
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Liu MG, Chen J. Preclinical research on pain comorbidity with affective disorders and cognitive deficits: Challenges and perspectives. Prog Neurobiol 2014; 116:13-32. [DOI: 10.1016/j.pneurobio.2014.01.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 12/31/2013] [Accepted: 01/02/2014] [Indexed: 12/12/2022]
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Wang RR, Jin JH, Womack AW, Lyu D, Kokane SS, Tang N, Zou X, Lin Q, Chen J. Neonatal ketamine exposure causes impairment of long-term synaptic plasticity in the anterior cingulate cortex of rats. Neuroscience 2014; 268:309-17. [PMID: 24674848 DOI: 10.1016/j.neuroscience.2014.03.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/14/2014] [Accepted: 03/14/2014] [Indexed: 01/27/2023]
Abstract
Ketamine, a dissociative anesthetic most commonly used in many pediatric procedures, has been reported in many animal studies to cause widespread neuroapoptosis in the neonatal brain after exposure in high doses and/or for a prolonged period. This neurodegenerative change occurs most severely in the forebrain including the anterior cingulate cortex (ACC) that is an important brain structure for mediating a variety of cognitive functions. However, it is still unknown whether such apoptotic neurodegeneration early in life would subsequently impair the synaptic plasticity of the ACC later in life. In this study, we performed whole-cell patch-clamp recordings from the ACC brain slices of young adult rats to examine any alterations in long-term synaptic plasticity caused by neonatal ketamine exposure. Ketamine was administered at postnatal day 4-7 (subcutaneous injections, 20mg/kg given six times, once every 2h). At 3-4weeks of age, long-term potentiation (LTP) was induced and recorded by monitoring excitatory postsynaptic currents from ACC slices. We found that the induction of LTP in the ACC was significantly reduced when compared to the control group. The LTP impairment was accompanied by an increase in the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated excitatory synaptic transmission and a decrease in GABA inhibitory synaptic transmission in neurons of the ACC. Thus, our present findings show that neonatal ketamine exposure causes a significant LTP impairment in the ACC. We suggest that the imbalanced synaptic transmission is likely to contribute to ketamine-induced LTP impairment in the ACC.
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Affiliation(s)
- R-R Wang
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, China; Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA; Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - J-H Jin
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - A W Womack
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - D Lyu
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - S S Kokane
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - N Tang
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - X Zou
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA
| | - Q Lin
- Department of Psychology, College of Science, The University of Texas at Arlington, Arlington, TX, USA.
| | - J Chen
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, China; Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China.
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Lu YF, Wang Y, He Y, Zhang FK, He T, Wang RR, Chen XF, Yang F, Gong KR, Chen J. Spatial and temporal plasticity of synaptic organization in anterior cingulate cortex following peripheral inflammatory pain: multi-electrode array recordings in rats. Neurosci Bull 2014; 30:1-20. [PMID: 23686522 PMCID: PMC5561851 DOI: 10.1007/s12264-013-1344-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/19/2013] [Indexed: 12/23/2022] Open
Abstract
To explore whether experiencing inflammatory pain has an impact upon intracortical synaptic organization, the planar multi-electrode array (MEA) technique and 2-dimensional current source density (2D-CSD) imaging were used in slice preparations of the anterior cingulate cortex (ACC) from rats. Synaptic activity across different layers of the ACC was evoked by deep layer stimulation through one electrode. The layer-localization of both local field potentials (LFPs) and the spread of current sink calculated by 2D-CSD analysis was characterized pharmacologically. Moreover, the induction of long-term potentiation (LTP) and changes in LTP magnitude were also evaluated. We found that under naïve conditions, the current sink was initially generated in layer VI, then spread to layer V and finally confined to layers II-III. This spatial pattern of current sink movement typically reflected changes in depolarized sites from deep layers (V-VI) to superficial layers (II-III) where intra- and extracortical inputs terminate. In the ACC slices from rats in an inflamed state (for 2 h) caused by intraplantar bee-venom injection, the spatial profile of intra-ACC synaptic organization was significantly changed, showing an enlarged current sink distribution and a leftward shift of the stimulus-response curves relative to the naïve and saline controls. The change was more distinct in the superficial layers (II-III) than in the deep site. In terms of temporal properties, the rate of LTP induction was significantly increased in layers II-III by inflammatory pain. However, the magnitude of LTP was not significantly enhanced by this treatment. Taken together, these results show that inflammatory pain results in distinct spatial and temporal plasticity of synaptic organization in the ACC, which may lead to altered synaptic transmission and modulation.
