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Objective: Preclinical models of seizures and epilepsy in rodents contributed substantially to the discovery of currently available antiseizure medications. These were also broadly used for investigation of processes of epileptogenesis. Nevertheless, rodent models pose some limitations, thus, new models using alternative species are in high demand. The aim of this study was to describe a new model of seizures/epilepsy induced by the cholinomimetic agent, pilocarpine (PILO), in larval zebrafish. Methods: Local field potential (LFP) recordings were conducted to analyze electroencephalographic discharges and correlate it with larval behavior. Hematoxylin and eosin (H&E) staining, as well as TUNEL staining were performed to analyze morphology and apoptosis, respectively. Real-time quantitative polymerase chain reaction (qRT-PCR) was undertaken for gene expression analysis. Results: Acute exposure to PILO, in a concentration-dependent manner, induces electroencephalographic discharges in larval zebrafish, which behaviorally manifest as decreased locomotion and moving time, but enhanced movement velocity. The PILO-induced seizure-like activity is behaviorally distinct from this induced by the application of chemoconvulsant pentylenetetrazole (PTZ). Zebrafish larvae previously exposed to PILO (2 h), after a washing out period, exhibit spontaneous, unprovoked discharges and apoptotic changes in their brains. Significance: Here, we comprehensively investigated a new model of PILO-induced seizures/epilepsy in larval zebrafish. We propose that this model may be used to study epileptogenesis and for antiseizure drug screening purposes.
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BACKGROUND: The present study elucidates a common significant postoperative complication of micropulse transscleral laser treatment (mTLT) and explores its potential management strategies for younger patients with good central vision. CASE PRESENTATION: Three younger Chinese glaucoma patients with good central vision maintained high intraocular pressures (IOPs) (36, 25, and 30 mmHg) on maximally tolerated topical anti-glaucoma medications. All patients were treated with mTLT because of a higher risk of complications with filtering surgery. After the procedure, their best-corrected visual acuities were not significantly changed, IOPs were significantly decreased, and the number of topical anti-glaucoma medicines was gradually decreased. However, all patients complained about reduced near visual acuity (NVA) for 1-5 months. Slit-lamp examination revealed pupillary dilation, and binocular accommodative function examination indicated accommodation loss. After treatment with 2% topical pilocarpine, all patients reported an improvement in NVA. Among them, we could observe pupillary constriction, recovery of accommodation function, and improved NVA, even discontinuation of pilocarpine in Patient 2. CONCLUSION: In younger patients with good central vision, topical pilocarpine might ameliorate accommodation loss and pupillary dilation after mTLT.
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Acomodación Ocular , Presión Intraocular , Pilocarpina , Humanos , Pilocarpina/uso terapéutico , Pilocarpina/administración & dosificación , Masculino , Femenino , Adulto , Presión Intraocular/fisiología , Acomodación Ocular/fisiología , Agudeza Visual , Mióticos/administración & dosificación , Mióticos/uso terapéutico , Pupila/efectos de los fármacos , Esclerótica/cirugía , Glaucoma/cirugía , Glaucoma/fisiopatología , Terapia por Láser/métodos , Soluciones Oftálmicas , Persona de Mediana Edad , Complicaciones Posoperatorias , Administración TópicaRESUMEN
Epilepsy, a neurological disorder characterized by excessive neuronal activity and synchronized electrical discharges, ranks among the most prevalent global neurological conditions. Despite common use, antiepileptic drugs often result in adverse effects and lack effectiveness in controlling seizures in temporal lobe epilepsy (TLE) patients. Recent research explored the potential of occidentalin-1202, a peptide inspired by Polybia occidentalis venom, in safeguarding Wistar rats from chemically induced seizures. The present study evaluated the new analog from occidentalin-1202 named NOR-1202 using acute and chronic pilocarpine-induced models and an acute kainic acid (KA) male mice model. NOR-1202 was administered through the intracerebroventricular (i.c.v.), subcutaneous, or intraperitoneal routes, with stereotaxic procedures for the i.c.v. injection. In the acute pilocarpine-induced model, NOR-1202 (i.c.v.) protected against generalized seizures and mortality but lacked systemic antiepileptic activity. In the KA model, it did not prevent generalized seizures but improved survival. In the chronic TLE model, NOR-1202's ED50 did not differ significantly from the epileptic or healthy groups regarding time spent in spontaneous recurrent seizures during the five-day treatment. However, the NOR-1202 group exhibited more seizures than the healthy group on the second day of treatment. In summary, NOR-1202 exhibits antiepileptic effects against chemoconvulsant-induced seizures, but no effect was observed when administered systemically.
