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Torres N, de Montalivet E, Borntrager Q, Benahmed S, Legrain A, Adesso E, Aubert N, Sauter-Starace F, Costecalde T, Martel F, Ratel D, Gaude C, Auboiroux V, Piallat B, Aksenova T, Molet J, Chabardes S. Focal cooling: An alternative treatment for drug-resistant epilepsy in a mesial temporal lobe epilepsy primate model-A preliminary study. Epilepsia 2024; 65:2069-2081. [PMID: 38794998 DOI: 10.1111/epi.18012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 05/27/2024]
Abstract
OBJECTIVE Focal cooling is emerging as a relevant therapy for drug-resistant epilepsy (DRE). However, we lack data on its effectiveness in controlling seizures that originate in deep-seated areas like the hippocampus. We present a thermoelectric solution for focal brain cooling that specifically targets these brain structures. METHODS A prototype implantable device was developed, including temperature sensors and a cannula for penicillin injection to create an epileptogenic zone (EZ) near the cooling tip in a non-human primate model of epilepsy. The mesial temporal lobe was targeted with repeated penicillin injections into the hippocampus. Signals were recorded from an sEEG (Stereoelectroencephalography) lead placed 2 mm from the EZ. Once the number of seizures had stabilized, focal cooling was applied, and temperature and electroclinical events were monitored using a customized detection algorithm. Tests were performed on two Macaca fascicularis monkeys at three temperatures. RESULTS Hippocampal seizures were observed 40-120 min post-injection, their duration and frequency stabilized at around 120 min. Compared to the control condition, a reduction in the number of hippocampal seizures was observed with cooling to 21°C (Control: 4.34 seizures, SD 1.704 per 20 min vs Cooling to 21°C: 1.38 seizures, SD 1.004 per 20 min). The effect was more pronounced with cooling to 17°C, resulting in an almost 80% reduction in seizure frequency. Seizure duration and number of interictal discharges were unchanged following focal cooling. After several months of repeated penicillin injections, hippocampal sclerosis was observed, similar to that recorded in humans. In addition, seizures were identified by detecting temperature variations of 0.3°C in the EZ correlated with the start of the seizures. SIGNIFICANCE In epilepsy therapy, the ultimate aim is total seizure control with minimal side effects. Focal cooling of the EZ could offer an alternative to surgery and to existing neuromodulation devices.
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Affiliation(s)
- Napoleon Torres
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | | | - Selimen Benahmed
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Antoine Legrain
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Eleonora Adesso
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Nicolas Aubert
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | | | - Felix Martel
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - David Ratel
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Christophe Gaude
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | - Brigitte Piallat
- Inserm, U1216, Grenoble Institute of Neurosciences, Universite Grenoble Alpes, Grenoble, France
| | - Tetiana Aksenova
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Jenny Molet
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Stephan Chabardes
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
- Department of Neurosurgery, Inserm, U1216, Universite Grenoble Alpes, Grenoble, France
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2
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Battin MR, Davis SL, Gardner M, Joe P, Rasmussen M, Haas R, Sharpe C. Seizures after initiation of rewarming in cooled infants with hypoxic ischaemic encephalopathy. Pediatr Res 2024; 95:752-757. [PMID: 37914821 DOI: 10.1038/s41390-023-02863-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 09/22/2023] [Accepted: 10/02/2023] [Indexed: 11/03/2023]
Abstract
BACKGROUND Seizures after initiation of rewarming from therapeutic hypothermia for neonatal encephalopathy are well recognised but not easy to predict. METHODS A secondary analysis was performed of NEOLEV2 trial data, a multicentre randomised trial of levetiracetam versus phenobarbital for neonatal seizures. Enrolled infants underwent continuous video EEG (cEEG) monitoring. The trial data were reviewed for 42 infants with seizures during therapeutic hypothermia and 118 infants who received therapeutic hypothermia but had no seizures on cEEG. RESULTS Overall, 112 of 160 (70%) had cEEG monitoring continued until rewarming was completed. Of the 42 infants with prior seizures, there were 30 infants with valid cEEG available and seizures occurred following the initiation of rewarming in 8 (26.6%). For the 118 seizure-naive infants, 82 (69.5%) continued cEEG until either rewarming was completed or 90 h of age and none had documented seizures. CONCLUSION Overall, just over a quarter of infants with prior seizures had cEEG evidence of at least one seizure in the 24 h after initiation of rewarming but no seizure-naive infant had cEEG evidence of seizure(s) on rewarming. Critically, by reporting the two groups separately, the data can provide guidance on the duration of EEG monitoring. IMPACT Infants with hypoxic ischaemic encephalopathy who have cEEG evidence of seizures during therapeutic hypothermia have a significant risk of further seizures on rewarming. For infants with hypoxic ischaemic encephalopathy but no cEEG evidence of seizures during therapeutic hypothermia, there is very little risk of de novo seizures. Ongoing work utilising large cohorts may generate EEG criteria that refine estimates of risk for rewarming seizures. Based on current experience, if seizures have occurred during therapeutic hypothermia for hypoxic ischaemic encephalopathy, the EEG monitoring should be continued during rewarming and for 12 h thereafter to minimise the risk of missing an event.
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Affiliation(s)
| | - Suzanne L Davis
- Paediatric Neurology, Starship Hospital, Auckland, New Zealand
| | - Marisa Gardner
- Pediatric Neurology, UCSF Benioff Children's Hospital, Oakland, CA, USA
| | - Priscilla Joe
- Neonatology, UCSF Benioff Children's Hospital, Oakland, CA, USA
| | - Maynard Rasmussen
- Neonatology, Sharp Mary Birch Hospital for Women and Newborns, San Diego, CA, USA
| | - Richard Haas
- Department of Neurosciences and Pediatrics, University of California, San Diego, CA, USA
| | - Cynthia Sharpe
- Paediatric Neurology, Starship Hospital, Auckland, New Zealand
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Niesvizky-Kogan I, Bass M, Goldenholz SR, Goldenholz DM. Focal Cooling for Drug-Resistant Epilepsy: A Review. JAMA Neurol 2022; 79:937-944. [PMID: 35877102 PMCID: PMC10101767 DOI: 10.1001/jamaneurol.2022.1936] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Epilepsy affects at least 1.2% of the population, with one-third of cases considered to be drug-resistant epilepsy (DRE). For these cases, focal cooling therapy may be a potential avenue for treatment, offering hope to people with DRE for freedom from seizure. The therapy leverages neuroscience and engineering principles to deliver a reversible treatment unhindered by pharmacology. Observations Analogous to (but safer than) the use of global cooling in postcardiac arrest and neonatal ischemic injury, extensive research supports the premise that focal cooling as a long-term treatment for epilepsy could be effective. The potential advantages of focal cooling are trifold: stopping epileptiform discharges, seizures, and status epilepticus safely across species (including humans). Conclusions and Relevance This Review presents the most current evidence supporting focal cooling in epilepsy. Cooling has been demonstrated as a potentially safe and effective treatment modality for DRE, although it is not yet ready for use in humans outside of randomized clinical trials. The Review will also offer a brief overview of the technical challenges related to focal cooling in humans, including the optimal device design and cooling parameters.
