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Physiological Research May 2024Starting from simple clinical statistics, the spectrum of methods used in epilepsy research in the Institute of Physiology of the Czechoslovak (now Czech) Academy of...
Starting from simple clinical statistics, the spectrum of methods used in epilepsy research in the Institute of Physiology of the Czechoslovak (now Czech) Academy of Sciences progressively increased. Professor Servít used electrophysiological methods for study of brain activity in lower vertebrates, neuropathology was focused on electronmicroscopic study of cortical epileptic focus and ion-sensitive microelectrodes were used for studies of cortical direct current potentials. Developmental studies used electrophysiological methods (activity and projection of cortical epileptic foci, EEG under the influence of convulsant drugs, hippocampal, thalamic and cortical electrical stimulation for induction of epileptic afterdischarges and postictal period). Extensive pharmacological studies used seizures elicited by convulsant drugs (at first pentylenetetrazol but also other GABA antagonists as well as agonists of glutamate receptors). Motor performance and behavior were also studied during brain maturation. The last but not least molecular biology was included into the spectrum of methods. Many original data were published making a background of position of our laboratory in the first line of laboratories interested in brain development.
PubMed: 38752773
DOI: No ID Found -
ENeuro May 2024The voltage-gated calcium channel subunit α2δ-2 controls calcium-dependent signaling in neurons, and loss of this subunit causes epilepsy in both mice and humans. To...
The voltage-gated calcium channel subunit α2δ-2 controls calcium-dependent signaling in neurons, and loss of this subunit causes epilepsy in both mice and humans. To determine whether mice without α2δ-2 demonstrate hippocampal activation or histopathological changes associated with seizure activity, we measured expression of the activity-dependent gene c and various histopathological correlates of temporal lobe epilepsy (TLE) in hippocampal tissue from wild-type (WT) and α2δ-2 knock-out ( KO) mice using immunohistochemical staining and confocal microscopy. Both genotypes demonstrated similarly sparse c- and expressions within the hippocampal dentate granule cell layer (GCL) at baseline, consistent with no difference in basal activity of granule cells between genotypes. Surprisingly, when mice were assayed 1 h after handling-associated convulsions, KO mice had fewer c--positive cells but dramatically increased expression in the dentate gyrus compared with WT mice. After administration of a subthreshold pentylenetetrazol dose, however, KO mice dentate had significantly more c- expression compared with WT mice. Other histopathological markers of TLE in these mice, including markers of neurogenesis, glial activation, and mossy fiber sprouting, were similar between WT and KO mice, apart from a small but statistically significant increase in hilar mossy cell density, opposite to what is typically found in mice with TLE. This suggests that the differences in seizure-associated dentate gyrus function in the absence of α2δ-2 protein are likely due to altered functional properties of the network without associated structural changes in the hippocampus at the typical age of seizure onset.
Topics: Animals; Mice, Knockout; Seizures; Hippocampus; Proto-Oncogene Proteins c-fos; Male; Calcium Channels; Mice, Inbred C57BL; Pentylenetetrazole; Mice; Disease Models, Animal; Neurons; Convulsants
PubMed: 38749701
DOI: 10.1523/ENEURO.0486-23.2024 -
Turkish Journal of Pharmaceutical... May 2024This study aimed to investigate whether Otto Kuntze organic and aqueous extracts are able to control seizures induced by pentylenetetrazol (PTZ) in mice based on...
OBJECTIVE
This study aimed to investigate whether Otto Kuntze organic and aqueous extracts are able to control seizures induced by pentylenetetrazol (PTZ) in mice based on flavonoid fingerprints and alkaloidal contents.
MATERIALS AND METHODS
Ethanolic extract and decoction-derived fractions from roots, leaves, and stems were subjected to chromatographic fingerprinting using AlCl and screening for their antiseizure effects using PTZ-induced acute seizure model. From the fractions that showed potent bioactivities, plausible antiseizure alkaloids were isolated using thin layer chromatography, and their structures were elucidated using H NMR, 2D NMR, C NMR, and FAB-HR ( or ).
RESULTS
All fractions, with the exception of the dichloromethane and hexane fractions, revealed remarkable flavonoid fingerprints. An acute PTZ-induced seizure test revealed that ethanolic extract of stem bark [500 mg/kg body weight (bw)], ethyl acetate extract of stem bark (500 mg/kg bw), and aqueous extract of leaves (300 mg/kg bw) significantly delayed the occurrence of hind limb tonic extension (HLTE); however, a non-significant delay was observed in the onset of first myoclonic jerk compared with control animals. Isolation yielded four main alkaloids: that are, pteropodine (1), isopteropodine (2), mitraphylline (3) and corynoxeine (4). Corynoxeine is a new compound derived from .
