1
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Dyomina AV, Smolensky IV, Zaitsev AV. Refinement of the Barnes and Morris water maze protocols improves characterization of spatial cognitive deficits in the lithium-pilocarpine rat model of epilepsy. Epilepsy Behav 2023; 147:109391. [PMID: 37619464 DOI: 10.1016/j.yebeh.2023.109391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/28/2023] [Accepted: 07/30/2023] [Indexed: 08/26/2023]
Abstract
Temporal lobe epilepsy (TLE) often causes cognitive impairment, especially a decline in spatial memory. Reductions in spatial memory and learning are also common in rodent models of TLE. The Morris water maze and the Barnes maze are the standard methods for evaluating spatial learning and memory in rodents. However, animals with TLE may exhibit agitation, distress, and fail to follow the paradigmatic context of these tests, making the interpretation of experimental data difficult. This study optimized the procedure of the Morris water maze and the Barnes maze to evaluate spatial learning and memory in rats with the lithium-pilocarpine TLE model (LPM rats). It was demonstrated that LPM rats required a mandatory and prolonged habituation stage for both tests. Therefore, the experimental rats performed relatively well on these tests. Nevertheless, LPM rats exhibited a slower learning process compared to the control rats. LPM rats also showed a reduction in spatial memory formation. This was more pronounced in the Barnes maze. Also, LPM rats utilized a sequential strategy for searching in the Barnes maze and were incapable of developing a more efficient spatial search strategy that is common in control animals. The Barnes maze may be a better choice for assessing search strategies, learning deficits, and spatial memory in rats with TLE when choosing between the two tests. This is because of the risk of unexpected seizure occurrence during the Morris water maze tests, and the potential risks for animal welfare.
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Affiliation(s)
- Alexandra V Dyomina
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg 194223, Russia
| | - Ilya V Smolensky
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg 194223, Russia; Department of Community Health, University of Fribourg, Chemin du Musée 4, 1700 Fribourg, Switzerland; Department of Biomedicine, University of Basel, Hebelstrasse 20, 4056 Basel, Switzerland
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg 194223, Russia.
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2
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McNerney MW, Gurkoff GG, Beard C, Berryhill ME. The Rehabilitation Potential of Neurostimulation for Mild Traumatic Brain Injury in Animal and Human Studies. Brain Sci 2023; 13:1402. [PMID: 37891771 PMCID: PMC10605899 DOI: 10.3390/brainsci13101402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Neurostimulation carries high therapeutic potential, accompanied by an excellent safety profile. In this review, we argue that an arena in which these tools could provide breakthrough benefits is traumatic brain injury (TBI). TBI is a major health problem worldwide, with the majority of cases identified as mild TBI (mTBI). MTBI is of concern because it is a modifiable risk factor for dementia. A major challenge in studying mTBI is its inherent heterogeneity across a large feature space (e.g., etiology, age of injury, sex, treatment, initial health status, etc.). Parallel lines of research in human and rodent mTBI can be collated to take advantage of the full suite of neuroscience tools, from neuroimaging (electroencephalography: EEG; functional magnetic resonance imaging: fMRI; diffusion tensor imaging: DTI) to biochemical assays. Despite these attractive components and the need for effective treatments, there are at least two major challenges to implementation. First, there is insufficient understanding of how neurostimulation alters neural mechanisms. Second, there is insufficient understanding of how mTBI alters neural function. The goal of this review is to assemble interrelated but disparate areas of research to identify important gaps in knowledge impeding the implementation of neurostimulation.
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Affiliation(s)
- M. Windy McNerney
- Mental Illness Research Education and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; (M.W.M.); (C.B.)
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gene G. Gurkoff
- Department of Neurological Surgery, and Center for Neuroscience, University of California, Davis, Sacramento, CA 95817, USA;
- Department of Veterans Affairs, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Charlotte Beard
- Mental Illness Research Education and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; (M.W.M.); (C.B.)
