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Casillas-Espinosa PM, Lin R, Li R, Nandakumar NM, Dawson G, Braine EL, Martin B, Powell KL, O'Brien TJ. Effects of the T-type calcium channel Ca V3.2 R1584P mutation on absence seizure susceptibility in GAERS and NEC congenic rats models. Neurobiol Dis 2023:106217. [PMID: 37391087 DOI: 10.1016/j.nbd.2023.106217] [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: 11/01/2022] [Revised: 06/13/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023] Open
Abstract
RATIONALE Low-voltage-activated or T-type Ca2+ channels play a key role in the generation of seizures in absence epilepsy. We have described a homozygous, gain of function substitution mutation (R1584P) in the CaV3.2 T-type Ca2+ channel gene (Cacna1h) in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS). The non-epileptic control (NEC) rats, derived from the same original Wistar strains as GAERS but selectively in-breed not to express seizures, are null for the R1584P mutation. To study the effects of this mutation in rats who otherwise have a GAERS or NEC genetic background, we bred congenic GAERS-Cacna1hNEC (GAERS null for R1584P mutation) and congenic NEC-Cacna1hGAERS (NEC homozygous for R1584P mutation) and evaluated the seizure and behavioral phenotype of these strains in comparison to the original GAERS and NEC strains. METHODS To evaluate seizure expression in the congenic strains, EEG electrodes were implanted in NEC, GAERS, GAERS-Cacna1hNEC without the R1584P mutation, and NEC-Cacna1hGAERS with the R1584P mutation rats. In the first study, continuous EEG recordings were acquired from week 4 (when seizures begin to develop in GAERS) to week 14 of age (when GAERS display hundreds of seizures per day). In the second study, the seizure and behavioral phenotype of GAERS and NEC-Cacna1hGAERS strains were evaluated during young age (6 weeks of age) and adulthood (16 weeks of age) of GAERS, NEC, GAERS-Cacna1hNEC and NEC-Cacna1hGAERS. The Open field test (OFT) and sucrose preference test (SPT) were performed to evaluate anxiety-like and depressive-like behavior, respectively. This was followed by EEG recordings at 18 weeks of age to quantify the seizures, and spike-wave discharge (SWD) cycle frequency. At the end of the study, the whole thalamus was collected for T-type calcium channel mRNA expression analysis. RESULTS GAERS had a significantly shorter latency to first seizures and an increased number of seizures per day compared to GAERS-Cacna1hNEC. On the other hand, the presence of the R1584P mutation in the NEC-Cacna1hGAERS was not enough to generate spontaneous seizures in their seizure-resistant background. 6 and 16-week-old GAERS and GAERS-Cacna1hNEC rats showed anxiety-like behavior in the OFT, in contrast to NEC and NEC-Cacna1hGAERS. Results from the SPT showed that the GAERS developed depressive-like in the SPT compared to GAERS-Cacna1hNEC, NEC, and NEC-Cacna1hGAERS. Analysis of the EEG at 18 weeks of age showed that the GAERS had an increased number of seizures per day, increased total seizure duration and a higher cycle frequency of SWD relative to GAERS-Cacna1hNEC. However, the average seizure duration was not significantly different between strains. Quantitative real-time PCR showed that the T-type Ca2+ channel isoform CaV3.2 channel expression was significantly increased in GAERS compared to NEC, GAERS-Cacna1hNEC and NEC-Cacna1hGAERS. The presence of the R1584P mutation increased the total ratio of CaV3.2 + 25/-25 splice variants in GAERS and NEC-Cacna1hGAERS compared to NEC and GAERS-Cacna1hNEC. DISCUSSION The data from this study demonstrate that the R1584P mutation in isolation on a seizure-resistant NEC genetic background was insufficient to generate absence seizures, and that a GAERS genetic background can cause seizures even without the mutation. However, the study provides evidence that the R1584P mutation acts as a modulator of seizures development and expression, and depressive-like behavior in the SPT, but not the anxiety phenotype of the GAERS model of absence epilepsy.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria, 3004, Victoria, Australia.
| | - Runxuan Lin
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Rui Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Nanditha M Nandakumar
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Georgia Dawson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Emma L Braine
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia
| | - Benoît Martin
- Univ Rennes, INSERM, LTSI - UMR 1099, F-35000 Rennes, France
| | - Kim L Powell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria, 3004, Victoria, Australia.
