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1.
Epilepsia ; 65(6): 1777-1790, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38491947

RESUMO

OBJECTIVE: Brain infection with Theiler's murine encephalomyelitis virus (TMEV) in C57BL/6J mice can induce acquired epileptogenesis. Diet alters acute seizure incidence in TMEV-infected mice; yet it is unclear whether intestinal dysbiosis may also impact acute or chronic behavioral comorbidities. This study thus assessed the impact of diet formulation and sterilization on acute seizure presentation, gut microbiome composition, and epilepsy-related chronic behavioral comorbidities. METHODS: Baseline fecal samples were collected from male C57BL/6J mice (4- to 5-weeks-old; Jackson Labs) upon facility arrival. Mice were randomized to either autoclaved (AC) or irradiated diet (IR) (Prolab RMH 3000) or IR (Picolab 5053). Three days later, mice underwent intracerebral TMEV or phosphate-buffered saline (PBS) injection. Fecal samples were collected from a subset of mice at infection (Day 0) and Day 7 post-infection. Epilepsy-related working memory deficits and seizure threshold were assessed 6 weeks post-infection. Gut microbiome diversity was determined by 16S rRNA amplicon sequencing of fecal samples. RESULTS: TMEV-infected mice displayed acute handling-induced seizures, regardless of diet: 28 of 57 IR Picolab 5053 (49.1%), 30 of 41 IR Prolab RMH 3000 (73.2%), and 47 of 77 AC Prolab RMH 3000 (61%) mice displayed seizures. The number of observed seizures differed significantly by diet: IR Picolab 5053 diet-fed mice had 2.2 ± 2.8 seizures (mean ± standard deviation), IR Prolab RMH 3000 diet-fed mice had 3.5 ± 2.9 seizures, and AC Prolab RMH 3000 diet-fed mice had 4.4 ± 3.8 seizures during the 7-day monitoring period. Gut microbiome composition differed significantly in TMEV-infected mice fed the AC Prolab RMH 3000 diet, with measured differences in gram-positive bacteria. These mice also displayed worsened long-term working memory deficits. SIGNIFICANCE: Diet-induced differences in intestinal dysbiosis in the TMEV model are associated with marked changes in acute seizure presentation, symptomatic recovery, and onset of chronic behavioral comorbidities of epilepsy. Our study reveals a novel disease-modifying impact of dietary manipulation on intestinal bacterial species after TMEV-induced acute seizures.


Assuntos
Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Convulsões , Theilovirus , Animais , Camundongos , Convulsões/etiologia , Masculino , Dieta , Infecções por Cardiovirus , Esterilização/métodos , Fezes/microbiologia , Doença Aguda
2.
Epilepsy Behav ; 151: 109618, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38184948

RESUMO

INTRODUCTION: Intermittent fasting enhances neural bioenergetics, is neuroprotective, and elicits antioxidant effects in various animal models. There are conflicting findings on seizure protection, where intermittent fasting regimens often cause severe weight loss resembling starvation which is unsustainable long-term. Therefore, we tested whether a less intensive intermittent fasting regimen such as time-restricted feeding (TRF) may confer seizure protection. METHODS: Male CD1 mice were assigned to either ad libitum-fed control, continuous 8 h TRF, or 8 h TRF with weekend ad libitum food access (2:5 TRF) for one month. Body weight, food intake, and blood glucose levels were measured. Seizure thresholds were determined at various time points using 6-Hz and maximal electroshock seizure threshold (MEST) tests. Protein levels and mRNA expression of genes, enzyme activity related to glucose metabolism, as well as mitochondrial dynamics were assessed in the cortex and hippocampus. Markers of antioxidant defence were evaluated in the plasma, cortex, and liver. RESULTS: Body weight gain was similar in the ad libitum-fed and TRF mouse groups. In both TRF regimens, blood glucose levels did not change between the fed and fasted state and were higher during fasting than in the ad libitum-fed groups. Mice in the TRF group had increased seizure thresholds in the 6-Hz test on day 15 and on day 19 in a second cohort of 2:5 TRF mice, but similar seizure thresholds at other time points compared to ad libitum-fed mice. Continuous TRF did not alter MEST seizure thresholds on day 28. Mice in the TRF group showed increased maximal activity of pyruvate dehydrogenase in the cortex, which was accompanied by increased protein levels of mitochondrial pyruvate carrier 1 in the cortex and hippocampus. There were no other major changes in protein or mRNA levels associated with energy metabolism and mitochondrial dynamics in the brain, nor markers of antioxidant defence in the brain, liver, or plasma. CONCLUSIONS: Both continuous and 2:5 TRF regimens transiently increased seizure thresholds in the 6-Hz model at around 2 weeks, which coincided with stability of blood glucose levels during the fed and fasted periods. Our findings suggest that the lack of prolonged anticonvulsant effects in the acute electrical seizure models employed may be attributed to only modest metabolic and antioxidant adaptations found in the brain and liver. Our findings underscore the potential therapeutic value of TRF in managing seizure-related conditions.


