Antinociceptive effects of gamma-linolenic acid in the formalin test in the rats.

Background: Gamma-linolenic acid (GLA) is found in animals and plants that play a role in brain function and metabolism. Objective: This study aimed to investigate the analgesic effects of GLA on peripheral formalin injection. Methods: Wistar rats were randomly assigned to four groups: Sham, formalin, formalin/GLA 100 mg/kg, and formalin/GLA 150 mg/kg. The Formalin test was utilized to create a pain model. A tissue sample was prepared from the spinal cords of rats to measure oxidative stress parameters and pro-inflammatory cytokines. Furthermore, the authors analyzed the expression of c-Fos protein in the spinal cords. Results: Our findings demonstrate that GLA has a reliable pain-relieving effect in the formalin test. GLA 100 increased superoxide dismutase (SOD) (P<0.05), glutathione (GSH) (P<0.001), and catalase (CAT) (P<0.05), and decreased the levels of c-Fos (P<0.001), interleukin-1 beta (IL-1ß) (P<0.001), tumour necrosis factor-alpha (TNF-α) (P<0.001), and malondialdehyde (MDA) (P<0.001) in the spinal cord. Also GLA 150 increased SOD (P<0.05), GSH (P<0.001), and CAT (P<0.05) and decreased the levels of c-Fos (P<0.001), IL-1ß (P<0.001), TNF-α (P<0.001), and MDA (P<0.001) in the spinal cord. Conclusion: The findings have validated the antinociceptive impact of GLA and hinted towards its immunomodulatory influence in the formalin test.

The impact of Dimethyl itaconate on c-Fos expression in the spinal cord in experimental pain models.

Itaconate has been found to have potent anti-inflammatory effects and is being explored as a potential treatment for inflammatory diseases. However, its ability to relieve nociception and the mechanisms behind it are not yet understood. Our research aims to investigate the nociception-relieving properties of dimethyl itaconate (DMI) in the formalin test and writhing test. In male Wistar rats, Itaconic acid was injected intraperitoneally (i.p.). The formalin test and writhing test were conducted to determine the nociceptive behaviors. The spinal cords were removed from the rats and analyzed for c-fos protein expression. The study found that administering DMI 10 and 20 mg/kg reduced nociception in formalin and writhing tests. Injection of formalin into the periphery of the body led to an increase in the expression of c-fos in the spinal cord, which was alleviated by DMI 20 mg/kg. Similarly, acetic acid injection into the peritoneal cavity caused an increase in c-fos expression in the spinal cord, which was then reduced by 20 mg/kg. According to our findings, DMI reduced nociception in rats during the formalin and writhing tests. One possible explanation for this outcome is that the decrease in c-fos protein expression may be attributed to the presence of DMI.

Alpha-pinene ameliorate behavioral deficit induced by early postnatal hypoxia in the rat: study the inflammatory mechanism.

Neonatal hypoxia has a negative impact on the developing brain during the sensitive period. Inflammation plays a key role in the physiological response to hypoxic stress. Considering the anti-inflammatory properties of alpha-pinene, which has received a lot of attention in recent years, in this research we focused on the impact of alpha-pinene on the behavioral responses and proinflammatory factors in rats subjected to the neonatal hypoxia. This study involved Wistar rats (7-day-old) that were divided into six experimental groups, including a control group, groups receiving different doses of alpha-pinene (5 and 10 mg/kg), a hypoxia group receiving 7% O2 and 93% N2, 90 min duration for 7 days, and groups receiving alpha-pinene 30 min before hypoxia. All injections were done intraperitoneally. The rats were evaluated for proinflammatory factors 24 h after exposure to hypoxia (PND14) and at the end of the behavioral test (PND54). The results showed that hypoxia led to decreased motor activity, coordination, and memory, as well as increased inflammation. However, the rats that received alpha-pinene showed improved behavioral responses and reduced inflammation compared to the hypoxia group (all cases p < 0.05). This suggests that alpha-pinene may have a protective effect via anti-inflammatory properties against the negative impacts of hypoxia on the developing brain.

