Zebrafish model of posttraumatic epilepsy.

OBJECTIVE: Posttraumatic epilepsy (PTE) is defined as recurrent and unprovoked seizures occurring >1 week after traumatic brain injury (TBI). Animal studies of PTE are lengthy and expensive. In this study, we developed a cost-effective PTE animal model using zebrafish to bridge the gap between in vitro studies and low-throughput animal studies. METHODS: We used two different sets of parameters (G1 and G2) to induce closed-head TBI in adult zebrafish using pulsed high-intensity focused ultrasound. Injured fish and naive controls were evaluated for behavioral deficits and spontaneous behavioral seizure activity up to 21 days postinjury (DPI). We also assessed behavioral seizure susceptibility to a subconvulsive dose of pentylenetetrazole (PTZ; 2.5 mmol·L-1 ) and recorded electrophysiological signals to confirm seizure activity up to 40 DPI. In addition, we investigated injury-related changes in the blood-brain barrier and expression levels of various proteins altered in rodent and human TBI. RESULTS: The G2 parameters resulted in a more severe TBI, with a mortality rate of 25%, as well as motor dysfunction and heightened anxiety persisting at 21 DPI. One hundred percent of the G2 group showed spontaneous myocloniclike behavior, and 80% demonstrated tonic-clonic-like behavioral seizures by 21 DPI. Such activities were not detected in the naive group. After the application of 2.5 mmol·L-1 PTZ, 100% of injured zebrafish had cloniclike seizures at 21 DPI, versus 30% of the naive group. We also demonstrated electrographic seizure activity at 40 DPI, which was not detected in the naive controls. Lastly, we observed acute blood-brain barrier dysfunction and increased levels of HMGB1 and ratios of phosphorylated/total Akt and tau through 21 DPI. SIGNIFICANCE: Together, the results indicate that severe TBI in the adult zebrafish leads to similar behavioral and physiological changes to those of more traditional models, including the development of PTE, and suggest this may be a useful model that can accelerate research in TBI/PTE.

Oxytocinergic system mediates the proconvulsant effects of sildenafil: The role of calcineurin.

Sildenafil is a phosphodiesterase type 5 inhibitor used to treat male erectile dysfunction and pulmonary hypertension. A potential side effect of sildenafil is a noticeable decrease in seizure threshold. Oxytocin (OXT) secretion and the subsequent cAMP-responsive element-binding (CREB) phosphorylation are involved in proconvulsant effects of sildenafil in experimental models. The aim of the present study was to investigate the potential role of OXT receptors and their downstream calcineurin (CN)/inducible nitric oxide synthase (iNOS) pathways in proconvulsant effects of sildenafil. The pentylenetetrazole (PTZ)-induced seizure was used as a standard convulsion model in this study. Cortical CN activity, hippocampal nitrite levels, and proinflammatory cytokine content were measured. Our results indicated that following PTZ administration, sildenafil significantly increased CN activity at 40 mg/kg, respectively, in the control group. The combination of sildenafil and OXT receptor antagonist, atosiban (10 µg/kg, i.c.v) 30 min before sildenafil administration significantly reduced the CN activity. Also, the subeffective dose of CN inhibitor cyclosporine (5 mg/kg) 30 min before the administration of effective dose of sildenafil (40 mg/kg) reversed proconvulsant actions of sildenafil. This effect was iNOS-dependent because pretreatment of a low dose of aminoguanidine (20 mg/kg) 15 min before the administration of a low dose of cyclosporine (1 mg/kg) reversed the proconvulsant action of sildenafil (40 mg/kg). Finally, sildenafil induced the elevation of tumor necrosis factor alpha (TNF-α) and the nitrite level was blocked by the administration of cyclosporine in PTZ-treated mice. Collectively, our data provide insights into the role of OXT receptor/CN/iNOS pathway in the proconvulsant aspect of sildenafil.

