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Ndode-Ekane XE, Ali I, Gomez CS, Andrade P, Immonen R, Casillas-Espinosa P, Paananen T, Manninen E, Puhakka N, Smith G, Brady RD, Silva J, Braine E, Hudson M, Yamakawa GR, Jones NC, Shultz SR, Harris N, Wright DK, Gröhn O, Staba R, O’Brien TJ, Pitkänen A. Epilepsy phenotype and its reproducibility after lateral fluid percussion-induced traumatic brain injury in rats: Multicenter EpiBioS4Rx study project 1. Epilepsia 2024; 65:511-526. [PMID: 38052475 PMCID: PMC10922674 DOI: 10.1111/epi.17838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/21/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023]
Abstract
OBJECTIVE This study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites. METHODS A total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis. RESULTS A total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites). SIGNIFICANCE The PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI.
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Affiliation(s)
- Xavier Ekolle Ndode-Ekane
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Idrish Ali
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Cesar Santana Gomez
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Pedro Andrade
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Riikka Immonen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Pablo Casillas-Espinosa
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Tomi Paananen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Eppu Manninen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Noora Puhakka
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Gregory Smith
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Rhys D. Brady
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Juliana Silva
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Emma Braine
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Matt Hudson
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Glen R. Yamakawa
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Nigel C. Jones
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Sandy R. Shultz
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Neil Harris
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - David K. Wright
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Olli Gröhn
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Terence J. O’Brien
- Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Asla Pitkänen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
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Yamakawa GR, Patel M, Lin R, O'Brien TJ, Mychasiuk R, Casillas‐Espinosa PM. Diurnal circadian clock gene expression is altered in models of genetic and acquired epilepsy. Epilepsia Open 2023; 8:1523-1531. [PMID: 37805809 PMCID: PMC10690682 DOI: 10.1002/epi4.12841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/12/2023] [Indexed: 10/09/2023] Open
Abstract
OBJECTIVES Growing evidence demonstrates a relationship between epilepsy and the circadian system. However, relatively little is known about circadian function in disease states, such as epilepsy. This study aimed to characterize brain and peripheral core circadian clock gene expression in rat models of genetic and acquired epilepsy. METHODS For the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) study, we used 40 GAERS and 40 non-epileptic control (NEC) rats. For the kainic acid status epilepticus (KASE) study, we used 40 KASE and 40 sham rats. Rats were housed in a 7 am:7 pm light-dark cycle. Hypothalamus, hippocampus, liver, and small intestine samples were collected every 3 h throughout the light period. We then assessed core diurnal clock gene expression of per1, cry1, clock, and bmal1. RESULTS In the GAERS rats, all tissues exhibited significant changes in clock gene expression (P < 0.05) when compared to NEC. In the KASE rats, there were fewer effects of the epileptic condition in the hypothalamus, hippocampus, or small intestine (P > 0.05) compared with shams. SIGNIFICANCE These results indicate marked diurnal disruption to core circadian clock gene expression in rats with both generalized and focal chronic epilepsy. This could contribute to epileptic symptomology and implicate the circadian system as a viable target for future treatments.
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Affiliation(s)
- Glenn R. Yamakawa
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Meshwa Patel
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Runxuan Lin
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Terence J. O'Brien
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe Alfred HospitalMelbourneVictoriaAustralia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Pablo M. Casillas‐Espinosa
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe Alfred HospitalMelbourneVictoriaAustralia
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Lauerer RJ, Lerche H. Voltage-gated calcium channels in genetic epilepsies. J Neurochem 2023. [PMID: 37822150 DOI: 10.1111/jnc.15983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/17/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Voltage-gated calcium channels (VGCC) are abundant in the central nervous system and serve a broad spectrum of functions, either directly in cellular excitability or indirectly to regulate Ca2+ homeostasis. Ca2+ ions act as one of the main connections in excitation-transcription coupling, muscle contraction and excitation-exocytosis coupling, including synaptic transmission. In recent years, many genes encoding VGCCs main α or additional auxiliary subunits have been associated with epilepsy. This review sums up the current state of knowledge on disease mechanisms and provides guidance on disease-specific therapies where applicable.