- Program in Neuroscience and Behavioral Biology, Emory University, Atlanta, GA 30322, USA
| | - Marian E. Berryhill
- Programs in Cognitive and Brain Sciences, and Integrative Neuroscience, Department of Psychology, University of Nevada, Reno, NV 89557, USA
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3
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Piper RJ, Richardson RM, Worrell G, Carmichael DW, Baldeweg T, Litt B, Denison T, Tisdall MM. Towards network-guided neuromodulation for epilepsy. Brain 2022; 145:3347-3362. [PMID: 35771657 PMCID: PMC9586548 DOI: 10.1093/brain/awac234] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/30/2022] [Accepted: 06/16/2022] [Indexed: 11/30/2022] Open
Abstract
Epilepsy is well-recognized as a disorder of brain networks. There is a growing body of research to identify critical nodes within dynamic epileptic networks with the aim to target therapies that halt the onset and propagation of seizures. In parallel, intracranial neuromodulation, including deep brain stimulation and responsive neurostimulation, are well-established and expanding as therapies to reduce seizures in adults with focal-onset epilepsy; and there is emerging evidence for their efficacy in children and generalized-onset seizure disorders. The convergence of these advancing fields is driving an era of 'network-guided neuromodulation' for epilepsy. In this review, we distil the current literature on network mechanisms underlying neurostimulation for epilepsy. We discuss the modulation of key 'propagation points' in the epileptogenic network, focusing primarily on thalamic nuclei targeted in current clinical practice. These include (i) the anterior nucleus of thalamus, now a clinically approved and targeted site for open loop stimulation, and increasingly targeted for responsive neurostimulation; and (ii) the centromedian nucleus of the thalamus, a target for both deep brain stimulation and responsive neurostimulation in generalized-onset epilepsies. We discuss briefly the networks associated with other emerging neuromodulation targets, such as the pulvinar of the thalamus, piriform cortex, septal area, subthalamic nucleus, cerebellum and others. We report synergistic findings garnered from multiple modalities of investigation that have revealed structural and functional networks associated with these propagation points - including scalp and invasive EEG, and diffusion and functional MRI. We also report on intracranial recordings from implanted devices which provide us data on the dynamic networks we are aiming to modulate. Finally, we review the continuing evolution of network-guided neuromodulation for epilepsy to accelerate progress towards two translational goals: (i) to use pre-surgical network analyses to determine patient candidacy for neurostimulation for epilepsy by providing network biomarkers that predict efficacy; and (ii) to deliver precise, personalized and effective antiepileptic stimulation to prevent and arrest seizure propagation through mapping and modulation of each patients' individual epileptogenic networks.
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Affiliation(s)
- Rory J Piper
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | | | | | - Torsten Baldeweg
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Brian Litt
- Department of Neurology and Bioengineering, University of Pennsylvania, Philadelphia, USA
| | | | - Martin M Tisdall
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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4
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Cole ER, Grogan DP, Laxpati NG, Fernandez AM, Skelton HM, Isbaine F, Gutekunst CA, Gross RE. Evidence supporting deep brain stimulation of the medial septum in the treatment of temporal lobe epilepsy. Epilepsia 2022; 63:2192-2213. [PMID: 35698897 DOI: 10.1111/epi.17326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 12/28/2022]
Abstract
Electrical brain stimulation has become an essential treatment option for more than one third of epilepsy patients who are resistant to pharmacological therapy and are not candidates for surgical resection. However, currently approved stimulation paradigms achieve only moderate success, on average providing approximately 75% reduction in seizure frequency and extended periods of seizure freedom in nearly 20% of patients. Outcomes from electrical stimulation may be improved through the identification of novel anatomical targets, particularly those with significant anatomical and functional connectivity to the epileptogenic zone. Multiple studies have investigated the medial septal nucleus (i.e., medial septum) as such a target for the treatment of mesial temporal lobe epilepsy. The medial septum is a small midline nucleus that provides a critical functional role in modulating the hippocampal theta rhythm, a 4-7-Hz electrophysiological oscillation mechanistically associated with memory and higher order cognition in both rodents and humans. Elevated theta oscillations are thought to represent a seizure-resistant network activity state, suggesting that electrical neuromodulation of the medial septum and restoration of theta-rhythmic physiology may not only reduce seizure frequency, but also restore cognitive comorbidities associated with mesial temporal lobe epilepsy. Here, we review the anatomical and physiological function of the septohippocampal network, evidence for seizure-resistant effects of the theta rhythm, and the results of stimulation experiments across both rodent and human studies, to argue that deep brain stimulation of the medial septum holds potential to provide an effective neuromodulation treatment for mesial temporal lobe epilepsy. We conclude by discussing the considerations necessary for further evaluating this treatment paradigm with a clinical trial.