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Affiliation(s)
- Itamar Niesvizky-Kogan
- Harvard Medical School, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | | | | | - Daniel M Goldenholz
- Harvard Medical School, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Boston, Massachusetts
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4
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Csernyus B, Szabó Á, Fiáth R, Zátonyi A, Lázár C, Pongrácz A, Fekete Z. A multimodal, implantable sensor array and measurement system to investigate the suppression of focal epileptic seizure using hypothermia. J Neural Eng 2021; 18. [PMID: 34280911 DOI: 10.1088/1741-2552/ac15e6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022]
Abstract
Objective.Local cooling of the brain as a therapeutic intervention is a promising alternative for patients with epilepsy who do not respond to medication.In vitroandin vivostudies have demonstrated the seizure-suppressing effect of local cooling in various animal models. In our work, focal brain cooling in a bicuculline induced epilepsy model in rats is demonstrated and evaluated using a multimodal micro-electrocorticography (microECoG) device.Approach.We designed and experimentally tested a novel polyimide-based sensor array capable of recording microECoG and temperature signals concurrently from the cortical surface of rats. The effect of cortical cooling after seizure onset was evaluated using 32 electrophysiological sites and eight temperature sensing elements covering the brain hemisphere, where injection of the epileptic drug was performed. The focal cooling of the cortex right above the injection site was accomplished using a miniaturized Peltier chip combined with a heat pipe to transfer heat. Control of cooling and collection of sensor data was provided by a custom designed Arduino based electronic board. We tested the experimental setup using an agar gel modelin vitro, and thenin vivoin Wistar rats.Main results.Spatial variation of temperature during the Peltier controlled cooling was evaluated through calibrated, on-chip platinum temperature sensors. We found that frequency of epileptic discharges was not substantially reduced by cooling the cortical surface to 30 °C, but was suppressed efficiently at temperature values around 20 °C. The multimodal array revealed that seizure-like ictal events far from the focus and not exposed to high drop in temperature can be also inhibited at an extent like the directly cooled area.Significance.Our results imply that not only the absolute drop in temperature determines the efficacy of seizure suppression, and distant cortical areas not directly cooled can be influenced.
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Affiliation(s)
- B Csernyus
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Á Szabó
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary.,Roska Tamás Interdisciplinary Doctoral School, Pázmány Péter Catholic University, Budapest, Hungary
| | - R Fiáth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - A Zátonyi
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - C Lázár
- Microsystems Laboratory, Institute of Technical Physics and Material Sciences, Center for Energy Research, Budapest, Hungary
| | - A Pongrácz
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Z Fekete
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
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5
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Gotoh M, Nagasaka K, Nakata M, Takashima I, Yamamoto S. Brain Temperature Alters Contributions of Excitatory and Inhibitory Inputs to Evoked Field Potentials in the Rat Frontal Cortex. Front Cell Neurosci 2020; 14:593027. [PMID: 33364923 PMCID: PMC7750431 DOI: 10.3389/fncel.2020.593027] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/15/2020] [Indexed: 01/06/2023] Open
Abstract
Changes in brain temperature have been reported to affect various brain functions. However, little is known about the effects of temperature on the neural activity at the network level, where multiple inputs are integrated. In this study, we recorded cortical evoked potentials while altering the local brain temperature in anesthetized rats. We delivered electrical stimulations to the midbrain dopamine area and measured the evoked potentials in the frontal cortex, the temperature of which was locally altered using a thermal control device. We focused on the maximum negative peaks, which was presumed to result mainly from polysynaptic responses, to examine the effect of local temperature on network activity. We showed that focal cortical cooling increased the amplitude of evoked potentials (negative correlation, >17°C); further cooling decreased their amplitude. This relationship would be graphically represented as an inverted-U-shaped curve. The pharmacological blockade of GABAergic inhibitory inputs eliminated the negative correlation (>17°C) and even showed a positive correlation when the concentration of GABAA receptor antagonist was sufficiently high. Blocking the glutamatergic excitatory inputs decreased the amplitude but did not cause such inversion. Our results suggest that the negative correlation between the amplitude of evoked potentials and the near-physiological local temperature is caused by the alteration of the balance of contribution between excitatory and inhibitory inputs to the evoked potentials, possibly due to higher temperature sensitivity of inhibitory inputs.
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Affiliation(s)
- Mizuho Gotoh
- Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Kazuaki Nagasaka
- Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Mariko Nakata
- Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Ichiro Takashima
- Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Shinya Yamamoto
- Integrative Neuroscience Research Group, Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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Recent antiepileptic and neuroprotective applications of brain cooling. Seizure 2020; 82:80-90. [PMID: 33011591 DOI: 10.1016/j.seizure.2020.09.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022] Open
Abstract
Hypothermia is a widely used clinical practice for neuroprotection and is a well-established method to mitigate the adverse effects of some clinical conditions such as reperfusion injury after cardiac arrest and hypoxic ischemic encephalopathy in newborns. The discovery, that lowering the core temperature has a therapeutic potential dates back to the early 20th century, but the underlying mechanisms are actively researched, even today. Especially, in the area of neural disorders such as epilepsy and traumatic brain injury, cooling has promising prospects. It is well documented in animal models, that the application of focal brain cooling can effectively terminate epileptic discharges. There is, however, limited data regarding human clinical trials. In this review article, we will discuss the main aspects of therapeutic hypothermia focusing on its use in treating epilepsy. The various experimental approaches and device concepts for focal brain cooling are presented and their potential for controlling and suppressing seizure activity are compared.
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7
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Abstract
The brain is the most complex organ of the body, and many pathological processes underlying various brain disorders are poorly understood. Limited accessibility hinders observation of such processes in the in vivo brain, and experimental freedom is often insufficient to enable informative manipulations. In vitro preparations (brain slices or cultures of dissociated neurons) offer much better accessibility and reduced complexity and have yielded valuable new insights into various brain disorders. Both types of preparations have their advantages and limitations with regard to lifespan, preservation of in vivo brain structure, composition of cell types, and the link to behavioral outcome is often unclear in in vitro models. While these limitations hamper general usage of in vitro preparations to study, e.g., brain development, in vitro preparations are very useful to study neuronal and synaptic functioning under pathologic conditions. This chapter addresses several brain disorders, focusing on neuronal and synaptic functioning, as well as network aspects. Recent progress in the fields of brain circulation disorders, excitability disorders, and memory disorders will be discussed, as well as limitations of current in vitro models.
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8
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Park HJ, Kang H, Jo J, Chung E, Kim S. Planar coil-based contact-mode magnetic stimulation: synaptic responses in hippocampal slices and thermal considerations. Sci Rep 2018; 8:13423. [PMID: 30194395 PMCID: PMC6128857 DOI: 10.1038/s41598-018-31536-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 08/16/2018] [Indexed: 12/30/2022] Open
Abstract
Implantable magnetic stimulation is an emerging type of neuromodulation using coils that are small enough to be implanted in the brain. A major advantage of this method is that stimulation performance could be sustained even though the coil is encapsulated by gliosis due to foreign body reactions. Magnetic fields can induce indirect electric fields and currents in neurons. Compared to transcranial magnetic stimulation, the coil size used in implantable magnetic stimulation can be greatly reduced. However, the size reduction is accompanied by an increase in coil resistance. Hence, the coil could potentially damage neurons from the excess heat generated. Therefore, it is necessary to study the stimulation performance and possible thermal damage by implantable magnetic stimulation. Here, we devised contact-mode magnetic stimulation (CMS), wherein magnetic stimulation was applied to hippocampal slices through a customized planar-type coil underneath the slice in the contact mode. With acute hippocampal slices, we investigated the synaptic responses to examine the field excitatory postsynaptic responses of CMS and the temperature rise during CMS. A long-lasting synaptic depression was exhibited in the CA1 stratum radiatum after CMS, while the temperature remained in a safe range so as not to seriously affect the neural responses.
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Affiliation(s)
- Hee-Jin Park
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Heekyung Kang
- Department of Biomedical Science and Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Jihoon Jo
- Biomedical Research Institute, Chonnam National University Hospital, Gwangju, Republic of Korea
| | - Euiheon Chung
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
- Department of Biomedical Science and Engineering, Institute of Integrated Technology, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
| | - Sohee Kim
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.
