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Lehmann LM, Barker-Haliski M. Loss of normal Alzheimer's disease-associated Presenilin 2 function alters antiseizure medicine potency and tolerability in the 6-Hz focal seizure model. Front Neurol 2023; 14:1223472. [PMID: 37592944 PMCID: PMC10427874 DOI: 10.3389/fneur.2023.1223472] [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: 05/16/2023] [Accepted: 07/14/2023] [Indexed: 08/19/2023] Open
Abstract
Introduction Patients with early-onset Alzheimer's disease (EOAD) experience seizures and subclinical epileptiform activity, which may accelerate cognitive and functional decline. Antiseizure medicines (ASMs) may be a tractable disease-modifying strategy; numerous ASMs are marketed with well-established safety. However, little information is available to guide ASM selection as few studies have rigorously quantified ASM potency and tolerability in traditional seizure models in rodents with EOAD-associated risk factors. Presenilin 2 (PSEN2) variants evoke EOAD, and these patients experience seizures. This study thus established the anticonvulsant profile of mechanistically distinct ASMs in the frontline 6-Hz limbic seizure test evoked in PSEN2-knockout (KO) mice to better inform seizure management in EOAD. Methods The median effective dose (ED50) of prototype ASMs was quantified in the 6-Hz test in male and female PSEN2-KO and wild-type (WT) C57BL/6J mice (3-4 months old). Minimal motor impairment (MMI) was assessed to estimate a protective index (PI). Immunohistological detection of cFos established the extent to which 6-Hz stimulation activates discrete brain regions in KO vs. WT mice. Results There were significant genotype-related differences in the potency and tolerability of several ASMs. Valproic acid and levetiracetam were significantly more potent in male KO than in WT mice. Additionally, high doses of valproic acid significantly worsened MMI in KO mice. Conversely, carbamazepine was significantly less potent in female KO vs. WT mice. In both male and female KO mice vs. WTs, perampanel and lamotrigine were equally potent. However, there were marked genotype-related shifts in PI of both carbamazepine and perampanel, with KO mice exhibiting less MMI at the highest doses tested. Gabapentin was ineffective against 6-Hz seizures in KO mice vs. WTs without MMI changes. Neuronal activation 90 min following 6-Hz stimulation was significantly increased in the posterior parietal association cortex overlying CA1 and in the piriform cortex of WT mice, while stimulation-induced increases in cFos immunoreactivity were absent in KO mice. Discussion Acute ASM potency and tolerability in the high-throughput 6-Hz test may be significantly altered with loss of normal PSEN2 function. Seizures in discrete EOAD populations may benefit from precisely selected medicines optimized for primary ASM pharmacological mechanisms.
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Affiliation(s)
| | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, United States
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Bleakley LE, McKenzie CE, Reid CA. Efficacy of antiseizure medication in a mouse model of HCN1 developmental and epileptic encephalopathy. Epilepsia 2023; 64:e1-e8. [PMID: 36300716 PMCID: PMC10953365 DOI: 10.1111/epi.17447] [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: 06/22/2022] [Revised: 10/25/2022] [Accepted: 10/25/2022] [Indexed: 01/21/2023]
Abstract
Acquisition of drug-sensitivity profiles is challenging in rare epilepsies. Anecdotal evidence suggests that antiseizure medications that block sodium channels as their primary mechanism of action exacerbate seizures in HCN1 developmental and epileptic encephalopathies (DEEs), whereas sodium valproate is effective for some patients. The Hcn1 M294L heterozygous knock-in (Hcn1M294L ) mouse carries the homologue of the recurrent gain-of-function HCN1 M305L pathogenic variant and recapitulates the seizure and some behavioral phenotypes observed in patients. We used this mouse model to study drug efficacy in HCN1 DEE. Hcn1M294L mice display epileptiform spiking on electrocorticography (ECoG), which we used as a quantifiable measure of drug effect. Phenytoin, lamotrigine, and retigabine significantly increased ECoG spike frequency, with lamotrigine and retigabine triggering seizures in a subset of the mice tested. In addition, there was a strong trend for carbamazepine to increase spiking. In contrast, levetiracetam, diazepam, sodium valproate, and ethosuximide all significantly reduced ECoG spike frequency. Drugs that reduced spiking did not cause any consistent ECoG spectral changes, whereas drugs that increased spiking all increased power in the slower delta and/or theta bands. These data provide a framework on which to build our understanding of gain-of-function HCN1 DEE pharmacosensitivity in the clinical setting.