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Affiliation(s)
- Eric R Cole
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | | | - Nealen G Laxpati
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Alejandra M Fernandez
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Henry M Skelton
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Faical Isbaine
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Claire-Anne Gutekunst
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Robert E Gross
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA.,Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
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5
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Wu L, Canna A, Narvaez O, Ma J, Sang S, Lehto LJ, Sierra A, Tanila H, Zhang Y, Gröhn O, Low WC, Filip P, Mangia S, Michaeli S. Orientation selective DBS of entorhinal cortex and medial septal nucleus modulates activity of rat brain areas involved in memory and cognition. Sci Rep 2022; 12:8565. [PMID: 35595790 PMCID: PMC9122972 DOI: 10.1038/s41598-022-12383-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 05/04/2022] [Indexed: 11/09/2022] Open
Abstract
The recently introduced orientation selective deep brain stimulation (OS-DBS) technique freely controls the direction of the electric field's spatial gradient by using multiple contacts with independent current sources within a multielectrode array. The goal of OS-DBS is to align the electrical field along the axonal track of interest passing through the stimulation site. Here we utilized OS-DBS with a planar 3-channel electrode for stimulating the rat entorhinal cortex (EC) and medial septal nucleus (MSN), two promising areas for DBS treatment of Alzheimer's disease. The brain responses to OS-DBS were monitored by whole brain functional magnetic resonance imaging (fMRI) at 9.4 T with Multi-Band Sweep Imaging with Fourier Transformation (MB-SWIFT). Varying the in-plane OS-DBS stimulation angle in the EC resulted in activity modulation of multiple downstream brain areas involved in memory and cognition. Contrary to that, no angle dependence of brain activations was observed when stimulating the MSN, consistent with predictions based on the electrode configuration and on the main axonal directions of the targets derived from diffusion MRI tractography and histology. We conclude that tuning the OS-DBS stimulation angle modulates the activation of brain areas relevant to Alzheimer's disease, thus holding great promise in the DBS treatment of the disease.
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Affiliation(s)
- Lin Wu
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Antonietta Canna
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.,University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Omar Narvaez
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jun Ma
- Department of Neurosurgery, University of Minnesota, Minneapolis, USA
| | - Sheng Sang
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Lauri J Lehto
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Alejandra Sierra
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Heikki Tanila
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Yuan Zhang
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Olli Gröhn
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Walter C Low
- Department of Neurosurgery, University of Minnesota, Minneapolis, USA
| | - Pavel Filip
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.,Department of Neurology, First Faculty of Medicine and General University Hospital, Charles University, Prague, Czech Republic
| | - Silvia Mangia
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Shalom Michaeli
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA. .,Radiology Department, Center for MR Research, University of Minnesota, 2021 6th St. SE, Minneapolis, MN, 55455, USA.
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6
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Abstract
There has been a major emphasis on defining the role of seizures in the causation of cognitive impairments like memory deficits in epilepsy. Here we focus on an alternative hypothesis behind these deficits, emphasizing the mechanisms of information processing underlying healthy cognition characterized as rate, temporal and population coding. We discuss the role of the underlying etiology of epilepsy in altering neural networks thereby leading to both the propensity for seizures and the associated cognitive impairments. In addition, we address potential treatments that can recover the network function in the context of a diseased brain, thereby improving both seizure and cognitive outcomes simultaneously. This review shows the importance of moving beyond seizures and approaching the deficits from a system-level perspective with the guidance of network neuroscience.
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Affiliation(s)
- Mohamed R. Khalife
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Rod C. Scott
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
- Institute of Child Health, Neurosciences Unit University College London, London, United Kingdom
| | - Amanda E. Hernan
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
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7
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da Silva Fiorin F, de Araújo E Silva M, Rodrigues AC. Electrical stimulation in animal models of epilepsy: A review on cellular and electrophysiological aspects. Life Sci 2021; 285:119972. [PMID: 34560081 DOI: 10.1016/j.lfs.2021.119972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/02/2021] [Accepted: 09/17/2021] [Indexed: 01/24/2023]
Abstract
Epilepsy is a debilitating condition, primarily refractory individuals, leading to the search for new efficient therapies. Electrical stimulation is an important method used for years to treat several neurological disorders. Currently, electrical stimulation is used to reduce epileptic crisis in patients and shows promising results. Even though the use of electricity to treat neurological disorders has grown worldwide, there are still many caveats that must be clarified, such as action mechanisms and more efficient stimulation treatment parameters. Thus, this review aimed to explore the comprehension of the main stimulation methods in animal models of epilepsy using rodents to develop new experimental protocols and therapeutic approaches.
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Affiliation(s)
- Fernando da Silva Fiorin
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Brazil.
