Pentylenetetrazole Injection Research Articles

Anticonvulsive and anti-epileptogenesis effects of Echinacea purpurea root extract, an involvement of CB2 receptor.

Phytocannabinoids beyond the Δ9-tetrahy-drocannabinol have shown anticonvulsive effects. Also, alkylamides from Echinacea purpurea have been proved as cannabinomimetics. We examined the effect of the hydroalcoholic root extract of E.purpurea on pentylenetetrazol (PTZ)-induced tonic-clonic seizures and kindling model of epileptogenesis and the involvement of CB2 receptors as the mediator of this effect. Male Wistar rats (200±20g) were used. Single intraperitoneal (i.p.) injection of PTZ (80mg/kg) was used to induce tonic-clonic seizures. The kindling model of epileptogenesis was induced by daily injections of PTZ (37mg/kg; i.p. for 15days). Latency and duration of the stages were monitored for analysis. The hydroalcoholic root extract of E.purpurea was injected (i.p.) 20min before seizure induction at the doses of 10, 50, 100 and 200mg/kg. CB2 receptor antagonist SR144528 was injected (0.1mg/kg; i.p.) 20min before the Echinacea injection. In the tonic-clonic model, pretreatment with E.purpurea at the doses of 100 and 200mg/kg significantly increased latencies to S2-S6, while it significantly decreased S6 duration and mortality rate. SR144528 injection before the injection of 100mg/kg of E.purpurea significantly prevented the effects of the extract on S4-S6 latencies. In the kindling model, E.purpurea at the doses of 100 and 200mg/kg significantly delayed epileptogenesis and decreased mortality rate, while SR144528 injection before the injection of 100mg/kg of E. purpurea significantly blocked this effect of the extract. These findings revealed the anticonvulsive and antiepileptogenesis effects of the E.purpurea root extract, which can be mediated by CB2 receptors.

Protective Effects of Anthocleista djalonensis Extracts against Pentylenetetrazole-Induced Epileptic Seizures and Neuronal Cell Loss: Role of Antioxidant Defense System.

Oxidative stress and neurodegeneration are involved in the initiation of epileptogenesis and progression of epileptic seizures. This study was aimed at investigating the anticonvulsant, antioxidant, and neuroprotective properties of active fractions isolated from Anthocleista djalonensis root barks in pentylenetetrazole mouse models of epileptic seizures. Bioactive-guided fractionation of Anthocleista djalonensis (AFAD) extracts using acute pentylenetetrazole (90 mg/kg) induced generalised tonic-clonic seizures, which afforded a potent anticonvulsant fraction (FPool 5). Further fractionation of AFAD was performed by high-performance liquid chromatography, which yielded fifteen subfractions, which were chemically characterised. In addition, AFAD was tested against convulsions or spontaneous kindled seizures induced, respectively, by acute (50 mg/kg) or subchronic (30 mg/kg) injection of pentylenetetrazole. Finally, oxidative stress markers, brain GABA content, and neuronal cell loss were evaluated in AFAD-treated pentylenetetrazole-kindled mice. Administration of AFAD significantly protected mice against acute pentylenetetrazole (90 mg/kg)-induced convulsions. In acute pentylenetetrazole (50 mg/kg)-induced hippocampal and cortical paroxysmal discharges, AFAD significantly decreased the number of crisis, the cumulative duration of crisis, and the mean duration of crisis. Additionally, AFAD significantly decreased the number of myoclonic jerks and improved the seizure score in subchronic pentylenetetrazole-induced kindled seizures. The pentylenetetrazole-induced alteration of oxidant-antioxidant balance, GABA concentration, and neuronal cells in the brain were attenuated by AFAD treatment. This study showed that AFAD protected mice against pentylenetetrazole-induced epileptic seizures possibly through the enhancement of antioxidant defence and GABAergic signalling. These events might be correlated with the amelioration of neuronal cell loss; hence, AFAD could be a potential candidate for the treatment of epilepsy.

The antioxidant and neuroprotective effects of the Psychotria camptopus Verd. Hook. (Rubiaceae) stem bark methanol extract contributes to its antiepileptogenic activity against pentylenetetrazol kindling in male Wistar rats.