Assuntos
Anticonvulsivantes , Jejum Intermitente , Humanos , Masculino , Animais , Camundongos , Anticonvulsivantes/uso terapêutico , Glicemia , Antioxidantes , Peso Corporal , Modelos Animais de Doenças , Convulsões/tratamento farmacológico , RNA Mensageiro
3.
Int J Mol Sci ; 24(23)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38069200

RESUMO

Febrile seizures during early childhood may result in central nervous system developmental disorders. However, the specific mechanisms behind the impact of febrile seizures on the developing brain are not well understood. To address this gap in knowledge, we employed a hyperthermic model of febrile seizures in 10-day-old rats and tracked their development over two months. Our objective was to determine the degree to which the properties of the hippocampal glutamatergic system are modified. We analyzed whether pyramidal glutamatergic neurons in the hippocampus die after febrile seizures. Our findings indicate that there is a reduction in the number of neurons in various regions of the hippocampus in the first two days after seizures. The CA1 field showed the greatest susceptibility, and the reduction in the number of neurons in post-FS rats in this area appeared to be long-lasting. Electrophysiological studies indicate that febrile seizures cause a reduction in glutamatergic transmission, leading to decreased local field potential amplitude. This impairment could be attributable to diminished glutamate release probability as evidenced by decreases in the frequency of miniature excitatory postsynaptic currents and increases in the paired-pulse ratio of synaptic responses. We also found higher threshold current causing hind limb extension in the maximal electroshock seizure threshold test of rats 2 months after febrile seizures compared to the control animals. Our research suggests that febrile seizures can impair glutamatergic transmission, which may protect against future seizures.


Assuntos
Hipertermia Induzida , Convulsões Febris , Estado Epiléptico , Pré-Escolar , Humanos , Ratos , Animais , Ratos Sprague-Dawley , Hipertermia Induzida/efeitos adversos , Hipocampo/fisiologia , Região CA1 Hipocampal , Estado Epiléptico/complicações , Modelos Animais de Doenças
4.
Biomedicines ; 11(9)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37760843

RESUMO

BACKGROUND: The seizure threshold 2 (SZT2) gene encodes a protein of unknown function, which is widely expressed, confers a low seizure threshold, and enhances epileptogenesis. It also comprises the KICSTOR protein complex, which inhibits the mTORC1 pathway. A pathogenic variant in the SZT2 gene could result in hyperactive mTORC1 signaling, which can lead to several neurological disorders. AIM OF THE STUDY: To review every reported case and present two novel cases to expand the current knowledge and understanding of the mutation. METHODS: Whole exome sequencing (WES) was used to identify the novel cases and present their clinical and radiological findings. A detailed revision of the literature was conducted to illustrate and compare findings. The clinical, genetical, neuroimaging, and electrophysiological data were extracted. RESULTS: The study included 16 female patients and 13 male patients in addition to the 2 novel male cases. Eighteen patients had heterozygous mutations; others were homozygous. The majority presented with facial dysmorphism (n = 22). Seizures were noted as the predominant hallmark (n = 26). Developmental delay and hypotonia were reported in 27 and 15 patients, respectively. The majority of patients had multifocal epileptiform discharges on the electroencephalogram (EEG) and short and thick corpus callosum on the magnetic resonance imaging (MRI). CONCLUSION: Several promising features are becoming strongly linked to patients with SZT2 mutations. High variability among the cases was observed. Developmental delay and facial dysmorphism can be investigated as potential hallmarks; aiding clinicians in diagnosing the condition and optimizing management plans.

