Ameliorative effect of lithium chloride on working and spatial memory deficit in a PTZ-induced seizure model

Background: The repetitive seizure attacks lead to widespread neuronal damage and cognitive deficit, e.g. memory and learning impairment. The single or repeated administration of pentylenetetrazole (PTZ) can induce seizure in rat. This study evaluates the neuroprotective effect of lithium chloride (LiCl) on PTZ-induced working and spatial memory deficit. Materials and Methods: To induce the PTZ-kindling model, repeated doses of PTZ (40mg/kg/BW/ip) were injected for 5 consecutive days. After observing five stages of seizure, the PTZ+Li20, PTZ+Li40 and PTZ+Li80 groups received 20, 40 and 80 mg/kg/BW of LiCl, respectively and the PTZ+Saline group, received Saline for 14 days. The Morris water maze (MWM) and Y maze tests were conducted in order to investigate the spatial and working memory. Results: Compared to Control group, the PTZ+Saline group showed a decrease in alteration behavior in Y maze and an increase in latency time and distance to hidden platform in MWM. LiCl-treated rats, especially in the lowest dose, showed a significant higher alteration behavior in Y maze and the lower latency time and distance to hidden platform in MWM than the PTZ+Saline group. Conclusion: The neuroprotective effects of LiCl can ameliorate the spatial and working memory impairment in a PTZ-kindling model

Heuristics for the Critical Node Detection Problem in Large Complex Networks

Complex networks have recently attracted a significant amount of research attention due to their ability to model real world phenomena. One important problem often encountered is to limit diffusive processes spread over the network, for example mitigating pandemic disease or computer virus spread. A number of problem formulations have been proposed that aim to solve such problems based on desired network characteristics, such as maintaining the largest network component after node removal. The recently formulated critical node detection problem aims to remove a small subset of vertices from the network such that the residual network has minimum pairwise connectivity. Unfortunately, the problem is NP-hard and also the number of constraints is cubic in number of vertices, making very large scale problems impossible to solve with traditional mathematical programming techniques. Even many approximation algorithm strategies such as dynamic programming, evolutionary algorithms, etc. all are unusable for networks that contain thousands to millions of vertices. A computationally efficient and simple approach is required in such circumstances, but none currently exist. In this thesis, such an algorithm is proposed. The methodology is based on a depth-first search traversal of the network, and a specially designed ranking function that considers information local to each vertex. Due to the variety of network structures, a number of characteristics must be taken into consideration and combined into a single rank that measures the utility of removing each vertex. Since removing a vertex in sequential fashion impacts the network structure, an efficient post-processing algorithm is also proposed to quickly re-rank vertices. Experiments on a range of common complex network models with varying number of vertices are considered, in addition to real world networks. The proposed algorithm, DFSH, is shown to be highly competitive and often outperforms existing strategies such as Google PageRank for minimizing pairwise connectivity

Effectiveness of Erythropoietin on Working Memory, Passive Avoidance Learning and Anxiety- Like Behaviors in Prenatal Food Restriction Model

Introduction: Prenatal Food Restriction (PFR) causes some disorders in prenatal development and neuro-developmental abnormalities. On the other hand, the studies indicated that erythropoietin can act as a neuro-protector. Therefore, the aim of this study is to analyze the effects of erythropoietin on working memory, passive avoidance learning, and anxiety level in rat PFR model. Methods: In this experimental study, 50 neonatal rats are exposed to PFR. Reduction of standard food portion up to 50% has been started on the embryonic day (ED) 14 in rats until postnatal period. Then, different doses of 500, 1000, and 2000 IU/kg weight erythropoietin were injected to experimental groups, subcutaneously. At post natal day (PND) 30; Y-maze, shuttle box and elevated plus maze (EPM) are used for evaluation of working memory, passive avoidance learning, and anxiety level, respectively. Differences between groups were analyzed by one way ANOVA with Tukey’s post hoc (p ˂ 0.05). Results: The results indicate that working memory and avoidance learning have reduced significantly in the control group (p ˂ 0.05). Moreover, anxiety level has increased in PFR group in comparison with the control group (p ˂ 0.001). On the other hand, working and avoidance memories have increased in those groups which received EPO in comparison with PFR groups and anxiety level have decreased significantly (p ˂ 0.05). Conclusion: Our results indicate that prenatal treatment of erythropoietin can ameliorate behavioral abnormalities in PFR model

Improving the Effects of Omega-3 Fatty Acid on the In Vitro Maturation of Oocytes

This research was conducted in order to determine the effects of omega-3 on oocyte in vitro maturation and the level of expression of tribbles (TRIB1, TRIB2 and TRIB3 genes) in cumulus cells. Eight-ten weeks old NMRI mice were super-ovulated using 7.5 IU pregnant mare’s serum gonadotropin (PMSG, Intraperitoneal) and they were killed after 44 hours and their ovaries were removed. The oocytes were used for in vitro maturation and the cumulus-oocyte complexes (COCs) were released. Cumulus cells and oocytes were assigned into control, ethanol-treated and groups exposed to 10 and 100 μg/ml of omega-3. The cells were prepared to assess the maturation stage in order to evaluate the gene expression level. The data were statistically analyzed. Exposing oocytes to low dose (10 μg/ml) and high dose (100 μg/ml) of omega-3 resulted in a reduced rate of GV-stage oocytes, decreased MI-oocytes and increased MII-oocytes. The enhanced maturity of COCs was also detected in response to a high dose of omega-3 (100 μg/ml). Exposure of cumulus cells to omega-3 (10 and 100 μg/ml) induced TRIB2 and inhibited TRIB3 gene expression level; however, TRIB1 gene expression level increased and decreased in response to low (10 μg/ml) and high (100 μg/ml) concentrations of omega-3, respectively. The addition of omega-3 to the environment of oocytes or cumulus cells affected the maturation of oocytes and cumulus cells, which was followed by the differential expression of TRIB genes, suggesting that there was a role of fatty acid metabolism in the differentiation and maturation of cumulus cells