A substantial number of epileptic patients are resistant to the current medication thus necessitating the search for alternative therapies for intractable forms of the disease. Previous studies demonstrated the acute anticonvulsant properties of the methanol extract of the stem bark of Psychotria camptopus (MEPC) in rats. This study investigated the effects of MEPC on pentylenetetrazole-kindled Wistar rats. Kindling was induced by intraperitoneal injection of pentylenetetrazole (37.5mg/kg) on every alternate day, 1h after each daily oral pretreatment of rats (8 ≤ n ≤ 10) with MEPC (40, 80 and 120mg/kg), vehicle or diazepam (3mg/kg) for 43days. The kindling development was monitored based on seizure episodes and severity. Rats' brains were collected on day 43 for the determination of oxidative stress parameters. The histomorphological features and neuronal cell viability of the prefrontal cortex (PFC) and hippocampus were also assessed using H&E and Cresyl violet stains. Chronic administration of pentylenetetrazole time-dependently decreased the latency to myoclonic and generalized seizures, and increased seizure scores and the number of kindled rats. MEPC and diazepam significantly increased the latencies to myoclonic jerks and generalized tonic-clonic seizures. These substances also reduced seizure score and the number of rats with PTZ-kindling. MEPC improved glutathione status and decreased lipid peroxidation in the brains of kindled rats. MEPC also exhibited neuroprotection against pentylenetetrazole-induced hippocampal and PFC neuronal damages. These results suggest that P. camptopus has antiepileptogenic activity, which might be related to the augmentation of antioxidant and neuroprotective defense mechanisms, and further confirm its usefulness in the management of epilepsy.

Anti-convulsive Effect of Thiamine and Melatonin Combination in Mice: Involvement of Oxidative Stress.

Epilepsy, the second most frequent neurological disease, is a chronic disorder with a high lifetime prevalence. Therefore, various studies are needed to find new effective therapeutic agents to treat seizures or prevent their complications. In this study, we investigated the effects of thiamine, melatonin and their combination on pentylenetetrazol (PTZ)-induced tonic-clonic seizures in mice. Male mice were randomly divided into six groups, including control, seizure control, diazepam, melatonin, thiamine and melatonin, and thiamine combination groups. Drugs were given orally in drinking water for 14 days. On the 15th day, the seizure was induced (except the control group) by intraperitoneal injection of PTZ. In all groups, the time between the injection and the start of the seizure (latency), and also the length of the seizure attack (duration), were measured in a 30-minute period. After measuring the latency and duration in all groups, mice were killed by CO2 Box and their brains were dissected to be analyzed for malondialdehyde (MDA) level as a marker of oxidative stress. The seizure duration was significantly lower in the groups of melatonin, thiamine and thiamine and melatonin combination compared to the seizure control group. The latency times in these groups were significantly greater than in the seizure control group. Moreover, MDA concentrations were lower in these groups compared to the seizure control group. Thiamine, melatonin and their combination can decrease the duration time of seizure and increase the latency period, which may result from inhibition of oxidative stress in the brain.

Modulation of PTZ-induced convulsions in rats using topiramate alone or combined with low dose gamma irradiation: Involving AKT/m-TOR pathway

ABSTRACT The current study evaluates the anticonvulsant effect low dose whole body gamma irradiation (LDR) alone or combined with topiramate (TOP) against pentylenetetrazol (PTZ)-induced convulsions. Male Wister rats received either saline or pentylenetetrazole (75 mg/kg i.p.). The other three groups were pretreated with single low dose radiation (o.5 Gy), Topiramate (50 mg/kg, p.o., 7 days) and TOP with LDR respectively before PTZ injection. Racine’ score, latency and duration of the convulsions were assessed. Glutamate and GABA were measured. As well as AKT/m-TOR signalling pathway including AKT (protein kinase –B), m-TOR (mammalian target of rapamycin), protein S6 and caspase3 were also assessed. Measurements of markers of oxidative stress including MDA (malondialdehyde), GSH (glutathione) and NO (nitric oxide) were carried out. Histological examinations of hippocampi were done. Results: PTZ produced behavioural changes (high Racine score, short latency and long duration. It elevated MDA and NO contents, while reduced GSH content. TOP treatment alone or combined with LDR ameliorated the PTZ-induced convulsions and caused significant improvement in behavioural changes, brain mediators, m-TOR pathway, oxidative stress and histological pictures in hippocampal regions. Histopathological examinations of the normal group showed normal structure with intact cells, while PTZ- treated rats exhibited necrosis, pyknosis and atrophy of pyramidal cells. The histological findings corroborated with the amendment of biochemical parameters. Conclusions The positive effects of LDR could offer a possible contributor in management of convulsions due to modulation of AkT/m-TOR signalling pathway, reduction of oxidative stress and modulation of brain amino acids. LDR improved the oxidative stress side effects of topiramate. Highlights Male Wistar rats were treated with topiramate 50 mg/kg p.o. for 7 days. on the 6th day of topiramate treatment, rats were exposed to a single low dose whole body gamma radiation (0.5 Gy). on the 7th day of topiramate treatment, rats were injected with pentylenetetrazole 75 mg/kg i.p. 2h after the 7th dose of TOP to illustrate the protective effects of TOP against acute convulsions induced by PTZ. Low dose whole body gamma irradiation purveyed novel anticonvulsant activity which could offer a possible contributor in the basic management of convulsions to avoid side effects of traditional anticonvulsant drugs such as liver and kidney impairments.