5.
Curr Neuropharmacol ; 21(10): 2070-2078, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37366350

RESUMO

Hyperpolarization-activated cyclic nucleotide-gated cation channel 1 (HCN1) is predominantly expressed in neurons from the neocortex and hippocampus, two important regions related to epilepsy. Both animal models for epilepsy and epileptic patients show decreased HCN1 expression and HCN1-mediated Ih current. It has been shown in neuroelectrophysiological experiments that a decreased Ih current can increase neuronal excitability. However, some studies have shown that blocking the Ih current in vivo can exert antiepileptic effects. This paradox raises an important question regarding the causal relationship between HCN1 alteration and epileptogenesis, which to date has not been elucidated. In this review, we summarize the literature related to HCN1 and epilepsy, aiming to find a possible explanation for this paradox, and explore the correlation between HCN1 and the mechanism of epileptogenesis. We analyze the alterations in the expression and distribution of HCN1 and the corresponding impact on brain function in epilepsy. In addition, we also discuss the effect of blocking Ih on epilepsy symptoms. Addressing these issues will help to inspire new strategies to explore the relationship between HCN1 and epileptogenesis, and ultimately promote the development of new targets for epilepsy therapy.


Assuntos
Epilepsia , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Canais de Potássio , Animais , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Epilepsia/genética , Epilepsia/metabolismo , Hipocampo/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Neurônios/metabolismo , Canais de Potássio/metabolismo
6.
Molecules ; 28(9)2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-37175220

RESUMO

In contrast to the other components of the medium-chain triglycerides ketogenic diet (MCT KD), i.e., caprylic acid (CA8), a comprehensive evaluation of caproic (CA6) and lauric acids' (CA12) properties in standard chemical and electrical seizure tests in mice has not yet been performed. We investigated their effects in maximal electroshock seizure threshold (MEST), 6 Hz seizure threshold and intravenous (i.v.) pentylenetetrazole (PTZ) seizure tests. Since ketone body production can be regulated by the activation of 5'AMP-activated protein kinase (AMPK), we hypothesized that metformin (an AMPK activator) enhance ketogenesis and would act synergistically with the fatty acids to inhibit convulsions. We assessed the effects of acute and chronic co-treatment with metformin and CA6/CA8 on seizures. CA6 and CA12 (p.o.) increased seizure threshold in the 6 Hz seizure test. CA6 at the highest tested dose (30 mmol/kg) developed toxicity in several mice, impaired motor performance and induced ketoacidosis. Acute and chronic co-treatment with metformin and CA6/CA8 did not affect seizure thresholds. Moreover, we observed the pro-convulsive effect of the acute co-administration of CA8 (5 mmol/kg) and metformin (100 mg/kg). Since this co-treatment was pro-convulsive, the safety profile and risk/benefit ratio of MCT KD and metformin concomitant therapy in epileptic patients should be further evaluated.


Assuntos
Epilepsia , Metformina , Camundongos , Animais , Anticonvulsivantes/efeitos adversos , Metformina/farmacologia , Metformina/uso terapêutico , Proteínas Quinases Ativadas por AMP , Convulsões/induzido quimicamente , Epilepsia/tratamento farmacológico , Pentilenotetrazol/efeitos adversos , Eletrochoque/efeitos adversos , Relação Dose-Resposta a Droga , Modelos Animais de Doenças
7.
Biochemistry (Mosc) ; 88(3): 353-363, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37076282

RESUMO

Status epilepticus (SE) triggers many not yet fully understood pathological changes in the nervous system that can lead to the development of epilepsy. In this work, we studied the effects of SE on the properties of excitatory glutamatergic transmission in the hippocampus in the lithium-pilocarpine model of temporal lobe epilepsy in rats. The studies were performed 1 day (acute phase), 3 and 7 days (latent phase), and 30 to 80 days (chronic phase) after SE. According to RT-qPCR data, expression of the genes coding for the AMPA receptor subunits GluA1 and GluA2 was downregulated in the latent phase, which may lead to the increased proportion of calcium-permeable AMPA receptors that play an essential role in the pathogenesis of many CNS diseases. The efficiency of excitatory synaptic neurotransmission in acute brain slices was decreased in all phases of the model, as determined by recording field responses in the CA1 region of the hippocampus in response to the stimulation of Schaffer collaterals by electric current of different strengths. However, the frequency of spontaneous excitatory postsynaptic potentials increased in the chronic phase, indicating an increased background activity of the glutamatergic system in epilepsy. This was also evidenced by a decrease in the threshold current causing hindlimb extension in the maximal electroshock seizure threshold test in rats with temporal lobe epilepsy compared to the control animals. The results suggest a series of functional changes in the properties of glutamatergic system associated with the epilepsy development and can be used to develop the antiepileptogenic therapy.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Estado Epiléptico , Ratos , Animais , Pilocarpina/toxicidade , Pilocarpina/metabolismo , Epilepsia do Lobo Temporal/metabolismo , Lítio/farmacologia , Lítio/metabolismo , Hipocampo/metabolismo , Epilepsia/metabolismo , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/metabolismo , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Modelos Animais de Doenças
8.
Biol Trace Elem Res ; 201(10): 4779-4792, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36602746

