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Journal of Visualized Experiments : JoVE Jun 2018Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas...
Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas sequential injections of a subconvulsive dose have been used for the development of chemical kindling, an epilepsy model. A single low-dose injection of PTZ induces a mild seizure without convulsion. However, repetitive low-dose injections of PTZ decrease the threshold to evoke a convulsive seizure. Finally, continuous low-dose administration of PTZ induces a severe tonic-clonic seizure. This method is simple and widely applicable to investigate the pathophysiology of epilepsy, which is defined as a chronic disease that involves repetitive seizures. This chemical kindling protocol causes repetitive seizures in animals. With this method, vulnerability to PTZ-mediated seizures or the degree of aggravation of epileptic seizures was estimated. These advantages have led to the use of this method for screening anti-epileptic drugs and epilepsy-related genes. In addition, this method has been used to investigate neuronal damage after epileptic seizures because the histological changes observed in the brains of epileptic patients also appear in the brains of chemical-kindled animals. Thus, this protocol is useful for conveniently producing animal models of epilepsy.
Topics: Animals; Brain; Disease Models, Animal; GABA Antagonists; Injections, Intraperitoneal; Kindling, Neurologic; Male; Mice; Pentylenetetrazole; Seizures
PubMed: 29985308
DOI: 10.3791/56573 -
Biomedicine & Pharmacotherapy =... Apr 2023Tiagabine (Tia), a new-generation antiseizure drug that mimics the GABAergic signaling by inhibiting GABA transporter type-1, is the least studied molecule in chronic...
Tiagabine suppresses pentylenetetrazole-induced seizures in mice and improves behavioral and cognitive parameters by modulating BDNF/TrkB expression and neuroinflammatory markers.
Tiagabine (Tia), a new-generation antiseizure drug that mimics the GABAergic signaling by inhibiting GABA transporter type-1, is the least studied molecule in chronic epilepsy models with comorbid neurobehavioral and neuroinflammatory parameters. Therefore, the current study investigated the effects of Tia in a real-time manner on electroencephalographic (EEG) activity, behavioral manifestations and mRNA expression in pentylenetetrazole (PTZ)-kindled mice. Male BALB/c mice were treated with tiagabine (0.5, 1 and 2 mg/kg) for 21 days with simultaneous PTZ (40 mg/kg) injection every other day for a total of 11 injections and monitored for seizure progression with synchronized validation through EEG recordings from cortical electrodes. The post-kindling protection from anxiety and memory deficit was verified by a battery of behavioral experiments. Isolated brains were evaluated for oxidative alterations and real-time changes in mRNA expression for BDNF/TrkB, GAT-1 and GAT-3 as well as neuroinflammatory markers. Experimental results revealed that Tia at the dose of 2 mg/kg maximally inhibited the development of full bloom seizure and reduced epileptic spike discharges from the cortex. Furthermore, Tia dose-dependently exerted the anxiolytic effects and protected from PTZ-evoked cognitive impairment. Tia reduced lipid peroxidation and increased superoxide dismutase and glutathione levels in the brain via augmentation of GABAergic modulation. PTZ-induced upregulated BDNF/TrkB signaling and pro-inflammatory cytokines were mitigated by Tia with upregulation of GAT-1 and GAT-3 transporters in whole brains. In conclusion, the observed effects of Tia might have resulted from reduced oxidative stress, BDNF/TrkB modulation and mitigated neuroinflammatory markers expression leading to reduced epileptogenesis and improved epilepsy-related neuropsychiatric effects.
Topics: Animals; Male; Mice; Anticonvulsants; Brain-Derived Neurotrophic Factor; Cognition; Epilepsy; Kindling, Neurologic; Pentylenetetrazole; RNA, Messenger; Seizures; Tiagabine
PubMed: 36791567
DOI: 10.1016/j.biopha.2023.114406 -
Annals of Clinical and Translational... Jul 2021To confirm the critical factors affecting seizure susceptibility in acute pentylenetetrazole (PTZ) mouse epilepsy models and evaluate the prior literature for these... (Review)
Review
OBJECTIVE
To confirm the critical factors affecting seizure susceptibility in acute pentylenetetrazole (PTZ) mouse epilepsy models and evaluate the prior literature for these factors.