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9
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Panuccio G, Colombi I, Chiappalone M. Recording and Modulation of Epileptiform Activity in Rodent Brain Slices Coupled to Microelectrode Arrays. J Vis Exp 2018. [PMID: 29863681 PMCID: PMC6101224 DOI: 10.3791/57548] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is the most common partial complex epileptic syndrome and the least responsive to medications. Deep brain stimulation (DBS) is a promising approach when pharmacological treatment fails or neurosurgery is not recommended. Acute brain slices coupled to microelectrode arrays (MEAs) represent a valuable tool to study neuronal network interactions and their modulation by electrical stimulation. As compared to conventional extracellular recording techniques, they provide the added advantages of a greater number of observation points and a known inter-electrode distance, which allow studying the propagation path and speed of electrophysiological signals. However, tissue oxygenation may be greatly impaired during MEA recording, requiring a high perfusion rate, which comes at the cost of decreased signal-to-noise ratio and higher oscillations in the experimental temperature. Electrical stimulation further stresses the brain tissue, making it difficult to pursue prolonged recording/stimulation epochs. Moreover, electrical modulation of brain slice activity needs to target specific structures/pathways within the brain slice, requiring that electrode mapping be easily and quickly performed live during the experiment. Here, we illustrate how to perform the recording and electrical modulation of 4-aminopyridine (4AP)-induced epileptiform activity in rodent brain slices using planar MEAs. We show that the brain tissue obtained from mice outperforms rat brain tissue and is thus better suited for MEA experiments. This protocol guarantees the generation and maintenance of a stable epileptiform pattern that faithfully reproduces the electrophysiological features observed with conventional field potential recording, persists for several hours, and outlasts sustained electrical stimulation for prolonged epochs. Tissue viability throughout the experiment is achieved thanks to the use of a small-volume custom recording chamber allowing for laminar flow and quick solution exchange even at low (1 mL/min) perfusion rates. Quick MEA mapping for real-time monitoring and selection of stimulating electrodes is performed by a custom graphic user interface (GUI).
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Affiliation(s)
- Gabriella Panuccio
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia;
| | - Ilaria Colombi
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia
| | - Michela Chiappalone
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia; Rehab Technologies, Istituto Italiano di Tecnologia
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10
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Soriano J, Kubo T, Inoue T, Kida H, Yamakawa T, Suzuki M, Ikeda K. Differential temperature sensitivity of synaptic and firing processes in a neural mass model of epileptic discharges explains heterogeneous response of experimental epilepsy to focal brain cooling. PLoS Comput Biol 2017; 13:e1005736. [PMID: 28981509 PMCID: PMC5628798 DOI: 10.1371/journal.pcbi.1005736] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/16/2017] [Indexed: 11/18/2022] Open
Abstract
Experiments with drug-induced epilepsy in rat brains and epileptic human brain region reveal that focal cooling can suppress epileptic discharges without affecting the brain's normal neurological function. Findings suggest a viable treatment for intractable epilepsy cases via an implantable cooling device. However, precise mechanisms by which cooling suppresses epileptic discharges are still not clearly understood. Cooling experiments in vitro presented evidence of reduction in neurotransmitter release from presynaptic terminals and loss of dendritic spines at post-synaptic terminals offering a possible synaptic mechanism. We show that termination of epileptic discharges is possible by introducing a homogeneous temperature factor in a neural mass model which attenuates the post-synaptic impulse responses of the neuronal populations. This result however may be expected since such attenuation leads to reduced post-synaptic potential and when the effect on inhibitory interneurons is less than on excitatory interneurons, frequency of firing of pyramidal cells is consequently reduced. While this is observed in cooling experiments in vitro, experiments in vivo exhibit persistent discharges during cooling but suppressed in magnitude. This leads us to conjecture that reduction in the frequency of discharges may be compensated through intrinsic excitability mechanisms. Such compensatory mechanism is modelled using a reciprocal temperature factor in the firing response function in the neural mass model. We demonstrate that the complete model can reproduce attenuation of both magnitude and frequency of epileptic discharges during cooling. The compensatory mechanism suggests that cooling lowers the average and the variance of the distribution of threshold potential of firing across the population. Bifurcation study with respect to the temperature parameters of the model reveals how heterogeneous response of epileptic discharges to cooling (termination or suppression only) is exhibited. Possibility of differential temperature effects on post-synaptic potential generation of different populations is also explored.
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Affiliation(s)
- Jaymar Soriano
- Mathematical Informatics Laboratory, Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Japan
- Department of Computer Science, University of the Philippines - Diliman, Quezon City, Philippines
| | - Takatomi Kubo
- Mathematical Informatics Laboratory, Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Takao Inoue
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hiroyuki Kida
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Toshitaka Yamakawa
- Organization for Innovation and Excellence, Kumamoto University, Kumamoto, Japan
| | - Michiyasu Suzuki
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Kazushi Ikeda
- Mathematical Informatics Laboratory, Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Japan
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Ren G, Yan J, Tao G, Gan Y, Li D, Yan X, Fu Y, Wang L, Wang W, Zhang Z, Yue F, Yang X. Rapid focal cooling attenuates cortical seizures in a primate epilepsy model. Exp Neurol 2017; 295:202-210. [PMID: 28601605 DOI: 10.1016/j.expneurol.2017.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 05/25/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
Abstract
Rapid focal cooling is an attractive nondestructive strategy to control and possibly prevent focal seizures. However, the temperature threshold necessary to abort seizures in primates is still unknown. Here, we explored this issue in a primate epilepsy model and observed the effect of rapid cooling on different electroencephalogram frequency bands, aiming at providing necessary experimental data for future clinical translational studies and exploring the mechanism of focal cooling in terminating seizures. We induced focal neocortical seizures using microinjection of 4-aminopyridine into premotor cortex in five anesthetized cynomolgus monkeys. The rapid focal cooling was implemented by using a thermoelectric (Peltier) device. As a result, the average durations of seizures and interictal intervals before cooling were 94.3±4.0s and 62.3±6.9s, respectively. When the cortex was cooled to 20°C or 18°C, there was no effect on seizure duration (109.4±30.0s, 91.3±19.3s) or interictal duration (99.4±26.8s, 83.2±11.5s, P>0.05). But when the cortex was cooled to 16°C, the seizure duration was reduced to 54.1±4.9s and the interictal duration was extended to 175.0±16.7s (P<0.05). Electroencephalogram spectral analysis showed that the power of delta, alpha, beta, gamma and ripples bands in seizures were significantly reduced at 20°C and 18°C. At 16°C, the power of theta band in seizures was also significantly reduced along with the other bands. Our data reveal that the temperature threshold in rapid focal cooling required to significantly shorten neocortical seizures in nonhuman primates is 16°C, and inhibition of electroencephalogram broadband spectrum power, especially power of theta band, may be the underlying mechanism to control seizures.
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Affiliation(s)
- Guoping Ren
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Jiaqing Yan
- College of Electrical and Control Engineering, North China University of Technology, Beijing, China
| | - Guoxian Tao
- Wincon TheraCells Biotechnologies Co., Ltd, Nanning, Guangxi, China
| | - Yunmeng Gan
- Wincon TheraCells Biotechnologies Co., Ltd, Nanning, Guangxi, China
| | - Donghong Li
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Xi Yan
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Yongjuan Fu
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Leiming Wang
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Weimin Wang
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhiming Zhang
- Department of Anatomy and Neurobiology, University of Kentucky Chandler Medical Center, Lexington, KY, USA
| | - Feng Yue
- Wincon TheraCells Biotechnologies Co., Ltd, Nanning, Guangxi, China
| | - Xiaofeng Yang
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China.