RESUMO

This study aims to explore the effects of zinc water on autism-like behavior, convulsion threshold, and neurogenesis in ASD model animals. This study used the young BTBR ASD mouse model to explore the effect of a 6-week zinc water supplementation on ASD-like behaviors such as repetitive behavior and social communication disorder, seizure threshold, and the correlation with excitability regulation. The mice were divided into four groups of normal controls (B6) and models (BTBR) who did and did not receive zinc supplementation in water (B6, B6 + zinc, BTBR, and BTBR + zinc). For morphological changes in the hippocampus, we selected two indicators: hippocampal mossy fiber sprouting and neurogenesis. ASD-like behavior testing, seizure threshold determination, Timm staining, and neurogenesis-related assays-represented by Ki67 and DCX-were performed after 6 weeks of zinc supplementation. Our results show that zinc water can prevent autism-like behavior, reduce susceptibility to convulsions, and increase the proliferation of hippocampal progenitor cells in BTBR mice but has less effect on mossy fiber sprouting and neural progenitor cell differentiation. Zinc water reduces autism-like behavior in a partially inherited autism model mice-BTBR-which may be associated with hippocampal neural precursor cell proliferation and reversed hyperexcitability.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Camundongos , Animais , Transtorno Autístico/prevenção & controle , Zinco/farmacologia , Zinco/uso terapêutico , Camundongos Endogâmicos , Comportamento Animal , Convulsões/prevenção & controle , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Comportamento Social
9.
Neurobiol Dis ; 178: 106014, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36702319

RESUMO

Status epilepticus (SE) is a life-threatening medical emergency with significant morbidity and mortality. SE is associated with a robust and sustained increase in serum glucocorticoids, reaching concentrations sufficient to activate the dense population of glucocorticoid receptors (GRs) expressed among hippocampal excitatory neurons. Glucocorticoid exposure can increase hippocampal neuron excitability; however, whether activation of hippocampal GRs during SE exacerbates seizure severity remains unknown. To test this, a viral strategy was used to delete GRs from a subset of hippocampal excitatory neurons in adult male and female mice, producing hippocampal GR knockdown mice. Two weeks after GR knockdown, mice were challenged with the convulsant drug pilocarpine to induce SE. GR knockdown had opposing effects on early vs late seizure behaviors, with sex influencing responses. For both male and female mice, the onset of mild behavioral seizures was accelerated by GR knockdown. In contrast, GR knockdown delayed the onset of more severe convulsive seizures and death in male mice. Concordantly, GR knockdown also blunted the SE-induced rise in serum corticosterone in male mice. GR knockdown did not alter survival times or serum corticosterone in females. To assess whether loss of GR affected susceptibility to SE-induced cell death, within-animal analyses were conducted comparing local GR knockdown rates to local cell loss. GR knockdown did not affect the degree of localized neuronal loss, suggesting cell-intrinsic GR signaling neither protects nor sensitizes neurons to acute SE-induced death. Overall, the findings reveal that hippocampal GRs exert an anti-convulsant role in both males and females in the early stages of SE, followed by a switch to a pro-convulsive role for males only. Findings reveal an unexpected complexity in the interaction between hippocampal GR activation and the progression of SE.