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Li R, Millist L, Foster E, Yuan X, Guvenc U, Radfar M, Marendy P, Ni W, O'Brien TJ, Casillas-Espinosa PM. Spike and wave discharges detection in genetic absence epilepsy rat from Strasbourg and patients with genetic generalized epilepsy. Epilepsy Res 2023; 194:107181. [PMID: 37364342 DOI: 10.1016/j.eplepsyres.2023.107181] [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: 10/19/2022] [Revised: 05/02/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023]
Abstract
OBJECTIVE Generalised spike and wave discharges (SWDs) are pathognomonic EEG signatures for diagnosing absence seizures in patients with Genetic Generalized Epilepsy (GGE). The Genetic Absence Epilepsy Rats from Strasbourg (GAERS) is one of the best-validated animal models of GGE with absence seizures. METHODS We developed an SWDs detector for both GAERS rodents and GGE patients with absence seizures using a neural network method. We included 192 24-hour EEG sessions recorded from 18 GAERS rats, and 24-hour scalp-EEG data collected from 11 GGE patients. RESULTS The SWDs detection performance on GAERS showed a sensitivity of 98.01% and a false positive (FP) rate of 0.96/hour. The performance on GGE patients showed 100% sensitivity in five patients, while the remaining patients obtained over 98.9% sensitivity. Moderate FP rates were seen in our patients with 2.21/hour average FP. The detector trained within our patient cohort was validated in an independent dataset, TUH EEG Seizure Corpus (TUSZ), that showed 100% sensitivity in 11 of 12 patients and 0.56/hour averaged FP. CONCLUSIONS We developed a robust SWDs detector that showed high sensitivity and specificity for both GAERS rats and GGE patients. SIGNIFICANCE This detector can assist researchers and neurologists with the time-efficient and accurate quantification of SWDs.
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Affiliation(s)
- Rui Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia
| | - Lyn Millist
- Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia; Department of Neurology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050, Australia
| | - Emma Foster
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia
| | - Xin Yuan
- Department of Cyber-Physical Systems, Data61, CSIRO, Marsfield, New South Wales 2122, Australia
| | - Umut Guvenc
- Department of Microsystems, Data61, CSIRO, Pullenvale, Queensland 4069, Australia
| | - Mohsen Radfar
- Department of Microsystems, Data61, CSIRO, Pullenvale, Queensland 4069, Australia
| | - Peter Marendy
- Department of Microsystems, Data61, CSIRO, Pullenvale, Queensland 4069, Australia
| | - Wei Ni
- Department of Cyber-Physical Systems, Data61, CSIRO, Marsfield, New South Wales 2122, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia; Department of Neurology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050, Australia; Department of Medicine, The University of Melbourne, Parkville 3050, Victoria, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia; Department of Medicine, The University of Melbourne, Parkville 3050, Victoria, Australia.
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Kundu B, Arain A, Davis T, Charlebois CM, Rolston JD. Using chronic recordings from a closed-loop neurostimulation system to capture seizures across multiple thalamic nuclei. Ann Clin Transl Neurol 2022; 10:136-143. [PMID: 36480536 PMCID: PMC9852392 DOI: 10.1002/acn3.51701] [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: 05/25/2022] [Revised: 10/21/2022] [Accepted: 10/26/2022] [Indexed: 12/13/2022] Open
Abstract
We report the case of a patient with unilateral diffuse frontotemporal epilepsy in whom we implanted a responsive neurostimulation system with leads spanning the anterior and centromedian nucleus of the thalamus. During chronic recording, ictal activity in the centromedian nucleus consistently preceded the anterior nucleus, implying a temporally organized seizure network involving the thalamus. With stimulation, the patient had resolution of focal impaired awareness seizures and secondarily generalized seizures. This report describes chronic recordings of seizure activity from multiple thalamic nuclei within a hemisphere and demonstrates the potential efficacy of closed-loop neurostimulation of multiple thalamic nuclei to control seizures.