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Affiliation(s)
- Yun-Fei Lu
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Yan Wang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Ying He
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Fu-Kang Zhang
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Ting He
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Rui-Rui Wang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Xue-Feng Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Fei Yang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Ke-Rui Gong
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Jun Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
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Jin J, Gong K, Zou X, Wang R, Lin Q, Chen J. The blockade of NMDA receptor ion channels by ketamine is enhanced in developing rat cortical neurons. Neurosci Lett 2013; 539:11-5. [PMID: 23395831 DOI: 10.1016/j.neulet.2013.01.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 12/03/2012] [Accepted: 01/18/2013] [Indexed: 10/27/2022]
Abstract
Ketamine is a non-competitive antagonist of NMDA receptors (NMDARs) commonly used as a dissociative anesthetic in many pediatric procedures. Ketamine acts primarily by blocking NMDA ligand-gated channels. Experimental studies indicate that ketamine administration used for inducing clinically relevant anesthesia can lead to neurotoxic effects, such as apoptosis, selectively on immature brain neurons. However, the underlying mechanisms remain unclear. This study used whole-cell patch-clamp recordings in an in vitro preparation of forebrain slices to analyze pharmacologically the differences in the effects of ketamine administration on the NMDAR channel activity between immature and mature neurons. NMDAR channel activity was recorded in the form of evoked NMDAR-mediated excitatory postsynaptic currents (eEPSCs) from the forebrain of both neonatal and adult rats. Results show that ketamine inhibited eEPSCs in a dose-dependent manner in both immature and mature neurons. However, at each concentration of ketamine applied to the brain slice, a more extensive inhibition could be seen in neonatal neurons than in adult neurons. Further, the blocking effect of ketamine on eEPSCs was measured during the period of 1, 3, and 6h after ketamine washout. Inhibition of eEPSCs in immature neurons was still evident 6h after washout. In contrast, the blockade of eEPSCs in mature neurons recovered completely from the inhibition by ketamine in a time-dependent manner. These results indicate that ketamine produces a greater and longer blocking effect on NMDAR channels in immature neurons than in mature neurons. This differential effect is likely to be a critical link to the higher vulnerability to ketamine-induced neurotoxicity in neurons of the developing brain.
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Affiliation(s)
- Jianhui Jin
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, China
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Use of multi-electrode array recordings in studies of network synaptic plasticity in both time and space. Neurosci Bull 2012; 28:409-22. [PMID: 22833039 DOI: 10.1007/s12264-012-1251-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Simultaneous multisite recording using multi-electrode arrays (MEAs) in cultured and acutely-dissociated brain slices and other tissues is an emerging technique in the field of network electrophysiology. Over the past 40 years, great efforts have been made by both scientists and commercial concerns, to advance this technique. The MEA technique has been widely applied to many regions of the brain, retina, heart and smooth muscle in various studies at the network level. The present review starts from the development of MEA techniques and their uses in brain preparations, and then specifically concentrates on the use of MEA recordings in studies of synaptic plasticity at the network level in both the temporal and spatial domains. Because the MEA technique helps bridge the gap between single-cell recordings and behavioral assays, its wide application will undoubtedly shed light on the mechanisms underlying brain functions and dysfunctions at the network level that remained largely unknown due to the technical difficulties before it matured.
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A procyanidin trimer, C1, promotes NO production in rat aortic endothelial cells via both hyperpolarization and PI3K/Akt pathways. Eur J Pharmacol 2012; 692:52-60. [PMID: 22796647 DOI: 10.1016/j.ejphar.2012.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/28/2012] [Accepted: 07/03/2012] [Indexed: 01/07/2023]
Abstract
Procyanidins, which are condensed catechins, have been elucidated as absorbable polyphenols, but their health-benefits remain unclear. The aim of this study was, thus, to clarify the efficacy and mechanism of each procyanidin oligomer in NO activation in rat aortic endothelial cells (RAECs). Treatment of RAECs with 50μM procyanidin C1 (4β→8 trimer) resulted in a time- and dose-dependent hyperpolarization using the membrane potential-sensitive probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol, while no effect was observed for (-)-epicatechin (a monomer) and procyanidin B2 (4β→8 dimer). The C1-induced hyperpolarization was inhibited by iberiotoxin, a specific inhibitor of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channel, as well as 2-aminoethyl diphenylborinate (2-APB), a store-operated Ca(2+) entry inhibitor. Procyanidin C1 caused a significant increase in NO production from RAECs via phosphorylation of both eNOS and Akt, and the effect was completely inhibited by N(G)-monomethyl-l-arginine or combined treatment with iberiotoxin and the phosphatidylinositol 3-kinase (PI3K) specific inhibitor, wortmannin, as well as combined treatment with 2-APB and wortmannin. Taken together, these findings provide critical evidence that procyanidin C1, but not B2, has potential to induce NO production in RAECs via both Ca(2+)-dependent BK(Ca) channel-mediated hyperpolarization and Ca(2+)-independent PI3K/Akt pathways.
