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Iwamoto M, Yonekura S, Atsumi N, Hirabayashi S, Kanazawa H, Kuniyoshi Y. Respiratory entrainment of the locus coeruleus modulates arousal level to avoid physical risks from external vibration. Sci Rep 2023; 13:7069. [PMID: 37127727 PMCID: PMC10151378 DOI: 10.1038/s41598-023-32995-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/05/2023] [Indexed: 05/03/2023] Open
Abstract
Slow rocking chairs can easily put people to sleep, while violent shaking, such as during earthquakes, may lead to rapid awakening. However, the influence of external body vibrations on arousal remains unclear. Herein, a computational model of a locus coeruleus (LC)-norepinephrine (NE) system and cardio-respiratory system were used to show that respiratory entrainment of the LC modulates arousal levels, which is an adaptation to avoid physical risks from external vibration. External vibrations of sinusoidal waves with different frequencies ranging from 0.1 to 20 [Hz] were applied to the LC based on the results of previous studies. We found that respiratory entrainment of the LC decreased the breathing rate (BR) and heart rate (HR) to maintain the HR within its normal range. Furthermore, 1:1 phase locking enhanced arousal level while phase-amplitude coupling decreased it for larger vibration stimuli. These findings suggest that respiratory entrainment of the LC might automatically modulate cardio-respiratory system homeostasis and arousal levels for performance readiness (fight/flight or freeze) to avoid physical risks from larger external vibrations.
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Affiliation(s)
- Masami Iwamoto
- Human Science Research-Domain, Toyota Central R &D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi, 480-1192, Japan.
| | - Shogo Yonekura
- Intelligent Systems and Informatics Laboratory, Mechano-Informatics Department of Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Noritoshi Atsumi
- Human Science Research-Domain, Toyota Central R &D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi, 480-1192, Japan
| | - Satoko Hirabayashi
- Human Science Research-Domain, Toyota Central R &D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi, 480-1192, Japan
| | - Hoshinori Kanazawa
- Intelligent Systems and Informatics Laboratory, Mechano-Informatics Department of Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yasuo Kuniyoshi
- Intelligent Systems and Informatics Laboratory, Mechano-Informatics Department of Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
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2
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Sun X, Lv Y, Lin J. The mechanism of sudden unexpected death in epilepsy: A mini review. Front Neurol 2023; 14:1137182. [PMID: 36815002 PMCID: PMC9939452 DOI: 10.3389/fneur.2023.1137182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/20/2023] [Indexed: 02/08/2023] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is defined as a sudden, unexpected, non-traumatic, non-drowning death in a person with epilepsy. SUDEP is generally considered to result from seizure-related cardiac dysfunction, respiratory depression, autonomic nervous dysfunction, or brain dysfunction. Frequency of generalized tonic clonic seizures (GTCS), prone posture, and refractory epilepsy are considered risk factors. SUDEP has also been associated with inherited cardiac ion channel disease and severe obstructive sleep apnea. Most previous studies of SUDEP mechanisms have focused on cardiac and respiratory dysfunction and imbalance of the neural regulatory system. Cardiac-related mechanisms include reduction in heart rate variability and prolongation of QT interval, which can lead to arrhythmias. Laryngospasm and amygdala activation may cause obstructive and central apnea, respectively. Neural mechanisms include impairment of 5-HT and adenosine neuromodulation. The research to date regarding molecular mechanisms of SUDEP is relatively limited. Most studies have focused on p-glycoprotein, catecholamines, potassium channels, and the renin-angiotensin system, all of which affect cardiac and respiratory function.
