1
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Garcia-Durillo M, Frenguelli BG. Antagonism of P2X7 receptors enhances lorazepam action in delaying seizure onset in an in vitro model of status epilepticus. Neuropharmacology 2023; 239:109647. [PMID: 37459909 DOI: 10.1016/j.neuropharm.2023.109647] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/19/2023] [Accepted: 06/24/2023] [Indexed: 08/06/2023]
Abstract
Approximately 30% of patients with status epilepticus (SE) become refractory to two or more antiseizure medications (ASMs). There is thus a real need to identify novel targets against which to develop new ASMs for treating this clinical emergency. Among purinergic receptors, the ionotropic ATP-gated P2X7 receptor (P2X7R) has received attention as a potential ASM target. This study evaluated the effect of the selective P2X7R antagonist A740003 on acute seizures in the dentate gyrus (DG) of hippocampal brain slices, where P2X7Rs are highly expressed, with a view to establishing the potential of P2X7R antagonists as a therapy or adjunct with lorazepam (LZP) in refractory SE. Extracellular electrophysiological recordings were made from the DG of male mouse hippocampal slices. Spontaneous seizure-like events (SLEs) were induced by removing extracellular Mg2+ and sequentially adding the K+ channel blocker 4-aminopyridine and the adenosine A1 receptor antagonist 8-cyclopentyltheophylline, during which the early and late application of A740003 and/or lorazepam was evaluated. Our study revealed that, in the absence of changes in mRNA for P2X7Rs or inflammatory markers, P2X7R antagonism did not reduce the frequency of SLEs. However, A740003 in conjunction with LZP delayed the onset of seizures. Furthermore, our results support the need for employing LZP before seizures become refractory during SE as delayed application of LZP increased seizure frequency. These studies reveal possible sites of intervention that could have a positive impact in patients with high risk of suffering SE.
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Affiliation(s)
| | - Bruno G Frenguelli
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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2
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Golub VM, Reddy DS. Post-Traumatic Epilepsy and Comorbidities: Advanced Models, Molecular Mechanisms, Biomarkers, and Novel Therapeutic Interventions. Pharmacol Rev 2022; 74:387-438. [PMID: 35302046 PMCID: PMC8973512 DOI: 10.1124/pharmrev.121.000375] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Post-traumatic epilepsy (PTE) is one of the most devastating long-term, network consequences of traumatic brain injury (TBI). There is currently no approved treatment that can prevent onset of spontaneous seizures associated with brain injury, and many cases of PTE are refractory to antiseizure medications. Post-traumatic epileptogenesis is an enduring process by which a normal brain exhibits hypersynchronous excitability after a head injury incident. Understanding the neural networks and molecular pathologies involved in epileptogenesis are key to preventing its development or modifying disease progression. In this article, we describe a critical appraisal of the current state of PTE research with an emphasis on experimental models, molecular mechanisms of post-traumatic epileptogenesis, potential biomarkers, and the burden of PTE-associated comorbidities. The goal of epilepsy research is to identify new therapeutic strategies that can prevent PTE development or interrupt the epileptogenic process and relieve associated neuropsychiatric comorbidities. Therefore, we also describe current preclinical and clinical data on the treatment of PTE sequelae. Differences in injury patterns, latency period, and biomarkers are outlined in the context of animal model validation, pathophysiology, seizure frequency, and behavior. Improving TBI recovery and preventing seizure onset are complex and challenging tasks; however, much progress has been made within this decade demonstrating disease modifying, anti-inflammatory, and neuroprotective strategies, suggesting this goal is pragmatic. Our understanding of PTE is continuously evolving, and improved preclinical models allow for accelerated testing of critically needed novel therapeutic interventions in military and civilian persons at high risk for PTE and its devastating comorbidities.
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Affiliation(s)
- Victoria M Golub
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
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3
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An On-Demand Drug Delivery System for Control of Epileptiform Seizures. Pharmaceutics 2022; 14:pharmaceutics14020468. [PMID: 35214199 PMCID: PMC8879600 DOI: 10.3390/pharmaceutics14020468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 02/03/2023] Open
Abstract
Drug delivery systems have the potential to deliver high concentrations of drug to target areas on demand, while elsewhere and at other times encapsulating the drug, to limit unwanted actions. Here we show proof of concept in vivo and ex vivo tests of a novel drug delivery system based on hollow-gold nanoparticles tethered to liposomes (HGN-liposomes), which become transiently permeable when activated by optical or acoustic stimulation. We show that laser or ultrasound simulation of HGN-liposomes loaded with the GABAA receptor agonist, muscimol, triggers rapid and repeatable release in a sufficient concentration to inhibit neurons and suppress seizure activity. In particular, laser-stimulated release of muscimol from previously injected HGN-liposomes caused subsecond hyperpolarizations of the membrane potential of hippocampal pyramidal neurons, measured by whole cell intracellular recordings with patch electrodes. In hippocampal slices and hippocampal–entorhinal cortical wedges, seizure activity was immediately suppressed by muscimol release from HGN-liposomes triggered by laser or ultrasound pulses. After intravenous injection of HGN-liposomes in whole anesthetized rats, ultrasound stimulation applied to the brain through the dura attenuated the seizure activity induced by pentylenetetrazol. Ultrasound alone, or HGN-liposomes without ultrasound stimulation, had no effect. Intracerebrally-injected HGN-liposomes containing kainic acid retained their contents for at least one week, without damage to surrounding tissue. Thus, we demonstrate the feasibility of precise temporal control over exposure of neurons to the drug, potentially enabling therapeutic effects without continuous exposure. For future application, studies on the pharmacokinetics, pharmacodynamics, and toxicity of HGN-liposomes and their constituents, together with improved methods of targeting, are needed, to determine the utility and safety of the technology in humans.
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4
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Chaihu plus Longgu Muli Decoction Alleviated Brain Injury in Pentylenetetrazole-Kindled Epileptic Mice by Regulating Cyclooxygenase-2/Prostaglandin E2/Multidrug Transporter Pathway. BIOMED RESEARCH INTERNATIONAL 2021. [DOI: 10.1155/2021/6652195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective. To evaluate the effect of CLMD administration on epileptic seizures and brain injury in pentylenetetrazole- (PZT-) kindled mice. Methods. The effect of pretreatment with CLMD (5, 10, and 20 ml/kg (mg/kg) by gavage) for seven days on PTZ-induced kindling, duration and grade of kindling-induced seizures, and pathological injury in the cortex and hippocampus was evaluated. Male BALB/c mice with adenosine A1 receptor knockout were subjected to intraperitoneal injection of PTZ (35 mg/kg) once every day until kindling was successfully induced. Quantitative reverse transcription polymerase chain reaction, immunofluorescence, and western blot were performed to assess the mRNA and protein levels of p-glycoprotein (PGP), multidrug resistance-associated protein 1 (MRP1), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and adenylate kinase (ADK) in the cortex and hippocampus. Results. PTZ successfully induced kindling in mice after 21 days, wherein CLMD showed an obvious dose-dependent antiepileptic effect. High-dose CLMD significantly increased the latency of epileptic seizures, decreased the sustained time of epileptic seizures and the seizure grade, and ameliorated the histopathological changes in the cortex and hippocampus. Furthermore, PTZ kindling induced significantly higher levels of PGP, MRP1, COX-2, PGE2, and ADK, but this effect was inhibited by pretreatment with CLMD in a dose-dependent manner. Conclusion. Pretreatment with CLMD attenuates PTZ-kindled convulsions and brain injury in mice. The mechanism may be related to the cyclooxygenase-2/prostaglandin E2/multidrug transporter pathway.
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5
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Juvale IIA, Che Has AT. Possible interplay between the theories of pharmacoresistant epilepsy. Eur J Neurosci 2020; 53:1998-2026. [PMID: 33306252 DOI: 10.1111/ejn.15079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/22/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023]
Abstract
Epilepsy is one of the oldest known neurological disorders and is characterized by recurrent seizure activity. It has a high incidence rate, affecting a broad demographic in both developed and developing countries. Comorbid conditions are frequent in patients with epilepsy and have detrimental effects on their quality of life. Current management options for epilepsy include the use of anti-epileptic drugs, surgery, or a ketogenic diet. However, more than 30% of patients diagnosed with epilepsy exhibit drug resistance to anti-epileptic drugs. Further, surgery and ketogenic diets do little to alleviate the symptoms of patients with pharmacoresistant epilepsy. Thus, there is an urgent need to understand the underlying mechanisms of pharmacoresistant epilepsy to design newer and more effective anti-epileptic drugs. Several theories of pharmacoresistant epilepsy have been suggested over the years, the most common being the gene variant hypothesis, network hypothesis, multidrug transporter hypothesis, and target hypothesis. In our review, we discuss the main theories of pharmacoresistant epilepsy and highlight a possible interconnection between their mechanisms that could lead to the development of novel therapies for pharmacoresistant epilepsy.