Assuntos
Receptores de Glucocorticoides , Estado Epiléptico , Camundongos , Masculino , Feminino , Animais , Receptores de Glucocorticoides/metabolismo , Corticosterona , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/metabolismo , Hipocampo/metabolismo , Convulsões/induzido quimicamente , Convulsões/metabolismo , Glucocorticoides/metabolismo , Pilocarpina/toxicidade , Convulsivantes
10.
Curr Neuropharmacol ; 21(8): 1755-1766, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35619263

RESUMO

Psychiatric disorder comorbidity in patients with epilepsy (PWE) is very frequent with a mean percentage prevalence of up to 50% and even higher. Such a high frequency suggests that epilepsy and psychiatric disorders might share common pathological pathways. Various aspects contribute in making the matter very complex from a therapeutic point of view. Some antiseizure medications (ASMs), namely valproic acid, carbamazepine, and lamotrigine, have mood-stabilising effects and are routinely used for the treatment of bipolar disorder in patients who do not have epilepsy. Pregabalin and, to a lesser extent, gabapentin, exerts anxiolytic effects. However, several ASMs, in particular levetiracetam, topiramate, and perampanel, may contribute to psychiatric disorders, including depression, aggressive behaviour, and even psychosis. If these ASMs are prescribed, the patient should be monitored closely. A careful selection should be made also with psychotropic drugs. Although most of these can be safely used at therapeutic doses, bupropion, some tricyclic antidepressants, maprotiline, and clozapine may alter seizure threshold and facilitate epileptic seizures. Interactions between ASMs and psychotropic medication may make it difficult to predict individual response. Pharmacokinetic interactions can be assessed with drug monitoring and are consequently much better documented than pharmacodynamic interactions. Another aspect that needs a careful evaluation is patient adherence to treatment. Prevalence of non-adherence in PWE and psychiatric comorbidities is reported to reach values even higher than 70%. A careful evaluation of all these aspects contributes in optimizing therapy with a positive impact on seizure control, psychiatric wellbeing, and quality of life.


Assuntos
Epilepsia , Qualidade de Vida , Humanos , Epilepsia/complicações , Epilepsia/tratamento farmacológico , Epilepsia/epidemiologia , Anticonvulsivantes/uso terapêutico , Comorbidade , Convulsões/tratamento farmacológico
11.
Epilepsy Behav ; 137(Pt A): 108964, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36343532

RESUMO

INTRODUCTION: Acetate has been shown to have neuroprotective and anti-inflammatory effects. It is oxidized by astrocytes and can thus provide auxiliary energy to the brain in addition to glucose. Therefore, we hypothesized that it may protect against seizures, which is investigated here by feeding glyceryl triacetate (GTA), to provide high amounts of acetate without raising sodium or acid levels. METHOD: CD1 male mice were fed controlled diets with or without GTA for up to three weeks. Body weights, blood glucose levels, plasma short-chain fatty acid levels, and other hematological parameters were monitored. Seizure thresholds were determined in 6 Hz and maximal electroshock seizure threshold (MEST) tests. Antioxidant capacities were evaluated in the cerebral cortex and plasma using a ferric reducing antioxidant power (FRAP) assay and Trolox equivalent antioxidant capacity assay. RESULTS: Body weight gain was similar with both diets with and without GTA in two experiments. Glyceryl triacetate-fed groups showed 2-3- and 1.6-fold increased acetate and propionate levels in plasma, respectively. Glucose levels were unaltered in blood collected from the tail tip but increased in trunk blood. No differences were found in the activity of cerebral cortex acetyl-CoA synthetase. In the 6 Hz threshold test, seizure thresholds were lower by 3 mA and 2.4 mA after 8 and 14 days, respectively, in the GTA compared to the control diet-fed group, but showed no difference on day 16, showing that GTA has small, but inconsistent proconvulsant effects in this model. In MEST tests, a slightly increased seizure threshold (1 mA) was found on day 19 in the GTA-fed group, but not in another experiment on day 21. There were no differences in antioxidant capacity in plasma or cortex between the two groups. CONCLUSION: Glyceryl triacetate feeding showed no antioxidant effects nor beneficial changes in acute electrical seizure threshold mouse models, despite its ability to increase plasma acetate levels.


