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Wang Y, Wei Y, Ren M, Sajja VS, Wilder DM, Arun P, Gist ID, Long JB, Yang F. Blast Exposure Alters Synaptic Connectivity in the Mouse Auditory Cortex. J Neurotrauma 2024; 41:1438-1449. [PMID: 38047526 DOI: 10.1089/neu.2023.0348] [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] [Indexed: 12/05/2023] Open
Abstract
Blast exposure can cause auditory deficits that have a lasting, significant impact on patients. Although the effects of blast on auditory functions localized to the ear have been well documented, the impact of blast on central auditory processing is largely undefined. Understanding the structural and functional alterations in the central nervous system (CNS) associated with blast injuries is crucial for unraveling blast-induced pathophysiological pathways and advancing development of therapeutic interventions. In this study, we used electrophysiology in combination with optogenetics assay, proteomic analysis, and morphological evaluation to investigate the impairment of synaptic connectivity in the auditory cortex (AC) of mice following blast exposure. Our results show that the long-range functional connectivity between the medial geniculate nucleus (MGN) and AC was impaired in the acute phase of blast injury. We also identified impaired synaptic transmission and dendritic spine alterations within 7 days of blast exposure, which recovered at 28 days post-blast. Additionally, proteomic analysis identified a few differentially expressed proteins in the cortex that are involved in synaptic signaling and plasticity. These findings collectively suggest that blast-induced alterations in the sound signaling network in the auditory cortex may underlie hearing deficits in the acute and sub-acute phases after exposure to shockwaves. This study may shed light on the perturbations underlying blast-induced auditory dysfunction and provide insights into the potential therapeutic windows for improving auditory outcomes in blast-exposed individuals.
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Affiliation(s)
- Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Ming Ren
- Lieber Institute for Brain Development, Johns Hopkins Medical Center, Baltimore, Maryland, USA
| | - Venkatasivasai S Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Feng Yang
- Lieber Institute for Brain Development, Johns Hopkins Medical Center, Baltimore, Maryland, USA
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Yang P, Chen HY, Zhang X, Wang T, Li L, Su H, Li J, Guo YJ, Su SY. Electroacupuncture Attenuates Neuropathic Pain in a Rat Model of Cervical Spondylotic Radiculopathy: Involvement of Spinal Cord Synaptic Plasticity. J Pain Res 2023; 16:2447-2460. [PMID: 37483411 PMCID: PMC10362917 DOI: 10.2147/jpr.s415111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 07/07/2023] [Indexed: 07/25/2023] Open
Abstract
Purpose Cervical spondylotic radiculopathy (CSR) is a common neurologic condition that causes chronic neck pain and motor functions, with neuropathic pain (NP) being the primary symptom. Although it has been established that electroacupuncture (EA) can yield an analgesic effect in clinics and synaptic plasticity plays a critical role in the development and maintenance of NP, the underlying mechanisms have not been fully elucidated. In this study, we explored the potential mechanisms underlying EA's effect on synaptic plasticity in CSR rat models. Materials and Methods The CSR rat model was established by spinal cord compression (SCC). Electroacupuncture stimulation was applied to LI4 (Hegu) and LR3 (Taichong) acupoints for 20 min once a day for 7 days. Pressure pain threshold (PPT) and mechanical pain threshold (MPT) were utilized to detect the pain response of rats. A gait score was used to evaluate the motor function of rats. Enzyme-linked immunosorbent assay (ELISA), Western blot (WB), immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM) were performed to investigate the effects of EA. Results Our results showed that EA alleviated SCC-induced spontaneous pain and gait disturbance. ELISA showed that EA could decrease the concentration of pain mediators in the cervical nerve root. WB, IHC, and IF results showed that EA could downregulate the expression of synaptic proteins in spinal cord tissues and promote synaptic plasticity. TEM revealed that the EA could reverse the synaptic ultrastructural changes induced by CSR. Conclusion Our findings reveal that EA can inhibit SCC-induced NP by modulating the synaptic plasticity in the spinal cord and provide the foothold for the clinical treatment of CSR with EA.