METHODS
Serial cohorts of wild-type mice administered intraperitoneal (IP)-PTZ were aggregated and analyzed by multivariate logistic regression for the effect of sex, age, background strain, dose, and physiologic stress (i.e., EEG implantation and/or single-housing) on seizure response. We assessed the reporting of these factors in a comprehensive literature review over the last 10 years (2010-2020).
RESULTS
We conducted aggregated analysis of pooled data of 307 mice (220 C57BL/6J mice and 87 mixed background mice; 202 males, 105 females) with median age of 10 weeks (range: 6-49 weeks) with acute PTZ injection (dose range 40-65 mg/kg). Significance in multivariate analysis was found between seizures and increased PTZ dose (odds ratio (OR) 1.149, 95% confidence interval (CI) 1.102-1.205), older age (OR 1.1, 95% CI 1.041-1.170), physiologic stress (OR 17.36, 95% CI 7.349-44.48), and mixed background strain (OR 0.4725, 95% CI 0.2315-0.9345). Literature review identified 97 papers using acute PTZ-seizure models. Age, housing, sex, and background were omitted by 61% (59/97), 51% (49/97), 18% (17/97), and 8% (8/97) papers, respectively. Only 17% of publications specified all four factors (16/97).
INTERPRETATION
Our analysis and literature review demonstrate a critical gap in standardization of acute PTZ-induced seizure paradigm in mice. We recommend that future studies specify and control for age, background strain, sex, and housing conditions of experimental animals.
Topics: Age Factors; Animals; Convulsants; Electroencephalography; Female; Male; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Inbred CBA; Pentylenetetrazole; Seizures; Sex Factors; Social Isolation; Species Specificity
PubMed: 34102033
DOI: 10.1002/acn3.51375 -
Journal of Traditional Chinese Medicine... Dec 2019To evaluate the effects of Rongchang capsule and Xifeng capsule on pentylenetetrazole- induced epilepsy in zebrafish larvae and to explore the possible mechanisms behind...
OBJECTIVE
To evaluate the effects of Rongchang capsule and Xifeng capsule on pentylenetetrazole- induced epilepsy in zebrafish larvae and to explore the possible mechanisms behind their actions.
METHODS
We utilized a trajectory tracking system to monitor seizures in zebrafish larva to confirm that certain concentrations of Rongchang capsule and Xifeng capsule produce antiepileptic effects. c-fos expression was assessed by quantitative reverse transcription-polymerase chain reaction to validate the efficacy of the capsules. Rest/wake behavior and correlation analysis predicted the targets of Rongchang capsule and Xifeng capsule.
RESULTS
Larval movement times and total distances traveled by zebrafish larvae experiencing pentylenetetrazole (PTZ)-induced seizures were decreased by valproate treatment. Rongchang (500 μg/mL) and Xifeng (200 μg/mL) rescued the epileptic behaviors and down-regulated c-fos expression in the brains of larvae, which indicated antiepileptic effects. The rest/wake behavioral profiles showed that Rongchang and Xifeng differentially decreased rest time at night and increased larval locomotor activities during the day. Based on correlation between the actions of the two capsules and known compounds, we predicted that they might change rest/wake behaviors by affecting serotonin, GABAergic and histamine signaling pathways.
CONCLUSION
The efficacy of Rongchang capsule and Xifeng capsule in alleviating epilepsy-like behaviors and molecular responses was confirmed. Our study provides insight into the capsules' effect on epilepsy.
Topics: Animals; Anticonvulsants; Drugs, Chinese Herbal; Larva; Male; Pentylenetetrazole; Rest; Seizures; Wakefulness; Zebrafish
PubMed: 32186159
DOI: No ID Found -
Disease Models & Mechanisms Jul 2021Danio rerio (zebrafish) are a powerful experimental model for genetic and developmental studies. Adaptation of zebrafish to study seizures was initially established...