Effects of probiotics on pentylenetetrazol-induced convulsions in mice

ObjectiveThere are some reports of the effect of the gut microbiota on the central nervous system. The aim of this study was to find out the effect of probiotics on pentylenetetrazol (PTZ)-induced convulsions in mice. MethodsThe mice were pretreated with probiotic powder (Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidum) suspended in normal saline by intragastric gavage (IG-gavage) for 14 (group 1) or 28 (group 2) days prior to injection of PTZ (90 mg/kg, intraperitoneally). Diazepam (DZP, 1 mg/kg, intraperitoneally) was used as the reference drug. The latency and duration of induced convulsion, as well as mortality protection percentage were recorded 30 min after PTZ injection. For the next step, flumazenil (FLZ) was used to block the effect of DZP. ResultsPretreatment with probiotics for 14 or 28 days had not a significant effect on the latency and duration of seizures induced by PTZ. Neither seizure nor mortality was observed in co-administration of probiotics with DZP. FLZ pretreatment decreased the DZP-induced seizure latency; however, FLZ could not have such an effect in probiotic and DZP group. ConclusionProbiotics alone did not show anticonvulsant effects, but enhanced the anticonvulsant effect of DZP; this suggests the involvement of GABAergic system.

Prenatal stress impairs recognition memory and leads to neurodevelopmental deficits in hippocampus of adolescent rats with early acute pentylenetetrazole-kindling

Objectives: This study aimed to investigate the effects of prenatal stress (PS) on hippocampus of early acute pentylenetetrazole (PTZ)-kindled offspring in adolescence. Recognition memory, morphological changes and synaptophysin levels in hippocampus were evaluated. Methods: Restraint stress was induced to a group of pregnant dams and non-stressed (NA) group remained undisturbed. Next, male and female offspring were divided as 1. PS-PTZ, 2. PS -control, 3. NA-PTZ and 4. NA-control (n = 12 in each group). The object recognition test was performed following PTZ injection (45 mg/kg) on postnatal day 10 (P10). Brains were collected on postnatal day 35 (P35) to determine neuronal density and synaptophysin expression by immuno/-histological studies. Further, oxidative stress products in hippocampus were analyzed with different biochemical assays. Results: PS impaired recognition memory in PTZ group significantly (p = 0.03); however, the impairment of PS was reversible in control group compared to PTZ (p = 0.04). Furthermore, PS caused neuronal loss in CA1 (p = 0.01) and decreased synaptophysin expression in the CA3 area of hippocampus in PTZ group (p = 0.03). PS also increased the oxidative stress markers in PTZ group significantly (p < 0.05). Conclusions: These results suggest that PS causes neurodevelopmental deficits in adolescent hippocampus and recognition memory after early-life seizures prominently. However, the damage of only PS in adolescence can be reversible. Therefore, the effects of PS in the adult hippocampus and other regions of brain need to be further studied.

Comparing the Seizure-Induced Impairment of Short-Term Plasticity in Dorsal and Ventral Hippocampus in Kindled Mice