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Affiliation(s)
- Pu Yang
- Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Hai-Yan Chen
- The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Xi Zhang
- The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Tian Wang
- Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Ling Li
- The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Hong Su
- Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Jing Li
- Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Yan-Jun Guo
- Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
| | - Sheng-Yong Su
- The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, Guangxi, People’s Republic of China
- Guangxi Key Laboratory of Molecular Biology of Preventive Medicine of Traditional Chinese Medicine, Nanning, Guangxi, People’s Republic of China
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Zhang S, Yan ML, Yang L, An XB, Zhao HM, Xia SN, Jin Z, Huang SY, Qu Y, Ai J. MicroRNA-153 impairs hippocampal synaptic vesicle trafficking via downregulation of synapsin I in rats following chronic cerebral hypoperfusion. Exp Neurol 2020; 332:113389. [PMID: 32580014 DOI: 10.1016/j.expneurol.2020.113389] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/02/2020] [Accepted: 06/18/2020] [Indexed: 02/07/2023]
Abstract
Chronic cerebral hypoperfusion (CCH) promotes the development of Alzheimer's pathology. However, whether and how CCH impairs the synaptic vesicle trafficking is still unclear. In the present study, we found that the hippocampal glutamatergic vesicle trafficking was impaired as indicated by a significant shortened delayed response enhancement (DRE) phase in CA3-CA1 circuit and decreased synapsin I in CCH rats suffering from bilateral common carotid artery occlusion (2VO). Further study showed an upregulated miR-153 in the hippocampus of 2VO rats. In vitro, overexpression of miR-153 downregulated synapsin I by binding the 3'UTRs of SYN1 mRNAs, which was prevented by its antisense AMO-153 and miRNA-masking antisense oligodeoxynucleotides (SYN1-ODN). In vivo, the upregulation of miR-153 elicited similar reduced DRE phase and synapsin I deficiency as CCH. Furthermore, miR-153 knockdown rescued the downregulated synapsin I and shortened DRE phase in 2VO rats. Our results demonstrate that CCH impairs hippocampal glutamatergic vesicle trafficking by upregulating miR-153, which suppresses the expression of synapsin I at the post-transcriptional level. These results will provide important references for drug research and treatment of vascular dementia.
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Affiliation(s)
- Shuai Zhang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Mei-Ling Yan
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Lin Yang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Xiao-Bin An
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Hong-Mei Zhao
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Sheng-Nan Xia
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Zhuo Jin
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Si-Yu Huang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Yang Qu
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Jing Ai
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China.
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Ahmed S, Mahmood Z, Javed A, Hashmi SN, Zerr I, Zafar S, Zahid S. Effect of Metformin on Adult Hippocampal Neurogenesis: Comparison with Donepezil and Links to Cognition. J Mol Neurosci 2017; 62:88-98. [PMID: 28378260 DOI: 10.1007/s12031-017-0915-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/29/2017] [Indexed: 01/02/2023]
Abstract
Recent studies have uncovered evidence suggesting that interference with hippocampal adult neurogenesis contributes to neurodegeneration in Alzheimer's disease (AD). Evidence supporting that AD is a metabolic disease with derangements in brain glucose utilization implies the use of anti-diabetics as an alternate therapeutic strategy. The present study drew comparison between the pro-neurogenic potential of metformin and donepezil in AlCl3-induced mouse model of neurodegeneration. Morris water maze task and subsequent immunohistochemical evaluation for NeuN was conducted. Expression of neurogenesis markers and hippocampal proteome analysis was determined by qRT-PCR and SDS-PAGE, respectively, followed by ESI-QTOFF MS/MS identification. The results demonstrated impaired spatial memory and differential expression of eight proteins in the AlCl3 group as compared to the controls. Interestingly, treatment with metformin normalized the proteome profile and expression levels of neurogenesis markers along with improvement in the spatial memory. Moreover, as compared to donepezil, metformin-treated mice exhibited an enhanced number of post-mitotic NeuN-positive neurons. It is suggested that underlying molecular mechanisms of metformin-mediated adult hippocampal neurogenesis may have implications in treatment of neurodegenerative disorders.