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Affiliation(s)
- Robert J Lauerer
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
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Ali I, Silva J, Casillas-Espinosa PM, Braine E, Yamakawa GR, Hudson MR, Brady RD, Major B, Thergarajan P, Haskali MB, Wright DK, Jupp B, Vivash L, Shultz SR, Mychasiuk R, Kwan P, Jones NC, Fukushima K, Sachdev P, Cheng JY, O'Brien TJ. E2730, an uncompetitive γ-aminobutyric acid transporter-1 inhibitor, suppresses epileptic seizures in a rat model of chronic mesial temporal lobe epilepsy. Epilepsia 2023; 64:2806-2817. [PMID: 37539645 DOI: 10.1111/epi.17735] [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: 03/21/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 08/05/2023]
Abstract
OBJECTIVE More than one third of mesial temporal lobe epilepsy (MTLE) patients are resistant to current antiseizure medications (ASMs), and half experience mild-to-moderate adverse effects of ASMs. There is therefore a strong need to develop and test novel ASMs. The objective of this work is to evaluate the pharmacokinetics and neurological toxicity of E2730, a novel uncompetitive inhibitor of γ-aminobutyric acid transporter-1, and to test its seizure suppression effects in a rat model of chronic MTLE. METHODS We first examined plasma levels and adverse neurological effects of E2730 in healthy Wistar rats. Adult male rats were implanted with osmotic pumps delivering either 10, 20, or 100 mg/kg/day of E2730 subcutaneously for 1 week. Blood sampling and behavioral assessments were performed at several timepoints. We next examined whether E2730 suppressed seizures in rats with chronic MTLE. These rats were exposed to kainic acid-induced status epilepticus, and 9 weeks later, when chronic epilepsy was established, were assigned to receive one of the three doses of E2730 or vehicle for 1 week in a randomized crossover design. Continuous video-electroencephalographic monitoring was acquired during the treatment period to evaluate epileptic seizures. RESULTS Plasma levels following continuous infusion of E2730 showed a clear dose-related increase in concentration. The drug was well tolerated at all doses, and any sedation or neuromotor impairment was mild and transient, resolving within 48 h of treatment initiation. Remarkably, E2730 treatment in chronically epileptic rats led to seizure suppression in a dose-dependent manner, with 65% of rats becoming seizure-free at the highest dose tested. Mean seizure class did not differ between the treatment groups. SIGNIFICANCE This study shows that continuous subcutaneous infusion of E2730 over 7 days results in a marked, dose-dependent suppression of spontaneous recurrent seizures, with minimal adverse neurological effects, in a rat model of chronic MTLE. E2730 shows strong promise as an effective new ASM to be translated into clinical trials.
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Affiliation(s)
- Idrish Ali
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Juliana Silva
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Emma Braine
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Glenn R Yamakawa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Matthew R Hudson
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Rhys D Brady
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Brendan Major
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | | | - Mohammad B Haskali
- Radiopharmaceutical Research Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - David K Wright
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Bianca Jupp
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Lucy Vivash
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Patrick Kwan
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Nigel C Jones
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | - Terence J O'Brien
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
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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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6
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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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Casillas-Espinosa PM, Anderson A, Harutyunyan A, Li C, Lee J, Braine EL, Brady RD, Sun M, Huang C, Barlow CK, Shah AD, Schittenhelm RB, Mychasiuk R, Jones NC, Shultz SR, O'Brien TJ. Disease-modifying effects of sodium selenate in a model of drug-resistant, temporal lobe epilepsy. eLife 2023; 12:e78877. [PMID: 36892461 PMCID: PMC10208637 DOI: 10.7554/elife.78877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 03/08/2023] [Indexed: 03/10/2023] Open