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Anticonvulsivantes , Modelos Animales de Enfermedad , Convulsiones , Animales , Masculino , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico , Ratones , Convulsiones/tratamiento farmacológico , Convulsiones/inducido químicamente , Pilocarpina , Ácido Kaínico/análogos & derivados , Péptidos/farmacología , Péptidos/uso terapéutico , Péptidos/administración & dosificación , Epilepsia del Lóbulo Temporal/tratamiento farmacológico , Epilepsia del Lóbulo Temporal/inducido químicamenteRESUMEN
Pharmacological treatment of presbyopia-spectacle free senescence Therefore, it is of interest to estimate improvement of near vision with 0.5%pilocarpine drops in presbyopic patients. It was a cross-sectional observational study done at tertiary care centre history, comprehensive eye examination, including distant visual acuity distant and near vision, IOP. 1 drop of 0.5%Pilocarpine eye-drops was instilled in both eyes in Patients with full distant vision and impaired near vision, near vision was checked after 2hours. Among 55 participants, 48% were males and 52% were females. Mean age of patients was 44.8 years. Out of 55 patients 58% patients showed improvement of 1 line after instilling drops, 41% patients showed no improvement. Topical 0.5%pilocarpine in treatment of near vision is attractive option for patients and would increase compliance with minimal side effects.
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OBJECTIVES: Pilocarpine is commonly used clinically to treat dry mouth. The long-term administration of pilocarpine reportedly improves salivary secretion more effectively than short-term administration. Therefore, we hypothesized that pilocarpine alters gene expression in salivary glands via muscarinic receptor stimulation. This study aimed to investigate the effects of pilocarpine use on gene expression mediated by mitogen-activated protein kinase (MAPK) activity. METHODS: The effects of pilocarpine on gene expression were investigated in rats and human salivary gland (HSY) cells using several inhibitors of intracellular signaling pathways. Gene expression in the rat submandibular gland and HSY cells was determined using reverse transcription-quantitative polymerase chain reaction analysis of total RNA. RESULTS: In animal experiments, at 7 days after pilocarpine stimulation, Ctgf and Sgk1 expressions were increased in the submandibular gland. In cell culture experiments, pilocarpine increased Ctgf expression in HSY cells. The mitogen-activated protein kinase kinase inhibitor trametinib, the Src inhibitor PP2, and the muscarinic acetylcholine receptor antagonist atropine suppressed the effect of pilocarpine on gene expression. CONCLUSIONS: Pilocarpine enhances Ctgf and Sgk1 expressions by activating Src-mediated MAPK activity. Although further studies are required to fully understand the roles of Ctgf and Sgk1, changes in gene expression may play an important role in improving salivary secretions.
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Increased vulnerability to seizures in aging has been well documented both clinically and in various models of aging in epilepsy. Seizures can exacerbate cognitive decline that is already prominent in aging. Senescent cells are thought to contribute to cognitive impairment in aging and clearing senescent cells with senolytic drugs improves cognitive function in animal models. It remains unclear whether senescent cells render the aged brain vulnerable to seizures. Here, we demonstrate that prophylactic senolytic treatment with Dasatinib and Quercetin (D&Q) reduced both seizure severity and mortality in aged C57BL/6J mice. We subjected the D&Q and VEH-treated aged mice to spatial memory testing before and after an acute seizure insult, Status Epilepticus [SE], which leads to epilepsy development. We found that senolytic therapy improved spatial memory before injury, however, spatial memory was not rescued after SE. Senescence-related proteins p16 and senescence-associated ß-galactosidase were reduced in D&Q-treated aged mice. Our findings indicate that senescent cells increase seizure susceptibility in aging. Thus, prophylactically targeting senescent cells may prevent age-related seizure vulnerability.