| | - Mariane de Araújo E Silva
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Brazil
| | - Abner Cardoso Rodrigues
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Brazil
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8
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Izadi A, Schedlbauer A, Ondek K, Disse G, Ekstrom AD, Cowen SL, Shahlaie K, Gurkoff GG. Early Intervention via Stimulation of the Medial Septal Nucleus Improves Cognition and Alters Markers of Epileptogenesis in Pilocarpine-Induced Epilepsy. Front Neurol 2021; 12:708957. [PMID: 34557145 PMCID: PMC8452867 DOI: 10.3389/fneur.2021.708957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Over one-third of patients with temporal lobe epilepsy are refractory to medication. In addition, anti-epileptic drugs often exacerbate cognitive comorbidities. Neuromodulation is an FDA treatment for refractory epilepsy, but patients often wait >20 years for a surgical referral for resection or neuromodulation. Using a rodent model, we test the hypothesis that 2 weeks of theta stimulation of the medial septum acutely following exposure to pilocarpine will alter the course of epileptogenesis resulting in persistent behavioral improvements. Electrodes were implanted in the medial septum, dorsal and ventral hippocampus, and the pre-frontal cortex of pilocarpine-treated rats. Rats received 30 min/day of 7.7 Hz or theta burst frequency on days 4-16 post-pilocarpine, prior to the development of spontaneous seizures. Seizure threshold, spikes, and oscillatory activity, as well as spatial and object-based learning, were assessed in the weeks following stimulation. Non-stimulated pilocarpine animals exhibited significantly decreased seizure threshold, increased spikes, and cognitive impairments as compared to vehicle controls. Furthermore, decreased ventral hippocampal power (6-10 Hz) correlated with both the development of spikes and impaired cognition. Measures of spikes, seizure threshold, and cognitive performance in both acute 7.7 Hz and theta burst stimulated animals were statistically similar to vehicle controls when tested during the chronic phase of epilepsy, weeks after stimulation was terminated. These data indicate that modulation of the septohippocampal circuit early after pilocarpine treatment alters the progression of epileptic activity, resulting in elevated seizure thresholds, fewer spikes, and improved cognitive outcome. Results from this study support that septal theta stimulation has the potential to serve in combination or as an alternative to high frequency thalamic stimulation in refractory cases and that further research into early intervention is critical.
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Affiliation(s)
- Ali Izadi
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Amber Schedlbauer
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States
| | - Katelynn Ondek
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Gregory Disse
- Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Arne D Ekstrom
- Department of Psychology, University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Stephen L Cowen
- Department of Psychology, University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
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9
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Takeuchi Y, Harangozó M, Pedraza L, Földi T, Kozák G, Li Q, Berényi A. Closed-loop stimulation of the medial septum terminates epileptic seizures. Brain 2021; 144:885-908. [PMID: 33501929 DOI: 10.1093/brain/awaa450] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/29/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022] Open
Abstract
Temporal lobe epilepsy with distributed hippocampal seizure foci is often intractable and its secondary generalization might lead to sudden death. Early termination through spatially extensive hippocampal intervention is not feasible directly, because of the large size and irregular shape of the hippocampus. In contrast, the medial septum is a promising target to govern hippocampal oscillations through its divergent connections to both hippocampi. Combining this 'proxy intervention' concept and precisely timed stimulation, we report here that closed-loop medial septum electrical stimulation can quickly terminate intrahippocampal seizures and suppress secondary generalization in a rat kindling model. Precise stimulus timing governed by internal seizure rhythms was essential. Cell type-specific stimulation revealed that the precisely timed activation of medial septum GABAergic neurons underlaid the effects. Our concept of time-targeted proxy stimulation for intervening pathological oscillations can be extrapolated to other neurological and psychiatric disorders, and has potential for clinical translation.
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Affiliation(s)
- Yuichi Takeuchi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.,Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan.,Neurocybernetics Excellence Center, University of Szeged, Szeged 6720, Hungary
| | - Márk Harangozó
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary
| | - Lizeth Pedraza
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.,Neurocybernetics Excellence Center, University of Szeged, Szeged 6720, Hungary
| | - Tamás Földi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.,Neurocybernetics Excellence Center, University of Szeged, Szeged 6720, Hungary
| | - Gábor Kozák
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary
| | - Qun Li
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.,Neurocybernetics Excellence Center, University of Szeged, Szeged 6720, Hungary
| | - Antal Berényi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.,Neurocybernetics Excellence Center, University of Szeged, Szeged 6720, Hungary.,HCEMM-USZ Magnetotherapeutics Research Group, University of Szeged, Szeged 6720, Hungary.,Neuroscience Institute, New York University, New York, NY 10016, USA
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10
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Takeuchi Y, Nagy AJ, Barcsai L, Li Q, Ohsawa M, Mizuseki K, Berényi A. The Medial Septum as a Potential Target for Treating Brain Disorders Associated With Oscillopathies. Front Neural Circuits 2021; 15:701080. [PMID: 34305537 PMCID: PMC8297467 DOI: 10.3389/fncir.2021.701080] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
The medial septum (MS), as part of the basal forebrain, supports many physiological functions, from sensorimotor integration to cognition. With often reciprocal connections with a broad set of peers at all major divisions of the brain, the MS orchestrates oscillatory neuronal activities throughout the brain. These oscillations are critical in generating sensory and emotional salience, locomotion, maintaining mood, supporting innate anxiety, and governing learning and memory. Accumulating evidence points out that the physiological oscillations under septal influence are frequently disrupted or altered in pathological conditions. Therefore, the MS may be a potential target for treating neurological and psychiatric disorders with abnormal oscillations (oscillopathies) to restore healthy patterns or erase undesired ones. Recent studies have revealed that the patterned stimulation of the MS alleviates symptoms of epilepsy. We discuss here that stimulus timing is a critical determinant of treatment efficacy on multiple time scales. On-demand stimulation may dramatically reduce side effects by not interfering with normal physiological functions. A precise pattern-matched stimulation through adaptive timing governed by the ongoing oscillations is essential to effectively terminate pathological oscillations. The time-targeted strategy for the MS stimulation may provide an effective way of treating multiple disorders including Alzheimer's disease, anxiety/fear, schizophrenia, and depression, as well as pain.