Fish oil ameliorates ethanol-induced gastric injury in rat by modulating gene related to apoptosis.

Gastric ulcers are a type of digestive disease that can severely affect a person's quality of life. Our study aimed to investigate the effects of fish oil on ethanol-induced gastric ulcers in rats, with the purpose of providing more comprehensive information on the topic. The study looked at various factors such as gastric ulcer index, and nitric oxide (NO) levels in stomach tissue. To investigate apoptosis, the mRNA levels of Bax, Bcl-2, and Caspase 3 were analyzed. The results showed that fish oil can reduce gastric acidity and the gastric ulcer index in cases of ethanol-induced gastric ulcers. It was found that fish oil can increase NO levels and improve the anti-apoptotic system by increasing the expression of Bcl-2 while decreasing the expression of Bax and Caspase 3. In general, the study demonstrates that fish oil can protect the stomach from ethanol-induced damage by reducing the apoptosis pathway via nitric oxide.

Nutritional Support of Crocin on Neurobehavioral Disabilities Induced by Cisplatin-Based Chemotherapy in Rats.

Cisplatin, a chemotherapy drug containing platinum, is considered a neurotoxic agent. On the other hand, crocin, the primary component of saffron, possesses neuroprotective and antioxidant properties. In this study, 28 healthy adult male Wistar rats weighing 200-250 g were used (6-7 weeks old). Rats were divided into a control group (Ctr), a crocin group (Cro), a cisplatin group (Cis), and a crocin with cisplatin group (Cro + Cis). Rotarod, open field, and shuttle box tests were performed to assess balance, explorative behavior, and avoidance memory. After behavioral testing, the hippocampus was extracted to analyze oxidative stress parameters such as GPx (glutathione peroxidase), SOD (superoxide dismutase), CAT (catalase), and MDA (malondialdehyde) activity. Shuttle box, rotarod, and open field results showed that crocin can substantially mitigate the deleterious effects of cisplatin on avoidance memory, explorative behavior, motor coordination, and balance. Crocin was also able to effectively avoid the negative effects of cisplatin on MDA, GPx, and CAT during the assessment of oxidative indicators, while the beneficial effect of crocin on cisplatin was not statistically significant in terms of SOD level. In conclusion, since free radicals produced by cisplatin are a contributing factor to memory loss and movement disorders, crocin, owing to its antioxidant properties, improved passive avoidance learning as well as motor activity.

Combined treatment of high-intensity interval training with neural stem cell generation on contusive model of spinal cord injury in rats.

INTRODUCTION: Spinal cord injury (SCI) leads to inflammation, axonal degeneration, and gliosis. A combined treatment of exercise and neural stem cells (NSC) has been proposed to improve neural repair. This study evaluated a combined treatment of high-intensity interval training (HIIT) with NSC generation from adipose-derived stem cells (ADSCs) on a contusive model of SCI in rats. MATERIALS AND METHODS: In vitro, rat ADSCs were isolated from the perinephric regions of Sprague-Dawley rats using enzymatic digestion. The ADSCs were transdifferentiated into neurospheres using B27, EGF, and bFGF. After production of NSC, they were labeled using green fluorescent protein (GFP). For the in vivo study, rats were divided into eight groups: control group, sham operation group, sham operation + HIIT group, sham operation + NSC group, SCI group, SCI + HIIT group, SCI + NSC group, and SCI/HIIT/NSC group. Laminectomy was carried out at the T12 level using the impactor system. HIIT was performed three times per week. To assess behavioral function, the Basso-Beattie-Bresnahan (BBB) locomotor test and H-reflex was carried out once a week for 12 weeks. We examined glial fibrillary acidic protein (GFAP), S100ß, and NF200 expression. RESULTS: NSC transplantation, HIIT and combined therapy with NSC transplantation, and the HIIT protocol improved locomotor function with decreased maximum H to maximum M reflexes (H/M ratio) and increased the Basso-Beattie-Bresnahan score. CONCLUSION: Combined therapy in contused rats using the HIIT protocol and neurosphere-derived NSC transplantation improves functional and histological outcomes.

