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Kleschevnikov AM. Enhanced GIRK2 channel signaling in Down syndrome: A feasible role in the development of abnormal nascent neural circuits. Front Genet 2022; 13:1006068. [PMID: 36171878 PMCID: PMC9510977 DOI: 10.3389/fgene.2022.1006068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 08/24/2022] [Indexed: 11/24/2022] Open
Abstract
The most distinctive feature of Down syndrome (DS) is moderate to severe cognitive impairment. Genetic, molecular, and neuronal mechanisms of this complex DS phenotype are currently under intensive investigation. It is becoming increasingly clear that the abnormalities arise from a combination of initial changes caused by triplication of genes on human chromosome 21 (HSA21) and later compensatory adaptations affecting multiple brain systems. Consequently, relatively mild initial cognitive deficits become pronounced with age. This pattern of changes suggests that one approach to improving cognitive function in DS is to target the earliest critical changes, the prevention of which can change the ‘trajectory’ of the brain development and reduce the destructive effects of the secondary alterations. Here, we review the experimental data on the role of KCNJ6 in DS-specific brain abnormalities, focusing on a putative role of this gene in the development of abnormal neural circuits in the hippocampus of genetic mouse models of DS. It is suggested that the prevention of these early abnormalities with pharmacological or genetic means can ameliorate cognitive impairment in DS.
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2
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Szewczyk A, Zagaja M, Szala-Rycaj J, Maj M, Andres-Mach M. Effect of Lacosamide and Ethosuximide Chronic Treatment on Neural Precursor Cells and Cognitive Functions after Pilocarpine Induced Status Epilepticus in Mice. Brain Sci 2021; 11:brainsci11081014. [PMID: 34439633 PMCID: PMC8392532 DOI: 10.3390/brainsci11081014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022] Open
Abstract
Seizures in about 40% of patients with epilepsy fail to respond to anti-seizure medication (ASM) and may lead to uncontrolled and prolonged seizures often inducing status epilepticus (SE). The aim of the study was to evaluate the impact of a long-term treatment with two different generation ASMs: ethosuximide (ETS, a classic ASM) and lacosamide (LCM, a 3rd generation ASM) on neural stem cells’ (NSCs’) proliferation and learning and memory functions after pilocarpine (PILO)-induced SE in mice. The following drugs were used: LCM (10 mg/kg), ETS (20 mg/kg), and PILO (300 mg/kg). Cell counting was done using confocal microscope and ImageJ software. Cognitive functions were evaluated with the Morris water maze (MWM) test. The level of several selected neurometabolites was measured with magnetic resonance spectroscopy (MRS). Obtained results indicated no significant impact of ETS treatment on the neurogenesis process in PILO mice. Interestingly, LCM significantly decreased the total amount of newborn neurons. The MWM test indicated no significant changes in the time and distance traveled by the ETS and LCM groups compared to PILO control mice, although all measured parameters were more favorable for the PILO mice treated with ASM. Conclusions: The presented results show that long term treatment with LCM and ETS seems to be safe for the cognitive functions and the proper course of neurogenesis in the mouse PILO-induced SE model, although one should remember that LCM administered chronically may act to reduce new neurons’ formation.
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Affiliation(s)
- Aleksandra Szewczyk
- Isobolographic Analysis Laboratory, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland; (A.S.); (M.Z.); (J.S.-R.)
| | - Mirosław Zagaja
- Isobolographic Analysis Laboratory, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland; (A.S.); (M.Z.); (J.S.-R.)
| | - Joanna Szala-Rycaj
- Isobolographic Analysis Laboratory, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland; (A.S.); (M.Z.); (J.S.-R.)
| | - Maciej Maj
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland;
| | - Marta Andres-Mach
- Isobolographic Analysis Laboratory, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin, Poland; (A.S.); (M.Z.); (J.S.-R.)