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Affiliation(s)
- Bornali Kundu
- Department of Neurosurgery, Clinical Neurosciences CenterUniversity of UtahSalt Lake CityUtahUSA
| | - Amir Arain
- Department of NeurologyUniversity of UtahSalt Lake CityUtahUSA
| | - Tyler Davis
- Department of Neurosurgery, Clinical Neurosciences CenterUniversity of UtahSalt Lake CityUtahUSA
| | | | - John D. Rolston
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
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Sharma R, Casillas-Espinosa PM, Dill LK, Rewell SSJ, Hudson MR, O'Brien TJ, Shultz SR, Semple BD. Pediatric traumatic brain injury and a subsequent transient immune challenge independently influenced chronic outcomes in male mice. Brain Behav Immun 2022; 100:29-47. [PMID: 34808288 DOI: 10.1016/j.bbi.2021.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 10/27/2021] [Accepted: 11/15/2021] [Indexed: 01/30/2023] Open
Abstract
Traumatic brain injury (TBI) is a major contributor to death and disability worldwide. Children are at particularly high risk of both sustaining a TBI and experiencing serious long-term consequences, such as cognitive deficits, mental health problems and post-traumatic epilepsy. Severe TBI patients are highly susceptible to nosocomial infections, which are mostly acquired within the first week of hospitalization post-TBI. Yet the potential chronic impact of such acute infections following pediatric TBI remains unclear. In this study, we hypothesized that a peripheral immune challenge, such as lipopolysaccharide (LPS)-mimicking a hospital-acquired infection-would worsen inflammatory, neurobehavioral, and seizure outcomes after experimental pediatric TBI. To test this, three-week old male C57Bl/6J mice received a moderate controlled cortical impact or sham surgery, followed by 1 mg/kg i.p. LPS (or 0.9% saline vehicle) at 4 days TBI. Mice were randomized to four groups; sham-saline, sham-LPS, TBI-saline or TBI-LPS (n = 15/group). Reduced general activity and increased anxiety-like behavior were observed within 24 h in LPS-treated mice, indicating a transient sickness response. LPS-treated mice also exhibited a reduction in body weights, which persisted chronically. From 2 months post-injury, mice underwent a battery of tests for sensorimotor, cognitive, and psychosocial behaviors. TBI resulted in hyperactivity and spatial memory deficits, independent of LPS; whereas LPS resulted in subtle deficits in spatial memory retention. At 5 months post-injury, video-electroencephalographic recordings were obtained to evaluate both spontaneous seizure activity as well as the evoked seizure response to pentylenetetrazol (PTZ). TBI increased susceptibility to PTZ-evoked seizures; whereas LPS appeared to increase the incidence of spontaneous seizures. Post-mortem analyses found that TBI, but not LPS, resulted in robust glial reactivity and loss of cortical volume. A TBI × LPS interaction in hippocampal volume suggested that TBI-LPS mice had a subtle increase in ipsilateral hippocampus tissue loss; however, this was not reflected in neuronal cell counts. Both TBI and LPS independently had modest effects on chronic hippocampal gene expression. Together, contrary to our hypothesis, we observed minimal synergy between TBI and LPS. Instead, pediatric TBI and a subsequent transient immune challenge independently influenced chronic outcomes. These findings have implications for future preclinical modeling as well as acute post-injury patient management.
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Affiliation(s)
- Rishabh Sharma
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, VIC, Australia
| | - Larissa K Dill
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia
| | - Sarah S J Rewell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia
| | - Matthew R Hudson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, VIC, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, VIC, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Prahran, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, VIC, Australia.
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Santana RF, Silva LARD, Achar E, Ballester G, Ribeiro Junior MAF, Ortiz SRM. C-Fos expression in epileptogenic areas of nephropathic rats undergoing star fruit poisoning. Acta Cir Bras 2020; 35:e202000705. [PMID: 32785417 PMCID: PMC7433670 DOI: 10.1590/s0102-865020200070000005] [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: 03/24/2020] [Accepted: 06/22/2020] [Indexed: 11/22/2022] Open
Abstract
Purpose Studies have demonstrated that star fruit consumption by nephropathic patients triggers severe neurotoxic effects that can lead to convulsions or even death. Brain areas likely susceptible to star fruit poisoning have not been investigated. The objective of the present study was to map possible epileptogenic areas susceptible to star fruit intoxication in nephropathic rats. Methods The study analyzed 25 rats (5 groups). Rats in the experimental group underwent bilateral ureteral obstruction surgery and orogastric gavages with star fruit juice. An electroencephalogram was used to confirm convulsive seizures. Urea and creatinine levels were used to confirm the uremia model. Immunohistochemical analysis was used to map cells with c-Fos protein (c-Fos+ cells) to identify brain areas with increased neuronal activity. Control groups included non-nephropathic and nephropathic rats that did not receive star fruit. Results A statistically significant increase (p<0.01) in c-Fos+ cells was noted in nephropathic animals receiving star fruit juice compared to control groups, in brain areas commonly related to epileptogenic neural circuits including the hippocampus, amygdala, rhinal cortex, anterior cingulate area, piriform area, and medial dorsal thalamus. Conclusion These data corroborate the neurotoxic capacity of star fruit in nephropathic patients.
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Affiliation(s)
| | | | - Eduardo Achar
- UNICID, Brazil; Universidade de São Caetano do Sul, Brazil
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