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Affiliation(s)
- Iman Imtiyaz Ahmed Juvale
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - Ahmad Tarmizi Che Has
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
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6
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Activity- and pH-dependent adenosine shifts at the end of a focal seizure in the entorhinal cortex. Epilepsy Res 2020; 165:106401. [PMID: 32599416 DOI: 10.1016/j.eplepsyres.2020.106401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/05/2020] [Accepted: 06/14/2020] [Indexed: 11/24/2022]
Abstract
Adenosine (ADO) is an endogenous modulator of neuronal excitability, with anticonvulsant and neuroprotective effects. It has been proposed that the activity-dependent release of ADO promoted by the extracellular acidification occurring during seizures contributes to seizure termination. To verify this hypothesis, we recorded field potentials, pH and ADO changes measured with enzymatic biosensors during acute focal seizures in the medial entorhinal cortex (mEC) of the isolated guinea-pig brain maintained in vitro. The effect of ADO on seizure-like events (SLEs) induced by GABAa receptor antagonism with bicuculline methiodide (BMI; 50 μM) was assessed by arterial applications of 1 mM ADO. ADO either reduced or prevented epileptiform activity. The A1 receptor antagonist DPCPX (100-500 μM) prolonged BMI-induced seizures and was able to precipitate SLEs in the absence of proconvulsant. Simultaneous recordings of brain activity, extracellular ADO and pH shifts demonstrated that ADO decreases at the onset and progressively rises toward the end of SLEs induced by either BMI or 4-aminopyridine (4AP; 50 μM), reaching maximal values 1-5 min after SLE termination. ADO changes were preceded by a SLE-dependent extracellular acid shift. Both pH acidification and ADO changes were abolished by 22 mM HEPES in the arterial perfusate. In these conditions, SLE duration was prolonged. Our data confirm that ADO plays a role in regulating brain excitability. Its increase depends on seizure-induced acid pH shift and it is maximal after the end of the SLE. These findings strongly suggest that ADO contributes to termination of focal seizures and to the establishment of the postictal depression.
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7
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Tescarollo FC, Rombo DM, DeLiberto LK, Fedele DE, Alharfoush E, Tomé ÂR, Cunha RA, Sebastião AM, Boison D. Role of Adenosine in Epilepsy and Seizures. J Caffeine Adenosine Res 2020; 10:45-60. [PMID: 32566903 DOI: 10.1089/caff.2019.0022] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Adenosine is an endogenous anticonvulsant and neuroprotectant of the brain. Seizure activity produces large quantities of adenosine, and it is this seizure-induced adenosine surge that normally stops a seizure. However, within the context of epilepsy, adenosine plays a wide spectrum of different roles. It not only controls seizures (ictogenesis), but also plays a major role in processes that turn a normal brain into an epileptic brain (epileptogenesis). It is involved in the control of abnormal synaptic plasticity and neurodegeneration and plays a major role in the expression of comorbid symptoms and complications of epilepsy, such as sudden unexpected death in epilepsy (SUDEP). Given the important role of adenosine in epilepsy, therapeutic strategies are in development with the goal to utilize adenosine augmentation not only for the suppression of seizures but also for disease modification and epilepsy prevention, as well as strategies to block adenosine A2A receptor overfunction associated with neurodegeneration. This review provides a comprehensive overview of the role of adenosine in epilepsy.
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Affiliation(s)
- Fabio C Tescarollo
- Deptartment of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Diogo M Rombo
- Faculty of Medicine, Institute of Pharmacology and Neurosciences, Lisbon, Portugal.,Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal
| | - Lindsay K DeLiberto
- Deptartment of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Denise E Fedele
- Deptartment of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Enmar Alharfoush
- Deptartment of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Ângelo R Tomé
- Faculty of Science and Technology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Ana M Sebastião
- Faculty of Medicine, Institute of Pharmacology and Neurosciences, Lisbon, Portugal.,Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal
| | - Detlev Boison
- Deptartment of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA.,Department of Neurosurgery, New Jersey Medical School, Rutgers University, Piscataway, New Jersey, USA
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8
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Ostroumova TM, Ostroumova OD, Akimova ES, Kochetkov AI. [Drug-induced seizures: prevalence, risk factors, treatment and prevention]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 119:86-97. [PMID: 31851178 DOI: 10.17116/jnevro201911911186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is a growing interest to the problem of drug-induced epileptic seizures (ES) due to their relatively high prevalence, poor prognosis, a large number of different drugs associated with the development of drug-induced ES, and low awareness among general practitioners. Drug-induced ES are most often associated with the use of antidepressants, antipsychotics, antiepileptic drugs (overdose or as a result of discontinuation), antibiotics, immunosuppressants and immunomodulators, antitumor agents, analgesics, central nervous system stimulators, anesthetics etc. The prevalence of drug-induced ES varies with different drugs. It is estimated that about 6.1% of the first occurring ES are drug-induced. Risk factors for drug-induced ES include a history of epilepsy or ES, cancer, blood-brain barrier dysfunction, several concomitant neurological diseases, mental disorders, childhood, old and very old age, fever, impaired liver metabolism in patients with liver diseases, impaired drug excretion in patients with kidney diseases, polypharmacy, pharmacokinetic properties of the drugs themselves, allowing them to penetrate the blood-brain barrier in the central nervous system (lipophilicity, transport and communication with blood plasma proteins), drug concentration in blood serum, method and frequency of drug administration, single and daily doses of drugs. No clinical guidelines for the management of patients with drug-induced ES are available. It is recommended to identify patients at risk: elderly patients, patients with impaired liver and kidney function and patients receiving drugs that can cause ES and/or lower the seizure threshold. Benzodiazepines are the first-line treatment in drug-induced status epilepticus, barbiturates and propofol are the second-line treatment. The general principles for the prevention of drug-induced ES include careful selection of the optimal dose of drugs that can cause ES, especially in patients with impaired liver and/or kidney function, monitoring of several parameters in blood serum (for example, liver enzymes, electrolytes, glucose etc.), monitoring of the blood plasma concentration of certain drugs, avoiding the simultaneous administration of several drugs that stimulate the central nervous system, and a rapid discontinuation of such drugs.
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Affiliation(s)
- T M Ostroumova
- Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation, Moscow,Russia
| | - O D Ostroumova
- Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation, Moscow,Russia; Pirogov Russian National Research Medical University' Russian Clinical and Research Center of Gerontology, Moscow, Russia
| | - E S Akimova
- Yevdokimov Moscow State University of Medicine and Dentistry, Moscow, Russia
| | - A I Kochetkov
- Pirogov Russian National Research Medical University' Russian Clinical and Research Center of Gerontology, Moscow, Russia
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9
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Kovács R, Gerevich Z, Friedman A, Otáhal J, Prager O, Gabriel S, Berndt N. Bioenergetic Mechanisms of Seizure Control. Front Cell Neurosci 2018; 12:335. [PMID: 30349461 PMCID: PMC6187982 DOI: 10.3389/fncel.2018.00335] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/12/2018] [Indexed: 12/14/2022] Open
Abstract
Epilepsy is characterized by the regular occurrence of seizures, which follow a stereotypical sequence of alterations in the electroencephalogram. Seizures are typically a self limiting phenomenon, concluding finally in the cessation of hypersynchronous activity and followed by a state of decreased neuronal excitability which might underlie the cognitive and psychological symptoms the patients experience in the wake of seizures. Many efforts have been devoted to understand how seizures spontaneously stop in hope to exploit this knowledge in anticonvulsant or neuroprotective therapies. Besides the alterations in ion-channels, transmitters and neuromodulators, the successive build up of disturbances in energy metabolism have been suggested as a mechanism for seizure termination. Energy metabolism and substrate supply of the brain are tightly regulated by different mechanisms called neurometabolic and neurovascular coupling. Here we summarize the current knowledge whether these mechanisms are sufficient to cover the energy demand of hypersynchronous activity and whether a mismatch between energy need and supply could contribute to seizure control.
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Affiliation(s)
- Richard Kovács
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Zoltan Gerevich
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel.,Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Jakub Otáhal
- Institute of Physiology, Czech Academy of Sciences, Prague, Czechia
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Siegrun Gabriel
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Nikolaus Berndt
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Biochemie, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute for Computational and Imaging Science in Cardiovascular Medicine, Berlin, Germany
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10
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Hall J, Frenguelli BG. The combination of ribose and adenine promotes adenosine release and attenuates the intensity and frequency of epileptiform activity in hippocampal slices: Evidence for the rapid depletion of cellular ATP during electrographic seizures. J Neurochem 2018; 147:178-189. [PMID: 29964329 PMCID: PMC6220757 DOI: 10.1111/jnc.14543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 06/05/2018] [Accepted: 06/28/2018] [Indexed: 12/25/2022]
Abstract
In addition to being the universal cellular energy source, ATP is the primary reservoir for the neuromodulator adenosine. Consequently, adenosine is produced during ATP-depleting conditions, such as epileptic seizures, during which adenosine acts as an anticonvulsant to terminate seizure activity and raise the threshold for subsequent seizures. These actions protect neurones from excessive ionic fluxes and hence preserve the remaining cellular content of ATP. We have investigated the consequences of manipulation of intracellular ATP levels on adenosine release and epileptiform activity in hippocampal slices by pre-incubating slices (3 h) with creatine (1 mM) and the combination of ribose (1 mM) and adenine (50 μM; RibAde). Creatine buffers and protects the concentration of cellular ATP, whereas RibAde restores the reduced cellular ATP in brain slices to near physiological levels. Using electrophysiological recordings and microelectrode biosensors for adenosine, we find that, while having no effect on basal synaptic transmission or paired-pulse facilitation, pre-incubation with creatine reduced adenosine release during Mg2+- free/4-aminopyridine-induced electrographic seizure activity, whereas RibAde increased adenosine release. This increased release of adenosine was associated with an attenuation of both the intensity and frequency of seizure activity. Given the depletion of ATP after injury to the brain, the propensity for seizures after trauma and the risk of epileptogenesis, therapeutic strategies elevating the cellular reservoir of adenosine may have value in the traumatized brain. Ribose and adenine are both in use in man and thus their combination merits consideration as a potential therapeutic for the acutely injured central nervous system.