- Correspondence: ; Tel.: +48-81-718-4488
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3
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Crunelli V, Lőrincz ML, McCafferty C, Lambert RC, Leresche N, Di Giovanni G, David F. Clinical and experimental insight into pathophysiology, comorbidity and therapy of absence seizures. Brain 2020; 143:2341-2368. [PMID: 32437558 PMCID: PMC7447525 DOI: 10.1093/brain/awaa072] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/19/2019] [Accepted: 01/31/2020] [Indexed: 12/24/2022] Open
Abstract
Absence seizures in children and teenagers are generally considered relatively benign because of their non-convulsive nature and the large incidence of remittance in early adulthood. Recent studies, however, show that 30% of children with absence seizures are pharmaco-resistant and 60% are affected by severe neuropsychiatric comorbid conditions, including impairments in attention, cognition, memory and mood. In particular, attention deficits can be detected before the epilepsy diagnosis, may persist even when seizures are pharmacologically controlled and are aggravated by valproic acid monotherapy. New functional MRI-magnetoencephalography and functional MRI-EEG studies provide conclusive evidence that changes in blood oxygenation level-dependent signal amplitude and frequency in children with absence seizures can be detected in specific cortical networks at least 1 min before the start of a seizure, spike-wave discharges are not generalized at seizure onset and abnormal cortical network states remain during interictal periods. From a neurobiological perspective, recent electrical recordings and imaging of large neuronal ensembles with single-cell resolution in non-anaesthetized models show that, in contrast to the predominant opinion, cortical mechanisms, rather than an exclusively thalamic rhythmogenesis, are key in driving seizure ictogenesis and determining spike-wave frequency. Though synchronous ictal firing characterizes cortical and thalamic activity at the population level, individual cortico-thalamic and thalamocortical neurons are sparsely recruited to successive seizures and consecutive paroxysmal cycles within a seizure. New evidence strengthens previous findings on the essential role for basal ganglia networks in absence seizures, in particular the ictal increase in firing of substantia nigra GABAergic neurons. Thus, a key feature of thalamic ictogenesis is the powerful increase in the inhibition of thalamocortical neurons that originates at least from two sources, substantia nigra and thalamic reticular nucleus. This undoubtedly provides a major contribution to the ictal decrease in total firing and the ictal increase of T-type calcium channel-mediated burst firing of thalamocortical neurons, though the latter is not essential for seizure expression. Moreover, in some children and animal models with absence seizures, the ictal increase in thalamic inhibition is enhanced by the loss-of-function of the astrocytic GABA transporter GAT-1 that does not necessarily derive from a mutation in its gene. Together, these novel clinical and experimental findings bring about paradigm-shifting views of our understanding of absence seizures and demand careful choice of initial monotherapy and continuous neuropsychiatric evaluation of affected children. These issues are discussed here to focus future clinical and experimental research and help to identify novel therapeutic targets for treating both absence seizures and their comorbidities.
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Affiliation(s)
- Vincenzo Crunelli
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - Magor L Lőrincz
- Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK.,Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Cian McCafferty
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Régis C Lambert
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Nathalie Leresche
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - François David
- Cerebral dynamics, learning and plasticity, Integrative Neuroscience and Cognition Center - UMR 8002, Paris, France
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Masicampo ML, Shan HQ, Xu V, Speagle M, Godwin DW. Selective Blockade of T-Type Ca2+ Channels is Protective Against Alcohol-Withdrawal Induced Seizure and Mortality. Alcohol Alcohol 2018; 53:526-531. [PMID: 29912275 DOI: 10.1093/alcalc/agy042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 06/04/2018] [Indexed: 11/13/2022] Open
Abstract
AIMS We have previously demonstrated that blockade of T-type calcium channels by the non-selective antagonist, ethosuximide (ETX), is effective at reducing electrographical and behavioral correlates of alcohol-withdrawal (WD) seizure. Here, we investigated whether blockade of these calcium channels with the selective antagonist TTA-P2 also reduces alcohol-WD seizure. SHORT SUMMARY The non-specific T-type calcium channel antagonist, ETX, is protective against alcohol-WD seizure. However, the mechanism of this effect is unclear. Here, we provide evidence that further suggests selective blockade of T-type calcium channels are protective against alcohol-WD seizure and WD-related mortality. METHODS We used an intermittent ethanol exposure model to produce WD-induced hyperexcitability in DBA/2 J mice. Seizure severity was intensified with the chemoconvulsant pentylenetetrazole (PTZ). RESULTS TTA-P2 (10 mg/kg) reduced seizure severity in mice undergoing alcohol WD with concurrent PTZ treatment (20 mg/kg). Moreover, TTA-P2 (20 and 40 mg/kg) was also protective against PTZ-induced (40 mg/kg) seizure and mortality. CONCLUSIONS These results are consistent with prior results using ETX, and suggest that the protective effects of ETX and TTA-P2 against EtOH WD seizures are mediated by T-type calcium channels.