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Status epilepticus (SE) is a medical emergency associated with high mortality and morbidity. Na+, K+-ATPase, is a promising therapeutic target for SE, given its critical role in regulation of neuron excitability and cellular homeostasis. We investigated the effects of a Na+, K+-ATPase-activating antibody (DRRSAb) on short-term electrophysiological and behavioral consequences of pilocarpine-induced SE. Rats were submitted to pilocarpine-induced SE, followed by intranasal administration (2 µg/nostril). The antibody increased EEG activity following SE, namely, EEG power in theta, beta, and gamma frequency bands, assessed by quantitative analysis of EEG power spectra. One week later, DRRSAb-treated animals displayed less behavioral hyperreactivity in pick-up tests and better performance in novel object recognition tests, indicating that the intranasal administration of this Na+, K+-ATPase activator immediately after SE improves behavioral outcomes at a later time point. These results suggest that Na+, K+-ATPase activation warrants further investigation as an adjunctive therapeutic strategy for SE.
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Administración Intranasal , Electroencefalografía , Pilocarpina , ATPasa Intercambiadora de Sodio-Potasio , Estado Epiléptico , Animales , Estado Epiléptico/inducido químicamente , Estado Epiléptico/tratamiento farmacológico , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Masculino , Pilocarpina/farmacología , Electroencefalografía/métodos , Electroencefalografía/efectos de los fármacos , Ratas , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Ratas Wistar , Anticuerpos/farmacología , Anticuerpos/administración & dosificaciónRESUMEN
Olfactory oscillations may enhance cognitive processing through coupling with beta (ß, 15-30 Hz) and gamma (γ, 30-160 Hz) activity in the hippocampus (HPC). We hypothesize that coupling between olfactory bulb (OB) and HPC oscillations is increased by cholinergic activation in control rats and is reduced in kainic-acid-treated epileptic rats, a model of temporal lobe epilepsy. OB γ2 (63-100 Hz) power was higher during walking and immobility-awake (IMM) compared to sleep, while γ1 (30-57 Hz) power was higher during grooming than other behavioral states. Muscarinic cholinergic agonist pilocarpine (25 mg/kg ip) with peripheral muscarinic blockade increased OB power and OB-HPC coherence at ß and γ1 frequency bands. A similar effect was found after physostigmine (0.5 mg/kg ip) but not scopolamine (10 mg/kg ip). Pilocarpine increased bicoherence and cross-frequency coherence (CFC) between OB slow waves (SW, 1-5 Hz) and hippocampal ß, γ1 and γ2 waves, with stronger coherence at CA1 alveus and CA3c than CA1 stratum radiatum. Bicoherence further revealed a nonlinear interaction of ß waves in OB with ß waves at the CA1-alveus. Beta and γ1 waves in OB or HPC were segregated at one phase of the OB-SW, opposite to the phase of γ2 and γ3 (100-160 Hz) waves, suggesting independent temporal processing of ß/γ1 versus γ2/γ3 waves. At CA1 radiatum, kainic-acid-treated epileptic rats compared to control rats showed decreased theta power, theta-ß and theta-γ2 CFC during baseline walking, decreased CFC of HPC SW with γ2 and γ3 waves during baseline IMM, and decreased coupling of OB SW with ß and γ2 waves at CA1 alveus after pilocarpine. It is concluded that ß and γ waves in the OB and HPC are modulated by a slow respiratory rhythm, in a cholinergic and behavior-dependent manner, and OB-HPC functional connectivity at ß and γ frequencies may enhance cognitive functions.