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Affiliation(s)
- Yuichi Takeuchi
- Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Anett J. Nagy
- MTA-SZTE ‘Momentum’ Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary
| | - Lívia Barcsai
- MTA-SZTE ‘Momentum’ Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary
| | - Qun Li
- MTA-SZTE ‘Momentum’ Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary
| | - Masahiro Ohsawa
- Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Kenji Mizuseki
- Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Antal Berényi
- MTA-SZTE ‘Momentum’ Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, Hungary
- Neurocybernetics Excellence Center, University of Szeged, Szeged, Hungary
- HCEMM-USZ Magnetotherapeutics Research Group, University of Szeged, Szeged, Hungary
- Neuroscience Institute, New York University, New York, NY, United States
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11
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Hristova K, Martinez-Gonzalez C, Watson TC, Codadu NK, Hashemi K, Kind PC, Nolan MF, Gonzalez-Sulser A. Medial septal GABAergic neurons reduce seizure duration upon optogenetic closed-loop stimulation. Brain 2021; 144:1576-1589. [PMID: 33769452 PMCID: PMC8219369 DOI: 10.1093/brain/awab042] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/16/2020] [Accepted: 12/06/2020] [Indexed: 11/22/2022] Open
Abstract
Seizures can emerge from multiple or large foci in temporal lobe epilepsy, complicating focally targeted strategies such as surgical resection or the modulation of the activity of specific hippocampal neuronal populations through genetic or optogenetic techniques. Here, we evaluate a strategy in which optogenetic activation of medial septal GABAergic neurons, which provide extensive projections throughout the hippocampus, is used to control seizures. We utilized the chronic intrahippocampal kainate mouse model of temporal lobe epilepsy, which results in spontaneous seizures and as is often the case in human patients, presents with hippocampal sclerosis. Medial septal GABAergic neuron populations were immunohistochemically labelled and were not reduced in epileptic conditions. Genetic labelling with mRuby of medial septal GABAergic neuron synaptic puncta and imaging across the rostral to caudal extent of the hippocampus, also indicated an unchanged number of putative synapses in epilepsy. Furthermore, optogenetic stimulation of medial septal GABAergic neurons consistently modulated oscillations across multiple hippocampal locations in control and epileptic conditions. Finally, wireless optogenetic stimulation of medial septal GABAergic neurons, upon electrographic detection of spontaneous hippocampal seizures, resulted in reduced seizure durations. We propose medial septal GABAergic neurons as a novel target for optogenetic control of seizures in temporal lobe epilepsy.
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Affiliation(s)
- Katerina Hristova
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | - Cristina Martinez-Gonzalez
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | - Thomas C Watson
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | - Neela K Codadu
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | | | - Peter C Kind
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | - Matthew F Nolan
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
| | - Alfredo Gonzalez-Sulser
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing
Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain and Patrick Wild Centre, University
of Edinburgh, Edinburgh, UK
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12
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Abstract
The treatment of epilepsy remains extremely challenging for the thirty percent of people that do not become seizure free. This is despite the introduction of multiple new drugs over that last several decades, highlighting the need for new approaches to identifying novel therapeutic strategies. Conceptualizing the brain as a complex adaptive system and applying the tools that are used in addressing such systems provides an opportunity for expanding the space in which to search for new therapies. Epilepsy has long been considered a network disease at the level of whole brain connectivity, but the application of the concepts to gene and protein expression networks as well as to the dynamic behaviors of microcircuits has been underexplored. These levels of the brain complex adaptive system will be reviewed and a case made for the epilepsy community to embrace these concepts in order to reap to enormous potential rewards.
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Affiliation(s)
- Rod C Scott
- University of Vermont, 95 Carrigan Drive, Burlington, VT, 05405, United States; University of Vermont Medical Center, United States; Great Ormond Street Hospital for Children NHS Trust, United Kingdom.