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Affiliation(s)
- Melissa L Masicampo
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA.,Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA
| | - Hong Qu Shan
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA
| | - Victoria Xu
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA
| | - Merritt Speagle
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA
| | - Dwayne W Godwin
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA.,Department of Physiology and Pharmacology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC, USA
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Orczyk JJ, Garraghty PE. The effects of ethosuximide on aversive instrumental learning in adult rats. Epilepsy Behav 2018; 84:1-9. [PMID: 29730499 DOI: 10.1016/j.yebeh.2018.03.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 12/29/2022]
Abstract
Antiepileptic medications are the frontline treatment for seizure conditions but are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin-, carbamazepine-, valproic acid-, and felbamate-treated rats. In this experiment, the effects found in ethosuximide (ETH)-treated rats have been compared with those in water-treated controls (controls) using the same instrumental training tasks. Rats treated with ETH did not display any performance deficits in any of the conditions tested relative to controls. These animals showed more rapid acquisition of the avoidance response than the control animals but only when they had prior experience in the appetitive condition. Of the drugs tested to date with these learning paradigms, ETH is the only one that did not impair performance relative to controls in any condition tested. Moreover, in comparison with rats treated with valproic acid, the only other available compound commonly recommended for the treatment of absence seizures, ETH-treated rats show substantially higher performance.
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Affiliation(s)
- John J Orczyk
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA.
| | - Preston E Garraghty
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA; Program in Neuroscience, Indiana University, Bloomington, IN, USA.
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Taguchi YH. Tensor decomposition-based unsupervised feature extraction identifies candidate genes that induce post-traumatic stress disorder-mediated heart diseases. BMC Med Genomics 2017; 10:67. [PMID: 29322921 PMCID: PMC5763504 DOI: 10.1186/s12920-017-0302-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background Although post-traumatic stress disorder (PTSD) is primarily a mental disorder, it can cause additional symptoms that do not seem to be directly related to the central nervous system, which PTSD is assumed to directly affect. PTSD-mediated heart diseases are some of such secondary disorders. In spite of the significant correlations between PTSD and heart diseases, spatial separation between the heart and brain (where PTSD is primarily active) prevents researchers from elucidating the mechanisms that bridge the two disorders. Our purpose was to identify genes linking PTSD and heart diseases. Methods In this study, gene expression profiles of various murine tissues observed under various types of stress or without stress were analyzed in an integrated manner using tensor decomposition (TD). Results Based upon the obtained features, ∼ 400 genes were identified as candidate genes that may mediate heart diseases associated with PTSD. Various gene enrichment analyses supported biological reliability of the identified genes. Ten genes encoding protein-, DNA-, or mRNA-interacting proteins—ILF2, ILF3, ESR1, ESR2, RAD21, HTT, ATF2, NR3C1, TP53, and TP63—were found to be likely to regulate expression of most of these ∼ 400 genes and therefore are candidate primary genes that cause PTSD-mediated heart diseases. Approximately 400 genes in the heart were also found to be strongly affected by various drugs whose known adverse effects are related to heart diseases and/or fear memory conditioning; these data support the reliability of our findings. Conclusions TD-based unsupervised feature extraction turned out to be a useful method for gene selection and successfully identified possible genes causing PTSD-mediated heart diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12920-017-0302-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Y-H Taguchi
- Department of Physics, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
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8
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Zhu Y, Feng J, Ji J, Hou H, Chen L, Wu S, Liu Q, Yao Q, Du P, Zhang K, Chen Q, Chen Z, Zhang H, Tian M. Alteration of Monoamine Receptor Activity and Glucose Metabolism in Pediatric Patients with Anticonvulsant-Induced Cognitive Impairment. J Nucl Med 2017; 58:1490-1497. [PMID: 28302757 DOI: 10.2967/jnumed.116.189290] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/27/2017] [Indexed: 01/03/2023] Open
Abstract
A landmark study from the Institute of Medicine reported that the assessment of cognitive difficulties in children with epilepsy is timely and imperative. Anticonvulsant-induced cognitive impairment could influence the quality of life more than seizure itself in patients. Although the monoaminergic system is involved in the regulation of cognitive process, its role in anticonvulsant-induced cognitive impairment remains unclear. Methods: To explore in vivo monoamine receptor binding activity in patients with anticonvulsant-induced cognitive impairment, each patient underwent PET imaging with both monoamine receptor binding agent 11C-N-methylspiperone and glucose metabolic agent 18F-FDG. Tests of intelligence quotient (IQ), including verbal IQ (VIQ), performance IQ (PIQ), and full-scale IQ (FSIQ), were performed in each patient. Results: Compared with the patients with monotherapy, patients with polytherapy had significantly lower VIQ, PIQ, and FSIQ (P < 0.01 in each comparison), as well as significantly lower monoamine receptor activities detected in the caudate nucleus, prefrontal cortex, dorsal anterior cingulate cortex, and amygdale (P < 0.05 in each comparison). However, regarding the glucose metabolism, there was no significant difference found in patients with monotherapy or polytherapy (P > 0.05). Conclusion: Monoamine receptor PET imaging could be a promising in vivo imaging biomarker for mapping anticonvulsant-induced cognitive impairment.