Assuntos
Anticonvulsivantes , Convulsões , Animais , Camundongos , Masculino , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Relação Dose-Resposta a Droga , Convulsões/tratamento farmacológico , Eletrochoque , Modelos Animais de Doenças , Acetatos/uso terapêutico , Glucose
12.
Neurobiol Dis ; 168: 105689, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35288304

RESUMO

Disruption of Interleukin-1ß (IL-1ß) signaling sensitized mice to convulsant stimuli, suggesting that this quintessential cytokine of the innate immune system contributes to maintenance of the innate seizure threshold (ST). However, much remains unknown about where and how IL-1ß secretion occurs in the normal brain. This study examined the possibility that neurons of the hippocampus are key sources of constitutive IL-1ß secretion and that the release from these cells is dependent on the purinoceptor, P2X7. It was posited that treatment with the P2X7 antagonist, JNJ-47965567 (JNJ), would cause IL-1ß to accumulate in cells that produce it, and consequently, lower the ST. No IL-1ß immunoreactivity was detected in any region of the hippocampal formation of mice treated with the JNJ vehicle, Sulfobutylether-ß-cyclodextrin. In contrast, prominent immunoreactivity was discovered in the pyramidal neurons of the CA3 region 60 min after treatment with the P2X7 antagonist. Lower levels were found in CA1 neurons, and no immunoreactivity was detected in granule cells of the dentate gyrus. JNJ also increased IL-1ß immunoreactivity in the cell bodies of hippocampal neurons in culture. Interestingly, JNJ potentiated bicuculline-induced Fos and COX-2 mRNA expression in the cultures and this was blocked by an NMDA receptor antagonist. Moreover, pentylenetetrazole-induced seizure severity and incidence of convulsions were increased in mice treated with JNJ and this resembled that observed with IL-1 signaling-deficient mice. Overall, the results from this study support the notion that constitutive P2X7-dependent IL-1ß release from hippocampal pyramidal neurons contributes to maintenance of the ST in the normal brain, perhaps by modulating neuronal excitability. These findings may have implications for epilepsy, a brain disorder in which the ST is compromised.


Assuntos
Células Piramidais , Convulsões , Animais , Encéfalo/metabolismo , Hipocampo/metabolismo , Interleucina-1beta , Camundongos , Células Piramidais/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Convulsões/induzido quimicamente , Convulsões/metabolismo
13.
Exp Neurol ; 347: 113880, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34597683

RESUMO

Epilepsy and autism spectrum disorders (ASD) frequently show comorbidity, suggesting shared or overlapping neurobiological basis underlying these conditions. R104Q is the first mutation in the PRICKLE 1(PK1) gene that was discovered in human patients with progressive myoclonus epilepsy (PME). Subsequently, a number of mutations in the PK1 gene were shown to be associated with either epilepsy, autism, or both, as well as other developmental disorders. Using CRISPR-Cas9-mediated gene editing, we generated a PK1R104Q mouse line. The mutant mice showed reduced density of excitatory synapses in hippocampus and impaired interaction between PK1 and the repressor element 1(RE-1) silencing transcription factor (REST). They also displayed reduced seizure threshold, impaired social interaction, and cognitive functions. Taken together, the PK1R104Q mice display characteristic behavioral features similar to the key symptoms of epilepsy and ASD, providing a useful model for studying the molecular and neural circuit mechanisms underlying the comorbidity of epilepsy and ASD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Transtorno do Espectro Autista/genética , Modelos Animais de Doenças , Epilepsia/genética , Proteínas com Domínio LIM/genética , Animais , Edição de Genes , Humanos , Camundongos , Mutação , Fenótipo
14.
Cell Rep ; 37(11): 110107, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34910912

RESUMO

What percentage of the protein function is required to prevent disease symptoms is a fundamental question in genetic disorders. Decreased transsynaptic LGI1-ADAM22 protein complexes, because of their mutations or autoantibodies, cause epilepsy and amnesia. However, it remains unclear how LGI1-ADAM22 levels are regulated and how much LGI1-ADAM22 function is required. Here, by genetic and structural analysis, we demonstrate that quantitative dual phosphorylation of ADAM22 by protein kinase A (PKA) mediates high-affinity binding of ADAM22 to dimerized 14-3-3. This interaction protects LGI1-ADAM22 from endocytosis-dependent degradation. Accordingly, forskolin-induced PKA activation increases ADAM22 levels. Leveraging a series of ADAM22 and LGI1 hypomorphic mice, we find that ∼50% of LGI1 and ∼10% of ADAM22 levels are sufficient to prevent lethal epilepsy. Furthermore, ADAM22 function is required in excitatory and inhibitory neurons. These results suggest strategies to increase LGI1-ADAM22 complexes over the required levels by targeting PKA or 14-3-3 for epilepsy treatment.