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Hernandez-Ojeda M, Ureña-Guerrero ME, Gutierrez-Barajas PE, Cardenas-Castillo JA, Camins A, Beas-Zarate C. KB-R7943 reduces 4-aminopyridine-induced epileptiform activity in adult rats after neuronal damage induced by neonatal monosodium glutamate treatment. J Biomed Sci 2017; 24:27. [PMID: 28486943 PMCID: PMC5423021 DOI: 10.1186/s12929-017-0335-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 05/03/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Neonatal monosodium glutamate (MSG) treatment triggers excitotoxicity and induces a degenerative process that affects several brain regions in a way that could lead to epileptogenesis. Na+/Ca2+ exchangers (NCX1-3) are implicated in Ca2+ brain homeostasis; normally, they extrude Ca2+ to control cell inflammation, but after damage and in epilepsy, they introduce Ca2+ by acting in the reverse mode, amplifying the damage. Changes in NCX3 expression in the hippocampus have been reported immediately after neonatal MSG treatment. In this study, the expression level of NCX1-3 in the entorhinal cortex (EC) and hippocampus (Hp); and the effects of blockade of NCXs on the seizures induced by 4-Aminopyridine (4-AP) were analysed in adult rats after neonatal MSG treatment. KB-R7943 was applied as NCXs blocker, but is more selective to NCX3 in reverse mode. METHODS Neonatal MSG treatment was applied to newborn male rats at postnatal days (PD) 1, 3, 5, and 7 (4 g/kg of body weight, s.c.). Western blot analysis was performed on total protein extracts from the EC and Hp to estimate the expression level of NCX1-3 proteins in relative way to the expression of β-actin, as constitutive protein. Electrographic activity of the EC and Hp were acquired before and after intracerebroventricular (i.c.v.) infusion of 4-AP (3 nmol) and KB-R7943 (62.5 pmol), alone or in combination. All experiments were performed at PD60. Behavioural alterations were also recorder. RESULTS Neonatal MSG treatment significantly increased the expression of NCX3 protein in both studied regions, and NCX1 protein only in the EC. The 4-AP-induced epileptiform activity was significantly higher in MSG-treated rats than in controls, and KB-R7943 co-administered with 4-AP reduced the epileptiform activity in more prominent way in MSG-treated rats than in controls. CONCLUSIONS The long-term effects of neonatal MSG treatment include increases on functional expression of NCXs (mainly of NCX3) in the EC and Hp, which seems to contribute to improve the control that KB-R7943 exerted on the seizures induced by 4-AP in adulthood. The results obtained here suggest that the blockade of NCXs could improve seizure control after an excitotoxic process; however, this must be better studied.
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Affiliation(s)
- Mariana Hernandez-Ojeda
- Laboratorio de Biología de la Neurotransmisión, Edificio de Posgrado, Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara, Km 15.5 Carretera a Nogales, Camino Ing. Ramón Padilla Sánchez Km 2, Zapopan, Jalisco Mexico 45221
| | - Monica E. Ureña-Guerrero
- Laboratorio de Biología de la Neurotransmisión, Edificio de Posgrado, Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara, Km 15.5 Carretera a Nogales, Camino Ing. Ramón Padilla Sánchez Km 2, Zapopan, Jalisco Mexico 45221
| | - Paola E. Gutierrez-Barajas
- Laboratorio de Biología de la Neurotransmisión, Edificio de Posgrado, Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara, Km 15.5 Carretera a Nogales, Camino Ing. Ramón Padilla Sánchez Km 2, Zapopan, Jalisco Mexico 45221
| | - Jazmin A. Cardenas-Castillo
- Laboratorio de Biología de la Neurotransmisión, Edificio de Posgrado, Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara, Km 15.5 Carretera a Nogales, Camino Ing. Ramón Padilla Sánchez Km 2, Zapopan, Jalisco Mexico 45221
| | - Antoni Camins
- Unitat de Farmacologia i Farmacognòsia, Institut de Neurociencias, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain
- Biomedical Research Networking Center in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Carlos Beas-Zarate
- Laboratorio de Biología de la Neurotransmisión, Edificio de Posgrado, Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara, Km 15.5 Carretera a Nogales, Camino Ing. Ramón Padilla Sánchez Km 2, Zapopan, Jalisco Mexico 45221
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Nomura S, Inoue T, Imoto H, Suehiro E, Maruta Y, Hirayama Y, Suzuki M. Effects of focal brain cooling on extracellular concentrations of neurotransmitters in patients with epilepsy. Epilepsia 2017; 58:627-634. [PMID: 28225164 DOI: 10.1111/epi.13704] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2017] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Brain hypothermia controls epileptic discharge and reduces extracellular concentrations of glutamate (Glu), an excitatory neurotransmitter. We aimed to determine the effects of focal brain cooling (FBC) on levels of γ-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. The relationship between Glu or GABA concentrations and the severity of epileptic symptoms was also analyzed. METHODS Patients with intractable epilepsy underwent FBC at lesionectomized (n = 11) or hippocampectomized (n = 8) regions at 15°C for 30 min using custom-made cooling devices. Concentrations of Glu (n = 18) and GABA (n = 12) were measured in extracellular fluid obtained through microdialysis using high-performance liquid chromatography (HPLC). The reduction rate of neurotransmitter levels and its relationship with electrocorticography (ECoG) signal changes in response to FBC were measured. RESULTS We found no relationship between the concentrations of Glu or GABA and seizure severity. There was a significant decrease in the concentration of Glu to 66.3% of control levels during the cooling period (p = 0.001). This rate of reduction correlated with ECoG power (r2 = 0.68). Cortical and hippocampal GABA levels significantly (p = 0.02) and nonsignificantly decreased to 47.7% and 32.4% of control levels, respectively. However, the rate of this reduction did not correlate with ECoG (r2 = 0.11). SIGNIFICANCE Although the decrease in hippocampal GABA levels was not significant due to wide variations in its concentration, the levels of cortical GABA and Glu were decreased following FBC. FBC suppresses epileptic discharge and the release of both excitatory and inhibitory neurotransmitters. The reduction in Glu levels further contributes to the reduction in epileptic discharge. However, the reduction in the levels of GABA has no impact on ECoG.
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Affiliation(s)
- Sadahiro Nomura
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan.,Epilepsy Center, Yamaguchi University Hospital, Ube, Japan
| | - Takao Inoue
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Hirochika Imoto
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan.,Epilepsy Center, Yamaguchi University Hospital, Ube, Japan
| | - Eiichi Suehiro
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Yuichi Maruta
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Yuya Hirayama
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Michiyasu Suzuki
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan.,Epilepsy Center, Yamaguchi University Hospital, Ube, Japan
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14
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Larsen LE, Lysebettens WV, Germonpré C, Carrette S, Daelemans S, Sprengers M, Thyrion L, Wadman WJ, Carrette E, Delbeke J, Boon P, Vonck K, Raedt R. Clinical Vagus Nerve Stimulation Paradigms Induce Pronounced Brain and Body Hypothermia in Rats. Int J Neural Syst 2016; 27:1750016. [PMID: 28178853 DOI: 10.1142/s0129065717500162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vagus nerve stimulation (VNS) is a widely used neuromodulation technique that is currently used or being investigated as therapy for a wide array of human diseases such as epilepsy, depression, Alzheimer's disease, tinnitus, inflammatory diseases, pain, heart failure and many others. Here, we report a pronounced decrease in brain and core temperature during VNS in freely moving rats. Two hours of rapid cycle VNS (7s on/18s off) decreased brain temperature by around [Formula: see text]C, while standard cycle VNS (30[Formula: see text]s on/300[Formula: see text]s off) was associated with a decrease of around [Formula: see text]C. Rectal temperature similarly decreased by more than [Formula: see text]C during rapid cycle VNS. The hypothermic effect triggered by VNS was further associated with a vasodilation response in the tail, which reflects an active heat release mechanism. Despite previous evidence indicating an important role of the locus coeruleus-noradrenergic system in therapeutic effects of VNS, lesioning this system with the noradrenergic neurotoxin DSP-4 did not attenuate the hypothermic effect. Since body and brain temperature affect most physiological processes, this finding is of substantial importance for interpretation of several previously published VNS studies and for the future direction of research in the field.