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Affiliation(s)
- Sara Ahmed
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Zahra Mahmood
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Aneela Javed
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Shoaib Naiyer Hashmi
- Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan
| | - Inga Zerr
- Department of Neurology, Clinical Dementia Center and DZNE, Georg-August University, University Medical Center Goettingen (UMG), Robert-Koch-Str. 40, 37075, Goettingen, Germany
| | - Saima Zafar
- Department of Neurology, Clinical Dementia Center and DZNE, Georg-August University, University Medical Center Goettingen (UMG), Robert-Koch-Str. 40, 37075, Goettingen, Germany
| | - Saadia Zahid
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
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Pan R, Cai J, Zhan L, Guo Y, Huang RY, Li X, Zhou M, Xu D, Zhan J, Chen H. Buyang Huanwu decoction facilitates neurorehabilitation through an improvement of synaptic plasticity in cerebral ischemic rats. Altern Ther Health Med 2017; 17:173. [PMID: 28351388 PMCID: PMC5371213 DOI: 10.1186/s12906-017-1680-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/11/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Loss of neural function is a critical but unsolved issue after cerebral ischemia insult. Neuronal plasticity and remodeling are crucial for recovery of neural functions after brain injury. Buyang Huanwu decoction, which is a classic formula in traditional Chinese medicine, can positively alter synaptic plasticity. This study assessed the effects of Buyang Huanwu decoction in combination with physical exercise on neuronal plasticity in cerebral ischemic rats. METHODS Cerebral ischemic rats were administered Buyang Huanwu decoction and participated in physical exercise after the induction of a permanent middle cerebral artery occlusion. The neurobehavioral functions and infarct volumes were evaluated. The presynaptic (SYN), postsynaptic (GAP-43) and cytoskeletal (MAP-2) proteins in the coronal brain samples were evaluated by immunohistochemistry and western blot analyses. The ultrastructure of the neuronal synaptic junctions in the same region were analyzed using transmission electron microscopy. RESULTS Combination treatment of Buyang Huanwu decoction and physical exercise ameliorated the neurobehavioral deficits (p < 0.05), significantly enhanced the expression levels of SYN, GAP-43 and MAP-2 (p < 0.05), and maintained the synaptic ultrastructure. CONCLUSIONS Buyang Huanwu decoction facilitated neurorehabilitation following a cerebral ischemia insult through an improvement in synaptic plasticity. Graphical abstract The Buyang Huanwu decoction (BYHWD) combined with physical exercise (PE) attenuates synaptic disruption and promotes synaptic plasticity following cerebral ischemia (stroke).
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Liu W, Zheng Q, Wang Y, Han X, Yuan L, Zhao M. Transplantation of olfactory ensheathing cells attenuates acute carbon monoxide poisoning-induced brain damages in rats. Neurochem Res 2014; 40:70-80. [PMID: 25370793 DOI: 10.1007/s11064-014-1467-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 10/22/2014] [Accepted: 10/27/2014] [Indexed: 02/02/2023]
Abstract
In this study, the therapeutic effect of olfactory ensheathing cells (OEC) transplantation on brain damage was evaluated on acute carbon monoxide (CO) poisoning rat model. Two weeks after primary culture, OECs were microinjected into hippocampus of CO poisoning rats. Survival of OECs in the host was observed and quantified. OECs survived at 2 weeks, but surviving cell number was found sharply decreased at 6 weeks and reduced to less than 10(3) at 8 weeks after transplantation. At 2 weeks after transplantation, motor function test and cerebral edema assay were performed and followed by pathological examination including hematoxylin and eosin and immunohistochemistry staining to observe the neuron injury and synapsin I and growth associated protein-43 (GAP-43) expression. Furthermore, biomarkers of oxidative stress and apoptosis related proteins in the hippocampus were detected. The results showed that CO exposure led to neurological dysfunction and cerebral edema in rats. After OEC transplantation, neurological function was significantly improved and the cerebral edema was alleviated. In addition, the numbers of neurons and Nissl bodies were increased and synapsin I and GAP-43 protein expressions were upregulated in the hippocampus. Compared with CO poisoned rats, superoxide dismutase activity and glutathione content were both increased and methane dicarboxylic aldehyde level was decreased in the hippocampus of OEC transplanted rats. Moreover, OEC transplantation reduced apoptosis induced by CO exposure. The Bcl-2 expression was significantly upregulated and Bax expression was significantly downregulated. The activity of caspase-3 and the cleaved-poly ADP-ribose polymerase expression were decreased. Taken together, our data suggest that OEC attenuates brain damages induced by acute CO poisoning within 2 weeks after transplantation.