Danio rerio (zebrafish) are a powerful experimental model for genetic and developmental studies. Adaptation of zebrafish to study seizures was initially established using the common convulsant agent pentylenetetrazole (PTZ). Larval PTZ-exposed zebrafish exhibit clear behavioral convulsions and abnormal electrographic activity, reminiscent of interictal and ictal epileptiform discharge. By using this model, our laboratory developed simple locomotion-based and electrophysiological assays to monitor and quantify seizures in larval zebrafish. Zebrafish also offer multiple advantages for rapid genetic manipulation and high-throughput phenotype-based drug screening. Combining these seizure assays with genetically modified zebrafish that represent Dravet syndrome, a rare genetic epilepsy, ultimately contributed to a phenotype-based screen of over 3500 drugs. Several drugs identified in these zebrafish screens are currently in clinical or compassionate-use trials. The emergence of this 'aquarium-to-bedside' approach suggests that broader efforts to adapt and improve upon this zebrafish-centric strategy can drive a variety of exciting new discoveries.
Topics: Animals; Anticonvulsants; Epilepsy; Pentylenetetrazole; Seizures; Zebrafish
PubMed: 34231838
DOI: 10.1242/dmm.049080 -
BMC Medicine Dec 2023Exposure to general anesthesia influences neuronal functions during brain development. Recently, interneurons were found to be involved in developmental neurotoxicity by...
BACKGROUND
Exposure to general anesthesia influences neuronal functions during brain development. Recently, interneurons were found to be involved in developmental neurotoxicity by anesthetic exposure. But the underlying mechanism and long-term consequences remain elusive.
METHODS
Pregnant mice received 2.5% sevoflurane for 6-h on gestational day 14.5. Pentylenetetrazole (PTZ)-induced seizure, anxiety- and depression-like behavior tests were performed in 30- and 60-day-old male offspring. Cortical interneurons were labeled using Rosa26-EYFP/-; Nkx2.1-Cre mice. Immunofluorescence and electrophysiology were performed to determine the cortical interneuron properties. Q-PCR and in situ hybridization (ISH) were performed for the potential mechanism, and the finding was further validated by in utero electroporation (IUE).
RESULTS
In this study, we found that maternal sevoflurane exposure increased epilepsy susceptibility by using pentylenetetrazole (PTZ) induced-kindling models and enhanced anxiety- and depression-like behaviors in adolescent offspring. After sevoflurane exposure, the highly ordered cortical interneuron migration was disrupted in the fetal cortex. In addition, the resting membrane potentials of fast-spiking interneurons in the sevoflurane-treated group were more hyperpolarized in adolescence accompanied by an increase in inhibitory synapses. Both q-PCR and ISH indicated that CXCL12/CXCR4 signaling pathway downregulation might be a potential mechanism under sevoflurane developmental neurotoxicity which was further confirmed by IUE and behavioral tests. Although the above effects were obvious in adolescence, they did not persist into adulthood.
CONCLUSIONS
Our findings demonstrate that maternal anesthesia impairs interneuron migration through the CXCL12/CXCR4 signaling pathway, and influences the interneuron properties, leading to the increased epilepsy susceptibility in adolescent offspring. Our study provides a novel perspective on the developmental neurotoxicity of the mechanistic link between maternal use of general anesthesia and increased susceptibility to epilepsy.
Topics: Humans; Pregnancy; Female; Mice; Animals; Male; Sevoflurane; Pentylenetetrazole; Maternal Exposure; Interneurons; Epilepsy
PubMed: 38129829
DOI: 10.1186/s12916-023-03210-0 -
International Journal of Molecular... Sep 2023Epilepsy is a chronic condition characterized by recurrent spontaneous seizures. The interaction between astrocytes and neurons has been suggested to play a role in the...