There are many differences among dorsal and ventral hippocampal neural circuits that affect the synaptic plasticity. In this study we compared the occurrence of short-term plasticity in the field excitatory post synaptic potentials (fEPSP) in dorsal and ventral hippocampal CA1 area following kindled seizures. Animals (male C57 B6/J mice, 12 weeks of age) were kindled by intraperitoneal injections of pentylenetetrazole (PTZ) and fEPSPs were recorded from dorsal and ventral hippocampal slices. Short-term plasticity was evaluated by measuring fEPSP-slope and fEPSP-area following paired-pulse stimulation delivered at three inter-pulse intervals (20, 80 and 160 ms). Obtained results showed that in control slices fEPSP-slope was greater in ventral- compared to dorsal hippocampus, but there was no difference in fEPSP-area among two regions. In hippocampal slices of kindled animals, fEPSP-slope was similar in dorsal and ventral regions, but fEPSP-area was greater in ventral- compared to dorsal hippocampus. In addition, fEPSP-area was greater in kindled compared to control group only in ventral hippocampus. PTZ kindled slices showed impaired short-term facilitation and the paired-pulse index was reduced only at dorsal hippocampal slices. Kindling had no significant effect on paired-pulse ratio in ventral hippocampal slices. Our findings indicated that the seizure occurrence affected the neural activity of hippocampus in a regional dependent manner. Although kindling increased fEPSP-area in ventral hippocampus, kindling-induced changes in short-term synaptic plasticity was significant only in dorsal hippocampal slices compared to control group. The difference in the responses of hippocampal dorsal and ventral poles has to be considered in the future researches.

Treatment effects of the combination of ceftriaxone and valproic acid on neuronal and behavioural functions in a rat model of epilepsy.

What is the central question of this study? Imbalance of activities between GABAergic and glutamatergic systems is involved in epilepsy. It is not known whether simultaneously increasing GABAergic and decreasing glutamatergic activity using valproic acid and ceftriaxone, respectively, leads to better seizure control. What is the central question of this study? Ceftriaxone suppressed seizure and cognitive deficits and restored neuronal density and the number of newborn cells in the hippocampus in a rat model of epilepsy. Combined treatment with ceftriaxone and valproic acid showed additive effects in seizure suppression. The pathophysiology of epilepsy is typically considered as an imbalance between inhibitory GABA and excitatory glutamate neurotransmission. Valproic acid (Val), a GABA agonist, is one of the first-line antiepileptic drugs in the treatment of epilepsy, but it exhibits adverse effects. Ceftriaxone (CEF) elevates expression of glutamate transporter-1, enhances the reuptake of synaptic glutamate, increases the number of newborn cells and exhibits neuroprotective effects in animal studies. In this study, we evaluated effects of the combination of CEF and Val on behavioural and neuronal measures in a rat epilepsy model. Male Wistar rats were injected i.p. with pentylenetetrazol (35mg/kg, every other day for 13days) to induce the epilepsy model. Ceftriaxone (10 or 50mg/kg), Val (50 or 100mg/kg) or the combination of CEF and Val were injected daily after the fourth pentylenetetrazol injection for seven consecutive days. Epileptic rats exhibited seizure and impairments in motor and cognitive functions. Treatment with CEF and Val reduced the seizure and enhanced motor and cognitive functions in a dose-dependent manner. The combination of CEF (10mg/kg) and Val (50mg/kg) improved behaviours considerably. Histologically, compared with control animals, epileptic rats exhibited lower neuronal density and a reduction in hippocampal newborn cells but higher apoptosis in the basolateral amygdala, all of which were restored by the treatment with CEF, Val or the combination of CEF and Val. The study findings demonstrated that the combination of low doses of CEF and Val has beneficial effects on seizure suppression, neuroprotection and improvement in motor and cognitive functions in epilepsy.

Pergularia daemia hydro-ethanolic extract protects against pentylenetetrazole kindling-induced seizures, oxidative stress, and neuroinflammation in mice