Coenzyme Q10 improves ovarian histology and attenuates the expression of angiogenesis-associated proteins in the ovary of rats with experimental hyperstimulation syndrome.

Objectives: Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication characterized by many side effects. Coenzyme Q10 (CoQ10) is a protective lipophilic molecule with an extensive range of biological functions, but its possible protective effect on the ovary in OHSS has not as yet been studied. The present study aimed to investigate the potential protective effects of CoQ10 on ovarian histological and molecular alterations in an experimental model of OHSS in rats. Materials and Methods: Thirty female (2 months old) Wistar rats were randomly divided into 6 equal groups: control, OHSS, OHSS+CoQ10 (OHSS+ 200 mg/kg CoQ10 for 10 days), OHSS+ cabergoline (CAB) (OHSS+ 100 µg/kg CAB for 6 days), and CoQ10 and CAB (rats receiving similar doses to treatment groups.( In the end, the effects of treatments were assessed by measuring expressions of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in the ovary via western blotting, ovarian histomorphological alterations assessments, and serum estradiol and progesterone levels via ELISA. Results: There were histological alterations in OHSS groups, including the elevation of diameter and numbers of the corpus luteum and atretic follicles, and decreasing follicular reserve count, hyperemia, and hemorrhage at ovarian stroma. Treatment of OHSS groups with CAB and CoQ10 could decrease histological changes, serum estrogen and progesterone, and overexpression of VEGF and COX-2 proteins. Conclusion: Our results showed that ovarian histological and molecular alterations observed in experimental OHSS can be ameliorated by administration of CoQ10, indicating that CoQ10 can be used as new supportive care for OHSS patients.

Dimorphic evaluation of hippocampal changes in rat model of demyelination: A comparative functional, morphometric, and histological study.

BACKGROUND: Multiple sclerosis (MS) is the most common autoimmune disease. Progressive depletion of the brain and spinal cord tissue appears at the onset of the disease. Several studies have shown the increased size of the ventricles of the brain and decreases in the area of the corpus callosum and the width of the brain. Other important symptoms of this disease are cognitive, learning, and memory disorders. AIM: The aim of this study was to compare morphometric, histological, and functional changes in the demyelination model in both sexes. MATERIALS AND METHODS: In this experimental study, male and female Wistar rats were studied in four experimental groups. Demyelination was induced by the injection of ethidium bromide in the ventricular region. The chronic effect of demyelination on spatial memory, movement, and coordination was investigated using the Morris Water Maze (MWM), and clinical and balance beam tests, respectively. Myelin degradation, cell death and neurogenesis were estimated using Luxol Fast Blue staining and immunohistochemistry (Caspase-3 and Nestin markers). In addition, morphometric findings were recorded for the brain and hippocampus (weight, volume, length, width). RESULT: Demyelination increased the time and distance index and decreased the residence time in the target quarter in the water maze test (p < .001). It also increases the neuromuscular and modified neurological severity score (p < .01). Demyelination increases caspase-3 (p < .05) expression and decreases Nestin expression (p < .001), which are directly related to the extent of damage. CONCLUSION: This study showed an interaction between hippocampal structural and functional networks in explaining spatial learning and memory in the early stages of MS.

Effects of omega-3 fatty acid supplementation during chronic maternal hypoxia on behavioral disorders in male rat offspring: the role of Trk family and oxidative stress.