Epilepsy is a chronic condition characterized by recurrent spontaneous seizures. The interaction between astrocytes and neurons has been suggested to play a role in the abnormal neuronal activity observed in epilepsy. However, the exact way astrocytes influence neuronal activity in the epileptogenic brain remains unclear. Here, using the PTZ-induced kindling mouse model, we evaluated the interaction between astrocyte and synaptic function by measuring astrocytic Ca activity, neuronal excitability, and the excitatory/inhibitory balance in the hippocampus. Compared to control mice, hippocampal slices from PTZ-kindled mice displayed an increase in glial fibrillary acidic protein (GFAP) levels and an abnormal pattern of intracellular Ca-oscillations, characterized by an increased frequency of prolonged spontaneous transients. PTZ-kindled hippocampal slices also showed an increase in the E/I ratio towards excitation, likely resulting from an augmented release probability of excitatory inputs without affecting inhibitory synapses. Notably, the alterations in the release probability seen in PTZ-kindled slices can be recovered by reducing astrocyte hyperactivity with the reversible toxin fluorocitrate. This suggests that astroglial hyper-reactivity enhances excitatory synaptic transmission, thereby impacting the E/I balance in the hippocampus. Altogether, our findings support the notion that abnormal astrocyte-neuron interactions are pivotal mechanisms in epileptogenesis.
Topics: Mice; Animals; Pentylenetetrazole; Astrocytes; Epilepsy; Kindling, Neurologic; Seizures; Hippocampus
PubMed: 37833953
DOI: 10.3390/ijms241914506 -
Molecules (Basel, Switzerland) Nov 2021Chondroitin sulfate is a proteoglycan component of the extracellular matrix (ECM) that supports neuronal and non-neuronal cell activity, provides a negative domain to...
Chondroitin sulfate is a proteoglycan component of the extracellular matrix (ECM) that supports neuronal and non-neuronal cell activity, provides a negative domain to the extracellular matrix, regulates the intracellular positive ion concentration, and maintains the hypersynchronous epileptiform activity. Therefore, the present study hypothesized an antiepileptic potential of chondroitin sulfate (CS) in pentylenetetrazole-induced kindled epilepsy and pilocarpine-induced status epilepticus in mice. Levels of various oxidative stress markers and inflammatory mediators were estimated in the brain tissue homogenate of mice, and histopathological changes were evaluated. Treatment with valproate (110 mg/kg; i.p.) as a standard drug and chondroitin sulfate (100 & 200 mg/kg, p.o.) significantly ( < 0.01) and dose-dependently prevented the severity of kindled and spontaneous recurrent seizures in mice. Additionally, chondroitin sulfate showed its antioxidant potential by restoring the various biochemical levels and anti-inflammatory properties by reducing NF-kB levels and pro-inflammatory mediators like TNF-alpha, IL-1β, and IL-6, indicating the neuroprotective effect as well as the suppressed levels of caspase-3, which indicated a neuroprotective treatment strategy in epilepsy. The proteoglycan chondroitin sulfate restores the normal physiology and configuration of the neuronal tissue. Further, the molecular docking of chondroitin sulfate at the active pockets of TNF-alpha, IL-1β, and IL-6 showed excellent interactions with critical amino acid residues. In conclusion, the present work provides preclinical evidence of chondroitin sulfate as a new therapeutic approach in attenuating and preventing seizures with a better understanding of the mechanism of alteration in ECM changes influencing abnormal neuronal activities.
Topics: Animals; Anticonvulsants; Chondroitin Sulfates; Male; Mice; Molecular Docking Simulation; Neuroprotective Agents; Oxidative Stress; Pentylenetetrazole; Pilocarpine; Seizures; Status Epilepticus; Valproic Acid
PubMed: 34833865
DOI: 10.3390/molecules26226773 -
Arquivos de Neuro-psiquiatria Jan 2022Epilepsy has neuropsychiatric comorbidities such as depression, bipolar disorder, and anxiety. Drugs that target epilepsy may also be useful for its neuropsychiatric...
BACKGROUND
Epilepsy has neuropsychiatric comorbidities such as depression, bipolar disorder, and anxiety. Drugs that target epilepsy may also be useful for its neuropsychiatric comorbidities.
OBJECTIVE
To investigate the effects of serotonergic modulation on pro-inflammatory cytokines and the seizures in pentylenetetrazole (PTZ)-induced seizure model in rats.
METHODS
Male Wistar rats were injected intraperitoneally with serotonin, selective serotonin reuptake inhibitor fluoxetine, 5-HT1B/D receptor agonist sumatriptan, or saline 30 min prior to PTZ treatment. Behavioral seizures were assessed by the Racine's scale. Concentrations of IL-1β, IL-6, and TNF-α in serum and brain tissue were determined by ELISA.