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Affiliation(s)
- Lars Emil Larsen
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Wouter Van Lysebettens
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Charlotte Germonpré
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Sofie Carrette
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Sofie Daelemans
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Mathieu Sprengers
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Lisa Thyrion
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Wytse Jan Wadman
- 2 Swammerdam Institute of Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1090GE, The Netherlands
| | - Evelien Carrette
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Jean Delbeke
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Paul Boon
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Kristl Vonck
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
| | - Robrecht Raedt
- 1 Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Internal Medicine, Ghent University, De Pintelaan 185, Ghent, 9000, Belgium
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Eid T, Gruenbaum SE, Dhaher R, Lee TSW, Zhou Y, Danbolt NC. The Glutamate-Glutamine Cycle in Epilepsy. ADVANCES IN NEUROBIOLOGY 2016; 13:351-400. [PMID: 27885637 DOI: 10.1007/978-3-319-45096-4_14] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Epilepsy is a complex, multifactorial disease characterized by spontaneous recurrent seizures and an increased incidence of comorbid conditions such as anxiety, depression, cognitive dysfunction, and sudden unexpected death. About 70 million people worldwide are estimated to suffer from epilepsy, and up to one-third of all people with epilepsy are expected to be refractory to current medications. Development of more effective and specific antiepileptic interventions is therefore requisite. Perturbations in the brain's glutamate-glutamine cycle, such as increased extracellular levels of glutamate, loss of astroglial glutamine synthetase, and changes in glutaminase and glutamate dehydrogenase, are frequently encountered in patients with epilepsy. Hence, manipulations of discrete glutamate-glutamine cycle components may represent novel approaches to treat the disease. The goal of his review is to discuss some of the glutamate-glutamine cycle components that are altered in epilepsy, particularly neurotransmitters and metabolites, enzymes, amino acid transporters, and glutamate receptors. We will also review approaches that potentially could be used in humans to target the glutamate-glutamine cycle. Examples of such approaches are treatment with glutamate receptor blockers, glutamate scavenging, dietary intervention, and hypothermia.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA.
| | - Shaun E Gruenbaum
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA
| | - Tih-Shih W Lee
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Yun Zhou
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Niels Christian Danbolt
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
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16
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Saghazadeh A, Mahmoudi M, Meysamie A, Gharedaghi M, Zamponi GW, Rezaei N. Possible role of trace elements in epilepsy and febrile seizures: a meta-analysis. Nutr Rev 2015; 73:760-79. [DOI: 10.1093/nutrit/nuv026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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17
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Seizures and hypothermia: importance of electroencephalographic monitoring and considerations for treatment. Semin Fetal Neonatal Med 2015; 20:103-8. [PMID: 25683598 DOI: 10.1016/j.siny.2015.01.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hypoxic-ischemic encephalopathy is a common cause of seizures in neonates. Despite the introduction of therapeutic hypothermia, seizure rates are similar to those reported in the pre-therapeutic hypothermia era. However, the seizure profile has been altered resulting in a lower overall seizure burden, shorter individual seizure durations, and seizures that are harder to detect. Electroencephalographic (EEG) monitoring is the gold standard for detecting all seizures in neonates and this is even more critical in neonates who are cooled, as they are often sedated, making seizures more difficult to detect. Several studies have shown that the majority of seizures in neonates undergoing therapeutic hypothermia remain subclinical, thus requiring EEG monitoring for diagnosis. Amplitude-integrated EEG monitoring is useful but shorter duration seizures are more likely to be missed. Evidence is emerging about the pharmacokinetic profile of routinely used antiepileptic drugs during therapeutic hypothermia and some modifications have been suggested, particularly for lidocaine use.
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18
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Yang X, Wang X. Potential mechanisms and clinical applications of mild hypothermia and electroconvulsive therapy on refractory status epilepticus. Expert Rev Neurother 2014; 15:135-44. [DOI: 10.1586/14737175.2015.992415] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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19
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Auricular electroacupuncture reduced inflammation-related epilepsy accompanied by altered TRPA1, pPKCα, pPKCε, and pERk1/2 signaling pathways in kainic acid-treated rats. Mediators Inflamm 2014; 2014:493480. [PMID: 25147437 PMCID: PMC4131505 DOI: 10.1155/2014/493480] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 12/23/2022] Open
Abstract
Background. Inflammation is often considered to play a crucial role in epilepsy by affecting iron status and metabolism. In this study, we investigated the curative effect of auricular acupuncture and somatic acupuncture on kainic acid- (KA-) induced epilepsy in rats. Methods. We established an epileptic seizure model in rats by KA (12 mg, ip). The 2 Hz electroacupuncture (EA) was applied at auricular and applied at Zusanli and Shangjuxu (ST36-ST37) acupoints for 20 min for 3 days/week for 6 weeks beginning on the day following the KA injection. Results. The electrophysiological results indicated that neuron overexcitation occurred in the KA-treated rats. This phenomenon could be reversed among either the auricular EA or ST36-ST37 EA treatment, but not in the sham-control rats. The Western blot results revealed that TRPA1, but not TRPV4, was upregulated by injecting KA and could be attenuated by administering auricular or ST36-ST37 EA, but not in the sham group. In addition, potentiation of TRPA1 was accompanied by increased PKCα and reduced PKCε. Furthermore, pERK1/2, which is indicated in inflammation, was also increased by KA. Furthermore, the aforementioned mechanisms could be reversed by administering auricular EA and could be partially reversed by ST36-ST37 EA. Conclusions. These results indicate a novel mechanism for treating inflammation-associated epilepsy and can be translated into clinical therapy.
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Qaddoumi MG, Ananthalakshmi KVV, Phillips OA, Edafiogho IO, Kombian SB. Evaluation of anticonvulsant actions of dibromophenyl enaminones using in vitro and in vivo seizure models. PLoS One 2014; 9:e99770. [PMID: 24945912 PMCID: PMC4063795 DOI: 10.1371/journal.pone.0099770] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 05/15/2014] [Indexed: 12/16/2022] Open
Abstract
Epilepsy and other seizure disorders are not adequately managed with currently available drugs. We recently synthesized a series of dibromophenyl enaminones and demonstrated that AK6 and E249 were equipotent to previous analogs but more efficacious in suppressing neuronal excitation. Here we examined the actions of these lead compounds on in vitro and in vivo seizure models. In vitro seizures were induced in the hippocampal slice chemically (zero Mg2+ buffer and picrotoxin) and electrically using patterned high frequency stimulation (HFS) of afferents. In vivo seizures were induced in rats using the 6 Hz and the maximal electroshock models. AK6 (10 µM) and E249 (10 µM) depressed the amplitude of population spikes recorded in area CA1 of the hippocampus by -50.5±4.3% and -40.1±3.1% respectively, with partial recovery after washout. In the zero Mg2+ model, AK6 (10 µM) depressed multiple population spiking (mPS) by -59.3±6.9% and spontaneous bursts (SBs) by -65.9±7.2% and in the picrotoxin-model by -43.3±7.2% and -50.0±8.3%, respectively. Likewise, E249 (10 µM) depressed the zero-Mg2+-induced mPS by -48.8±9.5% and SBs by -55.8±15.5%, and in the picrotoxin model by -37.1±5.5% and -56.5±11.4%, respectively. They both suppressed post-HFS induced afterdischarges and SBs. AK6 and E249 dose-dependently protected rats in maximal electroshock and 6 Hz models of in vivo seizures after 30 min pretreatment. Their level of protection in both models was similar to that obtained with phenytoin Finally, while AK6 had no effect on locomotion in rats, phenytoin significantly decreased locomotion. AK6 and E249, suppressed in vitro and in vivo seizures to a similar extent. Their in vivo activities are comparable with but not superior to phenytoin. The most efficacious, AK6 produced no locomotor suppression while phenytoin did. Thus, AK6 and E249 may be excellent candidates for further investigation as potential agents for the treatment of epilepsy syndromes with possibly less CNS side effects.