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Affiliation(s)
- Yuankai Zhu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Jianhua Feng
- Department of Paediatrics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China; and
| | - Jianfeng Ji
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Haifeng Hou
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Lin Chen
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Shuang Wu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qing Liu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qiong Yao
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Peizhen Du
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Kai Zhang
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qing Chen
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Zexin Chen
- Department of Clinical Epidemiology & Biostatistics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Hong Zhang
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Mei Tian
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China .,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
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Ghamkhari Nejad G, Shahabi P, Alipoor MR, Ghaderi Pakdel F, Asghari M, Sadighi Alvandi M. Ethosuximide Affects Paired-Pulse Facilitation in Somatosensory Cortex of WAG\Rij Rats as a Model of Absence Seizure. Adv Pharm Bull 2016; 5:483-9. [PMID: 26819920 DOI: 10.15171/apb.2015.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/28/2015] [Accepted: 07/27/2015] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The interaction between somatosensory cortex and thalamus via a thalamocortical loop is a theory behind induction of absence epilepsy. Inside peri-oral somatosensory (S1po) and primary somatosensory forelimb (S1fl) regions, excitatory and inhibitory systems are not balanced and GABAergic inhibitory synapses seem to play a fundamental role in short-term plasticity alterations. METHODS We investigated the effects of Ethosuximide on presynaptic changes by utilizing paired-pulse stimulation that was recorded from somatosensory cortex in 18 WAG\Rij rats during epileptic activity. A twisted tripolar electrode including two stimulating electrodes and one recording electrode was implanted into the S1po and S1FL according to stereotaxic landmarks. Paired-pulses (200 µs, 100-1000 µA, 0.1 Hz) were applied to somatosensory cortex at 50, 100, 400, 500 ms inter-pulse intervals for 50 min period. RESULTS The results showed that paired-pulse facilitation was significantly reduced at all intervals in all times, but compared to the control group of epileptic WAG/Rij rats (p<0.05), it was exceptional about the first 10 minutes after the injection. At the intervals of 50 and 100 ms, a remarkable PPD was found in second, third, fourth and fifth 10-min post injection. CONCLUSION These experiments indicate that Ethosuximide has effects on presynaptic facilitation in somatosensory cortex inhibitory loops by alteration in GABA levels that leads to a markedly diminished PPF in paired-pulse stimulation.
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Affiliation(s)
| | - Parviz Shahabi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohamad Reza Alipoor
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Firouz Ghaderi Pakdel
- Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Mohammad Asghari
- Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mina Sadighi Alvandi
- Drug Applied Research Center, Tabriz University of Medical Sciences,Tabriz, Iran
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Tiwari SK, Seth B, Agarwal S, Yadav A, Karmakar M, Gupta SK, Choubey V, Sharma A, Chaturvedi RK. Ethosuximide Induces Hippocampal Neurogenesis and Reverses Cognitive Deficits in an Amyloid-β Toxin-induced Alzheimer Rat Model via the Phosphatidylinositol 3-Kinase (PI3K)/Akt/Wnt/β-Catenin Pathway. J Biol Chem 2015; 290:28540-28558. [PMID: 26420483 DOI: 10.1074/jbc.m115.652586] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 01/20/2023] Open
Abstract
Neurogenesis involves generation of new neurons through finely tuned multistep processes, such as neural stem cell (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and subventricular zone. Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders, including Alzheimer disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizures. However, the effects of ETH on adult hippocampal neurogenesis and the underlying cellular and molecular mechanism(s) are yet unexplored. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation and adult hippocampal neurogenesis in an amyloid β (Aβ) toxin-induced rat model of AD-like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampus-derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation and reduced Aβ toxin-mediated toxicity and neurodegeneration, leading to behavioral recovery in the rat AD model. ETH inhibited Aβ-mediated suppression of neurogenic and Akt/Wnt/β-catenin pathway gene expression in the hippocampus. ETH activated the PI3K·Akt and Wnt·β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K·Akt and Wnt·β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1, and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K·Akt and Wnt·β-catenin signaling.