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Affiliation(s)
- Lauren E. Bleakley
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Chaseley E. McKenzie
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
| | - Christopher A. Reid
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleVictoriaAustralia
- Epilepsy Research Centre, Department of Medicine, University of MelbourneAustin HealthHeidelbergVictoriaAustralia
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Mensah JA, Johnson K, Reilly CA, Wilcox KS, Rower JE, Metcalf CS. Evaluating the efficacy of prototype antiseizure drugs using a preclinical pharmacokinetic approach. Epilepsia 2022; 63:2937-2948. [PMID: 36054499 PMCID: PMC9669179 DOI: 10.1111/epi.17402] [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: 07/11/2022] [Revised: 08/25/2022] [Accepted: 08/25/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Pharmacokinetics (PK) of a drug drive its exposure, efficacy, and tolerability. A thorough preclinical PK assessment of antiseizure medications (ASMs) is therefore essential to evaluate the clinical potential. We tested protection against evoked seizures of prototype ASMs in conjunction with analysis of plasma and brain PK as a proof-of-principle study to enhance our understanding of drug efficacy and duration of action using rodent seizure models. METHODS In vivo seizure protection assays were performed in adult male CF-1 mice and Sprague Dawley rats. Clobazam (CLB), N-desmethyl CLB (NCLB), carbamazepine (CBZ), CBZ-10,11-epoxide (CBZE), sodium valproate (VPA), and levetiracetam (LEV) concentrations were quantified in plasma and brain using liquid chromatography-tandem mass spectrometry. Mean concentrations of each analyte were calculated and used to determine PK parameters via noncompartmental analysis in Phoenix WinNonLin. RESULTS NCLB concentrations were approximately 10-fold greater than CLB in mice. The antiseizure profile of CLB was partially sustained by NCLB in mice. CLB concentrations were lower in rats than in mice. CBZE plasma exposures were approximately 70% of CBZ in both mice and rats, likely contributing to the antiseizure effect of CBZ. VPA showed a relatively short half-life in both mice and rats, which correlated with a sharp decline in efficacy. LEV had a prolonged brain and plasma half-life, associated with a prolonged duration of action in mice. SIGNIFICANCE The study demonstrates the utility of PK analyses for understanding the seizure protection time course in mice and rats. The data indicate that distinct PK profiles of ASMs between mice and rats likely drive differences in drug efficacy between rodent models.
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Affiliation(s)
- Jeffrey A. Mensah
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Kristina Johnson
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake, UT, USA
| | - Christopher A. Reilly
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, USA
- Center for Human Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Karen S. Wilcox
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake, UT, USA
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Joseph E. Rower
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, USA
- Center for Human Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Cameron S. Metcalf
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake, UT, USA
- Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, USA
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Gomes FV, Zhu X, Grace AA. The pathophysiological impact of stress on the dopamine system is dependent on the state of the critical period of vulnerability. Mol Psychiatry 2020; 25:3278-3291. [PMID: 31488866 PMCID: PMC7056584 DOI: 10.1038/s41380-019-0514-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/02/2019] [Accepted: 07/18/2019] [Indexed: 12/18/2022]
Abstract
Unregulated stress during critical periods of development is proposed to drive deficits consistent with schizophrenia in adults. If accurate, reopening the critical period could make the adult susceptible to pathology. We evaluated the impact of early adolescent and adult stress exposure (combination of daily footshock for 10 days and 3 restraint sessions) on (1) midbrain dopamine (DA) neuron activity, (2) ventral hippocampal (vHipp) pyramidal neuron activity, and (3) the number of parvalbumin (PV) interneurons in the vHipp and their associated perineuronal nets (PNNs). Ventral tegmental area (VTA) DA neuron population activity and vHipp activity was increased 1-2 and 5-6 weeks post-adolescent stress, along with a decrease in the number of PV+, PNN+, PV + /PNN + cells in the vHipp, which are consistent with the MAM model of schizophrenia. In contrast, adult stress decreased VTA DA neuron population activity only at 1-2 weeks post stress, which is consistent with what has been observed in animal models of depression, without impacting vHipp activity and PV/PNN expression. Administration of valproate (VPA), which can re-instate the critical period of plasticity via histone deacetylase (HDAC) inhibition, caused adult stress to produce changes similar to those induced by adolescent stress, presumably by increasing stress vulnerability to early adolescent levels. Our findings indicate that timing of stress is a critical determinant of the pathology produced in the adult: adolescent stress led to circuit deficits that recapitulates schizophrenia, whereas adult stress induced a depression-like hypodopaminergic state. Reopening the critical period in the adult restores vulnerability to stress-induced pathology resembling schizophrenia.