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Affiliation(s)
- Xinyi Sun
- School of Basic Medical Sciences, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Yehui Lv
- School of Basic Medical Sciences, Shanghai University of Medicine and Health Sciences, Shanghai, China,Institute of Wound Prevention and Treatment, Shanghai University of Medicine and Health Sciences, Shanghai, China,*Correspondence: Yehui Lv ✉
| | - Jian Lin
- Institute of Wound Prevention and Treatment, Shanghai University of Medicine and Health Sciences, Shanghai, China,Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai, China
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3
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Mulkey DK, Milla BM. Perspectives on the basis of seizure-induced respiratory dysfunction. Front Neural Circuits 2022; 16:1033756. [PMID: 36605420 PMCID: PMC9807672 DOI: 10.3389/fncir.2022.1033756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Epilepsy is an umbrella term used to define a wide variety of seizure disorders and sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in epilepsy. Although some SUDEP risk factors have been identified, it remains largely unpredictable, and underlying mechanisms remain poorly understood. Most seizures start in the cortex, but the high mortality rate associated with certain types of epilepsy indicates brainstem involvement. Therefore, to help understand SUDEP we discuss mechanisms by which seizure activity propagates to the brainstem. Specifically, we highlight clinical and pre-clinical evidence suggesting how seizure activation of: (i) descending inhibitory drive or (ii) spreading depolarization might contribute to brainstem dysfunction. Furthermore, since epilepsy is a highly heterogenous disorder, we also considered factors expected to favor or oppose mechanisms of seizure propagation. We also consider whether epilepsy-associated genetic variants directly impact brainstem function. Because respiratory failure is a leading cause of SUDEP, our discussion of brainstem dysfunction focuses on respiratory control.
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Affiliation(s)
- Daniel K. Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
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4
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Cheng HM, Gao CS, Lou QW, Chen Z, Wang Y. The diverse role of the raphe 5-HTergic systems in epilepsy. Acta Pharmacol Sin 2022; 43:2777-2788. [PMID: 35614227 PMCID: PMC9622810 DOI: 10.1038/s41401-022-00918-2] [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: 02/15/2022] [Accepted: 05/05/2022] [Indexed: 11/08/2022] Open
Abstract
The raphe nuclei comprise nearly all of 5-hydroxytryptaminergic (5-HTergic) neurons in the brain and are widely acknowledged to participate in the modulation of neural excitability. "Excitability-inhibition imbalance" results in a variety of brain disorders, including epilepsy. Epilepsy is a common neurological disorder characterized by hypersynchronous epileptic seizures accompanied by many psychological, social, cognitive consequences. Current antiepileptic drugs and other therapeutics are not ideal to control epilepsy and its comorbidities. Cumulative evidence suggests that the raphe nuclei and 5-HTergic system play an important role in epilepsy and epilepsy-associated comorbidities. Seizure activities propagate to the raphe nuclei and induce various alterations in different subregions of the raphe nuclei at the cellular and molecular levels. Intervention of the activity of raphe nuclei and raphe 5-HTergic system with pharmacological or genetic approaches, deep brain stimulation or optogenetics produces indeed diverse and even contradictory effects on seizure and epilepsy-associated comorbidities in different epilepsy models. Nevertheless, there are still many open questions left, especially regarding to the relationship between 5-HTergic neural circuit and epilepsy. Understanding of 5-HTergic network in a circuit- and molecule-specific way may not only be therapeutically relevant for increasing the drug specificity and precise treatment in epilepsy, but also provide critical hints for other brain disorders with abnormal neural excitability. In this review we focus on the roles of the raphe 5-HTergic system in epilepsy and epilepsy-associated comorbidities. Besides, further perspectives about the complexity and diversity of the raphe nuclei in epilepsy are also addressed.
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Affiliation(s)
- He-Ming Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Chen-Shu Gao
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Qiu-Wen Lou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
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Joyal KG, Kreitlow BL, Buchanan GF. The role of sleep state and time of day in modulating breathing in epilepsy: implications for sudden unexpected death in epilepsy. Front Neural Circuits 2022; 16:983211. [PMID: 36082111 PMCID: PMC9445500 DOI: 10.3389/fncir.2022.983211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with refractory epilepsy. While the exact etiology of SUDEP is unknown, mounting evidence implicates respiratory dysfunction as a precipitating factor in cases of seizure-induced death. Dysregulation of breathing can occur in epilepsy patients during and after seizures as well as interictally, with many epilepsy patients exhibiting sleep-disordered breathing (SDB), such as obstructive sleep apnea (OSA). The majority of SUDEP cases occur during the night, with the victim found prone in or near a bed. As breathing is modulated in both a time-of-day and sleep state-dependent manner, it is relevant to examine the added burden of nocturnal seizures on respiratory function. This review explores the current state of understanding of the relationship between respiratory function, sleep state and time of day, and epilepsy. We highlight sleep as a particularly vulnerable period for individuals with epilepsy and press that this topic warrants further investigation in order to develop therapeutic interventions to mitigate the risk of SUDEP.