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Affiliation(s)
- Shashi Kant Tiwari
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Brashket Seth
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Swati Agarwal
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Anuradha Yadav
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Madhumita Karmakar
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Shailendra Kumar Gupta
- Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
| | - Vinay Choubey
- Department of Pharmacology, Centre of Excellence for Translational Medicine; University of Tartu, Tartu 50411, Estonia
| | - Abhay Sharma
- CSIR-Institute of Genomics and Integrative Biology, Sukhdev Vihar, Mathura Road, 110025 New Delhi, India.
| | - Rajnish Kumar Chaturvedi
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India
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Beker van Woudenberg A, Snel C, Rijkmans E, de Groot D, Bouma M, Hermsen S, Piersma A, Menke A, Wolterbeek A. Zebrafish embryotoxicity test for developmental (neuro)toxicity: Demo case of an integrated screening approach system using anti-epileptic drugs. Reprod Toxicol 2014; 49:101-16. [DOI: 10.1016/j.reprotox.2014.07.082] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 07/14/2014] [Accepted: 07/31/2014] [Indexed: 01/26/2023]
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Lack of behavioral and cognitive effects of chronic ethosuximide and gabapentin treatment in the Ts65Dn mouse model of Down syndrome. Neuroscience 2012; 220:158-68. [PMID: 22728103 DOI: 10.1016/j.neuroscience.2012.06.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/06/2012] [Accepted: 06/13/2012] [Indexed: 11/22/2022]
Abstract
The Ts65Dn (TS) mouse model of Down syndrome (DS) displays a number of behavioral, neuromorphological and neurochemical phenotypes of the syndrome. Altered GABAergic transmission appears to contribute to the mechanisms responsible for the cognitive impairments in TS mice. Increased functional expression of the trisomic gene encoding an inwardly rectifying potassium channel, subfamily J, member 6 (KCNJ6) has been reported in DS and TS mice, along with the consequent impairment in GAB Aergic function. Partial display of DS phenotypes in mice harboring a single trisomy of Kcnj6 provides compelling evidence for a functional role of increased channel expression in some of the abnormal neurological phenotypes found in DS. Notably, the antiepileptic drug (AED) ethosuximide (ETH), but not other AEDs such as gabapentin (GAB), is known to inhibit KCNJ6 channels in mice. Here, we report the effect of chronic ETH and GAB on the behavioral and cognitive phenotypes of TS and disomic control (CO) mice. Neither drug significantly affected sensorimotor abilities, motor coordination or spontaneous activity in TS and CO mice. Also, ETH and GAB did not induce anxiety in the open field or plus maze tests, did not alter performance in the Morris water maze, and did not affect cued - or context - fear conditioning. Our results thus suggest that KCNJ6 may not be a promising drug target candidate in DS. As a corollary, they also show that long-term use of ETH and GAB is devoid of adverse behavioral and cognitive effects.
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Greenhill SD, Morgan NH, Massey PV, Woodhall GL, Jones RSG. Ethosuximide modifies network excitability in the rat entorhinal cortex via an increase in GABA release. Neuropharmacology 2011; 62:807-14. [PMID: 21945797 DOI: 10.1016/j.neuropharm.2011.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 09/01/2011] [Accepted: 09/06/2011] [Indexed: 10/17/2022]
Abstract
Ethosuximide is the drug of choice for treating generalized absence seizures, but its mechanism of action is still a matter of debate. It has long been thought to act by disrupting a thalamic focus via blockade of T-type channels and, thus, generation of spike-wave activity in thalamocortical pathways. However, there is now good evidence that generalized absence seizures may be initiated at a cortical focus and that ethosuximide may target this focus. In the present study we have looked at the effect ethosuximide on glutamate and GABA release at synapses in the rat entorhinal cortex in vitro, using two experimental approaches. Whole-cell patch-clamp studies revealed an increase in spontaneous GABA release by ethosuximide concurrent with no change in glutamate release. This was reflected in studies that estimated global background inhibition and excitation from intracellularly recorded membrane potential fluctuations, where there was a substantial rise in the ratio of network inhibition to excitation, and a concurrent decrease in excitability of neurones embedded in this network. These studies suggest that, in addition to well-characterised effects on ion channels, ethosuximide may directly elevate synaptic inhibition in the cortex and that this could contribute to its anti-absence effects. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- Stuart D Greenhill
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK
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