Maternal hypoxia due to a lack of blood flow and insufficient oxygen supply in the brain leads to behavioral disorders in adult offspring. Fish oil includes docosahexaenoic acid (DHA), a significant component of membrane phospholipids of nerve cells, which improved cognition, and memory. Trk family receptors are activated by hypoxic induction factor (HIF), and are involved in the neurotrophin's protective effects at the cellular level. Here we studied the biochemical, and molecular mechanisms of the protective effect of fish oil during the chronic maternal hypoxia model on behavioral responses in male rat offspring. Pregnant female rats were randomly divided into 4 experimental groups: 1) ctr; Control rats were pregnant 2) Hyp; Pregnant female rats received hypoxia from 6 to 15th day of pregnancy, with 10% oxygen intensity, and 90% nitrogen; 3) FO; Pregnant female rats received fish oil (F8020 1 ml / day, for ten consecutive days Orally), and 4) FO / Hyp; Pregnant female rats received hypoxia plus fish oil in the same manner. Behavioral parameters were evaluated in 28-day-old male offspring. HIF-1α, TrkB, and P75 gene expression were measured in the offspring's brain. Maternal hypoxia impaired memory performance, and locomotor activity in offspring. Besides, Trk family gene expression, and oxidative stress indicators showed a significant increase in the offspring's brain exposed to maternal hypoxia compared to the control group. Overall, fish oil improved behavioral parameters by inhibiting oxidative stress, and the expression of Trk family receptors.

Crocin mitigated cognitive impairment and brain molecular alterations induced by different intensities of prenatal hypoxia in neonatal rats.

INTRODUCTION: Brain hypoxia has important role to the onset and progression of sporadic form of Alzheimer disease via expression of hypoxia-inducible factor-1 (HIF-1). Crocin by anti-amyloidogenic property inhibits ß-amyloid formation. However, the molecular mechanism associated with anti-amyloidogenic activity of crocin is unknown. So, the present study was designed to investigate the effect of crocin on cognitive behavior and expression of HIF-1α and ß-secretase (BACE1) genes in the brain of neonate rats following different intensities of hypoxia during pregnancy. MATERIAL AND METHODS: Pregnant female rats were divided into six groups including sham, control crocin treated (CC), hypoxia with three different intensities (H1-H3), and most intense of hypoxic group treated with crocin (H3C) (30 mg/kg; i.p) at P14. Hypoxia induced on the 20th day of pregnancy. Animals in sham and CC were put in hypoxia chamber at the same time of hypoxia group without any hypoxia induction. Morris water maze (MWM) and qRT-PCR were used to evaluate the cognitive behavior and mRNA levels of BACE1 and HIF-1α genes in the brain tissues. RESULTS: Animal under 7% O2  + 93% N2 condition for 3 hr showed the highest cognitive behavior impairment and upregulated HIF-1α and BACE1 mRNA in brains of offspring (p < .001). Crocin treatment improved memory impairment and attenuated the gene expression of HIF-1α and BACE1 in the brains of neonate rat. CONCLUSIONS: It was concluded that crocin has beneficial effects on the brain of neonate rats under gestational hypoxia by improvement of memory impairment and molecular alteration related to hypoxia.

Modulation of behavioral responses and CA1 neuronal death by nitric oxide in the neonatal rat's hypoxia model.

INTRODUCTION: Neonatal hypoxia leads to cognitive and movement impairments that might persist throughout life. Hypoxia impairs hippocampal blood circulation and metabolism. The exact mechanisms underlying hypoxia-induced memory impairment are not fully understood. Nitric oxide (NO) is a key neuromodulator that regulates cerebral blood flow. In this study, we aimed to evaluate the possible role of NO on behavioral and histomorphometric changes in the hippocampus following hypoxia in neonate rats. MATERIAL AND METHODS: Neonate male rats (n = 28) were randomly divided into 4 groups: control, hypoxia, hypoxia plus L-NAME (20 mg/kg), and hypoxia plus L-arginine (200 mg/kg). Drugs were injected intraperitoneally for seven consecutive days. Hypoxia was induced by keeping rats in a hypoxic chamber (7% oxygen and 93% nitrogen intensity). Ten to 14 days after hypoxia, behavioral changes were measured using a shuttle box, a rotarod, and an open field test. The histological changes in the hippocampus were measured using H&E and Nissl staining methods. RESULTS: Findings showed that hypoxia caused significant atrophy in the hippocampus. Furthermore, the administration of L-NAME decreased the atrophy of the hippocampus in comparison with the hypoxic group. Behavioral results showed that hypoxia impaired memory performance and motor activity responses. Additionally, the administration of L-NAME improved behavioral performance in a significant manner compared with the hypoxic group. CONCLUSIONS: Hypoxia damaged the neurons of hippocampal CA1 region and induced memory impairment. The NOS inhibitor, L-NAME, significantly attenuated the negative effects of hypoxia on behavior and observed changes in the hippocampus.