Increased seizure susceptibility in a mouse model of neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder linked to higher rates of epilepsy as compared with the general population. Although some epilepsy cases in NF1 are related to intracranial lesions, epileptogenic lesions are not always identified. It is unknown whether the genetic mutation itself, which leads to lower levels of the tumor suppressor protein neurofibromin, alters seizure susceptibility. The purpose of this research was to determine whether Nf1+/- mice have altered seizure susceptibility to the chemical convulsants kainic acid and pilocarpine. Young adult Nf1+/- or WT control (Nf1+/+) mice were injected with either 20 mg/kg kainic acid or scopolamine 1 mg/kg and pilocarpine 300 mg/kg and assessed for various behavioral seizure parameters. Another subset of mice were implanted with intracranial electrodes and injected with 10 mg/kg kainic acid for electrographic seizure testing. Histological analyses were performed one week after kainic acid challenge to assess hippocampal damage. A higher proportion of Nf1+/- mice had behavioral seizures after kainic acid or pilocarpine challenge, with shorter seizure latency, longer seizure duration, and higher Racine scores compared to WT mice. Nf1+/- and WT mice with severe behavioral seizures demonstrated similar levels of hippocampal damage. EEG recordings confirmed decreased seizure latency and longer seizure duration in response to KA in the Nf1+/- group. These data demonstrate increased seizure susceptibility in a mouse model of NF1 and support the use of the Nf1+/- mouse for further investigations into the mechanistic link between NF1 and seizures.

Spatial exploration induced expression of immediate early genes Fos and Zif268 in adult-born neurons Is reduced after pentylenetetrazole kindling.

Seizure activity stimulates adult neurogenesis, the birth of new neurons, in the hippocampus. Many new neurons that develop in the presence of repeatedly induced seizures acquire abnormal morphological and functional characteristics that can promote network hyperexcitability and hippocampal dysfunction. However, the impact of seizure induced neurogenesis on behaviour remains poorly understood. In this study, we investigated whether adult-born neurons generated immediately before and during chronic seizures were capable of integration into behaviorally relevant hippocampal networks. Adult rats underwent pentylenetetrazole (PTZ) kindling for either 1 or 2 weeks. Proliferating cells were labelled with BrdU immediately before kindling commenced. Twenty-four hours after receiving their last kindling treatment, rats were placed in a novel environment and allowed to freely explore for 30 min. The rats were euthanized 90 min later to examine for behaviourally-induced immediate early gene expression (c-fos, Zif268). Using this approach, we found that PTZ kindled rats did not differ from control rats in regards to exploratory behaviour, but there was a marked attenuation in behaviour-induced expression of Fos and Zif268 for rats that received 2 weeks of PTZ kindling. Further examination revealed that PTZ kindled rats showed reduced colocalization of Fos and Zif268 in 2.5 week old BrdU + cells. The proportion of immature granule cells (doublecortin-positive) expressing behaviorally induced Zif268 was also significantly lower for PTZ kindled rats than control rats. These results suggest that chronic seizures can potentially disrupt the ability of adult-born cells to functionally integrate into hippocampal circuits important for the processing of spatial information.

Early α-linolenic acid exposure to embryo reduces pentylenetetrazol-induced seizures in zebrafish larva.