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Affiliation(s)
- Wei Liu
- Department of Emergency Medicine, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, 110004, People's Republic of China
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Imperlini E, Orrù S, Corbo C, Daniele A, Salvatore F. Altered brain protein expression profiles are associated with molecular neurological dysfunction in the PKU mouse model. J Neurochem 2014; 129:1002-12. [PMID: 24548049 PMCID: PMC4286000 DOI: 10.1111/jnc.12683] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/07/2014] [Accepted: 02/02/2014] [Indexed: 12/14/2022]
Abstract
Phenylketonuria (PKU), if not detected and treated in newborns, causes severe neurological dysfunction and cognitive and behavioral deficiencies. Despite the biochemical characterization of PKU, the molecular mechanisms underlying PKU-associated brain dysfunction remain poorly understood. The aim of this study was to gain insights into the pathogenesis of this neurological damage by analyzing protein expression profiles in brain tissue of Black and Tan BRachyury-PahEnu2 mice (a mouse model of PKU). We compared the cerebral protein expression of homozygous PKU mice with that of their heterozygous counterparts using two-dimensional difference gel electrophoresis analysis, and identified 21 differentially expressed proteins, four of which were over-expressed and 17 under-expressed. An in silico bioinformatic approach indicated that protein under-expression was related to neuronal differentiation and dendritic growth, and to such neurological disorders as progressive motor neuropathy and movement disorders. Moreover, functional annotation analyses showed that some identified proteins were involved in oxidative metabolism. To further investigate the proteins involved in the neurological damage, we validated two of the proteins that were most strikingly under-expressed, namely, Syn2 and Dpysl2, which are involved in synaptic function and neurotransmission. We found that Glu2/3 and NR1 receptor subunits were over-expressed in PKU mouse brain. Our results indicate that differential expression of these proteins may be associated with the processes underlying PKU brain dysfunction, namely, decreased synaptic plasticity and impaired neurotransmission.
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Clayton DF, London SE. Advancing avian behavioral neuroendocrinology through genomics. Front Neuroendocrinol 2014; 35:58-71. [PMID: 24113222 DOI: 10.1016/j.yfrne.2013.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 12/14/2022]
Abstract
Genome technologies are transforming all areas of biology, including the study of hormones, brain and behavior. Annotated reference genome assemblies are rapidly being produced for many avian species. Here we briefly review the basic concepts and tools used in genomics. We then consider how these are informing the study of avian behavioral neuroendocrinology, focusing in particular on lessons from the study of songbirds. We discuss the impact of having a complete "parts list" for an organism; the transformational potential of studying large sets of genes at once instead one gene at a time; the growing recognition that environmental and behavioral signals trigger massive shifts in gene expression in the brain; and the prospects for using comparative genomics to uncover the genetic roots of behavioral variation. Throughout, we identify promising new directions for bolstering the application of genomic information to further advance the study of avian brain and behavior.
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Affiliation(s)
- David F Clayton
- Biological & Experimental Psychology Division, School of Biological & Chemical Sciences, Queen Mary University of London, London E1 4NS, UK.
| | - Sarah E London
- Department of Psychology, Institute for Mind and Biology, Committee on Neurobiology, University of Chicago, 940 E 57th Street, Chicago, IL, USA.