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Affiliation(s)
- Jessicka Hall
- School of Life SciencesThe University of WarwickCoventryUK
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11
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Attenuation of pentylenetrazole-induced acute status epilepticus in rats by adenosine involves inhibition of the mammalian target of rapamycin pathway. Neuroreport 2018; 28:1016-1021. [PMID: 28902712 DOI: 10.1097/wnr.0000000000000878] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Adenosine (ADO) has been characterized as an endogenous anticonvulsant and alternative therapeutic drug, but its mechanism is not entirely clear. This study aimed to examine the relationship of ADO with the mammalian target of rapamycin (mTOR) in a Wistar rat model of pentylenetetrazole (PTZ)-induced acute status epilepticus. ADO (200 mg/kg) was administered intraperitoneally 30 min before PTZ (55-65 mg/kg) treatment, and Western blot assays and immunohistochemistry were performed 3 h after the onset of acute status epilepticus to detect phospho-TOR and the downstream target of mTOR, phospho-S6. The expression of these phosphoproteins in the hippocampus was significantly increased in PTZ-treated rats, but this increase was attenuated by the addition of ADO. To further verify a role for ADO in attenuating mTOR activity, we also evaluated its ability to suppress mTOR activity in normal rats that were not treated with PTZ. Our results suggest that ADO suppresses mTOR and S6 phosphorylation in normal rats and that this suppression can be reversed by the application of Compound C, an inhibitor of AMP-activated protein kinase, which functions as an upstream suppressor of the mTOR pathway. Thus, our results provide a novel antiepileptic mechanism for ADO in suppressing mTOR pathway activation upon PTZ-induced acute status epilepticus.
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12
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Lambertucci C, Marucci G, Dal Ben D, Buccioni M, Spinaci A, Kachler S, Klotz KN, Volpini R. New potent and selective A 1 adenosine receptor antagonists as potential tools for the treatment of gastrointestinal diseases. Eur J Med Chem 2018; 151:199-213. [PMID: 29614417 DOI: 10.1016/j.ejmech.2018.03.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 01/31/2023]
Abstract
The synthesis of 9-alkyl substituted adenine derivatives presenting aromatic groups and cycloalkyl rings in 8- and N6-position, respectively, is reported. The compounds were tested with radioligand binding studies showing, in some cases, a low nanomolar A1 adenosine receptor affinity and a very good selectivity versus the other adenosine receptor subtypes. Functional assays at human adenosine receptors and at a mouse ileum tissue preparation clearly demonstrate the antagonist profile of these molecules, with inhibitory potency at nanomolar level. A molecular modeling study, consisting in docking analysis at the recently reported A1 adenosine receptor crystal structure, was performed for the interpretation of the obtained pharmacological results. The N6-cyclopentyl-9-methyl-8-phenyladenine (17), resulting the most active derivative of the series (Ki = 2.8 nM and IC50 = 14 nM), was also very efficacious in counteracting the effect of the agonist CCPA on mouse ileum contractility. This new compound represents a tool for the development of new agents for the treatment of intestinal diseases as constipation and postoperative ileus.
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Affiliation(s)
- Catia Lambertucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy
| | - Gabriella Marucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy
| | - Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy
| | - Michela Buccioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy
| | - Andrea Spinaci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy
| | - Sonja Kachler
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Karl-Norbert Klotz
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | - Rosaria Volpini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy.
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13
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Nitrobenzylthioinosine mimics adenosine to attenuate the epileptiform discharge of hippocampal neurons from epileptic rats. Oncotarget 2018; 8:35573-35582. [PMID: 28415676 PMCID: PMC5482599 DOI: 10.18632/oncotarget.16012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/21/2022] Open
Abstract
Nitrobenzylthioinosine (NBTI), a specific inhibitor of type 1 equilibrative nucleoside transporter, could regulate the extracellular adenosine concentration and have protective roles in seizures. However, the protection mechanism of NBTI in seizures remains poorly understood. Here, the expression pattern and subcellular distribution of adenosine A1 receptor were detected by Western blot analysis and double-labeling immunofluorescence staining in Lithium Chloride-Pilocarpine induced epileptic rat model. At 24 h after pilocarpine induced rat seizures, hippocampal slices were prepared and the evoked excitatory postsynaptic currents (eEPSCs) amplitude of pyramidal neurons in hippocampus CA1 region was recorded using whole-cell patch clamp. In vivo, compared to control group, Western blotting analysis showed that the expression of adenosine A1 receptor protein was increased at 24 h and 72 h after seizure, didn't change at 0 min and 1 w, and decreased at 2 w. Double-label immunofluorescence revealed that adenosine A1 receptor was mainly expressed in the membrane and cytoplasm of neurons. In Vitro, adenosine decreased the eEPSCs amplitude of pyramidal neurons in hippocampus CA1 region, NBTI also had the same effect. Meantime, NBTI could further inhibit eEPSCs amplitude on the basis of lower concentration adenosine (50μM), and adenosine A1 receptor inhibitor DPCPX partially reversed this effect. Taken together, we confirmed that the expression of adenosine A1 receptor protein was increased in the early seizures and decreased in the late seizures. At the same time, NBTI mimics adenosine to attenuate the epileptiform discharge through adenosine A1 receptor, which might provide a novel therapeutic approach toward the control of epilepsy.
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14
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Raimondo JV, Heinemann U, de Curtis M, Goodkin HP, Dulla CG, Janigro D, Ikeda A, Lin CCK, Jiruska P, Galanopoulou AS, Bernard C. Methodological standards for in vitro models of epilepsy and epileptic seizures. A TASK1-WG4 report of the AES/ILAE Translational Task Force of the ILAE. Epilepsia 2017; 58 Suppl 4:40-52. [PMID: 29105075 DOI: 10.1111/epi.13901] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2017] [Indexed: 01/02/2023]
Abstract
In vitro preparations are a powerful tool to explore the mechanisms and processes underlying epileptogenesis and ictogenesis. In this review, we critically review the numerous in vitro methodologies utilized in epilepsy research. We provide support for the inclusion of detailed descriptions of techniques, including often ignored parameters with unpredictable yet significant effects on study reproducibility and outcomes. In addition, we explore how recent developments in brain slice preparation relate to their use as models of epileptic activity.
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Affiliation(s)
- Joseph V Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Uwe Heinemann
- Neuroscience Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Marco de Curtis
- Epilepsy and Experimental Neurophysiology Unit, The Foundation of the Carlo Besta Neurological Institute, Milan, Italy
| | - Howard P Goodkin
- Departments of Neurology and Pediatrics, University of Virginia, Charlottesville, Virginia, U.S.A
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, U.S.A
| | - Damir Janigro
- Flocel Inc., Cleveland, Ohio, U.S.A.,Case Western Reserve University, Cleveland, Ohio, U.S.A
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Chou-Ching K Lin
- Department of Neurology, College of Medicine and Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Premysl Jiruska
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Aristea S Galanopoulou
- Laboratory of Developmental Epilepsy, Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Einstein/Montefiore Epilepsy Center, Montefiore Medical Center, Bronx, New York, U.S.A
| | - Christophe Bernard
- Inserm, Institut de Neurosciences des Systemes UMRS 1106, Aix Marseille University, Marseille, France
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15
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Zhou Q, Zhu S, Guo Y, Lian L, Hu Q, Liu X, Xu F, Zhang N, Kang H. Adenosine A1 Receptors Play an Important Protective Role Against Cognitive Impairment and Long-Term Potentiation Inhibition in a Pentylenetetrazol Mouse Model of Epilepsy. Mol Neurobiol 2017; 55:3316-3327. [PMID: 28492982 DOI: 10.1007/s12035-017-0571-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/21/2017] [Indexed: 12/20/2022]
Abstract
Epilepsy is a complicated neurological disorder that occurs worldwide and features several kinds of comorbidities in addition to recurrent seizures. One of the most common comorbidities is cognitive impairment, which seriously affects patients' quality of life. Through activating pre- and postsynaptic adenosine A1 receptors (A1Rs), adenosine has demonstrated anticonvulsant and neuroprotective effects in many epileptic animal models. However, whether the neuroprotective effect of A1Rs will protect cognition during epileptogenesis remains unknown. Therefore, by using A1R knockout (KO) mice and establishing a pentylenetetrazole (PTZ)-kindled model of epilepsy, the present study investigated A1Rs' influences on memory and synaptic function. Morris water maze test results indicated that A1R knockout exacerbated the memory impairment induced by PTZ kindling compared with the wild-type group. To further study the synaptic function of epileptic A1Rs KO mice, we recorded long-term potentiation (LTP) in the hippocampal CA3-CA1 pathway, and LTP was highly inhibited in kindled A1R KO mice compared with kindled wild-type mice. To reveal the mechanisms underlying these effects, neuronal loss, cell apoptosis, and relevant synaptic protein levels in hippocampus were assessed. Epileptic A1R KO mice exhibited significant reductions in neuronal cell survival in the CA1 region and a marked increase in the activation of caspase-3 in the hippocampus compared with epileptic wild-type mice. In addition, an obvious decrease in the PSD95 and BDNF expression levels of epileptic A1R KO mice was observed 7 days after complete kindling. In conclusion, these findings indicated that A1Rs play an important protective role against cognitive impairment by reducing neuron loss and increasing BDNF and PSD95 levels. Activation of A1Rs during epileptogenesis might be beneficial to the preservation of epileptic individuals' cognitive functions.