Abstract
There are no pharmacological disease-modifying treatments with an enduring effect to mitigate the seizures and comorbidities of established chronic temporal lobe epilepsy (TLE). This study aimed to evaluate for disease modifying effects of sodium selenate treatment in the chronically epileptic rat post-status epilepticus (SE) model of drug-resistant TLE. Wistar rats underwent kainic acid-induced SE or sham. Ten-weeks post-SE, animals received sodium selenate, levetiracetam, or vehicle subcutaneousinfusion continuously for 4 weeks. To evaluate the effects of the treatments, one week of continuous video-EEG was acquired before, during, and 4, 8 weeks post-treatment, followed by behavioral tests. Targeted and untargeted proteomics and metabolomics were performed on post-mortem brain tissue to identify potential pathways associated with modified disease outcomes. Telomere length was investigated as a novel surrogate marker of epilepsy disease severity in our current study. The results showed that sodium selenate treatment was associated with mitigation of measures of disease severity at 8 weeks post-treatment cessation; reducing the number of spontaneous seizures (p< 0.05), cognitive dysfunction (p< 0.05), and sensorimotor deficits (p< 0.01). Moreover, selenate treatment was associated with increased protein phosphatase 2A (PP2A) expression, reduced hyperphosphorylated tau, and reversed telomere length shortening (p< 0.05). Network medicine integration of multi-omics/pre-clinical outcomes identified protein-metabolite modules positively correlated with TLE. Our results provide evidence that treatment with sodium selenate results in a sustained disease-modifying effect in chronically epileptic rats in the post-KA SE model of TLE, including improved comorbid learning and memory deficits.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
- Monash Proteomics & Metabolomics Facility and Monash Biomedicine Discovery Institute, Monash UniversityClayton, VictoriaAustralia
| | - Alison Anderson
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Anna Harutyunyan
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Crystal Li
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Jiyoon Lee
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
| | - Emma L Braine
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Rhys D Brady
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Cheng Huang
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Christopher K Barlow
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Anup D Shah
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Ralf B Schittenhelm
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Nigel C Jones
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Sandy R Shultz
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Terence J O'Brien
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
- Monash Proteomics & Metabolomics Facility and Monash Biomedicine Discovery Institute, Monash UniversityClayton, VictoriaAustralia
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Zhuang XF, Liu YX, Yang ZH, Gao Q, Wang L, Ju C, Wang K. Attenuation of Epileptogenesis and Cognitive Deficits by a Selective and Potent Kv7 Channel Opener in Rodent Models of Seizures. J Pharmacol Exp Ther 2023; 384:315-325. [PMID: 36396352 DOI: 10.1124/jpet.122.001328] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/12/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022] Open
Abstract
Targeting neuronal Kv7 channels by pharmacological activation has been proven to be an attractive therapeutic strategy for epilepsy. Here, we show that activation of Kv7 channels by an opener SCR2682 dose-dependently reduces seizure activity and severity in rodent models of epilepsy induced by a GABAa receptor antagonist pentylenetetrazole (PTZ), maximal electroshock, and a glutamate receptor agonist kainic acid (KA). Electroencephalographic recordings of rat cerebral cortex confirm that SCR2682 also decreases epileptiform discharges in KA-induced seizures. Nissl and neuronal nuclei staining further demonstrates that SCR2682 also protects neurons from injury induced by KA. In Morris water maze navigation and Y-maze tests, SCR2682 improves PTZ- and KA-induced cognitive impairment. Taken together, our findings demonstrate that pharmacological activation of Kv7 by novel opener SCR2682 may hold promise for therapy of epilepsy with cognitive impairment. SIGNIFICANCE STATEMENT: A neuronal Kv7 channel opener SCR2682 attenuates epileptogenesis and seizure-induced cognitive impairment in rodent models of seizures, thus possessing a developmental potential for effective therapy of epilepsy with cognitive impairment.