Ethnopharmacological relevanceCurrent antiepileptic drugs fail to control approximately 30% of epilepsies. Therefore, there is a need to develop more effective antiepileptic drugs, and medicinal plants provide an attractive source for new compounds. Pergularia daemia (Asclepiadaceae) is used in Cameroon traditional medicine to treat stroke, anemia, inflammation, and epilepsy. Recently, traditional healers claim that an hydro-ethanolic extract of the roots of P. daemia is more effective than an aqueous extract on refractory seizures. Aim of the studyThe antiepileptic effect of P. daemia hydro-ethanolic extract was investigated on the pentylenetetrazole kindling model of temporal lobe epilepsy in mice and possible mechanisms of action. Materials and methodsMice were divided into 8 groups treated as follows: normal group received distilled water (10 ml/kg, p.o.), control group received distilled water (10 ml/kg, p.o.), ethanol group received ethanol (5%, p.o.), positive control received sodium valproate (300 mg/kg, p.o.), and test groups received P. daemia hydro-ethanolic (HE) extract (1.6, 4, 8 and 16 mg/kg, p.o.). All groups were kindled by 11 injections of pentylenetetrazole (PTZ) (35 mg/kg, i.p.), once every alternate day (48 ± 2 h), until the development of kindling, i.e., the occurrence of stage 5 seizures for two consecutive trials. One week later, i.e., 29th day, mice were challenged with a single and lower dose of PTZ (25 mg/kg, i.p.) that does not induce seizures in normal mice but causes seizures in mice prone to seizures and behavioral alterations. After completion of the kindling procedure, Morris water maze, passive avoidance, and open field tests were performed. Afterward, animals were euthanized, and hippocampi were removed for the estimation of the levels of GABA-transaminase (GABA-T), L-glutamate decarboxylase (L-GAD), and γ-aminobutyric acid (GABA). Oxidative stress and neuroinflammation markers also were quantified. Finally, histological analysis of the hippocampus was carried out. ResultsPTZ-kindling induced myoclonic jerks and generalized tonic-clonic seizures in control mice. However, the HE extract of P. daemia (4–16 mg/kg), compared to sodium valproate, significantly protected mice against myoclonic jerks and generalized tonic-clonic seizures. Also, the HE extract (1.6–16 mg/kg) significantly increased the seizure score. Furthermore, the HE extract of P. daemia significantly reduced seizure-induced cognitive impairments. PTZ-kindling induced significant alterations in GABA, GABA-T, and L-GAD contents as well as oxidative stress, and neuroinflammation, and the HE extract significantly reversed these effects, suggesting possible mechanisms. All these activities of the HE extract were confirmed by its protective effect against neuronal loss in the hippocampus. ConclusionsThe HE extract of P. daemia protected mice against kindled seizures and cognitive impairments, and these effects were greater than those of sodium valproate, a widely used antiepileptic drug. These effects may be mediated by neuromodulatory, anti-oxidant, and anti-inflammatory activities, thus suggesting a neuroprotective effect. These findings help to explain the beneficial use of these HE extracts of P.daemia in traditional medicine to treat epilepsy in Cameroon.

Factors influencing the acute pentylenetetrazole-induced seizure paradigm and a literature review.

ObjectiveTo confirm the critical factors affecting seizure susceptibility in acute pentylenetetrazole (PTZ) mouse epilepsy models and evaluate the prior literature for these factors.MethodsSerial 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).ResultsWe 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).InterpretationOur 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.

Exercise Improved the Anti-Epileptic Effect of Carbamazepine through GABA Enhancement in Epileptic Rats.

Carbamazepine (CBZ) is an anticonvulsant drug that usually is used for the treatment of seizures. The anti-epileptic and the anti-epileptogenic effect of exercise has been reported, as well. This study was aimed to evaluate the synergic effect of combined therapy of exercise and CBZ in epileptic rats, as well as the alternation of the GABA pathway as a possible involved mechanism. The seizure was induced by pentylenetetrazol (PTZ) injection. Animals were divided into sham, seizure, exercise (EX), CBZ (25, 50 and 75), EX + CBZ (25, 50 and 75). Treadmill forced running for 30min has been considered as the exercise 5days per week for four weeks. CBZ was injected in doses of 25, 50 and 75mg/kg, half an hour before seizure induction and 5h after doing exercise in the animals forced to exercise. Seizure severity reduced and latency increased in the EX + CBZ (25) and EX + CBZ (50) groups compared to the seizure group. The distribution of GAD65 in both hippocampal CA1 and CA3 areas increased in the EX + CBZ (75) group. GABAA receptor α1 was up-regulated in the CA3 area of the EX + CBZ (75) group. The distribution of GAD65 in the cortical area increased in EX, EX + CBZ (50), CBZ (75) and EX + CBZ (75) groups. GABAA receptor α1 was up-regulated in the neocortex of EX + CBZ (50), CBZ (75) and EX + CBZ (75) groups. Our findings suggested that exercise has improved the efficacy of CBZ and reduced the anti-epileptic dose. The enhancement of GABA signaling might be involved in the synergistic effect of exercise and CBZ.