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Affiliation(s)
- Mohamed G. Qaddoumi
- Department of Pharmacology & Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
| | | | - Oludotun A. Phillips
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
| | - Ivan O. Edafiogho
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Saint Joseph, Hartford, Connecticut, United States of America
| | - Samuel B. Kombian
- Department of Pharmacology & Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
- * E-mail:
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Patel KS, Zhao M, Ma H, Schwartz TH. Imaging preictal hemodynamic changes in neocortical epilepsy. Neurosurg Focus 2014; 34:E10. [PMID: 23544406 DOI: 10.3171/2013.1.focus12408] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The ability to predict seizure occurrence is extremely important to trigger abortive therapies and to warn patients and their caregivers. Optical imaging of hemodynamic parameters such as blood flow, blood volume, and tissue and hemoglobin oxygenation has already been shown to successfully localize epileptic events with high spatial and temporal resolution. The ability to actually predict seizure occurrence using hemodynamic parameters is less well explored. METHODS In this article, the authors critically review data from the literature on neocortical epilepsy and optical imaging, and they discuss the preictal hemodynamic changes and their application in neurosurgery. RESULTS Recent optical mapping studies have demonstrated preictal hemodynamic changes in both human and animal neocortex. CONCLUSIONS Optical measurements of blood flow and oxygenation may become increasingly important for predicting and localizing epileptic events. The ability to successfully predict ictal onsets may be useful to trigger closed-loop abortive therapies.
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Affiliation(s)
- Kunal S Patel
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, New York 10065, USA
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Differential effects of cholinergic and noradrenergic neuromodulation on spontaneous cortical network dynamics. Neuropharmacology 2013; 72:259-73. [PMID: 23643755 DOI: 10.1016/j.neuropharm.2013.04.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 11/23/2022]
Abstract
Cholinergic and noradrenergic neuromodulation play a key role in determining overall behavioral state by shaping the underlying cortical network dynamics. The effects of these systems on synaptic and intrinsic cellular targets are quite diverse and a comprehensive understanding of how these neuromodulators regulate (spontaneous) cortical network activity has remained elusive. Here, we used multielectrode electrophysiology in vitro to investigate the effect of these neuromodulators on spontaneous network dynamics in acute slices of mouse visual cortex. We found that application of Carbachol (CCh) and Norepinephrine (NE) both enhanced the spontaneous network dynamics by increasing (1) the activity levels, (2) the temporal complexity of the network activity, and (3) the spatial complexity by decorrelating the network activity over a wide range of neuromodulator concentrations (1 μM, 10 μM, 50 μM, and 100 μM). Interestingly, we found that cholinergic neuromodulation was limited to the presence of CCh in the bath whereas the effects of NE, in particular for higher concentrations, induced plasticity that caused outlasting effects most prominently in the deep cortical layers. Together, these results provide a comprehensive network-level understanding of the similarities and differences of cholinergic and noradrenergic modulation of spontaneous network dynamics.
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Motamedi GK, Lesser RP, Vicini S. Therapeutic brain hypothermia, its mechanisms of action, and its prospects as a treatment for epilepsy. Epilepsia 2013; 54:959-70. [PMID: 23551057 DOI: 10.1111/epi.12144] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2013] [Indexed: 11/30/2022]
Abstract
Cooling the core body temperature to 32-35°C, is almost standard practice for conditions such as cardiac arrest in adults, and perinatal hypoxic ischemic encephalopathy in neonates. Limited clinical data, and more extensive animal experiments, indicate that hypothermia could help control seizures, and could be applied directly to the brain using implantable devices. These data have fostered further research to evaluate whether cooling would be a viable means to treat refractory epilepsy. Although the effect of temperature on cellular physiology has long been recognized, with possibly dual effects on pyramidal cells and interneurons, the exact mechanisms underlying its beneficial effects, in particular in epilepsy, are yet to be discovered. This article reviews currently available clinical and laboratory data with a focus on cellular mechanisms of action and prospects of hypothermia as a treatment for intractable seizures.
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Affiliation(s)
- Gholam K Motamedi
- Department of Neurology, Georgetown University Hospital, Washington, District of Columbia 20007, USA.
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Khadrawy YA, AboulEzz HS, Ahmed NA, Mohammed HS. The Anticonvulant Effect of Cooling in Comparison to α-Lipoic Acid: A Neurochemical Study. Neurochem Res 2013; 38:906-15. [DOI: 10.1007/s11064-013-0995-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 11/29/2022]
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Motamedi GK, Gonzalez-Sulser A, Dzakpasu R, Vicini S. Cellular mechanisms of desynchronizing effects of hypothermia in an in vitro epilepsy model. Neurotherapeutics 2012; 9:199-209. [PMID: 21913006 PMCID: PMC3271159 DOI: 10.1007/s13311-011-0078-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Hypothermia can terminate epileptiform discharges in vitro and in vivo epilepsy models. Hypothermia is becoming a standard treatment for brain injury in infants with perinatal hypoxic ischemic encephalopathy, and it is gaining ground as a potential treatment in patients with drug resistant epilepsy. However, the exact mechanism of action of cooling the brain tissue is unclear. We have studied the 4-aminopyridine model of epilepsy in mice using single- and dual-patch clamp and perforated multi-electrode array recordings from the hippocampus and cortex. Cooling consistently terminated 4-aminopyridine induced epileptiform-like discharges in hippocampal neurons and increased input resistance that was not mimicked by transient receptor potential channel antagonists. Dual-patch clamp recordings showed significant synchrony between distant CA1 and CA3 pyramidal neurons, but less so between the pyramidal neurons and interneurons. In CA1 and CA3 neurons, hypothermia blocked rhythmic action potential discharges and disrupted their synchrony; however, in interneurons, hypothermia blocked rhythmic discharges without abolishing action potentials. In parallel, multi-electrode array recordings showed that synchronized discharges were disrupted by hypothermia, whereas multi-unit activity was unaffected. The differential effect of cooling on transmitting or secreting γ-aminobutyric acid interneurons might disrupt normal network synchrony, aborting the epileptiform discharges. Moreover, the persistence of action potential firing in interneurons would have additional antiepileptic effects through tonic γ-aminobutyric acid release.
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Affiliation(s)
- Gholam K Motamedi
- Department of Neurology, Georgetown University Hospital, Washington, DC 20007, USA.
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Spontaneous Rhythmic Activity in the Adult Cerebral Cortex In Vitro. ISOLATED CENTRAL NERVOUS SYSTEM CIRCUITS 2012. [DOI: 10.1007/978-1-62703-020-5_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Abstract
Epileptic events initiate a large focal increase in metabolism and cerebral blood flow (CBF) to the ictal focus. In contrast, decreases in CBF have been demonstrated surrounding the focus, the etiology of which is unknown (i.e., arising either from active shunting of blood or passive steal). The relationship between these events and neuronal activity and metabolism are also unknown. We investigated neurovascular and neurometabolic coupling in the ictal surround using optical imaging of light scattering and cerebral blood volume, autofluorescence flavoprotein imaging (AFI), direct measurements of the cortical metabolic rate of oxygen and two-photon imaging of blood vessel diameter in a rat model of ictal events elicited with focal injection of 4-aminopyridine. We discovered a novel phenomenon, in which ictal events are preceded by preictal vasoconstriction of blood vessels in the surround, occurring 1-5 s before seizure onset, which may serve to actively shunt oxygenated blood to the imminently hypermetabolic focus or may be due to small local decreases in metabolism in the surround. Early ictal hypometabolism, transient decreases in cell swelling and cerebral blood volume in the surround are consistent with early ictal surround inhibition as a precipitating event in seizure onset as well as shaping the evolving propagating ictal wavefront, although the exact mechanism of these cerebrovascular and metabolic changes is currently unknown. AFI was extremely sensitive to the ictal onset zone and may be a useful mapping technique with clinical applications.