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Affiliation(s)
- Katelyn G. Joyal
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Benjamin L. Kreitlow
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gordon F. Buchanan
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- *Correspondence: Gordon F. Buchanan
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Respiratory dysfunction in two rodent models of chronic epilepsy and acute seizures and its link with the brainstem serotonin system. Sci Rep 2022; 12:10248. [PMID: 35715469 PMCID: PMC9205882 DOI: 10.1038/s41598-022-14153-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/02/2022] [Indexed: 11/22/2022] Open
Abstract
Patients with drug-resistant epilepsy can experience respiratory alterations, notably during seizures. The mechanisms underlying long-term alterations in respiratory function remain unclear. As the brainstem 5-HT system is a prominent modulator of respiratory function, this study aimed at determining whether epilepsy is associated with alterations in both the respiratory function and brainstem serotonin (5-HT) system in rats. Epilepsy was triggered by pilocarpine-induced status epilepticus in rats. Our results showed that 30–50% of epileptic (EPI) rats exhibited a sharp decrease in oxygen consumption (SDOC), low metabolic rate of oxygen, and slow regular ventilation (EPI/SDOC + rats). These alterations were detected only in rats with chronic epilepsy, independent of behavioral seizures, were persistent over time, and not associated with death. In these rats, 5-HT fiber density in the nucleus tractus solitarius was lower than that in the control and EPI/SDOC− rats. Both EPI/SDOC + rats and DBA/2 mice that present with audiogenic-induced seizure followed by fatal respiratory arrest—a model of sudden and expected death in epilepsy—had increased transcript levels of tryptophan hydroxylase 2 and 5-HT presynaptic transporter. Thus, our data support that 5-HT alterations are associated with chronic and acute epilepsy-related respiratory dysfunction.
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7
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Ganne C, Hampson JP, Toth E, Hupp NJ, Hampson JS, Mosher JC, Pati S, Lhatoo SD, Lacuey N. Limbic and paralimbic respiratory modulation: from inhibition to enhancement. Epilepsia 2022; 63:1799-1811. [PMID: 35352347 DOI: 10.1111/epi.17244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Increased understanding of the role of cortical structures in respiratory control may help the understanding of seizure-induced respiratory dysfunction that leads to sudden death in epilepsy (SUDEP). The aim of this study was to characterize respiratory responses to electrical stimulation (ES), including inhibition and enhancement of respiration. METHODS We prospectively recruited 19 consecutive patients with intractable epilepsy undergoing stereotactic EEG evaluation from June 2015 to June 2018. Inclusion criteria were patients ≥18 years and in whom ES was indicated for clinical mapping of ictal onset or eloquent cortex as part of the presurgical evaluation. ES was carried out at 50 Hz, 0.2 ms and 1-10 mA current intensity. Common brain regions sampled across all patients were- amygdala (AMY), hippocampus (HG), anterior cingulate gyrus (CING), orbitofrontal cortex (OrbF), temporal neocortex (TNC), temporal pole (TP) and entorhinal cortex (ERC). 755 stimulations were conducted. Quantitative analysis of breathing signal i.e., changes in breathing rate (BR), depth (TV), and minute ventilation (MV) was carried out during ES using the BreathMetrics breathing waveform analysis toolbox. Electrocardiogram, arterial oxygen saturation, end-tidal and transcutaneous carbon dioxide, nasal airflow, and abdominal and thoracic plethysmography were continuously monitored during stimulations. RESULTS Electrical stimulation of TP and CING (at lower current strengths <3mA) increased TV and MV. At 7-10mA, CING decreased TV and MV. On the other hand, decreased TV and MV occurred with stimulation of mesial temporal structures such as AMY and HG. Breathing changes were dependent on stimulation intensity. Lateral temporal, entorhinal, and orbitofrontal cortices did not affect breathing either way. SIGNIFICANCE These findings suggest that breathing responses other than apnea can be induced by ES. Identification of two regions, the temporal pole and anterior cingulate gyrus, for enhancement of breathing may be important in paving the way to future development of strategies for prevention of SUDEP.