CONCLUSION
This study suggests that flavonoid fingerprints are tracers of anticonvulsant ingredients. The stem bark ethanolic and ethyl acetate extracts and leaf aqueous extracts contain anticonvulsant bioactive principles that delay notifying the HLTE occurring in male naval medical research institute mice. Furthermore, alkaloidal contents also remain plausible bioactive anticonvulsant principles. All observations support the traditional use of to manage epilepsy. However, further studies are needed to understand the effects of alkaloid fractions, flavonoids, and the isolated compounds as promising antiseizure agents derived from in experimental animals.
PubMed: 38742766
DOI: 10.4274/tjps.galenos.2023.14704 -
Biomedicine & Pharmacotherapy =... Jun 2024Brain apoptosis is one of the main causes of epileptogenesis. The antiapoptotic effect and potential mechanism of Q808, an innovative anticonvulsant chemical, have never...
Brain apoptosis is one of the main causes of epileptogenesis. The antiapoptotic effect and potential mechanism of Q808, an innovative anticonvulsant chemical, have never been reported. In this study, the seizure stage and latency to reach stage 2 of pentylenetetrazol (PTZ) seizure rat model treated with Q808 were investigated. The morphological change and neuronal apoptosis in the hippocampus were detected by hematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, respectively. The hippocampal transcriptomic changes were observed using RNA sequencing (RNA-seq). The expression levels of hub genes were verified by quantitative reverse-transcription PCR (qRT-PCR). Results revealed that Q808 could allay the seizure score and prolong the stage 2 latency in seizure rats. The morphological changes of neurons and the number of apoptotic cells in the DG area were diminished by Q808 treatment. RNA-seq analysis revealed eight hub genes, including Map2k3, Nfs1, Chchd4, Hdac6, Siglec5, Slc35d3, Entpd1, and LOC103690108, and nine hub pathways among the control, PTZ, and Q808 groups. Hub gene Nfs1 was involved in the hub pathway sulfur relay system, and Map2k3 was involved in the eight remaining hub pathways, including Amyotrophic lateral sclerosis, Cellular senescence, Fc epsilon RI signaling pathway, GnRH signaling pathway, Influenza A, Rap1 signaling pathway, TNF signaling pathway, and Toll-like receptor signaling pathway. qRT-PCR confirmed that the mRNA levels of these hub genes were consistent with the RNA-seq results. Our findings might contribute to further studies exploring the new apoptosis mechanism and actions of Q808.
Topics: Animals; Pentylenetetrazole; Hippocampus; Apoptosis; Anticonvulsants; Male; Transcriptome; Epilepsy; Gene Expression Profiling; Rats; Rats, Sprague-Dawley; Disease Models, Animal; Neurons; Seizures
PubMed: 38739991
DOI: 10.1016/j.biopha.2024.116746 -
Molecules (Basel, Switzerland) Apr 2024Two series, "" and "", each consisting of nine chemical compounds, with 2,3-disubstituted quinazolin-4(3H)-one scaffold, were synthesized and evaluated for their...
Two series, "" and "", each consisting of nine chemical compounds, with 2,3-disubstituted quinazolin-4(3H)-one scaffold, were synthesized and evaluated for their anticonvulsant activity. They were investigated as dual potential positive allosteric modulators of the GABA receptor at the benzodiazepine binding site and inhibitors of carbonic anhydrase II. Quinazolin-4(3H)-one derivatives were evaluated in vivo (D = 50, 100, 150 mg/kg, administered intraperitoneally) using the pentylenetetrazole (PTZ)-induced seizure model in mice, with phenobarbital and diazepam, as reference anticonvulsant agents. The in silico studies suggested the compounds act as anticonvulsants by binding on the allosteric site of GABA receptor and not by inhibiting the carbonic anhydrase II, because the ligands-carbonic anhydrase II predicted complexes were unstable in the molecular dynamics simulations. The mechanism targeting GABA receptor was confirmed through the in vivo flumazenil antagonism assay. The pentylenetetrazole experimental anticonvulsant model indicated that the tested compounds, - and -, present a potential anticonvulsant activity. The evaluation, considering the percentage of protection against PTZ, latency until the onset of the first seizure, and reduction in the number of seizures, revealed more favorable results for the "" series, particularly for compound .