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Ritmo beta , Ritmo Gamma , Hipocampo , Bulbo Olfatorio , Pilocarpina , Animales , Ritmo Gamma/efectos de los fármacos , Ritmo Gamma/fisiología , Masculino , Bulbo Olfatorio/efectos de los fármacos , Bulbo Olfatorio/fisiopatología , Bulbo Olfatorio/fisiología , Hipocampo/efectos de los fármacos , Hipocampo/fisiopatología , Hipocampo/fisiología , Ratas , Pilocarpina/farmacología , Ritmo beta/efectos de los fármacos , Ritmo beta/fisiología , Ácido Kaínico/farmacología , Agonistas Muscarínicos/farmacología , Modelos Animales de Enfermedad , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/inducido químicamente , Escopolamina/farmacología , Fisostigmina/farmacología , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Antagonistas Muscarínicos/farmacologíaRESUMEN
In animal models of epilepsy, cranial surgery is often required to implant electrodes for electroencephalography (EEG) recording. However, electrode implants can lead to the activation of glial cells and interfere with physiological neuronal activity. In this study, we evaluated the impact of epidural electrode implants in the pilocarpine mouse model of temporal lobe epilepsy. Brain neuroinflammation was assessed 1 and 3 weeks after surgery by cytokines quantification, immunohistochemistry, and western blotting. Moreover, we investigated the effect of pilocarpine, administered two weeks after surgery, on mice mortality rate. The reported results indicate that implanted mice suffer from neuroinflammation, characterized by an early release of pro-inflammatory cytokines, microglia activation, and subsequent astrogliosis, which persists after three weeks. Notably, mice subjected to electrode implants displayed a higher mortality rate following pilocarpine injection 2 weeks after the surgery. Moreover, the analysis of EEGs recorded from implanted mice revealed a high number of single spikes, indicating a possible increased susceptibility to seizures. In conclusion, epidural electrode implant in mice promotes neuroinflammation that could lower the seizure thresholds to pilocarpine and increase the death rate. An improved protocol considering the persistent neuroinflammation induced by electrode implants will address refinement and reduction, two of the 3Rs principles for the ethical use of animals in scientific research.
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Modelos Animales de Enfermedad , Electrodos Implantados , Neuronas , Pilocarpina , Animales , Pilocarpina/efectos adversos , Ratones , Electrodos Implantados/efectos adversos , Masculino , Neuronas/metabolismo , Neuronas/patología , Neuroglía/metabolismo , Neuroglía/patología , Electroencefalografía , Epilepsia/inducido químicamente , Epilepsia/etiología , Epilepsia/patología , Citocinas/metabolismo , Epilepsia del Lóbulo Temporal/inducido químicamente , Microglía/metabolismo , Microglía/patología , Ratones Endogámicos C57BLRESUMEN
Introduction: The gut microbiota and the microbiota-gut-brain axis have gained considerable attention in recent years, emerging as key players in the mechanisms that mediate the occurrence and progression of many central nervous system-related diseases, including epilepsy. In clinical practice, one of the side effects of quinolone antibiotics is a lower seizure threshold or aggravation. However, the underlying mechanism remains unclear. Methods: We aimed to unravel the intrinsic mechanisms through 16S rRNA sequencing and serum untargeted metabolomic analysis to shed light on the effects of gut microbiota in ciprofloxacin-induced seizure susceptibility and lithium pilocarpine-induced epilepsy rat models. Results: We observed that ciprofloxacin treatment increased seizure susceptibility and caused gut dysbiosis. We also found similar changes in the gut microbiota of rats with lithium pilocarpine-induced epilepsy. Notably, the levels of Akkermansia and Bacteroides significantly increased in both the ciprofloxacin-induced seizure susceptibility and lithium pilocarpine-induced epilepsy rat models. However, Marvinbryantia, Oscillibacter, and Ruminococcaceae_NK4A214_group showed a coincidental reduction. Additionally, the serum untargeted metabolomic analysis revealed decreased levels of indole-3-propionic acid, a product of tryptophan-indole metabolism, after ciprofloxacin treatment, similar to those in the plasma of lithium pilocarpine-induced epilepsy in rats. Importantly, alterations in the gut microbiota, seizure susceptibility, and indole-3-propionic acid levels can be restored by fecal microbiota transplantation. Conclusion: In summary, our findings provide evidence that ciprofloxacin-induced seizure susceptibility is partially mediated by the gut microbiota and tryptophan-indole metabolism. These associations may play a role in epileptogenesis, and impacting the development progression and treatment outcomes of epilepsy.