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Affiliation(s)
- Chaitanya Ganne
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA
| | - Johnson P Hampson
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,The NINDS Center for SUDEP Research
| | - Emilia Toth
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA
| | - Norma J Hupp
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,The NINDS Center for SUDEP Research
| | - Jaison S Hampson
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA
| | - John C Mosher
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA
| | - Sandipan Pati
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA
| | - Samden D Lhatoo
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,The NINDS Center for SUDEP Research
| | - Nuria Lacuey
- Texas Institute of Restorative Neurotechnologies (TIRN), University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,Department of Neurology, University of Texas Health Science Center (UTHealth), Houston, Texas, USA.,The NINDS Center for SUDEP Research
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8
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Zhong Y, Wang Y, He Z, Lin Z, Pang N, Niu L, Guo Y, Pan M, Meng L. Closed-loop wearable ultrasound deep brain stimulation system based on EEG in mice. J Neural Eng 2021; 18. [PMID: 34388739 DOI: 10.1088/1741-2552/ac1d5c] [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: 05/15/2021] [Accepted: 08/13/2021] [Indexed: 01/19/2023]
Abstract
Objective. Epilepsy is one of the most common severe brain disorders. Ultrasound deep brain stimulation (UDBS) has shown a potential capability to suppress seizures. However, because seizures occur sporadically, it is necessary to develop a closed-loop system to suppress them. Therefore, we developed a closed-loop wearable UDBS system that delivers ultrasound to the hippocampus to suppress epileptic seizures.Approach.Mice were intraperitoneally injected with 10 mg kg-1kainic acid and divided into sham and UDBS groups. Epileptic seizures were detected by applying both long short-term memory (LSTM) and bidirectional LSTM (BILSTM) networks according to EEG signal characteristics. When epileptic seizures were detected, the closed-loop UDBS system automatically activated a trigger switch to stimulate the hippocampus for 10 min and continuously record EEG signals until 20 min after ultrasonic stimulation. EEG signals were analyzed using the MATLAB software. After EEG recording, we observed the survival rate of the experimental mice for 72 h.Main results.The BiLSTM network was found to have preferable classification performance over the LSTM network. The closed-loop UDBS system with BiLSTM could automatically detect epileptic seizures using EEG signals and effectively reduce epileptic EEG power spectral density and seizure duration by 10.73%, eventually improving the survival rate of early epileptic mice from 67.57% in the sham group to 88.89% in the UDBS group.Significance.The closed-loop UDBS system developed in this study could be an effective clinical tool for the control of epilepsy.
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Affiliation(s)
- Yongsheng Zhong
- Neurosurgery Center, Department of Functional Neurosurgery, The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular Disease, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, The Neurosurgery Institute of Guangdong Province, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, People's Republic of China.,Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
| | - Yibo Wang
- Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
| | - Zhuoyi He
- Neurosurgery Center, Department of Functional Neurosurgery, The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular Disease, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, The Neurosurgery Institute of Guangdong Province, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, People's Republic of China
| | - Zhengrong Lin
- Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
| | - Na Pang
- Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
| | - Lili Niu
- Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
| | - Yanwu Guo
- Neurosurgery Center, Department of Functional Neurosurgery, The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular Disease, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, The Neurosurgery Institute of Guangdong Province, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, People's Republic of China
| | - Min Pan
- Department of Ultrasound, Shenzhen Hospital (Futian) of Guangzhou University of Chinese Medicine, Shenzhen 518034, People's Republic of China
| | - Long Meng
- Institute of Biomedical and Health engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, People's Republic of China
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Revealing the Precise Role of Calretinin Neurons in Epilepsy: We Are on the Way. Neurosci Bull 2021; 38:209-222. [PMID: 34324145 PMCID: PMC8821741 DOI: 10.1007/s12264-021-00753-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/24/2021] [Indexed: 02/03/2023] Open
Abstract
Epilepsy is a common neurological disorder characterized by hyperexcitability in the brain. Its pathogenesis is classically associated with an imbalance of excitatory and inhibitory neurons. Calretinin (CR) is one of the three major types of calcium-binding proteins present in inhibitory GABAergic neurons. The functions of CR and its role in neural excitability are still unknown. Recent data suggest that CR neurons have diverse neurotransmitters, morphologies, distributions, and functions in different brain regions across various species. Notably, CR neurons in the hippocampus, amygdala, neocortex, and thalamus are extremely susceptible to excitotoxicity in the epileptic brain, but the causal relationship is unknown. In this review, we focus on the heterogeneous functions of CR neurons in different brain regions and their relationship with neural excitability and epilepsy. Importantly, we provide perspectives on future investigations of the role of CR neurons in epilepsy.