Assuntos
Proteínas 14-3-3/metabolismo , Proteínas ADAM/fisiologia , Encéfalo/metabolismo , Epilepsia/prevenção & controle , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mutação , Proteínas do Tecido Nervoso/fisiologia , Proteínas 14-3-3/genética , Animais , Encéfalo/patologia , Epilepsia/metabolismo , Epilepsia/patologia , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
15.
Artigo em Inglês | MEDLINE | ID: mdl-34886095

RESUMO

Experimental studies have demonstrated that general anesthetics administered during the period of synaptogenesis may induce widespread neurodegeneration, which results in permanent cognitive and behavioral deficits. What remains to be elucidated is the extent of the potential influence of the commonly used hypnotics on comorbidities including epilepsy, which may have resulted from increased neurodegeneration during synaptogenesis. This study aimed to test the hypothesis that neuropathological changes induced by anesthetics during synaptogenesis may lead to changes in the seizure threshold during adulthood. Wistar rat pups were treated with propofol, sevoflurane, or saline on the sixth postnatal day. The long-term effects of prolonged propofol and sevoflurane anesthesia on epileptogenesis were assessed using corneal kindling, pilocarpine-, and pentylenetetrazole-induced seizure models in adult animals. Body weight gain was measured throughout the experiment. No changes in the seizure threshold were observed in the three models. A significant weight gain after exposure to anesthetics during synaptogenesis was observed in the propofol group but not in the sevoflurane group. The results suggest that single prolonged exposure to sevoflurane or propofol during synaptogenesis may have no undesirable effects on epileptogenesis in adulthood.


Assuntos
Anestesia , Éteres Metílicos , Propofol , Adulto , Animais , Pré-Escolar , Humanos , Propofol/toxicidade , Ratos , Ratos Wistar , Convulsões/induzido quimicamente , Sevoflurano/toxicidade
16.
Toxins (Basel) ; 13(12)2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34941691

RESUMO

Few data are available in the literature describing the long-term effects of envenoming in the perinatal period. In this study, the relationship between envenoming of lactating rats and possible behavioral changes in the mother and in her offspring were investigated. Lactating Wistar rats received a single dose of T. serrulatus crude venom on postnatal days 2 (V2), 10 (V10) or 16 (V16), and had their maternal behavior evaluated. The seizure threshold was evaluated in adulthood offspring. A decrease in maternal care during envenoming was observed in V2 and V10 groups. The retrieval behavior was absent in the V2 group, and a lower seizure threshold in the adult offspring of all groups was observed. During envenoming, mothers stayed away from their offspring for a relatively long time. Maternal deprivation during the early postnatal period is one of the most potent stressors for pups and could be responsible, at least in part, for the decrease in the convulsive threshold of the offspring since stress is pointed to as a risk factor for epileptogenesis. Furthermore, the scorpionic accident generates an intense immune response, and inflammation in neonates increases the susceptibility to seizures in adulthood. Therefore, maternal envenoming during lactation can have adverse effects on offspring in adulthood.


Assuntos
Lactação , Comportamento Materno/efeitos dos fármacos , Venenos de Escorpião/toxicidade , Convulsões/induzido quimicamente , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos dos fármacos , Convulsivantes/administração & dosagem , Feminino , Masculino , Exposição Materna/efeitos adversos , Pentilenotetrazol/administração & dosagem , Ratos Wistar
17.
Front Psychiatry ; 12: 745734, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34744838

RESUMO

We describe a case of an adolescent male with Niemann-Pick Type C (NP-C), a neurodegenerative lysosomal lipid storage disorder, who presented with recurrent catatonia which required repeated treatment with electroconvulsive therapy (ECT). During the ECT-course, seizure threshold increased substantially, leading to questions about the influence of NP-C on neuronal excitability. In this exemplary ECT-patient, NP-C was diagnosed not until after the first ECT-course when initial psychopharmacology for catatonia had failed and antipsychotics and benzodiazepines showed significant side-effects. Clinicians should be aware of NP-C in patients referred for ECT, especially in the case of treatment resistance, neurological symptoms and intolerance of psychopharmacological drugs. As was shown in our NP-C patient, ECT can be repeatedly effective for catatonic features. In the literature, effectiveness of ECT in patients with NP-C has sparsely been reported. This case demonstrates that detection of NP-C is beneficial for patients because more optimal treatment with ECT can be provided earlier without further exposure to side-effects.