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The lithium-pilocarpine model is commonly used to recapitulate characteristics of human intractable focal epilepsy. In the current study, we explored the impact of topiramate (TPM) alone and in combination with pregabalin and lacosamide administration for 6 weeks on the evolution of spontaneous recurrent seizures (SRS) and disease-modifying potential on associated neuropsychiatric comorbidities. In addition, redox impairments and neurodegeneration in hippocampus regions vulnerable to temporal lobe epilepsy (TLE) were assessed by cresyl violet staining. Results revealed that acute electrophysiological (EEG) profiling of the ASD cocktail markedly halted sharp ictogenic spikes as well as altered dynamics of brain wave oscillations thus validating the need for polytherapy vs. monotherapy. In TLE animals, pharmacological intervention for 6 weeks with topiramate 10 mg/kg in combination with PREG and LAC at the dose of 20 mg/kg exhibited marked protection from SRS incidence, improved body weight, offensive aggression, anxiety-like behavior, cognitive impairments, and depressive-like behavior (p < 0.05). Moreover, combination therapy impeded redox impairments as evidenced by decreased MDA and AchE levels and increased activity of antioxidant SOD, GSH enzymes. Furthermore, polytherapy rescued animals from SE-induced neurodegeneration with increased neuronal density in CA1, CA3c, CA3ab, hilus, and granular cell layer (GCL) of the dentate gyrus. In conclusion, early polytherapy with topiramate in combination with pregabalin and lacosamide prompted synergy and prevented epileptogenesis with associated psychological and neuropathologic alterations.
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Modelos Animales de Enfermedad , Electroencefalografía , Lacosamida , Fármacos Neuroprotectores , Pregabalina , Topiramato , Animales , Lacosamida/farmacología , Lacosamida/uso terapéutico , Topiramato/farmacología , Topiramato/uso terapéutico , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Masculino , Pregabalina/farmacología , Pregabalina/uso terapéutico , Ratas , Conducta Animal/efectos de los fármacos , Epilepsia Refractaria/tratamiento farmacológico , Quimioterapia Combinada , Hipocampo/efectos de los fármacos , Hipocampo/fisiopatología , Hipocampo/patología , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico , Estado Epiléptico/tratamiento farmacológico , Estado Epiléptico/inducido químicamente , Estado Epiléptico/fisiopatología , Ratas Wistar , Epilepsia del Lóbulo Temporal/tratamiento farmacológico , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/inducido químicamenteRESUMEN
Objective: Various neurological complications have been reported after COVID-19. The study aimed to document an unusual case of Adie's tonic pupil following COVID-19. Methods: The study was a case report. Results: A 28-year-old female had suffered a flu-like disease about 2 months before and the SARSCoV-2 polymerase chain reaction test at that time was positive. Two weeks after infection she noticed an asymmetry between the pupils. The only pathological finding on examination was anisocoria with a larger left pupil in ambient light. Light reflexes were observed in the right eye, while in the left eye, they were absent. Also, there was no near response in the left pupil. A 0.1% pilocarpine test results validated Adie's pupil diagnosis. After one year of follow-up, the anisocoria decreased but did not completely recover. Discussion: COVID-19 may cause damage to neural structures due to autoimmune ways by activating immune pathways or because of vascular complications that may affect the vasa nervorum. Adie's tonic pupil is often idiopathic, but it may develop following viral infection. Conclusions: Ocular complications that involve pupil abnormalities may manifest following COVID-19. In the cases of Adie's tonic pupil, infectious diseases, including COVID-19, should be questioned. Abbreviations: RT PCR = reverse transcription polymerase chain reaction.