The Effects of Prenatal Norharman Exposure on Seizure Severity in Rats

Background: Norhraman is an alkaloid that can damage the nervous system. Objective: This experimental study aimed to investigate the effects of prenatal norharman exposure on seizure severity in adult rats. Methods: A total of 36 Wistar rats were randomly divided into 3 groups as follows: Control, sham (solvent), and norharman (1000 ug/kg). The sham and norharman groups were treated once daily for 8-18 of the fetal period. 2 months after birth, kindling was performed by the daily injection of Pentylenetetrazol (PTZ) (30 mg/kg); then, the seizure behavior was recorded for approximately 30 minutes. The obtained data were analyzed using Analysis of Variance (ANOVA) and Tukey’s posthoc test. Results: The present study data indicated that administrating norharman in the fetal period increased seizure responses to PTZ, i.e., significant in the examined female rats (P<0.05). Conclusion: According to the current research findings, the severity of seizures increases in subjects who have been exposed to norharman during the prenatal period.

Insulin injections inhibits PTZ-induced mitochondrial dysfunction, oxidative stress and neurological deficits via the SIRT1/PGC-1α/SIRT3 pathway

With an associated 20% death risk, epilepsy mainly involves seizures of an unpredictable and recurrent nature. This study was designed to evaluate the neuroprotective effects and underlying mechanisms of insulin on mitochondrial disruption, oxidative stress, cell apoptosis and neurological deficits after epilepsy seizures. Mice were exposed to repetitive injections of pentylenetetrazol at a dose of 37 mg per kg. The influence of insulin was assessed by many biochemical assays, histopathological studies and neurobehavioral experiments. The administration of insulin was proven to increase the latency of seizures while also decreasing their intensity. It also caused a reversal of mitochondrial dysfunction and ameliorated oxidative stress. Additionally, insulin pretreatment upregulated Bcl-2, downregulated Bax, and then played a neuroprotective role against hippocampal neuron apoptosis. Furthermore, when insulin was administered, SIRT1/PGC-1α/SIRT3 signals were activated, possibly due to the fact that insulin's neuroprotective and anti-mitochondrial damage characteristics added to its observed antiepileptic functions. Finally, insulin treatment is thus extremely valuable for effecting improvements in neurological functions, as has been estimated in a series of functional tests. In conclude, the results of this study consequently demonstrate insulin to have significant potential for future application in epilepsy management.

Fenofibrate protects the neurovascular unit and ameliorates plasma corticosterone levels in pentylenetetrazole-induced kindling seizure in mice

Epileptic seizures are the most common neurological diseases that change the function of neurovascular unit at molecular levels accompanied by activation of a wide variety of neurodegenerative cascades. Based on the pleiotropic functions of peroxisome proliferator-activated receptor-alpha (PPARα), the current study evaluated the neuroprotective effects of fenofibrate (an effective PPARα agonist) on the brain injuries induced by pentylenetetrazole (PTZ)-induced kindling seizure.Adult male NMRI mice were randomly assigned into four groups (n = 14) as follows; control, untreated kindled mice (PTZ) and two fenofibrate-treated kindled groups. Repeated intraperitoneal injections of PTZ (45 mg/kg) were used to develop kindling seizure every 48 h for 21 days. Treated mice were administered orally fenofibrate at doses of 30 and 50 mg/kg/day during the study. Plasma corticosterone and brain levels of brain-derived neurotrophic factor (BDNF), malondialdehyde (MDA) and mRNA transcription of p53, as well as blood–brain barrier (BBB) permeability, were determined at termination of the study.Fenofibrate considerably improved seizure latency and anxiety-like behaviors in treated kindled mice. Fenofibrate at doses of 30 and 50 mg/kg significantly (P < 0.001) decreased plasma corticosterone (56.88 ± 0.80 and 54.81 ± 0.29 ng/mL, respectively) compared to PTZ group (74.96 ± 1.60 ng/mL). It also significantly (P < 0.05) decreased BDNF levels in both treatment groups (8.13 ± 0.14 and 8.74 ± 0.09 ng/mL, respectively) compared to PTZ group (9.68 ± 0.20 ng/mL). Fenofibrate particularly at higher dose significantly (P < 0.01) decreased MDA content and mRNA expression levels of p53 in treated kindled mice by 67% and 28%, respectively, compared to PTZ group. Similarly, 50 mg/kg fenofibrate significantly (P < 0.05) decreased Evans blue extravasation into brain in treated kindled mice (8.72 ± 0.96 µg/g) compared to PTZ group (15.31 ± 2.18 µg/g).Our results revealed the anticonvulsive and neuroprotective effects of fenofibrate in PTZ-induced kindling seizure in mice. Fenofibrate also improved the neurovascular functions at molecular levels in kindling seizure that might be associated with ameliorating the seizure behaviors.