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Affiliation(s)
- Felipe V. Gomes
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, PA, USA
| | - Xiyu Zhu
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, PA, USA
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, PA, USA
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Bortel A, Pilgram R, Yao ZS, Shmuel A. Dexmedetomidine - Commonly Used in Functional Imaging Studies - Increases Susceptibility to Seizures in Rats But Not in Wild Type Mice. Front Neurosci 2020; 14:832. [PMID: 33192234 PMCID: PMC7658317 DOI: 10.3389/fnins.2020.00832] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 07/16/2020] [Indexed: 12/28/2022] Open
Abstract
Functional MRI (fMRI) utilizes changes in metabolic and hemodynamic signals to indirectly infer the underlying local changes in neuronal activity. To investigate the mechanisms of fMRI responses, spontaneous fluctuations, and functional connectivity in the resting-state, it is important to pursue fMRI in animal models. Animal studies commonly use dexmedetomidine sedation. It has been demonstrated that potent sensory stimuli administered under dexmedetomidine are prone to inducing seizures in Sprague-Dawley (SD) rats. Here we combined optical imaging of intrinsic signals and cerebral blood flow with neurophysiological recordings to measure responses in rat area S1FL to electrical forepaw stimulation administered at 8 Hz. We show that the increased susceptibility to seizures starts no later than 1 h and ends no sooner than 3 h after initiating a continuous administration of dexmedetomidine. By administering different combinations of anesthetic and sedative agents, we demonstrate that dexmedetomidine is the sole agent necessary for the increased susceptibility to seizures. The increased susceptibility to seizures prevails under a combination of 0.3–0.5% isoflurane and dexmedetomidine anesthesia. The blood-oxygenation and cerebral blood flow responses to seizures induced by forepaw stimulation have a higher amplitude and a larger spatial extent relative to physiological responses to the same stimuli. The epileptic activity and the associated blood oxygenation and cerebral blood flow responses stretched beyond the stimulation period. We observed seizures in response to forepaw stimulation with 1–2 mA pulses administered at 8 Hz. In contrast, responses to stimuli administered at 4 Hz were seizure-free. We demonstrate that such seizures are generated not only in SD rats but also in Long-Evans rats, but not in C57BL6 mice stimulated with similar potent stimuli under dexmedetomidine sedation. We conclude that high-amplitude hemodynamic functional imaging responses evoked by peripheral stimulation in rats sedated with dexmedetomidine are possibly due to the induction of epileptic activity. Therefore, caution should be practiced in experiments that combine the administration of potent stimuli with dexmedetomidine sedation. We propose stimulation paradigms that elicit seizure-free, well detectable neurophysiological and hemodynamic responses in rats. We further conclude that the increased susceptibility to seizures under dexmedetomidine sedation is species dependent.