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Affiliation(s)
- Xiao-Fei Zhuang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Yu-Xue Liu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Zhi-Hong Yang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Qin Gao
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Lei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Chuanxia Ju
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - KeWei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
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9
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Harman T, Udoh M, McElroy DL, Anderson LL, Kevin RC, Banister SD, Ametovski A, Markham J, Bladen C, Doohan PT, Greba Q, Laprairie RB, Snutch TP, McGregor IS, Howland JG, Arnold JC. MEPIRAPIM-derived synthetic cannabinoids inhibit T-type calcium channels with divergent effects on seizures in rodent models of epilepsy. Front Physiol 2023; 14:1086243. [PMID: 37082241 PMCID: PMC10110893 DOI: 10.3389/fphys.2023.1086243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/17/2023] [Indexed: 04/22/2023] Open
Abstract
Background: T-type Ca2+ channels (Cav3) represent emerging therapeutic targets for a range of neurological disorders, including epilepsy and pain. To aid the development and optimisation of new therapeutics, there is a need to identify novel chemical entities which act at these ion channels. A number of synthetic cannabinoid receptor agonists (SCRAs) have been found to exhibit activity at T-type channels, suggesting that cannabinoids may provide convenient chemical scaffolds on which to design novel Cav3 inhibitors. However, activity at cannabinoid type 1 (CB1) receptors can be problematic because of central and peripheral toxicities associated with potent SCRAs. The putative SCRA MEPIRAPIM and its analogues were recently identified as Cav3 inhibitors with only minimal activity at CB1 receptors, opening the possibility that this scaffold may be exploited to develop novel, selective Cav3 inhibitors. Here we present the pharmacological characterisation of SB2193 and SB2193F, two novel Cav3 inhibitors derived from MEPIRAPIM. Methods: The potency of SB2193 and SB2193F was evaluated in vitro using a fluorometric Ca2+ flux assay and confirmed using whole-cell patch-clamp electrophysiology. In silico docking to the cryo-EM structure of Cav3.1 was also performed to elucidate structural insights into T-type channel inhibition. Next, in vivo pharmacokinetic parameters in mouse brain and plasma were determined using liquid chromatography-mass spectroscopy. Finally, anticonvulsant activity was assayed in established genetic and electrically-induced rodent seizure models. Results: Both MEPIRAPIM derivatives produced potent inhibition of Cav3 channels and were brain penetrant, with SB2193 exhibiting a brain/plasma ratio of 2.7. SB2193 was further examined in mouse seizure models where it acutely protected against 6 Hz-induced seizures. However, SB2193 did not reduce spontaneous seizures in the Scn1a +/- mouse model of Dravet syndrome, nor absence seizures in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS). Surprisingly, SB2193 appeared to increase the incidence and duration of spike-and-wave discharges in GAERS animals over a 4 h recording period. Conclusion: These results show that MEPIRAPIM analogues provide novel chemical scaffolds to advance Cav3 inhibitors against certain seizure types.
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Affiliation(s)
- Thomas Harman
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Michael Udoh
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Dan L. McElroy
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lyndsey L. Anderson
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Jack Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Chris Bladen
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peter T. Doohan
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Quentin Greba
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robert B. Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - John G. Howland
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jonathon C. Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Jonathon C. Arnold,
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10
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Combining the neural mass model and Hodgkin–Huxley formalism: Neuronal dynamics modelling. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Negative effects of brain regulatory T cells depletion on epilepsy. Prog Neurobiol 2022; 217:102335. [PMID: 35931355 DOI: 10.1016/j.pneurobio.2022.102335] [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: 11/22/2021] [Revised: 07/18/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022]
Abstract
The infiltration of immune cells is observed in the epileptogenic zone; however, the relationship between epilepsy and regulatory T cells (Tregs) remains only partially understood. We aimed to investigate brain-infiltrating Tregs to reveal their underlying role in epilepsy. We analyzed the infiltration of Tregs in the epileptogenic zones from patients with epilepsy and a pilocarpine-induced temporal lobe epilepsy (TLE) model. Next, we evaluated the effects of brain Treg depletion on neuroinflammation, neuronal loss, oxidative stress, seizure activity and behavioral changes in the pilocarpine model. We also explored the impact of Treg expansion in the brain on seizure activity. There were a large number of Tregs in the epileptogenic zones of human and experimental epilepsy. The number of brain Tregs was negatively correlated with the frequency of seizures in patients with epilepsy. Our further findings demonstrated that brain Treg depletion promoted astrocytosis, microgliosis, inflammatory cytokine production, oxidative stress, and neuronal loss in the hippocampus after status epilepticus (SE). Moreover, brain Treg depletion increased seizure activity and contributed to behavioral impairments in experimental chronic TLE. Interestingly, intracerebroventricular injection of CCL20 amplified Tregs in brain tissue, thereby inhibiting seizure activity. Taken together, our study highlights the therapeutic potential of regulating Tregs in epileptic brain tissue.