Over the past few years, there has been a tremendous increase in interest of general population toward food-based therapies for management of chronic clinical conditions due to their lesser adverse effects with prolonged use over pharmacotherapies. Foods enriched with omega-3 fatty acids have shown some promising results in case of epilepsy. The present study was envisioned to investigate the effect of early exposure of α-linolenic acid (ALA), an essential omega-3 fatty acid in developing zebrafish (Danio rerio) embryos toward pentylenetetrazol (PTZ)-induced seizure susceptibility. The healthy wild-type zebrafish embryos were incubated in system water or system water containing different ALA concentrations (1-20 µM) till 7 dpf (days post fertilization). Each larva at 7 dpf was placed in 8 mM PTZ solution and seizure event was recorded. ALA incubation at 10 µM and 20 µM concentrations showed a dose-dependent reduction in PTZ-mediated hyperactive responses in larvae indicated by a marked decrease in total distance travelled and speed, as compared to vehicle control. Furthermore, both the treated groups showed increase in the latency to PTZ-induced clonus-like seizures in larvae, as compared to vehicle control. ALA incubated larvae at 10 µM and 20 µM concentrations also showed a significant reduction in c-fos mRNA level. A marked increase in the level of ALA and docosahexaenoic acid was also observed in the larvae incubated at highest effective concentration of ALA. The present study concluded that embryonic exposure of ALA reduced PTZ-induced seizures in zebrafish larva.

Pharmacological Evaluation of Novel Flavone from Morus alba in Pentylenetetrazole-Induced Kindling and Oxidative Stress.

The present study was designed to explore the effect of chronic administration of a new flavone [morusflavone, 5,7,4'-trihydroxy-8-(γ,γ-dimethylallyl)-2',3'-(10'-hydroxy-9',10'-dimethyl-cyclohex-8-enyl)-flavone (compound 1)] at doses of 25, 50, and 100 mg/kg, orally (p.o.) to pentylenetetrazole-induced kindling in rats (a model of human epilepsy). Compound 1 and four other compounds were isolated from the stem bark of Morus alba. The structure of compound 1 was elucidated and established using standard spectroscopic techniques, and malondialdehyde (MDA) and glutathione (GSH) were estimated as oxidative markers in brain tissues of rodents. The progression of kindling in rats was effectively and significantly suppressed at doses of 25, 50, and 100 mg/kg of compound 1. In addition, increased the levels of MDA and decreased levels of glutathione were also reversed by compound 1 in kindled rats. Compound 1 treatment was able to restore the reduced glutathione level in the brain tissues of PTZ-kindled rats, thus proving its neuroprotective potential.

Effect of atorvastatin on behavioral alterations and neuroinflammation during epileptogenesis.

Temporal lobe epilepsy (TLE) is the most frequent and medically refractory type of epilepsy in humans. In addition to seizures, patients with TLE suffer from behavioral alterations and cognitive deficits. Poststatus epilepticus model of TLE induced by pilocarpine in rodents has enhanced the understanding of the processes leading to epilepsy and thus, of potential targets for antiepileptogenic therapies. Clinical and experimental evidence suggests that inflammatory processes in the brain may critically contribute to epileptogenesis. Statins are inhibitors of cholesterol synthesis, and present pleiotropic effects that include antiinflammatory properties. We aimed the present study to test the hypothesis that atorvastatin prevents behavioral alterations and proinflammatory state in the early period after pilocarpine-induced status epilepticus. Male and female C57BL/6 mice were subjected to status epilepticus induced by pilocarpine and treated with atorvastatin (10 or 100mg/kg) for 14days. Atorvastatin slightly improved the performance of mice in the open-field and object recognition tests. In addition, atorvastatin dose-dependently decreased basal and status epilepticus-induced levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ) and increased interleukin-10 (IL-10) levels in the hippocampus and cerebral cortex. The antiinflammatory effects of atorvastatin were qualitatively identical in both sexes. Altogether, these findings extend the range of beneficial actions of atorvastatin and indicate that its antiinflammatory effects may be useful after an epileptogenic insult.

Manual acupuncture improves parameters associated with oxidative stress and inflammation in PTZ-induced kindling in mice.