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Affiliation(s)
- Qing Zhou
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Yuchen Guo
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Lifei Lian
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Qi Hu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Xiaoyan Liu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Feng Xu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Na Zhang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Huicong Kang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China.
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16
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Rassendren F, Audinat E. Purinergic signaling in epilepsy. J Neurosci Res 2016; 94:781-93. [PMID: 27302739 DOI: 10.1002/jnr.23770] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 12/24/2022]
Abstract
Until recently, analysis of the mechanisms underlying epilepsy was centered on neuron dysfunctions. Accordingly, most of the available pharmacological treatments aim at reducing neuronal excitation or at potentiating neuronal inhibition. These therapeutic options can lead to obvious secondary effects, and, moreover, seizures cannot be controlled by any known medication in one-third of the patients. A purely neurocentric view of brain functions and dysfunctions has been seriously questioned during the past 2 decades because of the accumulation of experimental data showing the functional importance of reciprocal interactions between glial cells and neurons. In the case of epilepsy, our current knowledge of the human disease and analysis of animal models clearly favor the involvement of astrocytes and microglial cells during the progression of the disease, including at very early stages, opening the way to the identification of new therapeutic targets. Purinergic signaling is a fundamental feature of neuron-glia interactions, and increasing evidence indicates that modifications of this pathway contribute to the functional remodeling of the epileptic brain. This Review discusses the recent experimental results indicating the roles of astrocytic and microglial P2X and P2Y receptors in epilepsy. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- François Rassendren
- CNRS, UMR 5203, Institut de Génomique Fonctionnelle, Montpellier, France.,INSERM, U1191, Montpellier, France.,Université de Montpellier, UMR5203, Montpellier, France.,Labex ICST, Montpellier, France
| | - Etienne Audinat
- INSERM, U1128, Paris, France.,Laboratory of Neurophysiology and New Microscopies, Paris Descartes University, Paris, France
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17
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Klaft ZJ, Hollnagel JO, Salar S, Calişkan G, Schulz SB, Schneider UC, Horn P, Koch A, Holtkamp M, Gabriel S, Gerevich Z, Heinemann U. Adenosine A1 receptor-mediated suppression of carbamazepine-resistant seizure-like events in human neocortical slices. Epilepsia 2016; 57:746-56. [PMID: 27087530 DOI: 10.1111/epi.13360] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The need for alternative pharmacologic strategies in treatment of epilepsies is pressing for about 30% of patients with epilepsy who do not experience satisfactory seizure control with present treatments. In temporal lobe epilepsy (TLE) even up to 80% of patients are pharmacoresistant, and surgical resection of the ictogenic tissue is only possible for a minority of TLE patients. In this study we investigate purinergic modulation of drug-resistant seizure-like events (SLEs) in human temporal cortex slices. METHODS Layer V/VI field potentials from a total of 77 neocortical slices from 17 pharmacoresistant patients were recorded to monitor SLEs induced by application of 8 mM [K(+) ] and 50 μm bicuculline. RESULTS Activating A1 receptors with a specific agonist completely suppressed SLEs in 73% of human temporal cortex slices. In the remaining slices, incidence of SLEs was markedly reduced. Because a subportion of slices can be pharmacosensitive, we tested effects of an A1 agonist, in slices insensitive to a high dose of carbamazepine (50 μm). Also in these cases the A1 agonist was equally efficient. Moreover, ATP and adenosine blocked or modulated SLEs, an effect mediated not by P2 receptors but rather by adenosine A1 receptors. SIGNIFICANCE Selective activation of A1 receptors mediates a strong anticonvulsant action in human neocortical slices from pharmacoresistant patients. We propose that our human slice model of seizure-like activity is a feasible option for future studies investigating new antiepileptic drug (AED) candidates.
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Affiliation(s)
- Zin-Juan Klaft
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jan-Oliver Hollnagel
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Seda Salar
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gürsel Calişkan
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Steffen B Schulz
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ulf C Schneider
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Horn
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Arend Koch
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Holtkamp
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Krankenhaus Königin Elisabeth Herzberge, Berlin, Germany
| | - Siegrun Gabriel
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Zoltan Gerevich
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Uwe Heinemann
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
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18
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Chen HY, Albertson TE, Olson KR. Treatment of drug-induced seizures. Br J Clin Pharmacol 2015; 81:412-9. [PMID: 26174744 DOI: 10.1111/bcp.12720] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 01/01/2023] Open
Abstract
Seizures are a common complication of drug intoxication, and up to 9% of status epilepticus cases are caused by a drug or poison. While the specific drugs associated with drug-induced seizures may vary by geography and change over time, common reported causes include antidepressants, stimulants and antihistamines. Seizures occur generally as a result of inadequate inhibitory influences (e.g., gamma aminobutyric acid, GABA) or excessive excitatory stimulation (e.g. glutamate) although many other neurotransmitters play a role. Most drug-induced seizures are self-limited. However, status epilepticus occurs in up to 10% of cases. Prolonged or recurrent seizures can lead to serious complications and require vigorous supportive care and anticonvulsant drugs. Benzodiazepines are generally accepted as the first line anticonvulsant therapy for drug-induced seizures. If benzodiazepines fail to halt seizures promptly, second line drugs include barbiturates and propofol. If isoniazid poisoning is a possibility, pyridoxine is given. Continuous infusion of one or more anticonvulsants may be required in refractory status epilepticus. There is no role for phenytoin in the treatment of drug-induced seizures. The potential role of ketamine and levetiracetam is promising but not established.
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Affiliation(s)
- Hsien-Yi Chen
- California Poison Control System, Department of Clinical Pharmacy, University of California, San Francisco, USA.,Department of Emergency Medicine, Chang-Gung Memorial Hospital, Taoyuan, Taiwan.,Division of Clinical Pharmacology & Toxicology, San Francisco General Hospital, San Francisco, USA
| | - Timothy E Albertson
- California Poison Control System, Department of Clinical Pharmacy, University of California, San Francisco, USA.,Department of Internal Medicine, University of California Davis School of Medicine and Veterans Administration Northern California Health Care System, California
| | - Kent R Olson
- California Poison Control System, Department of Clinical Pharmacy, University of California, San Francisco, USA.,Division of Clinical Pharmacology & Toxicology, San Francisco General Hospital, San Francisco, USA
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19
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Pannexin-1-mediated ATP release from area CA3 drives mGlu5-dependent neuronal oscillations. Neuropharmacology 2015; 93:219-28. [PMID: 25645390 DOI: 10.1016/j.neuropharm.2015.01.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 02/08/2023]
Abstract
The activation of Group I metabotropic glutamate receptors (GI mGluRs) in the hippocampus results in the appearance of persistent bursts of synchronised neuronal activity. In response to other stimuli, such activity is known to cause the release of the purines ATP and its neuroactive metabolite, adenosine. We have thus investigated the potential release and role of the purines during GI mGluR-induced oscillations in rat hippocampal areas CA3 and CA1 using pharmacological techniques and microelectrode biosensors for ATP and adenosine. The GI mGluR agonist DHPG induced both persistent oscillations in neuronal activity and the release of adenosine in areas CA1 and CA3. In contrast, the DHPG-induced release of ATP was only observed in area CA3. Whilst adenosine acting at adenosine A1 receptors suppressed DHPG-induced burst activity, the activation of mGlu5 and P2Y1 ATP receptors were necessary for the induction of DHPG-induced oscillations. Selective inhibition of pannexin-1 hemichannels with a low concentration of carbenoxolone (10 μM) or probenecid (1 mM) did not affect adenosine release in area CA3, but prevented both ATP release in area CA3 and DHPG-induced bursting. These data reveal key aspects of GI mGluR-dependent neuronal activity that are subject to bidirectional regulation by ATP and adenosine in the initiation and pacing of burst firing, respectively, and which have implications for the role of GI mGluRs in seizure activity and neurodevelopmental disorders.