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10
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K v1.1 channels mediate network excitability and feed-forward inhibition in local amygdala circuits. Sci Rep 2021; 11:15180. [PMID: 34312446 PMCID: PMC8313690 DOI: 10.1038/s41598-021-94633-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 07/14/2021] [Indexed: 01/15/2023] Open
Abstract
Kv1.1 containing potassium channels play crucial roles towards dampening neuronal excitability. Mice lacking Kv1.1 subunits (Kcna1−/−) display recurrent spontaneous seizures and often exhibit sudden unexpected death. Seizures in Kcna1−/− mice resemble those in well-characterized models of temporal lobe epilepsy known to involve limbic brain regions and spontaneous seizures result in enhanced cFos expression and neuronal death in the amygdala. Yet, the functional alterations leading to amygdala hyperexcitability have not been identified. In this study, we used Kcna1−/− mice to examine the contributions of Kv1.1 subunits to excitability in neuronal subtypes from basolateral (BLA) and central lateral (CeL) amygdala known to exhibit distinct firing patterns. We also analyzed synaptic transmission properties in an amygdala local circuit predicted to be involved in epilepsy-related comorbidities. Our data implicate Kv1.1 subunits in controlling spontaneous excitatory synaptic activity in BLA pyramidal neurons. In the CeL, Kv1.1 loss enhances intrinsic excitability and impairs inhibitory synaptic transmission, notably resulting in dysfunction of feed-forward inhibition, a critical mechanism for controlling spike timing. Overall, we find inhibitory control of CeL interneurons is reduced in Kcna1−/− mice suggesting that basal inhibitory network functioning is less able to prevent recurrent hyperexcitation related to seizures.
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11
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Cheng H, Qi Y, Lai N, Yang L, Xu C, Wang S, Guo Y, Chen Z, Wang Y. Inhibition of hyperactivity of the dorsal raphe 5-HTergic neurons ameliorates hippocampal seizure. CNS Neurosci Ther 2021; 27:963-972. [PMID: 33955651 PMCID: PMC8265946 DOI: 10.1111/cns.13648] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/08/2021] [Accepted: 04/11/2021] [Indexed: 01/07/2023] Open
Abstract
Aims Epilepsy, frequently comorbid with depression, easily develops drug resistance. Here, we investigated how dorsal raphe (DR) and its 5‐HTergic neurons are implicated in epilepsy. Methods In mouse hippocampal kindling model, using immunochemistry, calcium fiber photometry, and optogenetics, we investigated the causal role of DR 5‐HTergic neurons in seizure of temporal lobe epilepsy (TLE). Further, deep brain stimulation (DBS) of the DR with different frequencies was applied to test its effect on hippocampal seizure and depressive‐like behavior. Results Number of c‐fos+ neurons in the DR and calcium activities of DR 5‐HTergic neurons were both increased during kindling‐induced hippocampal seizures. Optogenetic inhibition, but not activation, of DR 5‐HTergic neurons conspicuously retarded seizure acquisition specially during the late period. For clinical translation, 1‐Hz‐specific, but not 20‐Hz or 100‐Hz, DBS of the DR retarded the acquisition of hippocampal seizure. This therapeutic effect may be mediated by the inhibition of DR 5‐HTergic neurons, as optogenetic activation of DR 5‐HTergic neurons reversed the anti‐seizure effects of 1‐Hz DR DBS. However, DBS treatment had no effect on depressive‐like behavior. Conclusion Inhibition of hyperactivity of DR 5‐HTergic neuron may present promising anti‐seizure effect and the DR may be a potential DBS target for the therapy of TLE.