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De la Cruz E, Zhao M, Guo L, Ma H, Anderson SA, Schwartz TH. Interneuron progenitors attenuate the power of acute focal ictal discharges. Neurotherapeutics 2011; 8:763-73. [PMID: 21748528 PMCID: PMC3250298 DOI: 10.1007/s13311-011-0058-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Interneuron progenitors from the embryonic medial ganglionic eminence (MGE) can migrate, differentiate, and enhance local inhibition after transplantation into the postnatal cortex. Whether grafted MGE cells can reduce ictal activity in adult neocortex is unknown. We transplanted live MGE or killed cells (control) from pan green fluorescent protein expressing mice into adult mouse sensorimotor cortex. One week, 2 and 1/2 weeks, or 6 to 8 weeks after transplant, acute focal ictal epileptiform discharges were induced by injection of 4-aminopyridine (4-AP) 2 mm away from the site of transplantation. The local field potential of the events was recorded with 2 electrodes, 1 located in the 4-AP focus and the other 1 in the transplantation site. In all control groups and in the 1-week live cell transplant, 4-AP ictal discharges revealed no attenuation in power and duration from the onset site to the site of transplantation. However, 2.5 or 6 ~ 8 weeks after MGE transplants, there was a dramatic decrease in local field potential power at the MGE transplanted site with little decrease in ictal duration. Surprisingly, there was no relationship between grafted cell distribution or density and the degree of attenuation. As remarkably low graft densities still significantly reduced discharge power, these data provide further support for the therapeutic potential of interneuron precursor transplants in the treatment of neocortical epilepsy.
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Affiliation(s)
- Estanislao De la Cruz
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
| | - Mingrui Zhao
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
| | - Lihua Guo
- Department of Psychiatry, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
| | - Hongtao Ma
- Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
| | - Stewart A. Anderson
- Department of Psychiatry, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
| | - Theodore H. Schwartz
- Departments of Neurological Surgery, Neurology and Neuroscience, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10065 USA
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Abstract
Abstract
Neuromodulation strategies have been proposed to treat a variety of neurological disorders, including medication-resistant epilepsy. Electrical stimulation of both central and peripheral nervous systems has emerged as a possible alternative for patients who are not deemed to be good candidates for resective procedures. In addition to well-established treatments such as vagus nerve stimulation, epilepsy centers around the world are investigating the safety and efficacy of neurostimulation at different brain targets, including the hippocampus, thalamus, and subthalamic nucleus. Also promising are the preliminary results of responsive neuromodulation studies, which involve the delivery of stimulation to the brain in response to detected epileptiform or preepileptiform activity. In addition to electrical stimulation, novel therapeutic methods that may open new horizons in the management of epilepsy include transcranial magnetic stimulation, focal drug delivery, cellular transplantation, and gene therapy. We review the current strategies and future applications of neuromodulation in epilepsy.
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Affiliation(s)
- Faisal A Al-Otaibi
- King Faisal Specialist Hospital & Research Centre, Neurosciences Department, Riyadh, Saudi Arabia
| | - Clement Hamani
- Division of Neurosurgery, Toronto Western Hospital, Toronto Western Research Institute, Ontario, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Toronto Western Hospital, Toronto Western Research Institute, Ontario, Canada
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30
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Yu L, Zhou Y, Chen W, Wang Y. Mild hypothermia pretreatment protects against pilocarpine-induced status epilepticus and neuronalapoptosis in immature rats. Neuropathology 2010; 31:144-51. [DOI: 10.1111/j.1440-1789.2010.01155.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Reig R, Mattia M, Compte A, Belmonte C, Sanchez-Vives MV. Temperature Modulation of Slow and Fast Cortical Rhythms. J Neurophysiol 2010; 103:1253-61. [DOI: 10.1152/jn.00890.2009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the local cortical network, spontaneous emergent activity self-organizes in rhythmic patterns. These rhythms include a slow one (<1 Hz), consisting in alternation of up and down states, and also faster rhythms (10–80 Hz) generated during up states. Varying the temperature in the bath between 26 and 41°C resulted in a strong modulation of the emergent network activity. Up states became shorter for warmer temperatures and longer with cooling, whereas down states were shortest at physiological (36–37°C) temperature. The firing rate during up states was robustly modulated by temperature, increasing with higher temperatures. The sparse firing rate during down states hardly varied with temperature, thus resulting in a progressive merging of up and down states for temperatures around 30°C. Below 30°C and down to 26°C the firing lost rhythmicity, becoming progressively continuous. The slope of the down-to-up transitions, which reflects the speed of recruitment of the local network, was progressively steeper for higher temperatures, whereas wave-propagation speed exhibited only a moderate increase. Fast rhythms were particularly sensitive to temperature. Broadband high-frequency fluctuations in the local field potential were maximal for recordings at 36–38°C. Overall, we found that maintaining cortical slices at physiological temperature is critical for the generated activity to be analogous to that in vivo. We also demonstrate that changes in activity with temperature were not secondary to oxygenation changes. Temperature variation sets the in vitro cortical network at different functional regimes, allowing the exploration of network activity generation and control mechanisms.
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Affiliation(s)
- R. Reig
- Institut d'Investigacions Biomèdiques August Pi i Sunyer
| | - M. Mattia
- Istituto Superiore di Sanità, Rome, Italy
| | - A. Compte
- Institut d'Investigacions Biomèdiques August Pi i Sunyer
| | - C. Belmonte
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, Consejo Superior de Investigaciones Científicas, San Juan de Alicante, Spain; and
| | - M. V. Sanchez-Vives
- Institut d'Investigacions Biomèdiques August Pi i Sunyer
- Institució Catalana de Recerca i Estudis Avançats, Barcelona
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32
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FUJII M, FUJIOKA H, OKU T, TANAKA N, IMOTO H, MARUTA Y, NOMURA S, KAJIWARA K, SAITO T, YAMAKAWA T, YAMAKAWA T, SUZUKI M. Application of Focal Cerebral Cooling for the Treatment of Intractable Epilepsy. Neurol Med Chir (Tokyo) 2010; 50:839-44. [DOI: 10.2176/nmc.50.839] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Masami FUJII
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Hiroshi FUJIOKA
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Takayuki OKU
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
| | - Nobuhiro TANAKA
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
| | - Hirochika IMOTO
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Yuichi MARUTA
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Sadahiro NOMURA
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Koji KAJIWARA
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
| | - Takashi SAITO
- Applied Medical Engineering Science, Graduate School of Medicine Yamaguchi University
| | - Toshitaka YAMAKAWA
- Kyushu Institute of Technology, Graduate School of Life Science and Systems Engineering
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Takeshi YAMAKAWA
- Applied Medical Engineering Science, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
| | - Michiyasu SUZUKI
- Department of Neurosurgery, Graduate School of Medicine Yamaguchi University
- Consortium of Advanced Epilepsy Treatment (CADET)
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Rothman SM. The therapeutic potential of focal cooling for neocortical epilepsy. Neurotherapeutics 2009; 6:251-7. [PMID: 19332317 PMCID: PMC5084201 DOI: 10.1016/j.nurt.2008.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 12/02/2008] [Accepted: 12/12/2008] [Indexed: 11/22/2022] Open
Abstract
The therapy of the focal cortical epilepsies remains unsatisfactory. Close to a third of patients fail to gain adequate control with antiepileptic drugs and a portion of those who do, experience unacceptable side effects. Morever, the favorable response rate after surgical resection, approximately 60%, is not nearly as high as the response rate of complex partial seizures caused by mesial temporal sclerosis. The suppressive effect of cooling on neuronal activity has been recognized for over a century. Therefore, we have begun to explore the possible application of cooling as a therapy for focal cortical seizures. In initial brain slice experiments, we found that cooling to 20 degrees C could rapidly terminate paroxysmal activity. Then we developed an in vivo model of focal seizures using a local injection of the convulsant 4-aminopyridine and found that cooling the injected area to less than 24 degrees C with a thermoelectric Peltier device aborted seizures within a few seconds. Other laboratories have independently confirmed our initial observations. More recent experiments from our laboratory have shown that cooling, per se, is not associated with significant cortical damage, even at surface temperatures as low as 5 degrees C. Advances in the fabrication of extremely thin thermoelectric devices, less than a few hundred microns thick, has raised the possibility of incorporating an implantable cooling unit into a closed loop seizure detection and treatment system.
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Affiliation(s)
- Steven M Rothman
- Department of Pediatrics (Clinical Neuroscience), University of Minnesota Medical School, Minneapolis, Minnesota 55455-0374, USA.
