Probiotics and Nigella sativa extract supplementation improved behavioral and electrophysiological effects of PTZ-induced chemical kindling in rats.

INTRODUCTION: Epilepsy is a most common neurological disorder that has negative effects on cognition. In the present study, we investigated the protective effect of Nigella sativa (NS) and probiotics on seizure activity, cognitive performance, and synaptic plasticity in pentylenetetrazole (PTZ) kindling model of epilepsy. METHODS: One hundred and forty-four rats were divided into 2 experiments: In experiment 1, animals were grouped and treated as follows: 1) control (PTZ + saline), 2) NS treatment, 3) probiotic treatment, and 4) NS and probiotic treatment. Six weeks after the treatment, PTZ kindling were performed, and 48 h after kindling, spatial learning and memory were measured in Morris water maze (MWM) test. Animals in experiment 2 received the same treatment as experiment 1: in control nonkindled groups, control animals were treated with probiotics, NS, and probiotics + NS. Six weeks after the treatment, PTZ kindling were performed, and 48 h after kindling, field potentials were recorded from the dentate gyrus area of the hippocampus; synaptic transmission and long-term potentiation (LTP) was measured. RESULTS: The results showed that the probiotic and NS supplementation significantly reduces kindling development so that animals in PTZ + NS + probiotic did not show full kindling. In MWM test, the escape latency and traveled path in the kindled group were significantly higher than the control group. In PTZ + NS + probiotics, these parameters were significantly lower than those in the PTZ + saline group. Adding probiotic and NS supplementation significantly reduced population spike (PS)-LTP as compared with the PTZ + saline group. CONCLUSION: Probiotic and NS supplementation have some protection against seizure, seizure-induced cognitive impairment, and hippocampal LTP in kindled rats.

Therapeutic effects of walnut oil on the animal model of multiple sclerosis.

OBJECTIVES: Therapeutic approaches for multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS), are accompanied by various undesirable side effects. Owing to the anti-inflammatory and antioxidant effects of walnut, we investigated its effects on the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. METHODS: After EAE induction in mice, the treated group was gavaged daily with walnut oil. The weights and clinical symptoms were monitored daily for 21 days following the onset of symptoms. The spleens and brains of the mouse were removed and used for ELISA and histological studies. RESULTS: The average disease severity and plaque formation in the brains of the walnut oil-treated group were significantly lower (P < 0.05) than those of the untreated group. Stimulated splenocytes of the treated group expressed significantly less INF-γ and interleukin (IL)-17 than the untreated group with no significant differences in IL-10 or IL-5 production. In serum from the treated group, IL-17 expression was also significantly less than in the untreated group, while IL-10 was greater (P < 0.05). CONCLUSION: Walnut oil significantly reduced disease severity, inhibited plaque formation, and altered cytokine production. More studies are required to identify the mechanism of action of walnut oil as a valuable supplement in the treatment of MS.

Improving effect of mild foot electrical stimulation on pentylenetetrazole-induced impairment of learning and memory.

Epilepsy is a common neurological disorder that affects learning and memory. Recently it has been shown that mild foot electrical stimulation (MFES) can increase learning and memory in normal rats. Pentylenetetrazole (PTZ) kindling is a model of human epilepsy. As with human epilepsy, PTZ kindling impairs learning and memory in rats. The purpose of this study was to investigate the effect MFES on kindling-induced learning and memory deficits in rats. Forty-nine male Wistar rats weighting 200 to 250 g were divided into the following seven groups: PTZ only, phenytoin only, MFES only, PTZ plus phenytoin, PTZ plus MFES, phenytoin plus MFES, and saline (control), with the treatments administered for 26 days. Forty-eight hours after the last injection, the animals performed the Morris water maze (MWM) task, and spatial learning and memory were measured. The results indicated that although chronic administration of phenytoin inhibited the development of PTZ kindling, it did not exert a protective effect against kindling-induced spatial learning and memory impairment in rats. On the other hand, pretreatment of PTZ-kindled animals with MFES significantly improved spatial working and reference memory. The results point to potential novel beneficial effects of MFES on learning and memory impairment induced by PTZ kindling in rats.