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Casillas-Espinosa PM, Powell KL, O'Brien TJ. Regulators of synaptic transmission: roles in the pathogenesis and treatment of epilepsy. Epilepsia 2013; 53 Suppl 9:41-58. [PMID: 23216578 DOI: 10.1111/epi.12034] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synaptic transmission is the communication between a presynaptic and a postsynaptic neuron, and the subsequent processing of the signal. These processes are complex and highly regulated, reflecting their importance in normal brain functioning and homeostasis. Sustaining synaptic transmission depends on the continuing cycle of synaptic vesicle formation, release, and endocytosis, which requires proteins such as dynamin, syndapin, synapsin, and synaptic vesicle protein 2A. Synaptic transmission is regulated by diverse mechanisms, including presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors and signaling, and modulators of neurotransmission. Neurotransmitters released presynaptically can bind to their postsynaptic receptors, the inhibitory γ-aminobutyric acid (GABA)ergic receptors or the excitatory glutamate receptors. Once released, glutamate activates a variety of postsynaptic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA), kainate, and metabotropic receptors. The activation of the receptors triggers downstream signaling cascades generating a vast array of effects, which can be modulated by a numerous auxiliary regulatory subunits. Moreover, different neuropeptides such as neuropeptide Y, brain-derived neurotrophic factor (BDNF), somatostatin, ghrelin, and galanin, act as regulators of diverse synaptic functions and along with the classic neurotransmitters. Abnormalities in the regulation of synaptic transmission play a critical role in the pathogenesis of numerous brain diseases, including epilepsy. This review focuses on the different mechanisms involved in the regulation of synaptic transmission, which may play a role in the pathogenesis of epilepsy: the presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors, and modulators of neurotransmission, including the mechanism by which drugs can modulate the frequency and severity of epileptic seizures.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- The Departments of Medicine and Neurology, The Royal Melbourne Hospital, The Melbourne Brain Centre, The University of Melbourne, Parkville, Victoria, Australia
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Barrera-Ocampo A, Gutierrez-Vargas J, Garcia-Segura LM, Cardona-Gómez GP. Glycogen synthase kinase-3β/β-catenin signaling in the rat hypothalamus during the estrous cycle. J Neurosci Res 2012; 90:1078-84. [PMID: 22331547 DOI: 10.1002/jnr.22816] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/06/2011] [Accepted: 09/15/2011] [Indexed: 11/11/2022]
Abstract
During the estrous cycle, a remodeling of synapses on somas and dendritic spines occurs in the rat hypothalamic arcuate nucleus. The synaptic remodeling is known to be induced by estradiol, but the molecular mechanisms involved still have not been fully clarified. β-catenin is known to regulate synaptic plasticity, so we have assessed possible modifications of β-catenin in the rat mediobasal hypothalamus during the estrous cycle. Our findings indicate that β-catenin expression is increased during proestrus and estrus in comparison with diestrus day. This increase was accompanied by an enhanced phosphorylation of Akt in Ser473 and of glycogen synthase kinase-3β (GSK3β) in Ser9. Also, the association of β-catenin with the synaptic protein PSD95 was increased during these same stages of the estrous cycle, whereas the levels of synapsin I were significantly decreased in proestrus. These findings suggest that Akt/GSK3β/β-catenin signaling is involved in the synaptic modifications that occur in the basal hypothalamus during the estrous cycle.
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Affiliation(s)
- Alvaro Barrera-Ocampo
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, University of Antioquia, Medellín, Colombia
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Vesely C, Tauber S, Sedlazeck FJ, von Haeseler A, Jantsch MF. Adenosine deaminases that act on RNA induce reproducible changes in abundance and sequence of embryonic miRNAs. Genome Res 2012; 22:1468-76. [PMID: 22310477 PMCID: PMC3409260 DOI: 10.1101/gr.133025.111] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Adenosine deaminases that act on RNA bind double-stranded and structured RNAs and convert adenosines to inosines by hydrolytic deamination. Inosines are recognized as guanosines, and, hence, RNA editing alters the sequence information but also structure of RNAs. Editing by ADARs is widespread and essential for normal life and development. Precursors of miRNAs are abundantly edited by ADARs, but neither the abundance nor the consequences of miRNA editing has been firmly established. Using transgenic mouse embryos that are deficient in the two enzymatically active editing enzymes ADAR and ADARB1, we compare relative frequencies but also sequence composition of miRNAs in these genetically modified backgrounds to wild-type mice by “next-generation sequencing.” Deficiency of ADARB1 leads to a reproducible change in abundance of specific miRNAs and their predicted targets. Changes in miRNA abundance seem unrelated to editing events. Additional deletion of ADAR has surprisingly little impact on the mature miRNA repertoire, indicating that miRNA expression is primarily dependent on ADARB1. A-to-G transitions reflecting A-to-I editing events can be detected at few sites and at low frequency during the early embryonic stage investigated. Again, most editing events are ADARB1-dependent with only few editing sites being specifically edited by ADAR. Besides known editing events in miRNAs, a few novel, previously unknown editing events were identified. Some editing events are located to the seed region of miRNAs, opening the possibility that editing leads to their retargeting.
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Affiliation(s)
- Cornelia Vesely
- Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria
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