Topics: Anticonvulsants; Animals; Mice; Seizures; Receptors, GABA-A; Pentylenetetrazole; Quinazolinones; Molecular Docking Simulation; Male; Structure-Activity Relationship; Molecular Dynamics Simulation; Computer Simulation; Disease Models, Animal; Molecular Structure; Allosteric Site
PubMed: 38731442
DOI: 10.3390/molecules29091951 -
Brain Research Sep 2024PTZ kindling induces oxidative stress, neuronal cell degeneration, and neurobehavioral alterations in rodents that mimic neuropsychiatric comorbidities of epilepsy,...
PTZ kindling induces oxidative stress, neuronal cell degeneration, and neurobehavioral alterations in rodents that mimic neuropsychiatric comorbidities of epilepsy, which could be initiated or aggravated by some antiepileptic drugs. Here, we investigated the effects of the methanol extract of Ficus platyphylla (FP) on severity scores for seizures, neuronal cell degeneration, and neurobehavioral alterations in rats kindled with pentylenetetrazole (PTZ) and probed the involvement of oxidative stress in these ameliorative effects of FP. FP (50 and 100 mg/kg, p.o.) ameliorated seizure severity, neuronal cell degeneration, depressive behaviors, cognitive dysfunctions, and oxidative stress in rats kindled with PTZ (42.5 mg/kg, i.p.). The findings from this study give additional insights into the potential values of FP in the treatment of persistent epilepsy and major neuropsychiatric comorbidities via modulation of oxidative stress.
Topics: Animals; Ficus; Oxidative Stress; Pentylenetetrazole; Plant Extracts; Kindling, Neurologic; Male; Seizures; Rats; Anticonvulsants; Rats, Wistar; Disease Models, Animal; Behavior, Animal; Epilepsy
PubMed: 38729331
DOI: 10.1016/j.brainres.2024.148994 -
MicroPublication Biology 2024Heterozygous de novo mutations in Munc18-1, which is essential for neurotransmitter release, cause early infantile epileptic encephalopathy. Munc18-1-linked epilepsy is...
Heterozygous de novo mutations in Munc18-1, which is essential for neurotransmitter release, cause early infantile epileptic encephalopathy. Munc18-1-linked epilepsy is currently an untreatable disorder and its precise disease mechanism remains elusive. Here, we investigated how Munc18-1 pathogenic variants affect inhibitory neurons using . Expression analysis revealed that three missense mutant proteins form aggregates in the cell body of gamma-aminobutyric-acid (GABA)-ergic motoneurons, resulting in a strong reduction of their expression in axons. Their defects of axonal expression correlated closely with pentylenetetrazol-induced convulsions, suggesting that the degree of instability of each mutant protein account for the severity of the epileptic phenotypes.
PubMed: 38716379
DOI: 10.17912/micropub.biology.001174 -
Current Drug Discovery Technologies May 2024The objective of the study was to design and synthesize a series of N-(6-substituted-1,3-benzothiazole-...
BACKGROUND
The objective of the study was to design and synthesize a series of N-(6-substituted-1,3-benzothiazole- 2-yl)-2-{[6-(3-substitutedphenyl)-5-cyano-2-sulfanylpyrimidine-4-yl)]amino}acetamide derivatives BPD (1-15) that contains key pharmacophores required for anticonvulsant action.
METHODS
The titled compounds (BPD 1-15) were synthesized by reacting 2-substituted-N-(6-chlorobenzo[d]thiazol2-yl)acetamide with 4-amino-6-(4-substituted phenyl)-2-mercapto pyrimidine 5-carbonitrile in the presence of potassium carbonate and dry acetone. The synthesized compounds BPD (1-15) were assessed in vivo by the maximum electric shock (MES) test and the subcutaneous pentylenetetrazol (scPTZ) test in mice. The neurotoxicity test was performed by the rotarod test. A molecular docking study of title compounds with a sodium channel receptor (PDB ID: 1BYY) was carried out using the SP Docking protocol of the Glide module of the Maestro. Pharmacophore modeling was used to qualitatively identify the chemical characteristics for ligand binding and their spatial configurations in the 3D space of the active site.
RESULT
Among the studied compounds, BPD-15 and BPD-5 compounds showed significant action in both the MES and scPTZ models, with no neurotoxicity. BPD-15 & BPD-5 were relatively safe in acute toxicity testing. Compounds BPD-15 and BPD-5 showed good dock scores of -6.434 and -6.191, respectively.