Anticonvulsive effects of endocannabinoids; an investigation to determine the role of regulatory components of endocannabinoid metabolism in the Pentylenetetrazol induced tonic- clonic seizures.

2-Arachidonoylglycerol (2-AG) and anandamide are two major endocannabinoids produced, released and eliminated by metabolic pathways. Anticonvulsive effect of 2-AG and CB1 receptor is well-established. Herein, we designed to investigate the anticonvulsive influence of key components of the 2-AG and anandamide metabolism. Tonic-clonic seizures were induced by an injection of Pentylenetetrazol (80 mg/kg, i.p.) in adult male Wistar rats. Delay and duration for the seizure stages were considered for analysis. Monoacylglycerol lipase blocker (JJKK048; 1 mg/kg) or alpha/beta hydroxylase domain 6 blocker (WWL70; 5 mg/kg) were administrated alone or with 2-AG to evaluate the anticonvulsive potential of these enzymes. To determine the CB1 receptor involvement, its blocker (MJ15; 3 mg/kg) was administrated associated with JJKK048 or WWL70. To assess anandamide anticonvulsive effect, anandamide membrane transporter blocker (LY21813240; 2.5 mg/kg) was used alone or associated with MJ15. Also, fatty acid amide hydrolase blocker (URB597; 1 mg/kg; to prevent intracellular anandamide hydrolysis) were used alone or with AMG21629 (transient receptor potential vanilloid; TRPV1 antagonist; 3 mg/kg). All compounds were dissolved in DMSO and injected i.p., before the Pentylenetetrazol. Both JJKK048 and WWL70 revealed anticonvulsive effect. Anticonvulsive effect of JJKK048 but not WWL70 was CB1 receptor dependent. LY2183240 showed CB1 receptor dependent anticonvulsive effect. However, URB597 revealed a TRPV1 dependent proconvulsive effect. It seems extracellular accumulation of 2-AG or anandamide has anticonvulsive effect through the CB1 receptor, while intracellular anandamide accumulation is proconvulsive through TRPV1.

Transgenerational modification of hippocampus TNF-α and S100B levels in the offspring of rats chronically exposed to morphine during adolescence.

BACKGROUND: TNF-α and S100B are important signaling factors that are involved in many aberrant conditions of the brain. Chronic morphine exposure causes aberrant modifications in the brain. OBJECTIVES: We examined the consequences of chronic morphine consumption by parents before mating on hippocampus TNF-α and S100B levels in the parents and their offspring. METHODS: A total of 12 adult female and 12 adult male Wistar rats were used as parents. Each gender was divided randomly into two groups: control and morphine consumer. Morphine consumer groups received morphine sulfate dissolved in drinking water (0.4 mg/ml) for 60 days. Control groups received water. Thirty days before mating, morphine was replaced with water. All offspring also received water. The hippocampus of both parental and offspring groups was extracted to measure TNF-α and S100B levels using an ELISA. RESULTS: Hippocampus TNF-α levels were significantly increased due to chronic morphine use in both male and female parents compared to those of control parents (P < 0.01). Moreover, both male and female offspring of morphine-exposed parents showed a significant increase in hippocampus TNF-α levels compared to those of control offspring (P < 0.01). Hippocampus levels of S100B were significantly decreased in male (P < 0.05) but not female morphine consumer parents relative to control parents. Both male and female offspring of morphine-exposed parents showed significant decreases in hippocampus S100B levels (P < 0.05) compared to those of control offspring. CONCLUSIONS: The consequences of chronic morphine use by parents, even when it is stopped long before mating and pregnancy, could induce modifications in the hippocampus of the next generation.

Cardiovascular physiology misconceptions and the potential of cardiovascular physiology teaching to alleviate these.