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Affiliation(s)
- Heming Cheng
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yingbei Qi
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Lin Yang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Guo
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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12
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Maia OAC, Malheiros-Lima MR, Oliveira MA, Castro CL, Moriya HT, Tavares-de-Lima W, Takakura AC, Moreira TS. Pilocarpine-induced status epilepticus reduces chemosensory control of breathing. Brain Res Bull 2020; 161:98-105. [PMID: 32433938 DOI: 10.1016/j.brainresbull.2020.05.002] [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: 12/04/2019] [Revised: 04/27/2020] [Accepted: 05/02/2020] [Indexed: 12/14/2022]
Abstract
One of the possible causes of death in epilepsy is breathing disorders, especially apneas, which lead to an increase in CO2 levels (hypercapnia) and/or a decrease in O2 levels in arterial blood (hypoxemia). The respiratory neurons located in the ventral brainstem respiratory column are the main groups responsible for controlling breathing. Recent data from our group demonstrated respiratory changes in two experimental models of epilepsy, i.e. audiogenic epilepsy, and amygdala rapid kindling. Here, we aimed to evaluate respiratory changes in the classic model of temporal lobe epilepsy induced by intra-hippocampal injection of pilocarpine. Adult Wistar rats with stainless-steel cannulas implanted in the hippocampus region were used. The animals were submitted to pilocarpine injection (2.4 mg/μL, N = 12-15) or saline (N = 9) into the hippocampus. The respiratory parameters analyzed by whole-body plethysmography were respiratory rate (fR), tidal volume (VT) and ventilation (VE). Respiratory mechanics such as Newtonian airway resistance (Rn), viscance of the pulmonary parenchyma (G) and the elastance of the pulmonary parenchyma (H) were also investigated. No changes in baseline breathing were detected 15 or 30 days after pilocarpine-induced status epilepticus (SE). However, 30 days after pilocarpine-induced SE, a significant reduction in VE was observed during hypercapnic (7% CO2) stimulation, without affecting the hypoxia (8% O2) ventilatory response. We also did not observe changes in respiratory mechanics. The present results suggest that the impairment of the hypercapnia ventilatory response in pilocarpine-induced SE could be related to a presumable degeneration of brainstem respiratory neurons but not to peripheral mechanisms.
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Affiliation(s)
- Octávio A C Maia
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of Sao Paulo, 1524 Prof Lineu Prestes Av 05508-000, Sao Paulo, SP, Brazil
| | - Milene R Malheiros-Lima
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of Sao Paulo, 1524 Prof Lineu Prestes Av 05508-000, Sao Paulo, SP, Brazil
| | - Maria A Oliveira
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Claudio L Castro
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of Sao Paulo, 1524 Prof Lineu Prestes Av 05508-000, Sao Paulo, SP, Brazil
| | - Henrique T Moriya
- Department of Engineering of Control and Telecommunication, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Wothan Tavares-de-Lima
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of Sao Paulo, 1524 Prof Lineu Prestes Av 05508-000, Sao Paulo, SP, Brazil.
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Somani A, Perry C, Patodia S, Michalak Z, Ellis M, Sisodiya SM, Thom M. Neuropeptide depletion in the amygdala in sudden unexpected death in epilepsy: A postmortem study. Epilepsia 2020; 61:310-318. [PMID: 31958887 DOI: 10.1111/epi.16425] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is typically unwitnessed but can be preceded by seizures in the period prior to death. Peri-ictal respiratory dysfunction is a likely mechanism for some SUDEP, and central apnea has been shown following amygdala stimulation. The amygdala is enriched in neuropeptides that modulate neuronal activity and can be transiently depleted following seizures. In a postmortem SUDEP series, we sought to investigate alterations of neuropeptidergic networks in the amygdala, including cases with recent poor seizure control. METHODS In 15 SUDEP cases, 12 epilepsy controls, and 10 nonepilepsy controls, we quantified the labeling index (LI) for galanin, neuropeptide Y (NPY), and somatostatin (SST) in the lateral, basal, and accessory basal nuclei and periamygdala cortex with whole slide scanning image analysis. Within the SUDEP group, seven had recent generalized seizures with recovery 24 hours prior to death (SUDEP-R). RESULTS Galanin, NPY, and SST LIs were significantly lower in all amygdala regions in SUDEP cases compared to epilepsy controls (P < .05 to P < .0005), and galanin LI was lower in the lateral nucleus compared to nonepilepsy controls (P < .05). There was no difference in the LI in the SUDEP-R group compared to other SUDEP. Higher LI was noted in epilepsy controls than nonepilepsy controls; this was significant for NPY in lateral and basal nuclei (P < .005 and P < .05). SIGNIFICANCE A reduction in galanin in the lateral nucleus in SUDEP could represent acute depletion, relevant to postictal amygdala dysfunction. In addition, increased amygdala neuropeptides in epilepsy controls support their seizure-induced modulation, which is relatively deficient in SUDEP; this could represent a vulnerability factor for amygdala dysfunction in the postictal period.
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Affiliation(s)
- Alyma Somani
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Charlotte Perry
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Smriti Patodia
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Zuzanna Michalak
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Matthew Ellis
- Neuropathology Division, National Hospital for Neurology and Neurosurgery, London, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Bucks, UK
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK.,Neuropathology Division, National Hospital for Neurology and Neurosurgery, London, UK
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