Trichostatin A Ameliorates Spatial Memory Deficits and Suppresses Hippocampal Pro- Inflammatory Cytokines in A Rat Model of Prenatal Stress

Introduction: Maternal stress during pregnancy leads to neuroinflammation of the fetus and cognitive disorders in children. On the other side, Trichostatin A (TSA) as a histone deacetylase inhibitor has anti-inflammatory and neuroprotective effects. The aim of the present study was an evaluation of TSA effect on amelioration of spatial memory deficit and modification of pro-inflammatory cytokines in rat’s hippocampus of prenatal footshock stress model. Methods: In the present study, 24 pregnant Wistar rats were divided into 4 groups including control, PFS+Saline, PFS+TSA5, and PFS+TSA10. In order to induce prenatal footshock stress (PFS), the pregnant rats were subjected to electrical shock at 1 mA, 50 Hz for 2 seconds with 5 repetitions at 3-minute intervals from 12 to 18 days of pregnancy. Two hours before applying the shock intraperitoneal administration of TSA was performed daily. When the offsprings were one-month old, their spatial memory was assessed by the Morris water maze. Finally, the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) were measured by ELISA method. Results: a reduction in spatial memory and an increase in the level of TNF-α, IL-1β, and IL-6 were observed in PFS+Saline group compared to the control. Besides, spatial learning showed a significant increase in TSA-treated groups compared to PFS+Saline. Conclusion: TSA with anti-inflammatory effects led to the reduction of hippocampal inflammatory cytokines and amelioration of spatial memory in offsprings who were exposed to stress in the prenatal period

The effect of swimming training, Gallic acid and high-fat diet on the serum levels of sex hormones in rats with polycystic ovary syndrome

Background: Polycystic ovary syndrome (PCOS) is characterized by hormonal-metabolic disorders, obesity, oxidative stress and ovulatory dysfunction. The aim of this study was to investigate the effect of four weeks of swimming training and Gallic acid (GA) administration on the serum level of sex hormones in rats with a polycystic ovary syndrome (PCOS) under the standard and high-fat diet. Materials and Methods: In this experimental study, 72 virgin female Sprague-Dawley rats were randomly divided into the nine groups: Control, PCOS, PCOS+HF (high fat diet), PCOS+EX (swimming training), PCOS+EX+HF (swimming training and high fat dietary), PCOS+GA (GA treatment), PCOS+GA+HF (GA treatment with high fat diet), PCOS+EX+GA (GA treatment and swimming training), PCOS+EX+GA+HF (GA treatment and swimming training with a high-fat diet). PCOS was induced with 1mg/kg letrozole and GA (100mg/kg, 4weeks) was administrated orally for 28 days. Then, the serum levels of LH, FSH, β-estradiol, progesterone and testosterone were measured using the ELISA method. Results: In the PCOS group, the progesterone level decreased and LH, FSH, β-estradiol and testosterone levels significantly increased compared to the control group (P<0.05). Treatment with GA or swimming training ameliorated the serum levels of these hormones. However, high fat diets reduced the ameliorative effect of GA and swimming training on the sex hormones in different groups. Conclusion: Gallic acid administration and swimming training can reduce dysregulation of sex hormones due to the PCOS in rats, but a high-fat diet increases PCOS pathogenesis

The Effects of Ellagic Acid on Hippocampal Cell Damage in Pentylenetetrazole Induced Kindling Seizure Model

Introduction: Epilepsy is a chronic neurological disease that is characterized by recurrent, spontaneous brain seizures. The aim of this study was to evaluate the effect of ellagic acid (EA) on hippocampal cell damage in penthylentetrazole (PTZ) induced kindling model. Methods: In this experimental study, 50 male Wistar rats were randomly divided into 5 groups (n= 10): control, PTZ (40 mg/kg, ip), PTZ+EA12,PTZ+EA25 and PTZ+EA51 (which received 12.5, 25 & 50 mg/kg, respectively) groups. After investigation of seizure delay in five consecutive days, the brains of rat’s skulls were removed and histopathological evaluation were performed. Comparison between different groups was assessed by one way ANOVA followed by Tukey’s post hoc test (p< 0.05). Results: Intraperitoneally injection of PTZ induced kindling seizure in animal model (p< 0.001). The data showed the seizure delay following the administration of EA increased (p< 0.001). In addition, after administration of EA the density of hippocampal cells increased in experimental groups (p< 0.001). Conclusion: The results of this study showed that EA decreases the severity of seizure in kindling seizures. Also, EA increased the neuronal density following the administration of PTZ. Therefore, EA possesses neuroprotective effects that enhance the hippocampal damages in animals and also perhaps in patients suffering from seizure