BACKGROUND: Misconceptions are mental models of phenomena that are at variance with accepted scientific models of these phenomena. AIM: The goal of this study was to investigate the prevalence of some misconceptions among students about cardiovascular physiology and to evaluate the effectiveness of cardiovascular physiology teaching in alleviating these misconceptions. METHOD: A descriptive-analytic survey was undertaken with 348 undergraduates from the fields of medicine, nursing, and biology. Students were divided into two groups on the basis of whether they had passed or not taken the cardiovascular physiology course. The students were asked to answer four questions relating to cardiovascular. Descriptive statistic analysis and two-tailed comparison of the proportions was used to analyze their answers. RESULTS: The prevalence of misconceptions about the left ventricular output versus the right ventricular output ranged from 80% to 98%. The misconception about pulse velocity compared with blood velocity in the vessels was 74% to 89%. Between 95% and 99% of answers to the effect of increased resistance on blood flow were incorrect in all groups. Between 69% and 73% of the students had trouble answering the question on parallel resistance and the effect of the removal of one limb on total peripheral resistance. For most of the questions, university lectures had no effect on alleviating these misconceptions. CONCLUSIONS: These results indicate that there is a high prevalence of misconceptions among students about at least four cardiovascular concepts associated with cardiovascular physiology and that teaching has failed to alleviate these misconceptions.

Antioxidant properties of Trifolium resupinatum and its therapeutic potential for Alzheimer's disease.

INTRODUCTION: Alzheimer's disease (AD) is the most common cause of dementia and is characterized by a progressive deterioration in cognitive function, which typically begins with impairment in memory. Persian clover (Trifolium resupinatum) is an annual plant found in central Asia. Due to its contents (high flavonoid and isoflavones), extensive researches have been done on its therapeutic properties, such as multiple sclerosis (MS) treatment. In this study, we investigate the neuroprotective effects of this plant on Streptozotocin (STZ)-induced AD in rats. MATERIAL AND METHODS: This research aimed to evaluate the neuroprotective effect of Trifolium resupinatum on the spatial learning and memory, superoxide dismutase (SOD), expressions of ß amyloid 1-42 (Ab 1-42 ), and b amyloid 1-40 (Ab 1-40 ) in the hippocampus of STZ-induced Alzheimer rats. RESULTS: Our data showed that Trifolium resupinatum extract administration for two weeks before and one week after AD induction significantly improves maze escape latency ( p = 0.027, 0.001 and 0.02 in 100, 200, and 300 mg of the extract, respectively) and maze retention time ( p = 0.003, 0.04 and 0.001 in 100, 200, and 300 mg of the extract, respectively). Also, the administration of this extract significantly increases the SOD levels from 1.72+0.20 to 2.31+0.45 ( p = 0.009), 2.48+0.32 ( p = 0.001) and 2.33+0.32 ( p = 0.007) and decreases the expressions of Ab 1-42 ) ( p = 0.001 in all concentrations of the extract) and Ab 1-40 ) ( p = 0.001 in all concentrations of the extract) in the rat's hippocampus. CONCLUSIONS: This study suggests that the alcoholic extract of Trifolium resupinatum has anti-Alzheimer and neuroprotective effects on rats.

Anxiety-like behavior induced by allergen is associated with decreased irregularity of breathing pattern in rats.

Allergic rhinitis (AR) is a chronic inflammatory disorder associated with a high prevalence of anxiety symptoms and respiratory disorders that adversely affect the quality of life. Studies have shown that allergen exposure induces anxiety-like behaviors. On the other hand, stress impairs the breathing pattern. However, the effect of stress on respiration and the relationship between anxiety-like behavior and stress-induced changes in breathing pattern has not been evaluated in AR. We assessed the impact of ovalbumin (OVA)-induced anxiety-like behaviors on stress-induced breathing pattern changes. Our findings showed that the allergic rhinitis induced by OVA challenge in sensitized rats induces anxiety-like behavior. Also, we found that stress decreases respiratory irregularity and increases respiratory variability, as well as the synchronization between IBI and RV time-series in AR animals. Moreover, in AR animals, we found a significant positive correlation between anxiety-like behavior and respiratory irregularity under non-stress conditions. Besides, a significant negative correlation was observed under stress conditions. The findings showed that anxiety-related behaviors may contribute to respiratory impairments under stress conditions in AR.

The effect of co-administration of pentylenetetrazole with pilocarpine: New modified PTZ models of kindling and seizure.