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12
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An Integrated Multi-Omic Network Analysis Identifies Seizure-Associated Dysregulated Pathways in the GAERS Model of Absence Epilepsy. Int J Mol Sci 2022; 23:ijms23116063. [PMID: 35682742 PMCID: PMC9181682 DOI: 10.3390/ijms23116063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/01/2022] [Accepted: 05/02/2022] [Indexed: 11/17/2022] Open
Abstract
Absence epilepsy syndromes are part of the genetic generalized epilepsies, the pathogenesis of which remains poorly understood, although a polygenic architecture is presumed. Current focus on single molecule or gene identification to elucidate epileptogenic drivers is unable to fully capture the complex dysfunctional interactions occurring at a genetic/proteomic/metabolomic level. Here, we employ a multi-omic, network-based approach to characterize the molecular signature associated with absence epilepsy-like phenotype seen in a well validated rat model of genetic generalized epilepsy with absence seizures. Electroencephalographic and behavioral data was collected from Genetic Absence Epilepsy Rats from Strasbourg (GAERS, n = 6) and non-epileptic controls (NEC, n = 6), followed by proteomic and metabolomic profiling of the cortical and thalamic tissue of rats from both groups. The general framework of weighted correlation network analysis (WGCNA) was used to identify groups of highly correlated proteins and metabolites, which were then functionally annotated through joint pathway enrichment analysis. In both brain regions a large protein-metabolite module was found to be highly associated with the GAERS strain, absence seizures and associated anxiety and depressive-like phenotype. Quantitative pathway analysis indicated enrichment in oxidative pathways and a downregulation of the lysine degradation pathway in both brain regions. GSTM1 and ALDH2 were identified as central regulatory hubs of the seizure-associated module in the somatosensory cortex and thalamus, respectively. These enzymes are involved in lysine degradation and play important roles in maintaining oxidative balance. We conclude that the dysregulated pathways identified in the seizure-associated module may be involved in the aetiology and maintenance of absence seizure activity. This dysregulated activity could potentially be modulated by targeting one or both central regulatory hubs.
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13
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Early life adversity accelerates epileptogenesis and enhances depression-like behaviors in rats. Exp Neurol 2022; 354:114088. [DOI: 10.1016/j.expneurol.2022.114088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 03/29/2022] [Accepted: 04/15/2022] [Indexed: 11/24/2022]
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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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15
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Mishra NK, Engel J, Liebeskind DS, Sharma VK, Hirsch LJ, Kasner SE, French JA, Devinsky O, Friedman A, Dawson J, Quinn TJ, Selim M, de Havenon A, Yasuda CL, Cendes F, Benninger F, Zaveri HP, Burneo JG, Srivastava P, Bhushan Singh M, Bhatia R, Vishnu VY, Bentes C, Ferro J, Weiss S, Sivaraju A, Kim JA, Galovic M, Gilmore EJ, Pitkänen A, Davis K, Sansing LH, Sheth KN, Paz JT, Singh A, Sheth S, Worrall BB, Grotta JC, Casillas-Espinos PM, Chen Z, Nicolo JP, Yan B, Kwan P. International Post Stroke Epilepsy Research Consortium (IPSERC): A consortium to accelerate discoveries in preventing epileptogenesis after stroke. Epilepsy Behav 2022; 127:108502. [PMID: 34968775 DOI: 10.1016/j.yebeh.2021.108502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 12/18/2022]
Affiliation(s)
| | - Jerome Engel
- Department of Neurology, University of California Los Angeles, Los Angeles, USA
| | - David S Liebeskind
- Department of Neurology, University of California Los Angeles, Los Angeles, USA
| | - Vijay K Sharma
- YLL School of Medicine, National University of Singapore and Division of Neurology, National University Health System, Singapore
| | | | - Scott E Kasner
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | - Jacqueline A French
- Department of Neurology, NYU Grossman School of Medicine, New York City, USA
| | - Orrin Devinsky