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20
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Miranda MF, Hamani C, de Almeida ACG, Amorim BO, Macedo CE, Fernandes MJS, Nobrega JN, Aarão MC, Madureira AP, Rodrigues AM, Andersen ML, Tufik S, Mello LE, Covolan L. Role of adenosine in the antiepileptic effects of deep brain stimulation. Front Cell Neurosci 2014; 8:312. [PMID: 25324724 PMCID: PMC4183090 DOI: 10.3389/fncel.2014.00312] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 09/17/2014] [Indexed: 12/20/2022] Open
Abstract
Despite the effectiveness of anterior thalamic nucleus (AN) deep brain stimulation (DBS) for the treatment of epilepsy, mechanisms responsible for the antiepileptic effects of this therapy remain elusive. As adenosine modulates neuronal excitability and seizure activity in animal models, we hypothesized that this nucleoside could be one of the substrates involved in the effects of AN DBS. We applied 5 days of stimulation to rats rendered chronically epileptic by pilocarpine injections and recorded epileptiform activity in hippocampal slices. We found that slices from animals given DBS had reduced hippocampal excitability and were less susceptible to develop ictal activity. In live animals, AN DBS significantly increased adenosine levels in the hippocampus as measured by microdialysis. The reduced excitability of DBS in vitro was completely abolished in animals pre-treated with A1 receptor antagonists and was strongly potentiated by A1 receptor agonists. We conclude that some of the antiepileptic effects of DBS may be mediated by adenosine.
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Affiliation(s)
- Maisa F Miranda
- Laboratório de Neurociência Experimental e Computacional, Universidade Federal de São João del-Rei São João del-Rei, Brazil
| | - Clement Hamani
- Disciplina de Neurofisiologia, Universidade Federal de São Paulo São Paulo, Brazil ; Behavioural Neurobiology Laboratory, Centre for Addiction and Mental Health Toronto, Canada ; Division of Neurosurgery, Toronto Western Hospital, University of Toronto Toronto, Canada
| | - Antônio-Carlos G de Almeida
- Laboratório de Neurociência Experimental e Computacional, Universidade Federal de São João del-Rei São João del-Rei, Brazil
| | - Beatriz O Amorim
- Disciplina de Neurofisiologia, Universidade Federal de São Paulo São Paulo, Brazil
| | - Carlos E Macedo
- Departamento de Psicobiologia, Universidade Federal de São Paulo São Paulo, Brazil
| | - Maria José S Fernandes
- Disciplina de Neurologia Experimental, Universidade Federal de São Paulo São Paulo, Brazil
| | - José N Nobrega
- Behavioural Neurobiology Laboratory, Centre for Addiction and Mental Health Toronto, Canada
| | - Mayra C Aarão
- Laboratório de Neurociência Experimental e Computacional, Universidade Federal de São João del-Rei São João del-Rei, Brazil
| | - Ana Paula Madureira
- Laboratório de Neurociência Experimental e Computacional, Universidade Federal de São João del-Rei São João del-Rei, Brazil
| | - Antônio M Rodrigues
- Laboratório de Neurociência Experimental e Computacional, Universidade Federal de São João del-Rei São João del-Rei, Brazil
| | - Monica L Andersen
- Departamento de Psicobiologia, Universidade Federal de São Paulo São Paulo, Brazil
| | - Sergio Tufik
- Departamento de Psicobiologia, Universidade Federal de São Paulo São Paulo, Brazil
| | - Luiz E Mello
- Disciplina de Neurofisiologia, Universidade Federal de São Paulo São Paulo, Brazil
| | - Luciene Covolan
- Disciplina de Neurofisiologia, Universidade Federal de São Paulo São Paulo, Brazil
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21
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Van Gompel JJ, Bower MR, Worrell GA, Stead M, Chang SY, Goerss SJ, Kim I, Bennet KE, Meyer FB, Marsh WR, Blaha CD, Lee KH. Increased cortical extracellular adenosine correlates with seizure termination. Epilepsia 2014; 55:233-44. [PMID: 24483230 DOI: 10.1111/epi.12511] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2013] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Seizures are currently defined by their electrographic features. However, neuronal networks are intrinsically dependent on neurotransmitters of which little is known regarding their periictal dynamics. Evidence supports adenosine as having a prominent role in seizure termination, as its administration can terminate and reduce seizures in animal models. Furthermore, microdialysis studies in humans suggest that adenosine is elevated periictally, but the relationship to the seizure is obscured by its temporal measurement limitations. Because electrochemical techniques can provide vastly superior temporal resolution, we test the hypothesis that extracellular adenosine concentrations rise during seizure termination in an animal model and humans using electrochemistry. METHODS White farm swine (n = 45) were used in an acute cortical model of epilepsy, and 10 human epilepsy patients were studied during intraoperative electrocorticography (ECoG). Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS)-based fast scan cyclic voltammetry (FSCV) and fixed potential amperometry were obtained utilizing an adenosine-specific triangular waveform or biosensors, respectively. RESULTS Simultaneous ECoG and electrochemistry demonstrated an average adenosine increase of 260% compared to baseline, at 7.5 ± 16.9 s with amperometry (n = 75 events) and 2.6 ± 11.2 s with FSCV (n = 15 events) prior to electrographic seizure termination. In agreement with these animal data, adenosine elevation prior to seizure termination in a human patient utilizing FSCV was also seen. SIGNIFICANCE Simultaneous ECoG and electrochemical recording supports the hypothesis that adenosine rises prior to seizure termination, suggesting that adenosine itself may be responsible for seizure termination. Future work using intraoperative WINCS-based FSCV recording may help to elucidate the precise relationship between adenosine and seizure termination.
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Affiliation(s)
- Jamie J Van Gompel
- Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, U.S.A
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22
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Masino SA, Kawamura M, Ruskin DN. Adenosine receptors and epilepsy: current evidence and future potential. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 119:233-55. [PMID: 25175969 PMCID: PMC6026023 DOI: 10.1016/b978-0-12-801022-8.00011-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Adenosine receptors are a powerful therapeutic target for regulating epileptic seizures. As a homeostatic bioenergetic network regulator, adenosine is perfectly suited to establish or restore an ongoing balance between excitation and inhibition, and its anticonvulsant efficacy is well established. There is evidence for the involvement of multiple adenosine receptor subtypes in epilepsy, but in particular the adenosine A1 receptor subtype can powerfully and bidirectionally regulate seizure activity. Mechanisms that regulate adenosine itself are increasingly appreciated as targets to thus influence receptor activity and seizure propensity. Taken together, established evidence for the powerful potential of adenosine-based epilepsy therapies and new strategies to influence receptor activity can combine to capitalize on this endogenous homeostatic neuromodulator.
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Affiliation(s)
- Susan A Masino
- Department of Psychology and Neuroscience Program, Trinity College, Hartford, Connecticut, USA.
| | - Masahito Kawamura
- Department of Pharmacology, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - David N Ruskin
- Department of Psychology and Neuroscience Program, Trinity College, Hartford, Connecticut, USA
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23
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Wang S, Kurada L, Cilz NI, Chen X, Xiao Z, Dong H, Lei S. Adenosinergic depression of glutamatergic transmission in the entorhinal cortex of juvenile rats via reduction of glutamate release probability and the number of releasable vesicles. PLoS One 2013; 8:e62185. [PMID: 23614032 PMCID: PMC3628342 DOI: 10.1371/journal.pone.0062185] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/19/2013] [Indexed: 02/05/2023] Open
Abstract
Adenosine is an inhibitory neuromodulator that exerts antiepileptic effects in the brain and the entorhinal cortex (EC) is an essential structure involved in temporal lobe epilepsy. Whereas microinjection of adenosine into the EC has been shown to exert powerful antiepileptic effects, the underlying cellular and molecular mechanisms in the EC have not been determined yet. We tested the hypothesis that adenosine-mediated modulation of synaptic transmission contributes to its antiepileptic effects in the EC. Our results demonstrate that adenosine reversibly inhibited glutamatergic transmission via activation of adenosine A1 receptors without effects on GABAergic transmission in layer III pyramidal neurons in the EC. Adenosine-induced depression of glutamatergic transmission was mediated by inhibiting presynaptic glutamate release probability and decreasing the number of readily releasable vesicles. Bath application of adenosine also reduced the frequency of the miniature EPSCs recorded in the presence of TTX suggesting that adenosine may interact with the exocytosis processes downstream of Ca2+ influx. Both Gαi/o proteins and the protein kinase A pathway were required for adenosine-induced depression of glutamatergic transmission. We further showed that bath application of picrotoxin to the EC slices induced stable epileptiform activity and bath application of adenosine dose-dependently inhibited the epileptiform activity in this seizure model. Adenosine-mediated depression of epileptiform activity was mediated by activation of adenosine A1 receptors and required the functions of Gαi/o proteins and protein kinase A pathway. Our results suggest that the depression of glutamatergic transmission induced by adenosine contributes to its antiepileptic effects in the EC.