CONCLUSION
Thus, the compounds BPD-15 and BPD-5 have shown a considerable affinity towards the sodium channel as compared to the standard drug Riluzole. Compound BPD-14 showed good drug compatibility, and compounds BPD-1, BPD-2, BPD-11, BPD-12, BPD-13, BPD-14, BPD-15 showed good ADME values.
PubMed: 38715333
DOI: 10.2174/0115701638299019240418055933 -
IBRO Neuroscience Reports Jun 2024Epilepsy poses a significant challenge, especially for drug-resistant cases, necessitating novel treatment avenues. This study explores the potential interplay between...
Epilepsy poses a significant challenge, especially for drug-resistant cases, necessitating novel treatment avenues. This study explores the potential interplay between nitric oxide (NO) and the anticonvulsant effects of betulin, a triterpene with promising neuroprotective properties. While betulin exhibits anticonvulsant effects, the specific involvement of NO remains inadequately understood, constituting a pivotal gap in current knowledge. One hundred NMRI mice were randomly assigned to diverse treatment groups, with seizures induced by pentylenetetrazol (PTZ). Parameters such as seizure threshold, nitrite levels, total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and iNOS/nNOS gene expressions were assessed. Betulin significantly increased seizure thresholds and mitigated PTZ-induced NO levels. These findings suggest a potential modulation of NO-related pathways, emphasizing betulin's anti-inflammatory and antioxidant attributes. The study sheds light on betulin's multifaceted impact on oxidative stress, NO regulation, and iNOS/nNOS gene expressions. The ability of betulin to suppress iNOS/nNOS gene expressions, leading to reduce NO production, underscores its potential as an anticonvulsant.
PubMed: 38706971
DOI: 10.1016/j.ibneur.2024.04.003 -
Epilepsia Open May 2024The objective of this study is to determine whether inhibition of mitophagy affects seizures through Clathrin-mediated endocytosis (CME).
OBJECTIVE
The objective of this study is to determine whether inhibition of mitophagy affects seizures through Clathrin-mediated endocytosis (CME).
METHODS
Pentylenetetrazol (PTZ) was intraperitoneally injected daily to establish a chronic PTZ-kindled seizure. The Western blot (WB) was used to compare the differences in Parkin protein expression between the epilepsy group and the control group. Immunofluorescence was used to detect the expression of MitoTracker and LysoTracker. Transferrin-Alexa488 (Tf-A488) was injected into the hippocampus of mice. We evaluated the effect of 3-methyladenine (3-MA) on epilepsy behavior through observation in PTZ-kindled models.
RESULTS
The methylated derivative of adenine, known as 3-MA, has been extensively utilized in the field of autophagy research. The transferrin protein is internalized from the extracellular environment into the intracellular space via the CME pathway. Tf-A488 uses a fluorescent marker to track CME. Western blot showed that the expression of Parkin was significantly increased in the PTZ-kindled model (p < 0.05), while 3-MA could reduce the expression (p < 0.05). The fluorescence uptake of MitoTracker and LysoTracker was increased in the primary cultured neurons induced by magnesium-free extracellular fluid (p < 0.05); the fluorescence uptake of Tf-A488 was significantly decreased in the 3-MA group compared with the control group (p < 0.05). Following hippocampal injection of Tf-A488, both the epilepsy group and the 3-MA group exhibited decreased fluorescence uptake, with a more pronounced effect observed in the 3-MA group. Inhibition of mitophagy by 3-MA from day 3 to day 9 progressively exacerbated seizure severity and shortened latency.
SIGNIFICANCE
It is speculated that the aggravation of seizures by 3-MA may be related to the failure to remove damaged mitochondria in time and effectively after inhibiting mitochondrial autophagy, affecting the vesicle endocytosis function of CME and increasing the susceptibility to epilepsy.
SUMMARY
Abnormal mitophagy was observed in a chronic pentylenetetrazol-induced seizure model and a Mg-free-induced spontaneous recurrent epileptiform discharge model. A fluorescent transferrin marker was utilized to track clathrin-mediated endocytosis. Using an autophagy inhibitor (3-methyladenine) on primary cultured neurons, we discovered that inhibition of autophagy led to a reduction in fluorescent transferrin uptake, while impairing clathrin-mediated endocytosis function mediated by mitophagy. Finally, we examined the effects of 3-methyladenine in an animal model of seizures showing that it exacerbated seizure severity. Ultimately, this study provides insights into potential mechanisms through which mitophagy regulates clathrin-mediated endocytosis in epilepsy.
PubMed: 38700951
DOI: 10.1002/epi4.12945