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Byun EB, Korematsu S, Ishikawa T, Nishizuka T, Ohshima S, Kanda T, Matsui T. Apple procyanidins induce hyperpolarization of rat aorta endothelial cells via activation of K+ channels. J Nutr Biochem 2011; 23:278-86. [PMID: 21543207 DOI: 10.1016/j.jnutbio.2010.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 12/02/2010] [Accepted: 12/03/2010] [Indexed: 11/26/2022]
Abstract
Apple procyanidins (AP), one of the polyphenol-rich compounds, showed an endothelial-dependent vasorelaxation in rat aorta, but the mechanisms of beneficial effects are still unclear. The present study was designed to clarify the potential role of AP in rat aorta endothelial cells (RAECs). The treatment of RAECs with AP (1-10 μg/ml) resulted in a dose-dependent hyperpolarization with a maximum effect at 10 μg/ml, and for this reason, AP (10 μg/ml) was used in all the following experiments. AP-induced hyperpolarization was significantly inhibited by pretreatment of nonspecific K(+) inhibitor, tetraethyl ammonium chloride or specific K(+) channel inhibitors, iberiotoxin, glibenclamide, 4-aminopyridine and BaCl(2), as well as by high KCl or Ca(2+)-free solution. AP-induced hyperpolarization was also proved using 64-channel multielectrode dish system that can monitor a direct and real-time change of membrane potential. Furthermore, AP treatment caused a significant increase of nitric oxide (NO) production and cyclic guanosine monophosphate levels via endothelial NO synthase messenger RNA expression. The NO production was inhibited by N(G)-monoethyl-l-arginine or Ca(2+)-free solution and was completely abolished by their combination. Also, AP inhibited endothelial proliferation, while the effect was significantly abolished by N(G)-monoethyl-l-arginine or tetraethyl ammonium chloride. These findings suggest that AP induces both hyperpolarization of RAECs via multiple activation of K(+) channels and activation of NO/cyclic guanosine monophosphate pathway via increasing NO production or is responsible for antiangiogenic effect. Diminishment of hyperpolarization as well as NO production of AP in Ca(2+)-free solution implicated that AP would play a crucial role in promoting Ca(2+) influx into endothelial cells so as to promote both actions.
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Affiliation(s)
- Eui-Baek Byun
- Division of Bioresources and Biosciences, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
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Differential roles of ERK, JNK and p38 MAPK in pain-related spatial and temporal enhancement of synaptic responses in the hippocampal formation of rats: Multi-electrode array recordings. Brain Res 2011; 1382:57-69. [DOI: 10.1016/j.brainres.2011.01.076] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 11/21/2010] [Accepted: 01/24/2011] [Indexed: 12/30/2022]
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Gong KR, Cao FL, He Y, Gao CY, Wang DD, Li H, Zhang FK, An YY, Lin Q, Chen J. Enhanced excitatory and reduced inhibitory synaptic transmission contribute to persistent pain-induced neuronal hyper-responsiveness in anterior cingulate cortex. Neuroscience 2010; 171:1314-25. [DOI: 10.1016/j.neuroscience.2010.10.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/08/2010] [Accepted: 10/12/2010] [Indexed: 12/31/2022]
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Wang DD, Li Z, Chang Y, Wang RR, Chen XF, Zhao ZY, Cao FL, Jin JH, Liu MG, Chen J. Neural circuits and temporal plasticity in hindlimb representation of rat primary somatosensory cortex: revisited by multi-electrode array on brain slices. Neurosci Bull 2010; 26:175-87. [PMID: 20502495 DOI: 10.1007/s12264-010-0308-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex (S1 area). METHODS Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid (95% O(2) and 5% CO(2)), and were mounted on a Med64 probe (64 electrodes, 8x8 array) for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes. RESULTS The local intracortical connection, which is involved in mediation of downward information flow across layers II-VI, was identified by electrical stimulation (ES) at layers II-III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II-IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus (CS) applied within layer IV of the S1 area could successfully induce long-term potentiation (LTP) in 5 of the 6 slices (83.3%), while the same CS application at layers II-III induced no LTP in any of the 6 tested slices. CONCLUSION The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices: one is the intracortical circuit (ICC) formed by interlaminar connections from layers II-III, and the other is the thalamocortical circuit (TCC) mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plasticity, while TCC is spatially extensive and exhibits a better plasticity in response to somatosensory afferent stimulation. The present data provide a useful experimental model for further studying microcircuit properties in S1 cortex at the network level in vitro.
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Affiliation(s)
- Dan-Dan Wang
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing 100069, China
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