18.
Genes (Basel) ; 12(10)2021 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-34680911

RESUMO

Fragile X syndrome results from the absence of the FMR1 gene product-Fragile X Mental Retardation Protein (FMRP). Fragile X animal research has lacked a reliable method to quantify FMRP. We report the development of an array of FMRP-specific monoclonal antibodies and their application for quantitative assessment of FMRP (qFMRPm) in mouse tissue. To characterize the assay, we determined the normal variability of FMRP expression in four brain structures of six different mouse strains at seven weeks of age. There was a hierarchy of FMRP expression: neocortex > hippocampus > cerebellum > brainstem. The expression of FMRP was highest and least variable in the neocortex, whereas it was most variable in the hippocampus. Male C57Bl/6J and FVB mice were selected to determine FMRP developmental differences in the brain at 3, 7, 10, and 14 weeks of age. We examined the four structures and found a developmental decline in FMRP expression with age, except for the brainstem where it remained stable. qFMRPm assay of blood had highest values in 3 week old animals and dropped by 2.5-fold with age. Sex differences were not significant. The results establish qFMRPm as a valuable tool due to its ease of methodology, cost effectiveness, and accuracy.


Assuntos
Teste em Amostras de Sangue Seco/métodos , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Teste em Amostras de Sangue Seco/normas , Feminino , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Imunoensaio/métodos , Imunoensaio/normas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Sensibilidade e Especificidade
19.
Asian J Psychiatr ; 66: 102874, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34624745

RESUMO

Available literature remains limited in the identification of risk factors for prolonged seizures in electroconvulsive therapy and much less is reported about the continuation of electroconvulsive therapy after prolonged seizures. We describe two cases with prolonged seizures early in their course of electroconvulsive therapy and the subsequent adjustment made that allowed for safe and effective continuation of electroconvulsive therapy. In both cases, right unilateral electroconvulsive therapy was continued at a suprathreshold stimulus dose of six times relative to seizure threshold. Both patients continued their course of electroconvulsive therapy with no further episodes of prolonged seizures. They did not experience significant cognitive side effects and were discharged after showing marked improvement in their clinical symptoms. Prolonged seizures do not preclude the use of electroconvulsive therapy. The selection of ultrabrief right unilateral electroconvulsive therapy allows for a higher suprathreshold dose with less cognitive side effects compared to bilateral placements. This mitigates the risk of prolonged seizures, allowing for safe and effective continuation of electroconvulsive therapy.


Assuntos
Eletroconvulsoterapia , Humanos , Convulsões , Resultado do Tratamento
20.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443428

RESUMO

Ellagic acid (EA) is a natural dietary polyphenol that has many beneficial properties, including anti-inflammatory, antioxidant, antiviral, antibacterial, and neuroprotective effects. Studies have revealed that EA may modulate seizure activity in chemically induced animal models of seizures. Therefore, the aim of the present study was to investigate the effect of EA on the seizure threshold in two acute seizure tests in male mice, i.e., in the intravenous (i.v.) pentylenetetrazole (PTZ) seizure test and in the maximal electroshock seizure threshold (MEST) test. The obtained results showed that EA (100 mg/kg) significantly elevated the threshold for both the first myoclonic twitch and generalized clonic seizure in the i.v. PTZ seizure test. At the highest dose tested (200 mg/kg), EA increased the threshold for tonic hindlimb extension in the MEST test. EA did not produce any significant changes in motor coordination (assessed in the chimney test) or muscular strength (investigated in the grip-strength test). The plasma and total brain concentration-time profiles of EA after intraperitoneal and oral administration were also determined. Although further studies are necessary to confirm the anticonvulsant activity of EA, our findings suggest that it may modulate seizure susceptibility in animal models.


Assuntos
Ácido Elágico/uso terapêutico , Convulsões/tratamento farmacológico , Doença Aguda , Animais , Encéfalo/metabolismo , Ácido Elágico/sangue , Ácido Elágico/farmacologia , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Pentilenotetrazol , Convulsões/sangue , Convulsões/induzido quimicamente
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