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Affiliation(s)
- Shouping Wang
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, P.R. China
| | - Lalitha Kurada
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Nicholas I. Cilz
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Xiaotong Chen
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
- Department of Emergency Medicine, Sun Yat-sen Memorial hospital, Sun Yat-sen University, Guangzhou, P.R. China
| | - Zhaoyang Xiao
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, P.R. China
| | - Hailong Dong
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, P.R. China
| | - Saobo Lei
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
- * E-mail:
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24
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Shinohara M, Saitoh M, Nishizawa D, Ikeda K, Hirose S, Takanashi JI, Takita J, Kikuchi K, Kubota M, Yamanaka G, Shiihara T, Kumakura A, Kikuchi M, Toyoshima M, Goto T, Yamanouchi H, Mizuguchi M. ADORA2A polymorphism predisposes children to encephalopathy with febrile status epilepticus. Neurology 2013; 80:1571-6. [PMID: 23535492 DOI: 10.1212/wnl.0b013e31828f18d8] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a childhood encephalopathy following severe febrile seizures, leaving neurologic sequelae in many patients. However, its pathogenesis remains unclear. In this study, we clarified that genetic variation in the adenosine A2A receptor (ADORA2A), whose activation is involved in excitotoxicity, may be a predisposing factor of AESD. METHODS We analyzed 4 ADORA2A single nucleotide polymorphisms in 85 patients with AESD. The mRNA expression in brain samples, mRNA and protein expression in lymphoblasts, as well as the production of cyclic adenosine monophosphate (cAMP) by lymphoblasts in response to adenosine were compared among ADORA2A diplotypes. RESULTS Four single nucleotide polymorphisms were completely linked, which resulted in 2 haplotypes, A and B. Haplotype A (C at rs2298383, T at rs5751876, deletion at rs35320474, and C at rs4822492) frequency in patients was significantly higher than in controls (p = 0.005). Homozygous haplotype A (AA diplotype) had a higher risk of developing AESD (odds ratio 2.32, 95% confidence interval 1.32-4.08; p = 0.003) via a recessive model. mRNA expression was significantly higher in AA than AB and BB diplotypes, both in the brain (p = 0.003 and 0.002, respectively) and lymphoblasts (p = 0.035 and 0.003, respectively). In lymphoblasts, ADORA2A protein expression (p = 0.024), as well as cellular cAMP production (p = 0.0006), was significantly higher in AA than BB diplotype. CONCLUSIONS AA diplotype of ADORA2A is associated with AESD and may alter the intracellular adenosine/cAMP cascade, thereby promoting seizures and excitotoxic brain damage in patients.
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Affiliation(s)
- Mayu Shinohara
- Department of Developmental Medical Sciences, Graduate School of Medicine, University of Tokyo, Japan
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Gottlieb SS, Ticho B, Deykin A, Abraham WT, DeNofrio D, Russell SD, Chapman D, Smith W, Goldman S, Thomas I. Effects of BG9928, an Adenosine A1Receptor Antagonist, in Patients With Congestive Heart Failure. J Clin Pharmacol 2013; 51:899-907. [DOI: 10.1177/0091270010375957] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Klaft ZJ, Schulz SB, Maslarova A, Gabriel S, Heinemann U, Gerevich Z. Extracellular ATP differentially affects epileptiform activity via purinergic P2X7 and adenosine A1 receptors in naive and chronic epileptic rats. Epilepsia 2012; 53:1978-86. [PMID: 23106524 DOI: 10.1111/j.1528-1167.2012.03724.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE Adenosine is considered an endogenous anticonvulsant. However, much less is known about the putative effects of its precursor, ATP, on epilepsy. Therefore, we tested whether ATP and its receptors are able to modulate epileptiform activity in the medial entorhinal cortex of the rat. METHODS Recurrent epileptiform discharges (REDs) were induced by elevating extracellular potassium concentration combined with application of bicuculline in brain slices from naive and pilocarpine-treated chronic epileptic rats. Field potentials were recorded from layer V/VI of the medial entorhinal cortex. KEY FINDINGS REDs in slices from naive animals had a higher incidence and a shorter duration than in slices from chronic epileptic animals. Exogenous application of ATP reversibly reduced the incidence of REDs in naive and chronic epileptic slices via activation of adenosine A(1) receptors without discernible P2 receptor effects. This effect was stronger in slices from chronic epileptic rats. In slices from naive rats, the P2X7 receptor antagonist A 740003 slightly but significantly reduced the amplitude of slow field potentials of REDs. In slices from chronic epileptic rats, none of the P2 receptor antagonists affected the parameters of REDs. SIGNIFICANCE Our results suggest that endogenously released ATP differentially modulates REDs by activation of A(1) and P2X7 receptors. Although it has a minor proepileptic effect by direct activation of P2X7 receptors, its metabolite adenosine reduces the epileptiform activity via activation of A(1) receptors. The exact effect of ATP on neural activity depends on the actual activity of ectonucleotidases and the expression level of the purinergic receptors, which both alter during epileptogenesis. In addition, our data suggest that P2X7 receptor antagonists have a minor antiepileptic effect.
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Affiliation(s)
- Zin-Juan Klaft
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitplatz 1, Berlin, Germany
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Palomero-Gallagher N, Schleicher A, Bidmon HJ, Pannek HW, Hans V, Gorji A, Speckmann EJ, Zilles K. Multireceptor analysis in human neocortex reveals complex alterations of receptor ligand binding in focal epilepsies. Epilepsia 2012; 53:1987-97. [DOI: 10.1111/j.1528-1167.2012.03634.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making.
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Affiliation(s)
- Ritchie E Brown
- Laboratory of Neuroscience, VA Boston Healthcare System and Harvard Medical School, Brockton, Massachusetts 02301, USA
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Endogenous adenosine induces NMDA receptor-independent persistent epileptiform discharges in dorsal and ventral hippocampus via activation of A2 receptors. Epilepsy Res 2012; 100:157-67. [DOI: 10.1016/j.eplepsyres.2012.02.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/14/2012] [Accepted: 02/11/2012] [Indexed: 11/19/2022]
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Li Y, Fan S, Yan J, Li B, Chen F, Xia J, Yu Z, Hu Z. Adenosine modulates the excitability of layer II stellate neurons in entorhinal cortex through A1 receptors. Hippocampus 2012; 21:265-80. [PMID: 20054814 DOI: 10.1002/hipo.20745] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Stellate neurons in layer II entorhinal cortex (EC) provide the main output from the EC to the hippocampus. It is believed that adenosine plays a crucial role in neuronal excitability and synaptic transmission in the CNS, however, the function of adenosine in the EC is still elusive. Here, the data reported showed that adenosine hyperpolarized stellate neurons in a concentration-dependent manner, accompanied by a decrease in firing frequency. This effect corresponded to the inhibition of the hyperpolarization-activated, cation nonselective (HCN) channels. Surprisingly, the adenosine-induced inhibition was blocked by 3 μM 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective A(1) receptor antagonists, but not by 10 μM 3,7-dimethyl-1-propargylxanthine (DMPX), a selective A(2) receptor antagonists, indicating that activation of adenosine A(1) receptors were responsible for the direct inhibition. In addition, adenosine reduced the frequency but not the amplitude of miniature EPSCs and IPSCs, suggesting that the global depression of glutamatergic and GABAergic transmission is mediated by a decrease in glutamate and GABA release, respectively. Again the presynaptic site of action was mediated by adenosine A(1) receptors. Furthermore, inhibition of spontaneous glutamate and GABA release by adenosine A(1) receptor activation was mediated by voltage-dependent Ca(2+) channels and extracellular Ca(2+) . Therefore, these findings revealed direct and indirect mechanisms by which activation of adenosine A(1) receptors on the cell bodies of stellate neurons and on the presynaptic terminals could regulate the excitability of these neurons.
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Affiliation(s)
- Yang Li
- Department of Physiology, Third Military Medical University, Chongqing, China
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Hamil NE, Cock HR, Walker MC. Acute down-regulation of adenosine A1 receptor activity in status epilepticus. Epilepsia 2011; 53:177-88. [DOI: 10.1111/j.1528-1167.2011.03340.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Intracerebroventricular administration of inosine is anticonvulsant against quinolinic acid-induced seizures in mice: An effect independent of benzodiazepine and adenosine receptors. Pharmacol Biochem Behav 2011; 100:271-4. [DOI: 10.1016/j.pbb.2011.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/01/2011] [Accepted: 09/06/2011] [Indexed: 11/21/2022]
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Abstract
Imbalance of the excitatory neurotransmitter glutamate and of the inhibitory neurotransmitter GABA is one of several causes of seizures. ATP has also been implicated in epilepsy. However, little is known about the mechanisms involved in the release of ATP from cells and the consequences of the altered ATP signaling during seizures. Pannexin1 (Panx1) is found in astrocytes and in neurons at high levels in the embryonic and young postnatal brain, declining in adulthood. Panx1 forms large-conductance voltage sensitive plasma membrane channels permeable to ATP that are also activated by elevated extracellular K(+) and following P2 receptor stimulation. Based on these properties, we hypothesized that Panx1 channels may contribute to seizures by increasing the levels of extracellular ATP. Using pharmacological tools and two transgenic mice deficient for Panx1 we show here that interference with Panx1 ameliorates the outcome and shortens the duration of kainic acid-induced status epilepticus. These data thus indicate that the activation of Panx1 in juvenile mouse hippocampi contributes to neuronal hyperactivity in seizures.