BACKGROUND: Drug resistance is a major problem in the treatment of epilepsy. There is a critical need for new epilepsy models to evaluate antiepileptic compounds. Pentylenetetrazole- (PTZ) and pilocarpine-induced seizures are well-established models of human epilepsy. Generally, PTZ or pilocarpine has been used to produce seizures in experimental models. In this study, we explored the possibility of creating new epilepsy and seizure models by co-administration of PTZ and pilocarpine. METHODS: The protocol was divided into three parts: A) Kindling experiments: the animals received PTZ or co-administration doses of PTZ and pilocarpine every other day for a period of 26 days. B) Seizure experiments, for induction of seizure, the animals received one dose of PTZ, pilocarpine or co-administration doses of PTZ and pilocarpine. C) Evaluation of antiepileptic drugs: the animals received phenytoin or sodium valproate 20 min before injection of PTZ, pilocarpine or co-administration doses of PTZ and pilocarpine. RESULTS: The co-administration of pilocarpine and PTZ could induce seizure, which has behavioral similarity between electrical and chemical kindling. Pilocarpine (50 mg/kg) + PTZ (37.5 mg/kg) was the appropriate dose for kindling induction. Animals with this dose reached the stage five seizures significantly faster than those with PTZ alone. Unlike the seizure induced by PTZ, or pilocarpine, induction of seizure by PTZ + pilocarpine was resistant to phenytoin and sodium valproate treatment. As compared to the PTZ model of kindling, this model visualized the seizure behavior better and had resistance to two most popular antiepileptic drugs. CONCLUSION: Our results indicated that co-administration of pilocarpine and PTZ could provide a new modified model of seizure and kindling resisting to phenytoin and sodium valproate.

Mild foot electrical stimulation is comparable with phenytoin in inhibiting pentylenetetrazol-induced kindling in rats.

Increasing evidence demonstrates that electric stimulation has anticonvulsant effects. The present study was undertaken to investigate the effects of mild foot electrical stimulation (MFES) on the development of pentylenetetrazol (PTZ) kindling and compare its effectiveness with the more commonly used treatment, phenytoin. Kindling was induced in rats by repeated injections (every 24 h) of PTZ (37.5 mg/kg). The rats were subjected to either MFES (0.2 mA in intensity for a 160 ms duration with a 160 ms interval for 20 min) or phenytoin (30 mg/kg) before PTZ injections. Following this treatment, rats received MFES every other day for 10 days or 26 days after establishment of PTZ kindling. The data showed that MFES significantly inhibited development of chemical kindling induced by PTZ in rats (p = 0.001, as compared to PTZ-treated animals). This inhibitory effect is comparable with the effect of 30 mg/kg doses of phenytoin (P = 0.99, as compared to phenytoin group). However, 10 days or 26 days durations of MFES had no effect on established kindled seizures (P = 0.58 as compared to PTZ-treated animals). Our data demonstrate that although MFES significantly inhibited the development of chemical kindling, this experimental paradigm had no effect on established kindled seizures.

Low, but Not High, Doses of Copper Sulfate Impair Synaptic Plasticity in the Hippocampal CA1 Region In Vivo.

Previous studies have shown the inhibitory effect of the in vitro application of copper sulfate on hippocampal long-term potentiation. While in vivo administration of copper did not affect spatial learning and memory. To find possible answers to this controversial issue, we evaluate the effect of different doses of copper sulfate on in vivo long-term potentiation, synaptic transmission, and paired-pulse behavior of CA1 pyramidal cells. Thirty-two male Wistar rats were divided into four groups: control, 5, 10, and 15 mg of copper sulfate. Field excitatory postsynaptic potential from the stratum radiatum of CA1 neurons was recorded following Schaffer collateral stimulation in rats. Spike amplitude, long-term potentiation and paired-pulse index were measured in all groups. The results of this study showed that 5 mg/kg copper sulfate increased synaptic transmission and inhibited long-term potentiation and decreased the hippocampal paired-pulse ratio, while 10 and 15 mg/kg copper sulfate did not affect CA1 synaptic transmission properties. Low, but not high, doses of copper sulfate affect synaptic plasticity. This finding may explain the difference between the effect of copper on synaptic plasticity and spatial learning and memory.