The use of acupuncture in the treatment of central nervous system (CNS) disorders is an age-old practice. Although only a few studies have proved its efficacy, evidence has indicated the use of acupuncture to treat different types of seizures. Therefore, the present study aimed to evaluate the effect of manual acupuncture (MAC) using the chemical kindling model. The role of MAC in oxidative stress and inflammation after pentylenetetrazole (PTZ)-induced kindling was investigated by measuring reactive oxygen species (ROS) production, superoxide dismutase (SOD), and catalase (CAT) activities, nitrite content, and deoxyribonucleic acid (DNA) damage in cerebral cortex. Mice received PTZ (60mg/kgs.c.) once every three days for 16days, totaling six treatments. MAC was applied at acupoint GV20 daily during the entire experimental protocol. Diazepam (DZP) (2mg/kg) was used as positive control. Also, we evaluated the MAC effect associated with DZP (MAC/DZP) at a low dose (0.15mg/kg). The results demonstrated that MAC or MAC/DZP were not able to reduce significantly seizure occurrence or to increase the latency to the first seizure during treatment. MAC/DZP promoted a difference in the first latency to seizure only on the third day. PTZ-induced kindling caused significant neuronal injury, oxidative stress, increased DNA damage, nitric oxide production, and expression of the pro-inflammatory Tumor Necrosis Factor-α (TNF-α). These effects were reversed by treatment with MAC or MAC/DZP. These results indicated that the stimulation of acupoint GV20 by MAC showed no potential antiepileptogenic effect in the model used, although it greatly promoted neuronal protection, which may result from antioxidant and anti-inflammatory effects observed here.

Development and characterization of embelin-loaded nanolipid carriers for brain targeting.

The objective of present work was to enquire the potential use of embelin-loaded nanolipid carriers for brain targeting. The average particle size and polydispersity index (PDI) of optimized formulation (F19) were found to be 152 ± 19.7 nm and 0.143 ± 0.023, respectively. Nanolipid carrier (NLC) was also significantly attenuated pentylenetetrazole (PTZ)-induced biochemical parameters in comparison to plain embelin that results in an increase in the level of malondialdehyde (MDA), nitrite, and reduction in the level of glutathione. From the results, it was concluded that embelin-NLCs developed as a beneficial carrier to achieve sustained release and brain targeting through nasal route.

Gastrodin Attenuates Pentylenetetrazole-Induced Seizures by Modulating the Mitogen-Activated Protein Kinase-Associated Inflammatory Responses in Mice.

Gastrodin, the major component isolated from the rhizome of the Chinese traditional medicinal herb Gastrodia elata ("Tianma"), has a long history in the treatment of epilepsy and other neurological disorders. However, the molecular mechanisms are not clear. Here, we found that gastrodin ameliorated pentylenetetrazole (PTZ)-induced epileptic seizures with improvement of the electroencephalographic pattern in mice. Further studies demonstrated that gastrodin decreased the levels of the pro-inflammatory cytokines interleukin-1ß and tumor necrosis factor-α while increasing interleukin-10, an anti-inflammatory cytokine in the brain. Furthermore, gastrodin attenuated the PTZ-induced microglial activation along with inhibition of mitogen-activated protein kinases, cAMP response element binding protein, and NF-κB. Our data suggest that gastrodin attenuates seizures by modulating the mitogen-activated protein kinase-associated inflammatory responses.

Effects of A1 receptor agonist/antagonist on spontaneous seizures in pilocarpine-induced epileptic rats.

Adenosine is an endogenous anticonvulsant that activates pre- and postsynaptic adenosine A1 receptors. A1 receptor agonists increase the latency for the development of seizures and status epilepticus following pilocarpine administration. Although hippocampal adenosine is increased in the chronic phase of the pilocarpine model, it is not known whether the modulation of A1 receptors may influence the frequency of spontaneous recurrent seizures (SRS). Here, we tested the hypothesis that the A1 receptor agonist RPia ([R]-N-phenylisopropyladenosine) and the A1 antagonist DPCPX (8-Cyclopentyl-1,3-dipropylxanthine) administered to chronic pilocarpine epileptic rats would respectively decrease and increase the frequency of SRS and hippocampal excitability. Four months after Pilo-induced SE, chronic epileptic rats were video-monitored for the recording of SRS before (basal) and after a 2-week treatment with RPia (25µg/kg) or DPCPX (50µg/kg). Following sacrifice, brain slices were studied with electrophysiology. We found that rats given RPia had a 93% nonsignificant reduction in the frequency of seizures compared with their own pretreatment baseline. In contrast, the administration of DPCPX resulted in an 87% significant increase in seizure rate. Nontreated epileptic rats had a similar frequency of seizures along the study. Corroborating our behavioral data, in vitro recordings showed that slices from animals previously given DPCPX had a shorter latency to develop epileptiform activity, longer and higher DC shifts, and higher spike amplitude compared with slices from nontreated Pilo controls. In contrast, smaller spike amplitude was recorded in slices from animals given RPia. In summary, the administration of A1 agonists reduced hippocampal excitability but not the frequency of spontaneous recurrent seizures in chronic epileptic rats, whereas A1 receptor antagonists increased both.