- Department of Neurology, NYU Grossman School of Medicine, New York City, USA
| | - Alon Friedman
- Department of Brain and Cognitive Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
| | - Jesse Dawson
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, UK
| | - Terence J Quinn
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, UK
| | - Magdy Selim
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | | | - Clarissa L Yasuda
- Department of Neurology, School of Medical Sciences, University of Campinas - UNICAMP, Sao Paulo, Brazil
| | - Fernando Cendes
- Department of Neurology, School of Medical Sciences, University of Campinas - UNICAMP, Sao Paulo, Brazil
| | - Felix Benninger
- Department of Neurology, Rabin Medical Center, Tel Aviv, Israel
| | | | - Jorge G Burneo
- Epilepsy Program, Department of Clinical Neurological Sciences, and Neuroepidemiology Unit, Western University, London, Ontario, Canada
| | - Padma Srivastava
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Mamta Bhushan Singh
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Rohit Bhatia
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - V Y Vishnu
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Carla Bentes
- Department of Neurology, University of Lisboa, Lisbon, Portugal
| | - Jose Ferro
- Department of Neurology, University of Lisboa, Lisbon, Portugal
| | - Shennan Weiss
- Department of Neurology, State University of New York (SUNY) Downstate, NY, USA
| | | | - Jennifer A Kim
- Department of Neurology, Yale University, New Haven, USA
| | - Marian Galovic
- Department of Neurology, University of Zurich, Zurich, Switzerland
| | | | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Kathryn Davis
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | | | - Kevin N Sheth
- Department of Neurology, Yale University, New Haven, USA
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, USA; Department of Neurology, University of California San Francisco, San Francisco, USA
| | - Anuradha Singh
- Department of Neurology, Icahn School of Medicine at Mt. Sinai, NY, USA
| | - Sunil Sheth
- Department of Neurology, University of Texas Health Sciences Center, Houston, USA
| | - Bradford B Worrall
- Departments of Neurology and Public Health Sciences, University of Virginia, Charlottesville, USA
| | - James C Grotta
- Department of Neurology, Memorial-Hermann Texas Medical Center, Houston, USA
| | - Pablo M Casillas-Espinos
- Department of Neuroscience, Monash University, Alfred Hospital, Melbourne, Australia; Departments of Neurology and Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Zhibin Chen
- Department of Neuroscience, Monash University, Alfred Hospital, Melbourne, Australia; Departments of Neurology and Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - John-Paul Nicolo
- Department of Neuroscience, Monash University, Alfred Hospital, Melbourne, Australia; Departments of Neurology and Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Bernard Yan
- Departments of Neurology and Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Patrick Kwan
- Department of Neuroscience, Monash University, Alfred Hospital, Melbourne, Australia; Departments of Neurology and Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia.
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16
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Altered cardiac structure and function is related to seizure frequency in a rat model of chronic acquired temporal lobe epilepsy. Neurobiol Dis 2021; 159:105505. [PMID: 34520843 DOI: 10.1016/j.nbd.2021.105505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 09/02/2021] [Accepted: 09/05/2021] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE This study aimed to prospectively examine cardiac structure and function in the kainic acid-induced post-status epilepticus (post-KA SE) model of chronic acquired temporal lobe epilepsy (TLE), specifically to examine for changes between the pre-epileptic, early epileptogenesis and the chronic epilepsy stages. We also aimed to examine whether any changes related to the seizure frequency in individual animals. METHODS Four hours of SE was induced in 9 male Wistar rats at 10 weeks of age, with 8 saline treated matched control rats. Echocardiography was performed prior to the induction of SE, two- and 10-weeks post-SE. Two weeks of continuous video-EEG