Flurothyl-induced seizure paradigm revealed higher seizure susceptibility in middle-aged Angelman syndrome mouse model

IntroductionEpilepsy is one of the main clinical problems in Angelman syndrome (AS). Seizures typically start in early childhood then decrease or are often alleviated by young adulthood. Several studies using AS model mice showed comparable seizure susceptibility during young adulthood. In contrast, the course of epilepsy post young adulthood differs from persistently relieved to rerising among reports. To elucidate this, we evaluated the seizure susceptibility of AS model mice of two different ages. MethodsMice lacking maternal Ube3a gene (Ube3am–/p+) of C57BL/6 background or their littermate wild type (WT) were divided into two groups by age, 2 to 3 months (2–3 M) and 6 to 12 months (6–12 M), corresponding to adolescent to young adult aged and middle aged humans, respectively. Seizure susceptibility was evaluated by flurothyl inhalation or intraperitoneal injection of pentylenetetrazole (PTZ IP)-induced acute seizure protocol. ResultsIn the flurothyl-induced seizure paradigm, the latency to seizure occurrence had a significant interaction with genotype and age. Post-hoc analysis revealed that the latency was significantly shorter at 6–12 M than at 2–3 M in Ube3am-/p+ mice, and in Ube3am-/p+ mice than in WT mice at 6–12 M. No significant interaction or difference was observed by PTZ IP. ConclusionThe flurothyl-induced seizure paradigm revealed that seizure susceptibility of Ube3am-/p+ mice increased with age, similar to clinical studies reporting the reappearance of epilepsy in older age. The flurothyl-induced seizure paradigm applied to middle-aged Ube3am–/p+ mice could be a suitable protocol for screening drugs against seizures in AS.

Pain sensitivity in male Wistar rats of different age after a single injection of pentylenetetrazole in subseizure and seizure doses

Pain sensitivity in male Wistar rats of different age after a single injection of pentylenetetrazole in subseizure and seizure doses

Effect of a single injection of pentylenetetrazole in sub-convulsive and convulsive doses on acute pain in Wistar rats of different age

<h3>ВВЕДЕНИЕ</h3> При диагностике и лечении целого ряда болевых синдромов необходимо учитывать особенности болевого восприятия у людей разного возраста. Боль является наиболее частым симптомом у пожилых людей и встречается у 62—73% пациентов. Влияние возраста на интенсивность восприятия боли до настоящего времени остается недостаточно изученным. Исследования болевой чувствительности у пожилых пациентов дают противоречивые результаты. По данным одних авторов, болевые пороги у пожилых пациентов повышаются, по данным других исследователей — понижаются или остаются неизменными. Результаты исследований изменения ноцицептивных реакций и болевого поведения у животных на протяжении жизни также неоднозначны. <h3>ЦЕЛЬ ИССЛЕДОВАНИЯ</h3> Изучение особенностей изменения болевой чувствительности (по тесту Tail flick) у крыс-самцов линии Wistar разного возраста (3 мес, 10 мес и 18 мес) после однократного внутрибрюшинного введения конвульсанта пентилентетразола (ПТЗ) в субсудорожных и судорожных дозах. <h3>МАТЕРИАЛ И МЕТОДЫ</h3> Проведено 2 серии опытов по одной и той же схеме на одних и тех же животных разного возраста. Во всех сериях опытов ПТЗ вводили однократно внутрибрюшинно в субсудорожной дозе 15 мг/кг и в судорожной дозе 60 мг/кг. Контрольным животным такого же возраста в аналогичных условиях опыта вводили физиологический раствор. Тяжесть судорожной реакции в ответ на введение ПТЗ оценивали по общепринятой шкале и выражали ее в баллах. Порог болевой чувствительности (ПБЧ) оценивали в тесте Tail flick при помощи прибора Ugo Basile (Италия), позволяющего подавать сфокусированный пучок света на хвост животного и фиксировать время появления болевой реакции (латентный период — ЛП) по отведению хвоста животного. Величина ПБЧ измерялась в секундах. ПБЧ у животных определяли до введения ПТЗ, а также через 30 мин, 24 ч и 6 сут после его введения. <h3>РЕЗУЛЬТАТЫ</h3> До введения ПТЗ у крыс возрастзависимого изменения ПБЧ не обнаружено. Однако введение субсудорожной и судорожной доз ПТЗ имело возрастзависимые особенности изменения ПБЧ. Введение 3-месячным животным ПТЗ в субсудорожной дозе оказывало проноцицептивное действие, а в судорожной дозе — антиноцицептивное. У животных в возрасте 10 мес характер изменения болевой чувствительности после введения ПТЗ был другим. Субсудорожная доза ПТЗ не влияла на ПБЧ, а введение ПТЗ в судорожной дозе вызывало краткосрочное антиноцицептивное действие только через 30 мин после введения. У этих же животных в возрасте 18 мес субсудорожная и судорожная дозы ПТЗ вызывали антиноцицептивное действие в течение всего периода наблюдения (6 дней). Выявлены особенности возрастных изменений ПБЧ в контрольной группе животных с введением физиологического раствора. У этих животных имелась тенденция изменения ПБЧ, схожая с группой животных с введением субсудорожной дозы ПТЗ: снижение ПБЧ после введения физиологического раствора в возрасте 3 и 10 мес и повышение ПБЧ в возрасте 18 мес. <h3>ЗАКЛЮЧЕНИЕ</h3> В результате исследования установлено, что введение субсудорожных доз ПТЗ у молодых животных оказывает ноцицептивный эффект, у стареющих животных — антиноцицептивный. Введение судорожных доз ПТЗ оказывает антиноцицептивное действие независимо от возраста животных.