Evaluation of antiepileptic effect of S-adenosyl methionine and its role in memory impairment in pentylenetetrazole-induced kindling model in rats.

BACKGROUND: Epilepsy is the third most common cause of neurological disability worldwide. Despite the introduction of antiepileptic drugs (AEDs) in the past 20years, the seizures of around 30% of patients with epilepsy remain refractory to available treatment. Also, available AEDs and the disease itself have the potential to exert detrimental effects on cognitive function and therefore compromise patient wellbeing. S-adenosyl methionine has potential antiepileptic and memory-enhancing properties because of its involvement in the transmethylation reaction. OBJECTIVES: The present study was designed to evaluate the antiepileptic effect of S-adenosyl methionine and its role in memory impairment in the pentylenetetrazole (PTZ)-induced kindling model in rats. MATERIALS AND METHODS: The antiepileptic effect of 2 doses of SAM (50 and 100mg/kg) was tested by evaluating seizure severity score and seizure latency in the pentylenetetrazole-induced kindling model in rats. At the end of the study, spatial memory was evaluated in an elevated plus maze (EPM) test, and animals were sacrificed for estimation of oxidative stress markers in brain tissue homogenate. RESULTS: A higher dose of SAM (100mg/kg) exhibited an increase in seizure latency and a decrease in seizure severity score, suggesting its antiepileptic activity in the PTZ-induced kindling model. Also, the administration of SAM (50 and 100mg/kg) showed a decrease in transfer latency in the EPM test compared to the disease control group (p<0.0001). Biochemical analysis of rat brain tissue revealed significantly decreased malondialdehyde (p<0.0001) and increased glutathione (GSH) (p<0.0001) in the SAM 100-mg/kg group compared with that in the disease control group. CONCLUSION: The results demonstrated that S-adenosyl methionine exerts antiepileptic, memory-enhancing, and antioxidant properties in a pentylenetetrazole-induced kindling model of epilepsy.

[PATHOLOGICAL CHANGES DEVELOPMENT IN THE HEART WITH UNDERLYING CONVULSIVE SYNDROME MODEL OF VARIOUS ETIOLOGIES.]

The basic mechanisms of myocardial damage were determined experimentally in case of electroconvulsive (n = 30) and corazole (n = 20) induced seizures in Wistar rats by histochemical, pathological, electron microscopy and biochemical methods. It has been founded that pathological changes in the myocardium underlying with electroconvulsive and corazole induced seizures have unidirectional origin; nevertheless electrocohvulsive model has more intensity. It has been shown that structural base of myocardial pathology development results in parallel changes of microvessels and contractile myocardium with the main focus on development of contractile changes of cardiomyocytes and intramuscular capillaries spasm, which causes blood flow impairment and reducing supply of oxygen to the working cells. Structural changes in the myocardium develop due to energy shifts which have been elucidated by confirmed decrease SDG in cardiac activity (control 2,65±0,03 act. Units; electroconvulsive model 2,15±0,02 act. Units; and corazole model 2,25±0,02 act. Units), and increased - LDH (control 2,20±0,01 act. Units. electroconvulsive model 2,55±0,01 act. Units; corazole model 2,45±0,01 act. Units.) histochemically, showing evidence of hypoxia progression in the myocardium tissue. It has been also shown processes of increasing degradation as well as reducing synthesis of ATP biochemically(43% electroconvulsive model and 41% corazole model). All this results indicate the presence of hypoenergetics in case of elec- troconvulsive and corazole experimental models of seizures. The received results of complex researches allow considering that adequate and rational treatment and prevention of seizures (large and small epilepsy) requires anticonvulsants choose as well as drug correction of the most affected parts of energy metabolism via afitihypoxants and antioxidants administration. Key words: electroconvulsive and carozole convulsive syn- dromes; heart; metabolism; structure; pathogenesis.

Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17ß-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17ß-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.

Type 1 diabetes exacerbates blood-brain barrier alterations during experimental epileptic seizures in an animal model.

The aim of this study was to perform the effects of diabetes on the permeability of the blood-brain barrier (BBB) during pentylenetetrazole (PTZ)-induced epileptic attacks. For this propose, the animals were divided into four groups. These groups contained were intact, PTZ-treated, diabetic and PTZ-treated diabetic individuals, respectively. To evaluate the functioning of the BBB, Evans blue was used as a BBB permeability indicator, and the expressions of zonula occludens-1 and glial fibrillary acidic protein involving the functioning of the BBB were determined immunohistochemically. Also, the changes in the release of serum tumour necrosis factor-alpha and interleukin-10 and interleukin-12 were studied by using enzyme-linked immunosorbent assay method. BBB permeability in the seizures under diabetic conditions showed a considerable increase (p < 0·01) in all of the brain we studied. The immunoreactive staining intensity of zonula occludens-1 and glial fibrillary acidic protein was found reduced in the brain regions of diabetic rats (p < 0·01). However, the serum level of tumour necrosis factor-alpha increased in diabetes and diabetes + PTZ groups, and the serum level of interleukin-12 increased significantly in all experimental groups (p < 0·05). In conclusion, diabetes dramatically increases BBB damage during epileptic seizures, and it may be derived from an elevation of paracellular passage.

Curcumin supplementation improves mitochondrial and behavioral deficits in experimental model of chronic epilepsy.

The present study was aimed to investigate the potential beneficial effect of curcumin, a polyphenol with pleiotropic properties, on mitochondrial dysfunctions, oxidative stress and cognitive deficits in a kindled model of epilepsy. Kindled epilepsy was induced in rats by administering a sub-convulsive dose of pentylenetetrazole (PTZ, 40 mg/kg body weight) every alternate day for 30 days. PTZ administered rats exhibited marked cognitive deficits assessed using active and passive avoidance tasks. This was accompanied by a significant decrease in NADH:cytochrome-c reductase (complex I) and cytochrome-c oxidase (complex IV) activities along with an increase in ROS, lipid peroxidation and protein carbonyls. The levels of glutathione also decreased in the cortex and hippocampus. Electron micrographs revealed disruption of mitochondrial membrane integrity with distorted cristae in PTZ treated animals. Histopathological examination showed pyknotic nuclei and cell loss in the hippocampus as well as in the cortex of PTZ treated animals. Curcumin administration at a dose of 100 mg/kg, p.o. throughout the treatment paradigm was able to ameliorate cognitive deficits with no significant effect on seizure score. Curcumin was able to restore the activity of mitochondrial complexes. In addition, significant reduction in ROS generation, lipid peroxidation and protein carbonyls was observed in PTZ animals supplemented with curcumin. Moreover, glutathione levels were also restored in PTZ treated rats supplemented with curcumin. Curcumin protected mitochondria from seizure induced structural alterations. Further, the curcumin supplemented PTZ rats had normal cell morphology and reduced cell loss. These results suggest that curcumin supplementation has potential to prevent mitochondrial dysfunctions and oxidative stress with improved cognitive functions in a chronic model of epilepsy.