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COVID-19 , SARS-CoV-2 , Pupila Tónica , Adulto , Femenino , Humanos , Anisocoria/diagnóstico , Anisocoria/etiología , COVID-19/diagnóstico , COVID-19/complicaciones , Pupila Tónica/diagnóstico , Pupila Tónica/etiologíaRESUMEN
Introduction: Status epilepticus (SE) is a seizure lasting more than 5 min that can have lethal consequences or lead to various neurological disorders, including epilepsy. Using a pilocarpine-induced SE model in mice we investigated temporal changes in the hippocampal transcriptome. Methods: We performed mRNA-seq and microRNA-seq analyses at various times after drug treatment. Results: At 1 h after the start of seizures, hippocampal cells upregulated transcription of immediate early genes and genes involved in the IGF-1, ERK/MAPK and RNA-PolII/transcription pathways. At 8 h, we observed changes in the expression of genes associated with oxidative stress, overall transcription downregulation, particularly for genes related to mitochondrial structure and function, initiation of a stress response through regulation of ribosome and translation/EIF2 signaling, and upregulation of an inflammatory response. During the middle of the latent period, 36 h, we identified upregulation of membrane components, cholesterol synthesis enzymes, channels, and extracellular matrix (ECM), as well as an increased inflammatory response. At the end of the latent period, 120 h, most changes in expression were in genes involved in ion transport, membrane channels, and synapses. Notably, we also elucidated the involvement of novel pathways, such as cholesterol biosynthesis pathways, iron/BMP/ferroptosis pathways, and circadian rhythms signaling in SE and epileptogenesis. Discussion: These temporal changes in metabolic reactions indicate an immediate response to injury followed by recovery and regeneration. CREB was identified as the main upstream regulator. Overall, our data provide new insights into molecular functions and cellular processes involved at different stages of seizures and offer potential avenues for effective therapeutic strategies.
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At least 3 months after systemic treatment with pilocarpine to induce status epilepticus, Long-Evans and Sprague-Dawley rats were video-EEG monitored for seizures continuously for 1 month. Rats were then perfused, hippocampi were processed for Nissl staining, and hilar neurons were quantified. Seizure frequency in Long-Evans rats was 1/10th of that in Sprague-Dawley rats, and more variable. Hilar neuron loss was also less severe in Long-Evans rats. However, there was no correlation between hilar neuron loss and seizure frequency in either strain. The low and variable seizure frequency suggests limited usefulness of pilocarpine-treated Long-Evans rats for some epilepsy experiments.
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Electroencefalografía , Neuronas , Pilocarpina , Ratas Long-Evans , Ratas Sprague-Dawley , Convulsiones , Animales , Pilocarpina/toxicidad , Ratas , Convulsiones/inducido químicamente , Convulsiones/tratamiento farmacológico , Convulsiones/fisiopatología , Neuronas/efectos de los fármacos , Neuronas/patología , Masculino , Especificidad de la Especie , Hipocampo/efectos de los fármacos , Hipocampo/patología , Modelos Animales de Enfermedad , Estado Epiléptico/inducido químicamente , Estado Epiléptico/patología , Estado Epiléptico/tratamiento farmacológicoRESUMEN
Patients with epilepsy are prone to cognitive decline, depression, anxiety and other behavioral disorders. Cognitive comorbidities are particularly common and well-characterized in people with temporal lobe epilepsy, while inconsistently addressed in epileptic animals. Therefore, the aim of this study was to ascertain whether there is good evidence of cognitive comorbidities in animal models of epilepsy, in particular in the rat pilocarpine model of temporal lobe epilepsy. We searched the literature published between 1990 and 2023. The association of spontaneous recurrent seizures induced by pilocarpine with cognitive alterations has been evaluated by using various tests: contextual fear conditioning (CFC), novel object recognition (NOR), radial and T-maze, Morris water maze (MWM) and their variants. Combination of results was difficult because of differences in methodological standards, in number of animals employed, and in outcome measures. Taken together, however, the analysis confirmed that pilocarpine-induced epilepsy has an effect on cognition in rats, and supports the notion that this is a valid model for assessment of cognitive temporal lobe epilepsy comorbidities in preclinical research.