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Ablah E, Tran MP, Isaac M, Kaufman DA, Moufarrij N, Liow K. Effect of cortical cooling on interictal epileptiform activities. Seizure 2009; 18:61-3. [DOI: 10.1016/j.seizure.2008.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 05/16/2008] [Accepted: 06/20/2008] [Indexed: 11/29/2022] Open
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Fournier N, Galic M, Kalynchuk L, Persinger M. Profound hypothermia determines the anticonvulsant and neuroprotective effects of swim stress. Brain Res 2008; 1240:153-64. [DOI: 10.1016/j.brainres.2008.08.081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 08/15/2008] [Accepted: 08/21/2008] [Indexed: 01/22/2023]
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36
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Synthesis and structure–activity relationship studies of theophylline analogs on population responses in the rat hippocampus in vitro. Bioorg Med Chem 2008; 16:8142-50. [DOI: 10.1016/j.bmc.2008.07.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2008] [Revised: 07/15/2008] [Accepted: 07/17/2008] [Indexed: 11/21/2022]
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Galic MA, Riazi K, Heida JG, Mouihate A, Fournier NM, Spencer SJ, Kalynchuk LE, Teskey GC, Pittman QJ. Postnatal inflammation increases seizure susceptibility in adult rats. J Neurosci 2008; 28:6904-13. [PMID: 18596165 PMCID: PMC3547980 DOI: 10.1523/jneurosci.1901-08.2008] [Citation(s) in RCA: 228] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Accepted: 05/19/2008] [Indexed: 01/28/2023] Open
Abstract
There are critical postnatal periods during which even subtle interventions can have long-lasting effects on adult physiology. We asked whether an immune challenge during early postnatal development can alter neuronal excitability and seizure susceptibility in adults. Postnatal day 14 (P14) male Sprague Dawley rats were injected with the bacterial endotoxin lipopolysaccharide (LPS), and control animals received sterile saline. Three weeks later, extracellular recordings from hippocampal slices revealed enhanced field EPSP slopes after Schaffer collateral stimulation and increased epileptiform burst-firing activity in CA1 after 4-aminopyridine application. Six to 8 weeks after postnatal LPS injection, seizure susceptibility was assessed in response to lithium-pilocarpine, kainic acid, and pentylenetetrazol. Rats treated with LPS showed significantly greater adult seizure susceptibility to all convulsants, as well as increased cytokine release and enhanced neuronal degeneration within the hippocampus after limbic seizures. These persistent increases in seizure susceptibility occurred only when LPS was given during a critical postnatal period (P7 and P14) and not before (P1) or after (P20). This early effect of LPS on adult seizures was blocked by concurrent intracerebroventricular administration of a tumor necrosis factor alpha (TNFalpha) antibody and mimicked by intracerebroventricular injection of rat recombinant TNFalpha. Postnatal LPS injection did not result in permanent changes in microglial (Iba1) activity or hippocampal cytokine [IL-1beta (interleukin-1beta) and TNFalpha] levels, but caused a slight increase in astrocyte (GFAP) numbers. These novel results indicate that a single LPS injection during a critical postnatal period causes a long-lasting increase in seizure susceptibility that is strongly dependent on TNFalpha.
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Affiliation(s)
- Michael A Galic
- Epilepsy and Brain Circuits Program, Hotchkiss Brain Institute, Department of Neuroscience, University of Calgary, Calgary, Alberta, Canada.
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Tanaka N, Fujii M, Imoto H, Uchiyama J, Nakano K, Nomura S, Fujisawa H, Kunitsugu I, Saito T, Suzuki M. Effective suppression of hippocampal seizures in rats by direct hippocampal cooling with a Peltier chip. J Neurosurg 2008; 108:791-7. [PMID: 18377260 DOI: 10.3171/jns/2008/108/4/0791] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The use of focal brain cooling to eliminate epileptic discharges (EDs) has attracted increasing attention in the scientific community. In this study, the inhibitory effect of selective hippocampal cooling on experimental hippocampal seizures was investigated using a newly devised cooling system with a thermoelectric (Peltier) chip. METHODS A copper needle coated with silicone and attached to the Peltier chip was used for the cooling device. The experiments were performed first in a phantom model with thermography and second in adult male Sprague-Dawley rats in a state of halothane anesthesia. The cooling needle, a thermocouple, and a needle electrode for electroencephalography recording were inserted into the right hippocampus. Kainic acid (KA) was injected into the right hippocampus to provoke the EDs. The animals were divided into hippocampal cooling (10 rats) and noncooling (control, 10 rats) groups. RESULTS In the phantom study, the cooling effects (9 degrees C) occurred in the spherical areas around the needle tip. In the rats the temperature of the cooled hippocampus decreased below 20 degrees C within a 1.6-mm radius and below 25 degrees C within a 2.4-mm radius from the cooling center. The temperature at the needle tip decreased below 20 degrees C within 1 minute and was maintained at the same level until the end of the cooling process. The amplitude of the EDs was suppressed to 68.1 +/- 4.8% of the precooling value and remained low thereafter. No histological damage due to cooling was observed in the rat hippocampus. CONCLUSIONS Selective hippocampal cooling effectively suppresses the KA-induced hippocampal EDs. Direct hippocampal cooling with a permanently implantable system is potentially useful as a minimally invasive therapy for temporal lobe epilepsy and therefore could be an alternative to the temporal lobectomy.
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Affiliation(s)
- Nobuhiro Tanaka
- Department of Neurosurgery, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
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Ananthalakshmi KVV, Edafiogho IO, Kombian SB. Anticonvulsant enaminone E139 suppresses epileptiform activity in rat hippocampal slices. Epilepsy Res 2007; 76:85-92. [PMID: 17728105 DOI: 10.1016/j.eplepsyres.2007.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 06/30/2007] [Accepted: 07/03/2007] [Indexed: 10/22/2022]
Abstract
Some enaminones are reported to have in vivo anticonvulsant activity. We asked if methyl 4-(4'-bromophenyl)aminocyclohex-3-en-6-methyl-2-oxo-1-oate (E139), one of such enaminones produced in vitro effects that may underlie or explain these in vivo anticonvulsant actions by testing if E139 suppressed in vitro seizures. In vitro seizures were generated chemically in hippocampal slices using picrotoxin and zero Mg(2+) buffer and electrically by high frequency stimulation (HFS). E139 (10 microM) depressed evoked field population spike (PS) amplitude by -28.6+/-4.5% (n=5), an effect that was blocked by 1 microM CGP55845 (2.7+/-5.5%, n=6). Picrotoxin (100 microM) transformed single PS into multiple PS (4.5+/-0.2, n=5) and E139 reversibly reduced the number of these multiple PS by -23.4+/-1.8% (n=5). Similarly, zero Mg(2+) buffer produced multiple spikes (3.6+/-0.6, n=5) that were suppressed by E139 (-54.8+/-9.7%, n=5). This effect was also blocked by CGP55845 (2.3+/-5.7%, n=6). Furthermore, E139 suppressed the frequency of spontaneous bursts (SB) that were recorded in zero Mg(2+) by -65.8+/-10.5% (n=12). CGP55845 significantly reduced this E139-induced SB suppression (-21.7+/-9.6%, n=6). In the electrical model, afterdischarges (AD) and SB recorded in area CA3 after a pattern of HFS (100Hz) were suppressed by E139 (-48.6+/-14.3% and -66.7+/-6.7%, respectively, n=6). These E139 effects on AD and SB were reduced, but not completely blocked, by CGP55845 (-32.1+/-5.3% and -44.4+/-9.7%, respectively, n=7). Finally, pretreatment of slices with E139 did not prevent zero Mg(2+)-induced multiple spikes and SB. We conclude that E139 suppresses in vitro seizures in the hippocampus by synaptic and non-synaptic mechanisms. These actions on network activity may underlie their reported in vivo anticonvulsant effects.
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