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13
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Wang Y, Shen Y, Cai X, Yu J, Chen C, Tan B, Tan N, Cheng H, Fan X, Wu X, Liu J, Wang S, Wang Y, Chen Z. Deep brain stimulation in the medial septum attenuates temporal lobe epilepsy via entrainment of hippocampal theta rhythm. CNS Neurosci Ther 2021; 27:577-586. [PMID: 33502829 PMCID: PMC8025637 DOI: 10.1111/cns.13617] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/13/2022] Open
Abstract
Aims Temporal lobe epilepsy (TLE), often associated with cognitive impairment, is one of the most common types of medically refractory epilepsy. Deep brain stimulation (DBS) shows considerable promise for the treatment of TLE. However, the optimal stimulation targets and parameters of DBS to control seizures and related cognitive impairment are still not fully illustrated. Methods In the present study, we evaluated the therapeutic potential of DBS in the medial septum (MS) on seizures and cognitive function in mouse acute and chronic epilepsy models. Results We found that DBS in the MS alleviated the severity of seizure activities in both kainic acid‐induced acute seizure model and hippocampal‐kindled epilepsy model. DBS showed antiseizure effects with a wide window of effective stimulation frequencies. The antiseizure effects of DBS were mediated by the hippocampal theta rhythm, as atropine, which reversed the DBS‐induced augmentation of the hippocampal theta oscillation, abolished the antiseizure effects of DBS. Further, in the kainic acid‐induced chronic TLE model, DBS in the MS not only reduced spontaneous seizures, but also improved behavioral performance in novel object recognition. Conclusion DBS in the MS is a promising approach to attenuate TLE probably through entrainment of the hippocampal theta rhythm, which may be therapeutically significant for refractory TLE treatment.
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Affiliation(s)
- Ying Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China.,Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yating Shen
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xianhui Cai
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jie Yu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cong Chen
- Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Bei Tan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Na Tan
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Heming Cheng
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xiang Fan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiaohua Wu
- Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Jinggen Liu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang 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.,Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China.,Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
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14
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Ondek K, Pevzner A, Tercovich K, Schedlbauer AM, Izadi A, Ekstrom AD, Cowen SL, Shahlaie K, Gurkoff GG. Recovery of Theta Frequency Oscillations in Rats Following Lateral Fluid Percussion Corresponds With a Mild Cognitive Phenotype. Front Neurol 2020; 11:600171. [PMID: 33343499 PMCID: PMC7746872 DOI: 10.3389/fneur.2020.600171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/21/2020] [Indexed: 01/31/2023] Open
Abstract
Whether from a fall, sports concussion, or even combat injury, there is a critical need to identify when an individual is able to return to play or work following traumatic brain injury (TBI). Electroencephalogram (EEG) and local field potentials (LFP) represent potential tools to monitor circuit-level abnormalities related to learning and memory: specifically, theta oscillations can be readily observed and play a critical role in cognition. Following moderate traumatic brain injury in the rat, lasting changes in theta oscillations coincide with deficits in spatial learning. We hypothesized, therefore, that theta oscillations can be used as an objective biomarker of recovery, with a return of oscillatory activity corresponding with improved spatial learning. In the current study, LFP were recorded from dorsal hippocampus and anterior cingulate in awake, behaving adult Sprague Dawley rats in both a novel environment on post-injury days 3 and 7, and Barnes maze spatial navigation on post-injury days 8–11. Theta oscillations, as measured by power, theta-delta ratio, peak theta frequency, and phase coherence, were significantly altered on day 3, but had largely recovered by day 7 post-injury. Injured rats had a mild behavioral phenotype and were not different from shams on the Barnes maze, as measured by escape latency. Injured rats did use suboptimal search strategies. Combined with our previous findings that demonstrated a correlation between persistent alterations in theta oscillations and spatial learning deficits, these new data suggest that neural oscillations, and particularly theta oscillations, have potential as a biomarker to monitor recovery of brain function following TBI. Specifically, we now demonstrate that oscillations are depressed following injury, but as oscillations recover, so does behavior.