The anti-seizure drugs vinpocetine and carbamazepine, but not valproic acid, reduce inflammatory IL-1ß and TNF-α expression in rat hippocampus.

In the present study, the effects of the two classical anti-epileptic drugs, carbamazepine and valproic acid, and the non-classical anti-seizure drug vinpocetine were investigated on the expression of the pro-inflammatory cytokines IL-1ß and TNF-α in the hippocampus of rats by PCR or western blot after the administration of one or seven doses. Next, the effects of the anti-seizure drugs were investigated on the rise in cytokine expression induced by lipopolysaccharides (LPS) inoculation in vivo. To validate our methods, the changes induced by the pro-convulsive agents 4-aminopyridine, pentylenetetrazole and pilocarpine were also tested. Finally, the effect of the anti-seizure drugs on seizures and on the concomitant rise in pro-inflammatory cytokine expression induced by 4-aminopyridine was explored. Results show that vinpocetine and carbamazepine reduced the expression of IL-1ß and TNF-α from basal conditions, and the increase in both pro-inflammatory cytokines induced by LPS. In contrast, valproic acid failed to reduce both the expression of the cytokines from basal conditions and the rise in IL-1ß and TNF-α expression induced by LPS. Tonic-clonic seizures induced either by 4-aminopyridine, pentylenetetrazole or pilocarpine increased the expression of IL-1ß and TNF-α markedly. 4-aminopyridine-induced changes were reduced by all the tested anti-seizure drugs, although valproic acid was less effective. We conclude that the anti-seizure drugs, vinpocetine and carbamazepine, whose mechanisms of action involve a decrease in ion channels permeability, also reduce cerebral inflammation. The mechanism of action of anti-seizure drugs like vinpocetine and carbamazepine involves a decrease in Na(+) channels permeability. We here propose that this mechanism of action also involves a decrease in cerebral inflammation.

Intrastriatal transplantation of adenovirus-generated induced pluripotent stem cells for treating neuropathological and functional deficits in a rodent model of Huntington's disease.

Induced pluripotent stem cells (iPSCs) show considerable promise for cell replacement therapies for Huntington's disease (HD). Our laboratory has demonstrated that tail-tip fibroblasts, reprogrammed into iPSCs via two adenoviruses, can survive and differentiate into neuronal lineages following transplantation into healthy adult rats. However, the ability of these cells to survive, differentiate, and restore function in a damaged brain is unknown. To this end, adult rats received a regimen of 3-nitropropionic acid (3-NP) to induce behavioral and neuropathological deficits that resemble HD. At 7, 21, and 42 days after the initiation of 3-NP or vehicle, the rats received intrastriatal bilateral transplantation of iPSCs. All rats that received 3-NP and vehicle treatment displayed significant motor impairment, whereas those that received iPSC transplantation after 3-NP treatment had preserved motor function. Histological analysis of the brains of these rats revealed significant decreases in optical densitometric measures in the striatum, lateral ventricle enlargement, as well as an increase in striosome size in all rats receiving 3-NP when compared with sham rats. The 3-NP-treated rats given transplants of iPSCs in the 7- or 21-day groups did not exhibit these deficits. Transplantation of iPSCs at the late-stage (42-day) time point did not protect against the 3-NP-induced neuropathology, despite preserving motor function. Transplanted iPSCs were found to survive and differentiate into region-specific neurons in the striatum of 3-NP rats, at all transplantation time points. Taken together, these results suggest that transplantation of adenovirus-generated iPSCs may provide a potential avenue for therapeutic treatment of HD.

Understanding the anti-kindling role and its mechanism of Resveratrol in Pentylenetetrazole induced-kindling in a rat model.