Changes in neuromodulatory effect of adenosine A1 receptors on piriform cortex field potentials in amygdala kindled rats.

Adenosine exerts its anticonvulsants effect through different brain regions including piriform cortex. In this study, the effect of amygdala kindled seizures on adenosine A1 receptor-mediated neuromodulation in piriform cortex pyramidal neurons was tested at 24 h and 1 month after kindling. Animals were kindled by daily electrical stimulation of amygdala. Field potentials were recorded from layer II of piriform cortex pyramidal cells following stimulation of the lateral olfactory tract. Obtained results showed that N6-cyclohexyladenosine (CHA), a selective adenosine A1 receptor agonist (1, 10 and 100 microM; i.c.v.), reduced A1 slope and B1 amplitude of field potentials in both kindled and non-kindled (control) rats. However, its effects on kindled animals were more potent at 24 h, but not 1 month post-kindling. 8 cyclopenthyl-1,3-dimethylxanthine (CPT), a selective adenosine A1 receptor antagonist (50 microM, i.c.v.), had no significant effect on the field potential parameters. However, CPT (50 microM, i.c.v.) pretreatment eliminated effects of CHA (10 microM; i.c.v.) on the field potentials. These results indicate that activation of adenosine A1 receptors has an inhibitory effect on the field potentials of piriform cortex pyramidal neurons and the efficiency of adenosine A1 receptor neuromodulation in piriform cortex is increased at short-term (24 h) but return to normal at long-term (1 month) after kindling implementation.

Sumatriptan, an Antimigraine Drug, Inhibits Pentylenetetrazol-induced Seizures in NMRI Mice.

Sumatriptan has been used for the acute treatment of migraine attacks. There are many similarities between migraine and epilepsy and the medications used to treat one of these disorders can effectively be used to treat the other. The purpose of this study was to evaluate and compare the anticonvulsant effects of sumatriptan with sodium valproate in NMRI mice. 62 male NMRI mice were divided into 8 groups. The groups consisted of a saline (control) group, 4 intraperitoneally (ip) administered sumatriptan groups (1, 10, 50, and 100 mg/kg, ip), and 3 sodium valproate groups (50, 150, and 300 mg/kg, ip). 20-min after the injection of either saline or one of the drug doses, pentylenetetrazol (100 mg/kg, ip) was injected and seizure parameters were evaluated. The results showed that 300 mg/kg sodium valproate markedly inhibited the seizure stage, whereas none of the sumatriptan doses had any significant effect on this parameter. The latency to stages 2 and 4 of the seizures and the interval between the pentylenetetrazol injection to death was significantly increased by both sodium valproate and sumatriptan.Sumatriptan is commonly used for the treatment of migraine and also has a protective effect against seizures induced by pentylenetetrazol in mice.

Changes in Synaptic Transmission and Long-term Potentiation Induction as a Possible Mechanism for Learning Disability in an Animal Model of Multiple Sclerosis.

PURPOSE: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. It has been shown that memory deficits is common in patients with MS. Recent studies using experimental autoimmune encephalomyelitis (EAE) as an animal model of MS have shown that indicated that EAE causes hippocampal-dependent impairment in learning and memory. Thus far, there have been no in vivo electrophysiological reports describing synaptic transmission in EAE animals. The aim of the present work is to evaluate the synaptic changes in the CA1 region of the hippocampus of EAE rats. METHODS: To evaluate changes in synaptic transmission in the CA1 region of the hippocampus of EAE rats, field excitatory postsynaptic potentials (fEPSPs) from the stratum radiatum of CA1 neurons, were recorded following Schaffer collateral stimulation. RESULTS: The results showed that EAE causes deficits in synaptic transmission and long-term potentiation (LTP) in the hippocampus. In addition, paired-pulse index with a 120 msec interstimulus interval was decreased in the EAE group. These findings indicate that EAE might induce suppression in synaptic transmission and LTP by increasing the inhibitory effect of GABAB receptors on the glutamate-mediated EPSP. CONCLUSIONS: In conclusion, influence of inflammation-triggered mechanisms on synaptic transmission may explain the negative effect of EAE on learning abilities in rats.