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Affiliation(s)
- Katelynn Ondek
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Aleksandr Pevzner
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States
| | - Kayleen Tercovich
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Amber M Schedlbauer
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Ali Izadi
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Arne D Ekstrom
- Department of Psychology, The University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, The University of Arizona, Tucson, AZ, United States
| | - Stephen L Cowen
- Department of Psychology, The University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, The University of Arizona, Tucson, AZ, United States
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
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15
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Mihály I, Orbán-Kis K, Gáll Z, Berki ÁJ, Bod RB, Szilágyi T. Amygdala Low-Frequency Stimulation Reduces Pathological Phase-Amplitude Coupling in the Pilocarpine Model of Epilepsy. Brain Sci 2020; 10:brainsci10110856. [PMID: 33202818 PMCID: PMC7696538 DOI: 10.3390/brainsci10110856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/31/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023] Open
Abstract
Temporal-lobe epilepsy (TLE) is the most common type of drug-resistant epilepsy and warrants the development of new therapies, such as deep-brain stimulation (DBS). DBS was applied to different brain regions for patients with epilepsy; however, the mechanisms of action are not fully understood. Therefore, we tried to characterize the effect of amygdala DBS on hippocampal electrical activity in the lithium-pilocarpine model in male Wistar rats. After status epilepticus (SE) induction, seizure patterns were determined based on continuous video recordings. Recording electrodes were inserted in the left and right hippocampus and a stimulating electrode in the left basolateral amygdala of both Pilo and age-matched control rats 10 weeks after SE. Daily stimulation protocol consisted of 4 × 50 s stimulation trains (4-Hz, regular interpulse interval) for 10 days. The hippocampal electroencephalogram was analyzed offline: interictal epileptiform discharge (IED) frequency, spectral analysis, and phase-amplitude coupling (PAC) between delta band and higher frequencies were measured. We found that the seizure rate and duration decreased (by 23% and 26.5%) and the decrease in seizure rate correlated negatively with the IED frequency. PAC was elevated in epileptic animals and DBS reduced the pathologically increased PAC and increased the average theta power (25.9% ± 1.1 vs. 30.3% ± 1.1; p < 0.01). Increasing theta power and reducing the PAC could be two possible mechanisms by which DBS may exhibit its antiepileptic effect in TLE; moreover, they could be used to monitor effectiveness of stimulation.
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Affiliation(s)
- István Mihály
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (K.O.-K.); (Á.-J.B.); (R.-B.B.), (T.S.)
- Correspondence: ; Tel.: +40-749-768-257
| | - Károly Orbán-Kis
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (K.O.-K.); (Á.-J.B.); (R.-B.B.), (T.S.)
| | - Zsolt Gáll
- Department of Pharmacology and Clinical Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania;
| | - Ádám-József Berki
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (K.O.-K.); (Á.-J.B.); (R.-B.B.), (T.S.)
| | - Réka-Barbara Bod
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (K.O.-K.); (Á.-J.B.); (R.-B.B.), (T.S.)
| | - Tibor Szilágyi
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (K.O.-K.); (Á.-J.B.); (R.-B.B.), (T.S.)
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16
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Mankin EA, Fried I. Modulation of Human Memory by Deep Brain Stimulation of the Entorhinal-Hippocampal Circuitry. Neuron 2020; 106:218-235. [PMID: 32325058 DOI: 10.1016/j.neuron.2020.02.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/13/2020] [Accepted: 01/27/2020] [Indexed: 01/02/2023]
Abstract
Neurological disorders affecting human memory present a major scientific, medical, and societal challenge. Direct or indirect deep brain stimulation (DBS) of the entorhinal-hippocampal system, the brain's major memory hub, has been studied in people with epilepsy or Alzheimer's disease, intending to enhance memory performance or slow memory decline. Variability in the spatiotemporal parameters of stimulation employed to date notwithstanding, it is likely that future DBS for memory will employ closed-loop, nuanced approaches that are synergistic with native physiological processes. The potential for editing human memory-decoding, enhancing, incepting, or deleting specific memories-suggests exciting therapeutic possibilities but also raises considerable ethical concerns.
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Affiliation(s)
- Emily A Mankin
- Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Itzhak Fried
- Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA; Tel Aviv Medical Center and Tel Aviv University, Tel Aviv, Israel.
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17
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Mouchati PR, Kloc ML, Holmes GL, White SL, Barry JM. Optogenetic "low-theta" pacing of the septohippocampal circuit is sufficient for spatial goal finding and is influenced by behavioral state and cognitive demand. Hippocampus 2020; 30:1167-1193. [PMID: 32710688 DOI: 10.1002/hipo.23248] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/04/2020] [Accepted: 06/20/2020] [Indexed: 12/21/2022]
Abstract
Hippocampal theta oscillations show prominent changes in frequency and amplitude depending on behavioral state or cognitive demands. How these dynamic changes in theta oscillations contribute to the spatial and temporal organization of hippocampal cells, and ultimately behavior, remain unclear. We used low-theta frequency optogenetic stimulation to pace coordination of cellular and network activity between the medial septum (MS) and hippocampus during baseline and MS stimulation while rats were at rest or performing a spatial accuracy task with a visible or hidden goal zone. Hippocampal receptivity to pan-neuronal septal stimulation at low-theta frequency was primarily determined by speed and secondarily by task demands. Competition between artificial and endogenous field potentials at theta frequency attenuated hippocampal phase preference relative to local theta, but the spike-timing activity of hippocampal pyramidal cells was effectively driven by artificial septal output, particularly during the hidden goal task. Notwithstanding temporal reorganization by artificial theta stimulation, place field properties were unchanged and alterations to spatial behavior were limited to goal zone approximation. Our results indicate that even a low-theta frequency timing signal in the septohippocampal circuit is sufficient for spatial goal finding behavior. The results also advance a mechanistic understanding of how endogenous or artificial somatodendritic timing signals relate to displacement computations during navigation and spatial memory.