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Burnstock G, Krügel U, Abbracchio MP, Illes P. Purinergic signalling: from normal behaviour to pathological brain function. Prog Neurobiol 2011; 95:229-74. [PMID: 21907261 DOI: 10.1016/j.pneurobio.2011.08.006] [Citation(s) in RCA: 314] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/07/2023]
Abstract
Purinergic neurotransmission, involving release of ATP as an efferent neurotransmitter was first proposed in 1972. Later, ATP was recognised as a cotransmitter in peripheral nerves and more recently as a cotransmitter with glutamate, noradrenaline, GABA, acetylcholine and dopamine in the CNS. Both ATP, together with some of its enzymatic breakdown products (ADP and adenosine) and uracil nucleotides are now recognised to act via P2X ion channels and P1 and P2Y G protein-coupled receptors, which are widely expressed in the brain. They mediate both fast signalling in neurotransmission and neuromodulation and long-term (trophic) signalling in cell proliferation, differentiation and death. Purinergic signalling is prominent in neurone-glial cell interactions. In this review we discuss first the evidence implicating purinergic signalling in normal behaviour, including learning and memory, sleep and arousal, locomotor activity and exploration, feeding behaviour and mood and motivation. Then we turn to the involvement of P1 and P2 receptors in pathological brain function; firstly in trauma, ischemia and stroke, then in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's, as well as multiple sclerosis and amyotrophic lateral sclerosis. Finally, the role of purinergic signalling in neuropsychiatric diseases (including schizophrenia), epilepsy, migraine, cognitive impairment and neuropathic pain will be considered.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
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Neuroglial interactions mediated by purinergic signalling in the pathophysiology of CNS disorders. Semin Cell Dev Biol 2011; 22:252-9. [DOI: 10.1016/j.semcdb.2011.02.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/11/2011] [Accepted: 02/07/2011] [Indexed: 11/23/2022]
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Wagner AK, Miller MA, Scanlon J, Ren D, Kochanek PM, Conley YP. Adenosine A1 receptor gene variants associated with post-traumatic seizures after severe TBI. Epilepsy Res 2010; 90:259-72. [PMID: 20609566 DOI: 10.1016/j.eplepsyres.2010.06.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 05/22/2010] [Accepted: 06/01/2010] [Indexed: 01/07/2023]
Abstract
Post-traumatic seizures (PTS) are a significant complication from traumatic brain injury (TBI). Adenosine, a major neuroprotective and neuroinhibitory molecule, is important in experimental epilepsy models. Thus, we investigated the adenosine A1 receptor (A1AR) gene and linked it with clinical data extracted for 206 subjects with severe TBI. Tagging SNPs rs3766553, rs903361, rs10920573, rs6701725, and rs17511192 were genotyped, and variant and haplotype associations with PTS were explored. We investigated further genotype, grouped genotype, and allelic associations with PTS for rs3766553 and rs10920573. Multivariate analysis of rs3766553 demonstrated an association between the AA genotype and increased early PTS incidence. In contrast, the GG genotype was associated with increased late and delayed-onset PTS rates. Multivariate analysis of rs10920573 revealed an association between the CT genotype and increased late PTS. Multiple risk genotype analysis showed subjects with both risk genotypes had a 46.7% chance of late PTS. To our knowledge, this is the first report implicating genetic variability in the A1AR with PTS, or any type of seizure disorder. These results provide a rationale for further studies investigating how adenosine neurotransmission impacts PTS, evaluating anticonvulsants in preventing and treating PTS, and developing and testing targeted adenosinergic therapies aimed at reducing PTS.
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Affiliation(s)
- Amy K Wagner
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Suite 202, Pittsburgh, PA 15213, USA.
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Katoh-Semba R, Kaneko R, Kitajima S, Tsuzuki M, Ichisaka S, Hata Y, Yamada H, Miyazaki N, Takahashi Y, Kato K. Activation of p38 mitogen-activated protein kinase is required for in vivo brain-derived neurotrophic factor production in the rat hippocampus. Neuroscience 2009; 163:352-61. [PMID: 19524026 DOI: 10.1016/j.neuroscience.2009.06.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 04/26/2009] [Accepted: 06/04/2009] [Indexed: 10/20/2022]
Abstract
Several lines of evidence strongly suggest that brain-derived neurotrophic factor (BDNF) is associated with the formation, storage and recall of memory in the hippocampus and that it is important to maintain a considerable level of hippocampal BDNF in order to keep normal functions. BDNF can be synthesized in an activity-dependent manner. In fact, kainic acid or AMPA enhances BDNF levels in hippocampal granule neurons. However, the mechanisms of BDNF production are largely unclear. Recently, we have found that riluzole, which blocks voltage-gated sodium channels and thereby reduces glutamate release, actually strengthens immunoreactivity of BDNF in hippocampal granule neurons of rats. Therefore, we examined the riluzole-activated signaling pathways for BDNF production. Riluzole increased levels of phospho-p38 mitogen-activated protein kinase (p38 MAPK), as well as BDNF levels. Inhibition of p38 MAPK by SB203580 reduced riluzole effects, while activation of p38 MAPK by anisomycin increased levels of BDNF, suggesting that p38 MAPK can mediate BDNF production. Riluzole-induced elevation of phospho-activating transcription factor-2, a transcription factor downstream of p38 MAPK, was also observed. A blocker of N-type voltage-gated calcium channels reduced the effects of riluzole on BDNF production and p38 MAPK activation. We also examined a possible involvement of the adenosine A1 receptor in BDNF production because riluzole can influence ecto-nucleotide levels. An A1 receptor agonist inhibited riluzole-induced elevation of BDNF levels, whereas an antagonist not only increased levels of BDNF and active p38 MAPK but also augmented riluzole effects. These results indicate that, in the rat hippocampus, there is an in vivo signaling pathway for BDNF synthesis mediated by p38 MAPK, and that N-type voltage-gated calcium channels and/or adenosine A1 receptors contribute to p38 MAPK activation.
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Affiliation(s)
- R Katoh-Semba
- Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, 480-0392, Japan.
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Slawsky MT, Givertz MM. Rolofylline: a selective adenosine 1 receptor antagonist for the treatment of heart failure. Expert Opin Pharmacother 2009; 10:311-22. [PMID: 19236201 DOI: 10.1517/14656560802682213] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Co-existent cardiac and renal dysfunction is increasingly recognized as both a predictor and mediator of poor outcomes in patients with advanced heart failure. Novel therapies, including adenosine receptor antagonists, are currently under development for the treatment of 'cardiorenal syndrome'. OBJECTIVES To review the pathophysiologic rationale for using rolofylline, a selective adenosine 1 receptor antagonist, in patients with cardiorenal syndrome; and to provide a critical overview of safety and efficacy data from clinical studies. METHODS We reviewed published data on the pharmacology of rolofylline, and used this to inform a comprehensive summary of preclinical and clinical trials. Cardiac and renal effects, and safety data with a particular reference to seizures, are highlighted. RESULTS/CONCLUSION Rolofylline facilitates diuresis and preserves renal function in patients with acute decompensated heart failure and renal dysfunction. Pilot data also suggest beneficial effects on symptoms and short-term outcomes. The risk of seizures may be minimized by excluding high-risk patients.
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Affiliation(s)
- Mara T Slawsky
- Tufts University School of Medicine, Baystate Medical Center, Division of Cardiology, Springfield, MA (MTS), USA
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Hargus NJ, Bertram EH, Patel MK. Adenosine A1 receptors presynaptically modulate excitatory synaptic input onto subiculum neurons. Brain Res 2009; 1280:60-8. [PMID: 19450566 DOI: 10.1016/j.brainres.2009.05.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/08/2009] [Accepted: 05/12/2009] [Indexed: 12/20/2022]
Abstract
Adenosine is an endogenous neuromodulator previously shown to suppress synaptic transmission and membrane excitability in the CNS. In this study we have determined the actions of adenosine on excitatory synaptic transmission in the subiculum, the main output area for the hippocampus. Adenosine (10 microM) reversibly inhibited excitatory post synaptic currents (EPSCs) recorded from subiculum neurons. These actions were mimicked by the A(1) receptor-specific agonist, N(6)-cyclopentyl-adenosine (CPA, 10 nM) and blocked by the A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 500 nM), but were unaffected by the A(2A) antagonist ZM 241385 (50 nM). In membrane excitability experiments, bath application of adenosine and CPA reversibly inhibited action potentials (AP) in subiculum neurons that were evoked by stimulation of the pyramidal cell layer of the CA1, but not by depolarizing current injection steps in subiculum neurons, suggesting a presynaptic mechanism of action. In support, adenosine and CPA application reduced mEPSC frequency without modulating mEPSC amplitude. These studies suggest that modulation of subiculum neuron excitability by adenosine is mediated via presynaptic A(1) receptors.