RESULTS
Serotonin and fluoxetine, but not sumatriptan, alleviated PTZ-induced seizures by prolonging onset times of myoclonic-jerk and generalized tonic-clonic seizures. The anti-seizure effect of fluoxetine was greater than that of serotonin. Likewise, serotonin and fluoxetine, but not sumatriptan, reduced PTZ-induced increases in the levels of IL-1β and IL-6 in both serum and brain tissue. None of the administered drugs including PTZ affected TNF-α concentrations.
CONCLUSIONS
Our findings suggest that endogenous and exogenous serotonin exhibits anticonvulsant effects by suppressing the neuroinflammation. It seems that 5-HT1B/D receptors do not mediate anticonvulsant and anti-neuroinflammatory effects of serotonin.
Topics: Animals; Anticonvulsants; Epilepsy; Fluoxetine; Humans; Interleukin-6; Male; Neuroinflammatory Diseases; Pentylenetetrazole; Rats; Rats, Wistar; Seizures; Serotonin; Sumatriptan; Tumor Necrosis Factor-alpha
PubMed: 35239805
DOI: 10.1590/0004-282X-ANP-2021-0101 -
Cells Jun 2023Zebrafish (Danio rerio) assays provide a versatile pharmacological platform to test compounds on a wide range of behaviors in a whole organism. A major challenge lies in...
Zebrafish (Danio rerio) assays provide a versatile pharmacological platform to test compounds on a wide range of behaviors in a whole organism. A major challenge lies in the lack of knowledge about the bioavailability and pharmacodynamic effects of bioactive compounds in this model organism. Here, we employed a combined methodology of LC-ESI-MS/MS analytics and targeted metabolomics with behavioral experiments to evaluate the anticonvulsant and potentially toxic effects of the angular dihydropyranocoumarin pteryxin (PTX) in comparison to the antiepileptic drug sodium valproate (VPN) in zebrafish larvae. PTX occurs in different Apiaceae plants traditionally used in Europe to treat epilepsy but has not been investigated so far. To compare potency and efficacy, the uptake of PTX and VPN into zebrafish larvae was quantified as larvae whole-body concentrations together with amino acids and neurotransmitters as proxy pharmacodynamic readout. The convulsant agent pentylenetetrazole (PTZ) acutely reduced the levels of most metabolites, including acetylcholine and serotonin. Conversely, PTX strongly reduced neutral essential amino acids in a LAT1 (SLCA5)-independent manner, but, similarly to VPN specifically increased the levels of serotonin, acetylcholine, and choline, but also ethanolamine. PTX dose and time-dependent manner inhibited PTZ-induced seizure-like movements resulting in a ~70% efficacy after 1 h at 20 µM (the equivalent of 4.28 ± 0.28 µg/g in larvae whole-body). VPN treated for 1 h with 5 mM (the equivalent of 18.17 ± 0.40 µg/g in larvae whole-body) showed a ~80% efficacy. Unexpectedly, PTX (1-20 µM) showed significantly higher bioavailability than VPN (0.1-5 mM) in immersed zebrafish larvae, possibly because VPN in the medium dissociated partially to the readily bioavailable valproic acid. The anticonvulsive effect of PTX was confirmed by local field potential (LFP) recordings. Noteworthy, both substances specifically increased and restored whole-body acetylcholine, choline, and serotonin levels in control and PTZ-treated zebrafish larvae, indicative of vagus nerve stimulation (VNS), which is an adjunctive therapeutic strategy to treat refractory epilepsy in humans. Our study demonstrates the utility of targeted metabolomics in zebrafish assays and shows that VPN and PTX pharmacologically act on the autonomous nervous system by activating parasympathetic neurotransmitters.
Topics: Humans; Animals; Pentylenetetrazole; Valproic Acid; Zebrafish; Vagus Nerve Stimulation; Serotonin; Acetylcholine; Tandem Mass Spectrometry; Seizures; Anticonvulsants; Choline
PubMed: 37296660
DOI: 10.3390/cells12111540