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Status epilepticus (SE) is a medical and neurologic emergency that may lead to permanent brain damage, morbidity, or death. Animal models of SE are particularly important to study the pathophysiology of SE and mechanisms of SE resistance to antiseizure medications with the aim to develop new, more effective treatments. In addition to rodents (rats or mice), larger mammalian species such as dogs, pigs, and nonhuman primates are used. This short review describes and discusses the value and limitations of the most frequently used mammalian models of SE. Issues that are discussed include (1) differences between chemical and electrical SE models; (2) the role of genetic background and environment on SE in rodents; (3) the use of rodent models (a) to study the pathophysiology of SE and mechanisms of SE resistance; (b) to study developmental aspects of SE; (c) to study the efficacy of new treatments, including drug combinations, for refractory SE; (d) to study the long-term consequences of SE and identify biomarkers; (e) to develop treatments that prevent or modify epilepsy; (e) to study the pharmacology of spontaneous seizures; (4) the limitations of animal models of induced SE; and (5) the advantages (and limitations) of naturally (spontaneously) occurring SE in epileptic dogs and nonhuman primates. Overall, mammalian models of SE have significantly increased our understanding of the pathophysiology and drug resistance of SE and identified potential targets for new, more effective treatments. This paper was presented at the 9th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in April 2024.
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Modelos Animales de Enfermedad , Estado Epiléptico , Estado Epiléptico/fisiopatología , Animales , Humanos , Perros , Anticonvulsivantes/uso terapéuticoRESUMEN
OSA is known to increase the risk for SUDEP in persons with epilepsy, but the relationship between these two factors is not clear. Also, there is no study showing the acute responses to obstructive apnea in a chronic epilepsy model. Therefore, this study aimed to characterize cardiorespiratory responses to obstructive apnea and chemoreceptor stimulation in rats. In addition, we analyzed respiratory centers in the brain stem by immunohistochemistry. Epilepsy was induced with pilocarpine. About 30-60 days after the first spontaneous seizure, tracheal and thoracic balloons, and electrodes for recording the electroencephalogram, electromyogram, and electrocardiogram were implanted. Intermittent apneas were made by inflation of the tracheal balloon during wakefulness, NREM sleep, and REM sleep. During apnea, respiratory effort increased, and heart rate fell, especially with apneas made during wakefulness, both in control rats and rats with epilepsy. Latency to awake from apnea was longer with apneas made during REM than NREM, but rats with epilepsy awoke more rapidly than controls with apneas made during REM sleep. Rats with epilepsy also had less REM sleep. Cardiorespiratory responses to stimulation of carotid chemoreceptors with cyanide were similar in rats with epilepsy and controls. Immunohistochemical analysis of Phox2b, tryptophan hydroxylase, and NK1 in brain stem nuclei involved in breathing and sleep (retrotrapezoid nucleus, pre-Bötzinger complex, Bötzinger complex, and caudal raphe nuclei) revealed no differences between control rats and rats with epilepsy. In conclusion, our study showed that rats with epilepsy had a decrease in the latency to awaken from apneas during REM sleep, which may be related to neuroplasticity in some other brain regions related to respiratory control, awakening mechanisms, and autonomic modulation.
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Modelos Animales de Enfermedad , Electroencefalografía , Epilepsia , Apnea Obstructiva del Sueño , Vigilia , Animales , Vigilia/fisiología , Masculino , Epilepsia/fisiopatología , Apnea Obstructiva del Sueño/fisiopatología , Apnea Obstructiva del Sueño/complicaciones , Ratas , Enfermedad Crónica , Pilocarpina/toxicidad , Tronco Encefálico/fisiopatología , Frecuencia Cardíaca/fisiología , Electromiografía , Ratas Sprague-Dawley , Ratas WistarRESUMEN
An epilepsy diagnosis reduces a patient's quality of life tremendously, and it is a fate shared by over 50 million people worldwide. Temporal lobe epilepsy (TLE) is largely considered a nongenetic or acquired form of epilepsy that develops in consequence of neuronal trauma by injury, malformations, inflammation, or a prolonged (febrile) seizure. Although extensive research has been conducted to understand the process of epileptogenesis, a therapeutic approach to stop its manifestation or to reliably cure the disease has yet to be developed. In this review, we briefly summarize the current literature predominately based on data from excitotoxic rodent models on the cellular events proposed to drive epileptogenesis and thoroughly discuss the major molecular pathways involved, with a focus on neurogenesis-related processes and transcription factors. Furthermore, recent investigations emphasized the role of the genetic background for the acquisition of epilepsy, including variants of neurodevelopmental genes. Mutations in associated transcription factors may have the potential to innately increase the vulnerability of the hippocampus to develop epilepsy following an injury-an emerging perspective on the epileptogenic process in acquired forms of epilepsy.