The Therapeutic Effects of Low-Frequency Electrical Stimulations Adjunct to Sodium Valproate on Seizure and Behaviors.

INTRODUCTION: Consuming antidepressant medications induce several problems leading to the need for alternative agents for emotional disturbances. Antidepressant medications increase the seizure risk; thus, alternative treatments, like Antiepileptic Drugs (AED), might be useful for patients with epilepsy comorbid with a psychiatric disorder. The present study evaluated the behavioral effects of sodium valproate, a none effective dose in seizure treatment [100 mg/kg; Intraperitoneal (IP)] along with the application of Low-Frequency Stimulations (LFS) during CA1 hippocampal kindling. METHODS: In total, 42 male rats were randomly divided into 6 groups, including control group with intact animals handled daily (I); sham group which was subjected to the surgical process, but received no real stimulation (II); saline-kindled Kindled group (S.kindled) which were stimulated daily with the following protocol: 3 strain of 50Hz monophasic pulses of 1ms duration applied 12 times a day with the threshold intensity at intervals of 10 minutes where saline was administrated 15 min before kindling stimulations (III); saline-kindled-LFS group (K4LFS) in which saline was injected 15 min before kindling stimulations and LFS was applied daily after the termination of kindling stimulation (IV); drug-kindle group (Drug100.kindled) that underwent rapid kindling procedure daily where sodium valproate (100 mg/kg) was administrated 15 min before kindling stimulations(V), and drug-kindled-LFS (Drug100.kindled.4LFS) group in which drug and LFS were administrated respectively before and after kindling stimulations (VI). The behavioral tests were assessed using elevated plus maze, open field, and forced swim tests. RESULTS: The combination of sodium valproate (100 mg/kg) and LFS significantly decreased cumulative seizure severity compared with the kindle group. Thus, it provided a strong seizure suppressing effect. Additionally, sodium valproate and LFS increased the percentage of Open Arms (OAs) entries and the OAs exploration; they also decreased jumping from elevated plus maze test and rearing in open field test. Furthermore, there was no significant change in the OAs entries and OAs exploration percentages, jumping from apparatus, and rearing in open field in Drug100. Kindled, K4LFS, and Drug100.kindled.LFS groups, compared with the sham group. There was no significant difference in the latency to first immobility and the duration of immobility in K4LFS groups compared with the S. kindled group. In the drug-kindled group, the latency to first immobility significantly increased, and the duration of immobility decreased, compared with the S. kindled group. Besides, the latency to first immobility significantly increased, and the duration of immobility decreased in drug-kindled-LFS, compared to S. kindled group; however, the latency to first immobility was not significantly changed, compared to drug-kindled groups. CONCLUSION: Sodium valproate and LFS can modulate the function of the brain regions involved in emotional processing in epilepsy, as well as anxiety- and depressive-like behaviors. Such a combination could also decrease emotional disturbances induced by the kindling process.

Interaction of Sodium Valproate With Low-Frequency Electrical Stimulation During Kindlingn.