and simultaneous ECG recordings were acquired for two weeks from 11 weeks post-KA SE. The video-EEG recordings were analyzed blindly to quantify the number and severity of spontaneous seizures, and the ECG recordings analyzed for measures of heart rate variability (HRV). PicroSirius red histology was performed to assess cardiac fibrosis, and intracellular Ca2+ levels and cell contractility were measured by microfluorimetry. RESULTS All 9 post-KA SE rats were demonstrated to have spontaneous recurrent seizures on the two-week video-EEG recording acquired from 11 weeks SE (seizure frequency ranging from 0.3 to 10.6 seizures/day with the seizure durations from 11 to 62 s), and none of the 8 control rats. Left ventricular wall thickness was thinner, left ventricular internal dimension was shorter, and ejection fraction was significantly decreased in chronically epileptic rats, and was negatively correlated to seizure frequency in individual rats. Diastolic dysfunction was evident in chronically epileptic rats by a decrease in mitral valve deceleration time and an increase in E/E` ratio. Measures of HRV were reduced in the chronically epileptic rats, indicating abnormalities of cardiac autonomic function. Cardiac fibrosis was significantly increased in epileptic rats, positively correlated to seizure frequency, and negatively correlated to ejection fraction. The cardiac fibrosis was not a consequence of direct effect of KA toxicity, as it was not seen in the 6/10 rats from separate cohort that received similar doses of KA but did not go into SE. Cardiomyocyte length, width, volume, and rate of cell lengthening and shortening were significantly reduced in epileptic rats. SIGNIFICANCE The results from this study demonstrate that chronic epilepsy in the post-KA SE rat model of TLE is associated with a progressive deterioration in cardiac structure and function, with a restrictive cardiomyopathy associated with myocardial fibrosis. Positive correlations between seizure frequency and the severity of the cardiac changes were identified. These results provide new insights into the pathophysiology of cardiac disease in chronic epilepsy, and may have relevance for the heterogeneous mechanisms that place these people at risk of sudden unexplained death.
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Selected Molecular Targets for Antiepileptogenesis. Int J Mol Sci 2021; 22:ijms22189737. [PMID: 34575901 PMCID: PMC8466306 DOI: 10.3390/ijms22189737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 02/07/2023] Open
Abstract
The term epileptogenesis defines the usually durable process of converting normal brain into an epileptic one. The resistance of a significant proportion of patients with epilepsy to the available pharmacotherapy prompted the concept of a causative treatment option consisting in stopping or modifying the progress of epileptogenesis. Most antiepileptic drugs possess only a weak or no antiepileptogenic potential at all, but a few of them appear promising in this regard; these include, for example, eslicarbazepine (a sodium and T-type channel blocker), lamotrigine (a sodium channel blocker and glutamate antagonist) or levetiracetam (a ligand of synaptic vehicle protein SV2A). Among the approved non-antiepileptic drugs, antiepileptogenic potential seems to reside in losartan (a blocker of angiotensin II type 1 receptors), biperiden (an antiparkinsonian drug), nonsteroidal anti-inflammatory drugs, antioxidative drugs and minocycline (a second-generation tetracycline with anti-inflammatory and antioxidant properties). Among other possible antiepileptogenic compounds, antisense nucleotides have been considered, among these an antagomir targeting microRNA-134. The drugs and agents mentioned above have been evaluated in post-status epilepticus models of epileptogenesis, so their preventive efficacy must be verified. Limited clinical data indicate that biperiden in patients with brain injuries is well-tolerated and seems to reduce the incidence of post-traumatic epilepsy. Exceptionally, in this regard, our own original data presented here point to c-Fos as an early seizure duration, but not seizure intensity-related, marker of early epileptogenesis. Further research of reliable markers of early epileptogenesis is definitely needed to improve the process of designing adequate antiepileptogenic therapies.