Butyrate alleviates PTZ-induced mitochondrial dysfunction, oxidative stress and neuron apoptosis in mice via Keap1/Nrf2/HO-1 pathway

This study aims to evaluate the neuroprotective effect of sodium butyrate against the pentylenetetrazol (PTZ)-induced kindling epilepsy. Sodium butyrate (SB) (5, 10 and 20 mg/kg) and sodium valproate for 40 days and PTZ (37 mg/kg) injection every day were conducted for Kunming mice, to investigate seizure intensity and latency, oxidative stress parameters, mitochondrial structure and function, histopathology, and Keap1/Nrf2/HO-1 expressions. It is shown that seizure latency was effectively increased and the intensity of seizures decreased by treatment with sodium butyrate. It was also found to reverse the structural disruption of the mitochondria, reduce the ROS level and improve the levels of NAD + and ATP in the brains of epileptic mice. Furthermore, pretreatment with SB led to an increase in antioxidant enzyme activity (CAT, SOD and GSH-PX) in the brain as well as conferred a neuroprotective effect against neuron loss and apoptosis. The activation of Keap1/Nrf2/HO-1 signals was also identified, in which the antiepileptic effect of SB may be partially due to its anti-mitochondrial injury and neuroprotective activities. Accordingly, the results of a series of functional tests indicate a significant improvement of neurological function following SB treatment. In a mouse model of seizures, brain injury and neurological deficits can be attenuated by treatment with butyrate through the activation of Nrf2 pathway and the improvement of mitochondrial function.

D-limonene Inhibits Pentylenetetrazole-Induced Seizure via Adenosine A2A Receptor Modulation on GABAergic Neuronal Activity.

Background: Epilepsy is a chronic neurological disorder characterized by the recurrence of seizures. One-third of patients with epilepsy may not respond to antiseizure drugs. Purpose: We aimed to examine whether D-limonene, a cyclic monoterpene, exhibited any antiseizure activity in the pentylenetetrazole (PTZ)-induced kindling mouse model and in vitro. Methods: PTZ kindling mouse model was established by administering PTZ (30 mg/kg) intraperitoneally to mice once every 48 h. We performed immunoblot blots, immunohistochemistry (IHC), and high-performance liquid chromatography (HPLC) analysis after the behavioral study. Results: An acute injection of PTZ (60 mg/kg) induced seizure in mice, while pretreatment with D-limonene inhibited PTZ-induced seizure. Repeated administration of PTZ (30 mg/kg) increased the seizure score gradually in mice, which was reduced in D-limonene (10 mg/kg)-pretreated group. In addition, D-limonene treatment increased glutamate decarboxylase-67 (GAD-67) expression in the hippocampus. Axonal sprouting of hippocampal neurons after kindling was inhibited by D-limonene pretreatment. Moreover, D-limonene reduced the expression levels of Neuronal PAS Domain Protein 4 (Npas4)-induced by PTZ. Furthermore, the adenosine A2A antagonist SCH58261 and ZM241385 inhibited anticonvulsant activity and gamma-aminobutyric acid (GABA)ergic neurotransmission-induced by D-limonene. Conclusion: These results suggest that D-limonene exhibits anticonvulsant activity through modulation of adenosine A2A receptors on GABAergic neuronal function.