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Affiliation(s)
- Philippe R Mouchati
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Michelle L Kloc
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Gregory L Holmes
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Sheryl L White
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Jeremy M Barry
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
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18
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Kahn JB, Port RG, Yue C, Takano H, Coulter DA. Circuit-based interventions in the dentate gyrus rescue epilepsy-associated cognitive dysfunction. Brain 2019; 142:2705-2721. [PMID: 31363737 PMCID: PMC6736326 DOI: 10.1093/brain/awz209] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/26/2019] [Accepted: 05/22/2019] [Indexed: 12/15/2022] Open
Abstract
Temporal lobe epilepsy is associated with significant structural pathology in the hippocampus. In the dentate gyrus, the summative effect of these pathologies is massive hyperexcitability in the granule cells, generating both increased seizure susceptibility and cognitive deficits. To date, therapeutic approaches have failed to improve the cognitive symptoms in fully developed, chronic epilepsy. As the dentate's principal signalling population, the granule cells' aggregate excitability has the potential to provide a mechanistically-independent downstream target. We examined whether normalizing epilepsy-associated granule cell hyperexcitability-without correcting the underlying structural circuit disruptions-would constitute an effective therapeutic approach for cognitive dysfunction. In the systemic pilocarpine mouse model of temporal lobe epilepsy, the epileptic dentate gyrus excessively recruits granule cells in behavioural contexts, not just during seizure events, and these mice fail to perform on a dentate-mediated spatial discrimination task. Acutely reducing dorsal granule cell hyperactivity in chronically epileptic mice via either of two distinct inhibitory chemogenetic receptors rescued behavioural performance such that they responded comparably to wild type mice. Furthermore, recreating granule cell hyperexcitability in control mice via excitatory chemogenetic receptors, without altering normal circuit anatomy, recapitulated spatial memory deficits observed in epileptic mice. However, making the granule cells overly quiescent in both epileptic and control mice again disrupted behavioural performance. These bidirectional manipulations reveal that there is a permissive excitability window for granule cells that is necessary to support successful behavioural performance. Chemogenetic effects were specific to the targeted dorsal hippocampus, as hippocampal-independent and ventral hippocampal-dependent behaviours remained unaffected. Fos expression demonstrated that chemogenetics can modulate granule cell recruitment via behaviourally relevant inputs. Rather than driving cell activity deterministically or spontaneously, chemogenetic intervention merely modulates the behaviourally permissive activity window in which the circuit operates. We conclude that restoring appropriate principal cell tuning via circuit-based therapies, irrespective of the mechanisms generating the disease-related hyperactivity, is a promising translational approach.
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Affiliation(s)
- Julia B Kahn
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Russell G Port
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- The Research Institute of the Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Cuiyong Yue
- The Research Institute of the Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Hajime Takano
- The Research Institute of the Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Douglas A Coulter
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- The Research Institute of the Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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19
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Moxon KA, Shahlaie K, Girgis F, Saez I, Kennedy J, Gurkoff GG. From adagio to allegretto: The changing tempo of theta frequencies in epilepsy and its relation to interneuron function. Neurobiol Dis 2019; 129:169-181. [PMID: 30798003 DOI: 10.1016/j.nbd.2019.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 12/29/2022] Open
Abstract
Despite decades of research, our understanding of epilepsy, including how seizures are generated and propagate, is incomplete. However, there is growing recognition that epilepsy is more than just the occurrence of seizures, with patients often experiencing comorbid deficits in cognition that are poorly understood. In addition, the available therapies for treatment of epilepsy, from pharmaceutical treatment to surgical resection and seizure prevention devices, often exacerbate deficits in cognitive function. In this review, we discuss the hypothesis that seizure generation and cognitive deficits have a similar pathological source characterized by, but not limited to, deficits in theta oscillations and their influence on interneurons. We present a new framework that describes oscillatory states in epilepsy as alternating between hyper- and hypo-synchrony rather than solely the spontaneous transition to hyper-excitability characterized by the seizures. This framework suggests that as neural oscillations, specifically in the theta range, vary their tempo from a slowed almost adagio tempo during interictal periods to faster, more rhythmic allegretto tempo preictally, they impact the function of interneurons, modulating their ability to control seizures and their role in cognitive processing. This slow wave oscillatory framework may help explain why current therapies that work to reduce hyper-excitability do not completely eliminate seizures and often lead to exacerbated cognitive deficits.
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Affiliation(s)
- Karen A Moxon
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, United States of America.
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Fady Girgis
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America
| | - Ignacio Saez
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Jeffrey Kennedy
- Department of Neurology, University of California Davis, Sacramento, CA 95817, United States of America
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
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