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Affiliation(s)
- Nicholas J Hargus
- Department of Anesthesiology, University of Virginia, Charlottesville, VA 22908, USA
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Cotter G, Dittrich HC, Davison Weatherley B, Bloomfield DM, O'connor CM, Metra M, Massie BM. The PROTECT Pilot Study: A Randomized, Placebo-Controlled, Dose-Finding Study of the Adenosine A1 Receptor Antagonist Rolofylline in Patients With Acute Heart Failure and Renal Impairment. J Card Fail 2008; 14:631-40. [DOI: 10.1016/j.cardfail.2008.08.010] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 08/28/2008] [Accepted: 08/29/2008] [Indexed: 01/08/2023]
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Kumaria A, Tolias CM, Burnstock G. ATP signalling in epilepsy. Purinergic Signal 2008; 4:339-46. [PMID: 18568425 PMCID: PMC2583203 DOI: 10.1007/s11302-008-9115-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 05/12/2008] [Indexed: 01/23/2023] Open
Abstract
This paper focuses on a role for ATP neurotransmission and gliotransmission in the pathophysiology of epileptic seizures. ATP along with gap junctions propagates the glial calcium wave, which is an extraneuronal signalling pathway in the central nervous system. Recently astrocyte intercellular calcium waves have been shown to underlie seizures, and conventional antiepileptic drugs have been shown to attenuate these calcium waves. Blocking ATP-mediated gliotransmission, therefore, represents a potential target for antiepileptic drugs. Furthermore, while knowledge of an antiepileptic role for adenosine is not new, a recent study showed that adenosine accumulates from the hydrolysis of accumulated ATP released by astrocytes and is believed to inhibit distant synapses by acting on adenosine receptors. Such a mechanism is consistent with a surround-inhibitory mechanism whose failure would predispose to seizures. Other potential roles for ATP signalling in the initiation and spread of epileptiform discharges may involve synaptic plasticity and coordination of synaptic networks. We conclude by making speculations about future developments.
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Affiliation(s)
- Ashwin Kumaria
- Department of Neurosurgery, King's College Hospital, London, UK,
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Pentoxifylline ameliorates lithium-pilocarpine induced status epilepticus in young rats. Epilepsy Behav 2008; 12:354-65. [PMID: 18203664 DOI: 10.1016/j.yebeh.2007.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 12/04/2007] [Accepted: 12/08/2007] [Indexed: 11/23/2022]
Abstract
The neuroprotective effects of pentoxifylline (PTX) against lithium-pilocarpine (Li-Pc)-induced status epilepticus (SE) in young rats are described. Animals treated with PTX (0, 20, 40, and 60 mg/kg) before induction of SE were examined for latency to and frequency of SE, behavioral changes, oxidative stress, neurochemical alterations in the hippocampus and striatum, and histological abnormalities in the hippocampus. Treatment with PTX significantly ameliorated the frequency and severity of epileptic seizures in a dose-dependent manner. Our behavioral studies using the elevated plus-maze, rotarod, and water maze tests suggested a significant reduction in anxiety, enhanced motor performance, and improved learning and memory in PTX-treated rats. Li-Pc-induced neuronal cell loss and sprouting of mossy fibers in the hippocampus were also attenuated by PTX. The neuroprotective activity of PTX was accompanied by reduction in oxidative stress and reversal of SE-induced depletion of dopamine and 5-hydroxytryptamine in hippocampus and striatum. The results of this study provide a good rationale to explore the prophylactic/therapeutic potential of PTX in SE.
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Affiliation(s)
- Hannah Cock
- Epilepsy Group, Department of Cardiac and Vascular Sciences, St. Georges, University of London and Atkinson Morley Regional Neuroscience Centre, St. Georges Hospital, London, United Kingdom.
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Givertz MM, Massie BM, Fields TK, Pearson LL, Dittrich HC. The Effects of KW-3902, an Adenosine A1-Receptor Antagonist,on Diuresis and Renal Function in Patients With Acute Decompensated Heart Failure and Renal Impairment or Diuretic Resistance. J Am Coll Cardiol 2007; 50:1551-60. [DOI: 10.1016/j.jacc.2007.07.019] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/22/2007] [Accepted: 07/11/2007] [Indexed: 11/16/2022]
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Oses JP, Viola GG, de Paula Cognato G, Júnior VHC, Hansel G, Böhmer AE, Leke R, Bruno AN, Bonan CD, Bogo MR, Portela LV, Souza DO, Sarkis JJF. Pentylenetetrazol kindling alters adenine and guanine nucleotide catabolism in rat hippocampal slices and cerebrospinal fluid. Epilepsy Res 2007; 75:104-11. [PMID: 17544258 DOI: 10.1016/j.eplepsyres.2007.04.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 04/18/2007] [Accepted: 04/19/2007] [Indexed: 11/21/2022]
Abstract
Pentylenetetrazol (PTZ) is commonly used as a convulsant drug. The enhanced seizure susceptibility induced by kindling is probably attributable to plastic changes in the synaptic efficacy. Adenosine and guanosine act both as important neuromodulators and neuroprotectors with mostly inhibitory effects on neuronal activity. Adenosine and guanosine can be released per se or generated from released nucleotides (ATP, ADP, AMP, GTP, GDP, and GMP) that are metabolized and rapidly converted to adenosine and guanosine. The aim of this study was to evaluate nucleotide hydrolysis by ecto- and soluble nucleotidases (hippocampal slices and CSF, respectively) after PTZ-kindling (stages 3, 4, or 5 seizures) or saline treatment in rats. Additionally, the levels of purines in rat cerebrospinal fluid (CSF), as well as ecto-NTPDases (1, 2, 3, 5, 6 and 8) and ecto- 5'-nucleotidase expression were determined. Ecto-enzyme assays demonstrated that ATP, AMP, GDP, and GMP hydrolysis enhanced when compared with controls. In addition, there was an increase of ADP, GDP, and GMP hydrolysis by soluble nucleotidases in PTZ-kindling rats compared to control group. The HPLC analysis showed a marked increase in PTZ-kindled CSF concentrations of GTP, ADP, and uric acid, but GDP, AMP, and hypoxanthine concentrations were decreased. Such alterations indicate that the modulatory role of purines in CNS could be affected by PTZ-kindling. However, the physiological significance of these findings remains to be elucidated.
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Affiliation(s)
- Jean Pierre Oses
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, RS, Brazil.
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Abstract
(1) Status epilepticus is a significant health problem that is under-recognized, yet is associated with major morbidity and mortality. (2) Mechanisms accounting for status epilepticus emergence from a single seizure, and for prolonged status epilepticus duration, remain unclear. (3) No randomized controlled trials, systematic reviews, or meta-analyses were found in any of the databases searched regarding the pathophysiologic mechanisms of status epilepticus in humans. (4) Ongoing and future research is likely to more clearly define the pathogenetic mechanisms of status epilepticus. This, in turn, is likely to encourage better treatment 'targeting' for particular aspects of the condition.
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Abstract
This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration. Emphasis is placed on the physiology and pathophysiology of ATP, but extracellular roles of its breakdown product, adenosine, are also considered because of their intimate interactions. The early history of the involvement of ATP in autonomic and skeletal neuromuscular transmission and in activities in the central nervous system and ganglia is reviewed. Brief background information is given about the identification of receptor subtypes for purines and pyrimidines and about ATP storage, release, and ectoenzymatic breakdown. Evidence that ATP is a cotransmitter in most, if not all, peripheral and central neurons is presented, as well as full accounts of neurotransmission and neuromodulation in autonomic and sensory ganglia and in the brain and spinal cord. There is coverage of neuron-glia interactions and of purinergic neuroeffector transmission to nonmuscular cells. To establish the primitive and widespread nature of purinergic neurotransmission, both the ontogeny and phylogeny of purinergic signaling are considered. Finally, the pathophysiology of purinergic neurotransmission in both peripheral and central nervous systems is reviewed, and speculations are made about future developments.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neurscience Centre, Royal Free and University College Medical School, London, UK.
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Lasztóczi B, Kardos J. Cyclothiazide Prolongs Low [Mg2+]–Induced Seizure-Like Events. J Neurophysiol 2006; 96:3538-44. [PMID: 16914619 DOI: 10.1152/jn.00287.2006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Here we address the effects of cyclothiazide (CTZ), an allosteric inhibitor of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor desensitization, on low [Mg2+]–induced seizure-like events (SLEs) recorded from the CA3 pyramidal layer of juvenile rat hippocampal slices. CTZ (100 μM) made the period of tonic-like discharges (161 ± 18% of control) and the whole SLE (151 ± 15% of control) longer (in 7 of 9 slices) or induced endless SLE by stabilizing clonic-like bursting (in 2 of 9 slices). CTZ (30 μM) had no significant effects on SLE dynamics ( n = 4), whereas 300 μM CTZ induced endless SLEs in four of eight slices. Coapplication of CTZ (100 μM) with 100 μM GYKI-52466, the allosteric inhibitor of AMPA receptor function, restrained the effects of CTZ and shortened SLEs and their tonic phases to 37 ± 4.2 and 47 ± 4.2% of the control, respectively. Effects of GYKI-52466 and GYKI-52466 with CTZ on SLE dynamics were indistinguishable. 4-aminopyridine (4-AP; 50 μM) alone ( n = 5) or in combination with CTZ ( n = 6) transformed recurrent SLE pattern into incessant epileptiform activity with patterns distinguishable from those under 100 μM CTZ application. The effect of 4-AP may suggest a role for facilitated presynaptic glutamate release in disrupting recurrent dynamics. In contrast, the self-similar slow-down of low [Mg2+]–induced SLE dynamics by CTZ indicate AMPA receptor desensitization as a parameter shaping SLEs.
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Affiliation(s)
- Bálint Lasztóczi
- Department of Neurochemistry, Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út 59-67, Budapest H-1025, Hungary.
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