BACKGROUND: Resveratrol is a polyphone chemical found in a number of plant species, including peanuts and grapes, but with significant amounts in red wine. In normal plant physiology, Resveratrol is produced as a defensive response to injury or parasitic attacks. Resveratrol has diverse biological properties and actions with potential clinical applications, including anti-inflammatory, antioxidant, anti proliferative, and neuroprotective effects. AIM: The aim of the present study was to explore the effect and mechanism of Resveratrol in Pentylenetetrazole (PTZ) induced kindling in rats. MATERIALS AND METHODS: In a PTZ kindled Wistar rat model, different doses of Resveratrol (25mg/kg, 50mg/kg and 75 mg/kg) were administered orally 30 min before the PTZ injection. The PTZ injection was given on alternate day till the animal became fully kindled or till 10 weeks. The following parameters were compared between control and various experimental groups: the course of kindling, stages of seizures, histopathological scoring of hippocampus, antioxidant parameters, DNA fragmentation and caspase-3 expression in the hippocampus, and neuron-specific enolase in the blood. One way ANOVA followed by Bonferroni post hoc analysis and Fischer's Exact test were used for statistical analyses. THE RESULTS: In the present study, Resveratrol showed dose-dependent anti-seizure effect. Resveratrol (75 mg/kg) significantly increased the latency to myoclonic jerks, clinic seizures as well as generalized tonic-clinic seizures, improved the seizure score and decreased the number of myoclonic jerks. PTZ induced kindling caused a significant neuronal injury, oxidative stress and apoptosis which were reversed by pretreatment with Resveratrol in a dose-dependent manner. CONCLUSION: Our study suggests that Resveratrol has a potential antiepileptogenic effect on PTZ-induced kindling in rats. The possible underlying mechanisms of Resveratrol as an antiepileptic agent may be due to its antioxidative property and neuroprotective effect.

Novel anticonvulsive effects of progesterone in a mouse model of hippocampal electrical kindling.

Progesterone is a known anticonvulsant, with its inhibitory effects generally attributed to its secondary metabolite, 5α,3α-tetrahydroprogesterone (THP), and THP's enhancement of GABAA receptor activity. Accumulating evidence, however, suggests that progesterone may have non-genomic actions independent of the GABAA receptor. In this study, we explored THP/GABAA-independent anticonvulsive actions of progesterone in a mouse model of hippocampal kindling and in mouse entorhinal slices in vitro. Specifically, we examined the effects of progesterone in kindled mice with or without pretreatments with finasteride, a 5α-reductase inhibitor known to block the metabolism of progesterone to THP. In addition, we examined the effects of progesterone on entorhinal epileptiform potentials in the presence of a GABAA receptor antagonist picrotoxin and finasteride. Adult male mice were kindled via a daily stimulation protocol. Electroencephalographic (EEG) discharges were recorded from the hippocampus or cortex to assess "focal" or "generalized" seizure activity. Kindled mice were treated with intra-peritoneal injections of progesterone (10, 35, 100 and 160mg/kg) with or without finasteride pretreatment (50 or 100mg/kg), THP (1, 3.5, 10 and 30mg/kg), midazolam (2mg/kg) and carbamazepine (50mg/kg). Entorhinal cortical slices were prepared from naïve young mice, and repetitive epileptiform potentials were induced by 4-aminopyridine (100µM), picrotoxin (100µM) and finasteride (1µM). Pretreatment with finasteride did not abolish the anticonvulsant effects of progesterone. In finasteride-pretreated mice, progesterone at 100 and 160mg/kg decreased cortical but not hippocampal afterdischarges (ADs). Carbamazepine mimicked the effects of progesterone with finasteride pretreatments in decreasing cortical discharges and motor seizures, whereas midazolam produced effects similar to progesterone alone or THP in decreasing hippocampal ADs and motor seizures. In brain slices, progesterone at 1µM inhibited entorhinal epileptiform potentials in the presence of picrotoxin and finasteride. We suggest that progesterone may have THP/GABAA-dependent and independent anticonvulsive actions in the hippocampal-kindled mouse model.