Prediction of seizure incidence probability in PTZ model of kindling through spatial learning ability in male and female rats.

Epilepsy is a common neurological disease characterized by periodic seizures. Cognitive deficits and impairments in learning and memory are also associated with epilepsy. Neuronal changes and synaptic modifications in kindling model of epilepsy are similar to those occur during the learning procedure and memory formation. Herein we investigated whether seizure susceptibility in pentylenetetrazol (PTZ) model of kindling is predictable based on the learning ability in the Morris water maze (MWM) task in male and female rats. Allocentric learning was tested using MWM in present of light while egocentric learning was evaluated by MWM in dark room. The results indicated no significant differences in allocentric learning abilities between male and female rats. However, male rats were able to memorize the location of the platform more effectively compared to females in egocentric test. In addition, a statistically significant negative correlation between learning abilities (working memory) and seizure susceptibility in male rats was found while this correlation was positive in female rats. On the other hand, although there was no significant correlation between retrieval (reference memory) of spatial memories and seizure parameters in male rats, female rats showed a significant negative correlation. These findings may provide some evidences for prediction of seizure susceptibility according to learning ability and memory retention.

Comparison between standard protocol and a novel window protocol for induction of pentylenetetrazol kindled seizures in the rat.

Experimental models of epilepsy, including pentylenetetrazol (PTZ) chemical kindling, are very important in studying the pathophysiology of epilepsy. The aim of the present study was to provide behavioral, electrophysiological and molecular evidences to confirm the similarities between standard and a modified protocol named window- (win-) PTZ kindling method. Standard PTZ kindling model was induced by injection of PTZ (37.5mg/kg) every other days. In win-PTZ kindling method, animals received 4 initial PTZ injections and the time of 3 last PTZ injections were determined according to the number of PTZ injections in standard PTZ kindling model. The behavioral signs of kindled seizures were observed for 20 min after each PTZ injection. Field potential recordings were done from the dentate gyrus granular cells following perforant path stimulation. In addition, the expression of γ2 subunit of GABAA receptor, NR2A subunit of NMDA receptor, adenosine A1 receptor, α-CaMKII and GAP-43 were evaluated in the hippocampus and dentate gyrus using RT-PCR technique. All the animals in win-PTZ kindling method group achieved fully kindled state after 3 last PTZ injections. There was no significant difference in population spike amplitude and expression of the mentioned genes during kindling acquisition between standard PTZ kindling model and win-PTZ kindling method. The similarities in electrophysiological and molecular parameters remained after 8 days post fully kindled state. Obtained data showed the similarities between this win-PTZ kindling method and standard PTZ kindling model. Thus, it may be suggested that not all PTZ injections are need for induction of PTZ induced fully kindled state.

Anticonvulsant effect of A1 but not A2A adenosine receptors of piriform cortex in amygdala-kindled rats.

In this study, the effect of A1 and A2A adenosine receptor activity of the piriform cortex (PC) on amygdala-kindled seizures was investigated in rats. Animals were kindled by daily electrical stimulation of the amygdala. In fully kindled rats, N6-cyclohexyladenosine (CHA, a selective A1 agonist), 8-cyclopentyl-1,3-dimethylxanthine (CPT, a selective A1 antagonist), CGS21,680 hydrochloride (CGS, a selective A2A agonist), and ZM241,385 (ZM, a selective A2A antagonist) were microinjected bilaterally into the PC. Rats were stimulated 5 min post-drug microinjection and seizure parameters were measured. Results showed that intra-PC CHA (10 and 100 micromol/L) decreased the duration of both afterdischarge and stage 5 seizure and significantly increased the latency to stage 4 seizure. Intra-PC CPT increased afterdischarge and stage 5 seizure duration at the dose of 20 micromol/L. The anticonvulsant effect of CHA (100 micromol/L) was eliminated by CPT (10 micromol/L) pretreatment. On the other hand, neither intra-PC CGS nor ZM had a significant effect on kindled seizures. These results suggest that activity of A1, but not A2A, receptors of the PC have anticonvulsant effects on kindled seizures elicited from electrical stimulation of the amygdala.