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Epilepsia del Lóbulo Temporal , Epilepsia del Lóbulo Temporal/genética , Humanos , Animales , Hipocampo/metabolismo , Hipocampo/patología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Neurogénesis/genética , MutaciónRESUMEN
A ketogenic diet (KD) is a high-fat, low-carbohydrate, and low-protein diet that exerts antiepileptic effects by attenuating spontaneous recurrent seizures, ameliorating learning and memory impairments, and modulating the gut microbiota composition. However, the role of the gut microbiome in the antiepileptic effects of a KD on temporal lobe epilepsy (TLE) induced by lithium-pilocarpine in adult rats is still unknown. Our study provides evidence demonstrating that a KD effectively mitigates seizure behavior and reduces acute-phase epileptic brain activity and that KD treatment alleviates hippocampal neuronal damage and improves cognitive impairment induced by TLE. We also observed that the beneficial effects of a KD are compromised when the gut microbiota is disrupted through antibiotic administration. Analysis of gut microbiota components via 16S rRNA gene sequencing in fecal samples collected from TLE rats fed either a KD or a normal diet. The Chao1 and ACE indices showed decreased species variety in KD-fed rats compared to TLE rats fed a normal diet. A KD increased the levels of Actinobacteriota, Verrucomicrobiota and Proteobacteria and decreased the level of Bacteroidetes. Interestingly, the abundances of Actinobacteriota and Verrucomicrobiota were positively correlated with learning and memory ability, and the abundance of Proteobacteria was positively correlated with seizure susceptibility. In conclusion, our study revealed the significant antiepileptic and neuroprotective effects of a KD on pilocarpine-induced epilepsy in rats, primarily mediated through the modulation of the gut microbiota. However, whether the gut microbiota mediates the antiseizure effects of a KD still needs to be better elucidated.
RESUMEN
Globally, an estimated 50 million people are affected by epilepsy, a persistent, noncommunicable neurological ailment. Quercetin (QR) is a prevalent flavonoid substance extensively dispersed throughout agricultural life. In a pilocarpine (PILO)-induced epilepsy model in mice, this investigation aimed to determine whether QR has an antiepileptic effect and explore its putative mechanism of action. Fifty mice were allocated into seven groups, with six in every group. The first group received physiological saline, the second group was given diazepam (1 mg/kg), and four groups were administered QR at 50, 100, 150, and 200 mg/kg, respectively. The seventh group (the induction group) received normal saline. After 30 min, all groups were injected intraperitoneally with PILO. The impact of QR on motor coordination was assessed using the rotarod test, while measures such as latency to first seizure, generalized tonic-clonic seizures (GTCS), number of convulsions, and mortality were recorded. Serum samples were collected through the retro-orbital route to measure prostaglandin E2 (PGE2) and interleukin 1 beta (IL-1ß) levels. QR showed no significant difference in motor impairment, but increased duration until the initial seizure occurred and declined the mortality rate, duration of GTCS, and incidence of convulsions. All doses of QR significantly reduced PGE2 levels (P ≤ 0.05). However, QR's effect on IL-1ß reduction was statistically insignificant (P > 0.05). QR's capacity to inhibit PILO-induced epilepsy by decreasing IL-1 and PGE2 levels is supported by this study. The results of this work indicate that QR could have a function to treat acute epilepsy.