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Affiliation(s)
- Aleksandra Bortel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Roland Pilgram
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Ze Shan Yao
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, Canada.,Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Amir Shmuel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
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Bellera CL, Talevi A. Quantitative structure-activity relationship models for compounds with anticonvulsant activity. Expert Opin Drug Discov 2019; 14:653-665. [PMID: 31072145 DOI: 10.1080/17460441.2019.1613368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Introduction: Third-generation antiepileptic drugs have seemingly failed to improve the global figures of seizure control and can still be regarded as symptomatic treatments. Quantitative structure-activity relationships (QSAR) can be used to guide hit-to-lead and lead optimization projects and applied to the large-scale virtual screening of chemical libraries. Areas covered: In this review, the authors cover reports on QSAR models related to antiepileptic drugs and drug targets in epilepsy, analyzing whether they refer to classic or non-classic QSAR and if they apply QSAR as a descriptive or predictive approach, among other considerations. The article finally focuses on a more detailed discussion of those predictive studies which include some sort of experimental validation, i.e. papers in which the reported models have been used to identify novel active compounds which have been tested in vitro and/or in vivo. Expert opinion: There are significant opportunities to apply the QSAR methodology to assist the discovery of more efficacious antiepileptic drugs. Considering the intrinsic complexity of the disorder, such applications should focus on state-of-the-art approximations (e.g. systemic, multi-target and multi-scale QSAR as well as ensemble and deep learning) and modeling the effects on novel drug targets and modern screening tools.
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Affiliation(s)
- Carolina L Bellera
- a Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences , University of La Plata (UNLP) , La Plata, Buenos Aires , Argentina.,b CCT La Plata , Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Buenos Aires , Argentina
| | - Alan Talevi
- a Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences , University of La Plata (UNLP) , La Plata, Buenos Aires , Argentina.,b CCT La Plata , Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) , Buenos Aires , Argentina
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Sanon NT, Gagné J, Wolf DC, Aboulamer S, Bosoi CM, Simard A, Messiet E, Desgent S, Carmant L. Favorable adverse effect profile of brivaracetam vs levetiracetam in a preclinical model. Epilepsy Behav 2018; 79:117-125. [PMID: 29287214 DOI: 10.1016/j.yebeh.2017.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/15/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
Abstract
Levetiracetam (LEV), and its newer selective analog brivaracetam (BRV), are two seizure medications that share an innovative mechanism of action targeting the Synaptic Vesicle Protein 2A (SV2A), altering neurotransmitter release and decreasing seizure frequency. Behavioral changes are the most significant adverse effects reported by patients taking LEV. We hypothesize that BRV, the more potent SV2A analog, could exert less behavioral side effects, as it requires lower doses than LEV. Using Kainic Acid (KA)-treated and control rats, we measured adverse behavioral effect profiles of LEV, BRV, or Saline, on social and nonsocial behaviors. Our data indicate that both tested drugs had no effect on locomotion, anxiety levels, fear learning, depression-like behavior, and memory retention in rats. However, when considering social interactions, we first confirmed the epilepsy-induced strong increase in aggressive behaviors and specific hippocampal neuronal loss. We furthermore observed, in Sham rats, that LEV-treated animals were 2 times faster to attack at first encounter, had 5 times more aggressive behaviors, and had significantly less social behaviors than control rats. In all circumstances, BRV rats behaved like Saline rats, suggesting that BRV treatment in rats leads to significantly less aggressive behaviors than LEV treatment at the doses used, while there are limited differential effects between these two drugs on other types of behaviors. Since increased aggressiveness has been reported in patients well controlled on LEV, this study indicates based on our findings, that BRV could represent an effective alternative to LEV to limit aggressiveness problems due to this antiepileptic drug (AED) therapy.
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Affiliation(s)
- Nathalie T Sanon
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada.
| | - Jonathan Gagné
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Sciences Biomédicales, Université de Montréal, Québec, Canada
| | - Daniele C Wolf
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada
| | - Soumia Aboulamer
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Ciprian M Bosoi
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Alexe Simard
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Estelle Messiet
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Sébastien Desgent
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada
| | - Lionel Carmant
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada.
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