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18
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Harding EK, Dedek A, Bonin RP, Salter MW, Snutch TP, Hildebrand ME. The T-type calcium channel antagonist, Z944, reduces spinal excitability and pain hypersensitivity. Br J Pharmacol 2021; 178:3517-3532. [PMID: 33871884 PMCID: PMC8453510 DOI: 10.1111/bph.15498] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/02/2021] [Accepted: 04/05/2021] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose T‐type voltage‐gated calcium channels are an emerging therapeutic target for neurological disorders including epilepsy and pain. Inhibition of T‐type channels reduces the excitability of peripheral nociceptive sensory neurons and reverses pain hypersensitivity in male rodent pain models. However, administration of peripherally restricted T‐type antagonists failed to show efficacy in multiple clinical and preclinical pain trials, suggesting that inhibition of peripheral T‐type channels alone may be insufficient for pain relief. Experimental Approach We utilized the selective and CNS‐penetrant T‐type channel antagonist, Z944, in electrophysiological, calcium imaging and behavioural paradigms to determine its effect on lamina I neuron excitability and inflammatory pain behaviours. Key Results Voltage‐clamp recordings from lamina I spinal neurons of adult rats revealed that approximately 80% of neurons possess a low threshold T‐type current, which was blocked by Z944. Due to this highly prevalent T‐type current, Z944 potently blocked action‐potential evoked somatic and dendritic calcium transients in lamina I neurons. Moreover, application of Z944 to spinal cord slices attenuated action potential firing rates in over half of laminae I/II neurons. Finally, we found that intraperitoneal injection of Z944 (1–10 mg·kg−1) dose‐dependently reversed mechanical allodynia in the complete Freund's adjuvant model of persistent inflammatory pain, with a similar magnitude and time course of analgesic effects between male and female rats. Conclusion and Implications T‐type calcium channels critically shape the excitability of lamina I pain processing neurons and inhibition of these channels by the clinical stage antagonist Z944 potently reverses pain hypersensitivity across sexes.
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Affiliation(s)
- Erika K Harding
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.,Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Annemarie Dedek
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.,Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Robert P Bonin
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.,University of Toronto Centre for the Study of Pain, University of Toronto, Toronto, Ontario, Canada
| | - Michael W Salter
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael E Hildebrand
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.,Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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Bladen C, Mirlohi S, Santiago M, Longworth M, Kassiou M, Banister S, Connor M. Modulation of human T-type calcium channels by synthetic cannabinoid receptor agonists in vitro. Neuropharmacology 2021; 187:108478. [PMID: 33600843 DOI: 10.1016/j.neuropharm.2021.108478] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/07/2021] [Accepted: 01/26/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND AND PURPOSE Consumption of Synthetic Cannabinoid Receptor agonists (SCRAs) is associated with severe adverse reactions including seizures, arrhythmias and death, but the molecular mechanisms surrounding SCRA toxicity are not yet established. These disease-like symptoms are also synonymous with altered T-type calcium channel activity which controls rhythmicity in the heart and brain. This study examined whether SCRAs alter T-type activity and whether this represents a possible mechanism of toxicity. EXPERIMENTAL APPROACH Fluorescence-based and electrophysiology assays were used to screen 16 structurally related synthetic cannabinoids for their ability to inhibit human T-type calcium channels expressed in HEK293 cells. The most potent compounds were then further examined using patch clamp electrophysiology. KEY RESULTS MDMB-CHMICA and AMB-CHMINACA potently blocked Cav3.2 with IC50 values of 1.5 and 0.74 μM respectively. Current inhibition increased from 47 to 80% and 45-87% respectively when the channel was in slow-inactivated state. Both SCRAs had little effect on steady state inactivation, however MDMB-CHMICA significantly shifted the half activation potential by -7mV. Neither drug produced frequency dependent block, in contrast to the phytocannabinoid Δ9-THC. CONCLUSIONS AND IMPLICATIONS SCRAs are potent agonists of CB1 receptors and can be extremely toxic, but observed toxicity also resembles symptoms associated with altered Cav3.2 activity. Many SCRAs tested were potent modulators of Cav3.2, raising the possibility that SC toxicity may be due in part to Cav3.2 modulation. This potent T-type channel modulation suggests the possibility of SCRAs as a new drug class with potential to treat diseases associated with altered T-type channel activity. This article is part of the special issue on 'Cannabinoids'.
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Affiliation(s)
- Chris Bladen
- Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Somayeh Mirlohi
- Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Marina Santiago
- Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | | | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, NSW, 2006, Australia
| | - Sam Banister
- School of Chemistry, University of Sydney, Sydney, NSW, 2006, Australia; The Lambert Initiative for Cannabinoid Therapeutics, University of Sydney, Sydney, NSW, 2006, Australia
| | - Mark Connor
- Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
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