INTRODUCTION: The interaction between antiepileptic drugs and brain electrical stimulation is a potential therapy to control seizures in patients with pharmacoresistance to drugs. So, the present study aimed to design to determine the effect of a subeffective dose of sodium valproate combined with low-frequency electrical stimulation during kindling. METHODS: One tripolar electrode was implanted stereotactically in the CA1 hippocampus of male Wistar rats. One week after surgery, the rats were kindled by electrical stimulation of hippocampus in a rapid manner (12 stimulations/day) for 6 days with sodium valproate alone or combined with low-frequency electrical stimulation (four packages contained 200 monophasic square wave pulses of 0.1-ms duration at 1 Hz, immediately after kindling stimulations). The duration of afterdischarge, maximum latency to stages 4 and 5, and the maximum duration of these stages were recorded by electromadule during kindling. RESULTS: Application of sodium valproate with low-frequency electrical stimulation caused a reduction in cumulative afterdischarge duration. The maximum latency to the onset of stage 5 seizure increased after sodium valproate application alone, without having a significant effect on the fourth stage. Our findings showed reductions in the seizures duration and increasing in the latency times of both stages after the application of sodium valproate with low-frequency electrical stimulation. CONCLUSION: It seems that usage of sodium valproate with low-frequency electrical stimulation during kindling was more effective to suppress the epileptic activity than its administration alone and may have a critical role on the antiepileptic effects of sodium valproate.

Crocin Treatment after Maternal Hypoxia Attenuates Spatial Memory Impairment and Expression of BACE1 and HIF-1α in Rat Offspring Brain.

INTRODUCTION: Hypoxia via expression of Hypoxia-Inducible Factor-1 (HIF-1) is an important and effective factor in the onset and progression of memory disorders, such as Alzheimer Disease (AD). The activity of ß-secretase (BACE1) is increased in hypoxia conditions. BACE1 triggers a cascade of pathological events resulting in AD. Crocin acts as a memoryimproving agent but its molecular mechanism is not well-known. Therefore, in this study, the effect of crocin on spatial memory, HIF-1α, and BACE1 gene expression was investigated in rat offspring under maternal hypoxia. METHODS: Female pregnant rats on the 20th day of pregnancy were divided into 4 groups, including sham, crocin-treated, hypoxia, and hypoxia group treated with crocin. In the hypoxia groups, pregnant rats were exposed to 7% oxygen and 93% nitrogen intensity for 3 h. In the crocin-treated group, crocin (30 mg/kg) was injected at P14-28 (i.p). At the end, Morris water maze was used to assess spatial memory and real-time polymerase chain reaction was performed to measure the expression of BACE1 and HIF-1α genes in the brain of offspring. RESULTS: Maternal hypoxia impaired memory compared with the sham group. However, crocin treatment improved cognitive behavior. HIF-1α and BACE1 expressions were upregulated in the brain of offspring in the hypoxia group. Crocin treatment could attenuate the expression of both genes. CONCLUSION: According to our results, down-regulation of HIF-1α and BACE1 gene expressions in the brain of rat offspring after crocin treatment can be suggested as a molecular mechanism for crocin to improve spatial memory.

Study the effect of crocin in three maternal hypoxia protocols with different oxygen intensities on motor activity and balance in rat offspring.

Hypoxia as one of the most common clinical disturbances in pregnancy period can cause destructive changes in motor sensory cortex and can lead to imperfect organization in motor reactions. Crocin, a water-soluble carotenoid, is the most active ingredients of saffron and a lot of studies declare its positive effectiveness on improving motor activity. Since the hypoxia intensity affects its malicious amount on movement, in this paper, we have studied the effect of crocin in three maternal hypoxia protocols with different oxygen intensities on motor activity and balance in rat offspring. In this experiment, female rats (Wistar) were used on the 20th day of pregnancy. The rats were randomly divided into eight experimental groups: sham, crocin, hypoxia with three different intensities: 10% oxygen and 90% nitrogen for 1 h (hypoxia-ɪ), 7% oxygen and 93% nitrogen for 1 h (hypoxia-ɪɪ), 7% oxygen and 93% nitrogen for 3 h (hypoxia-ɪɪɪ) and treated-crocin hypoxia groups. To produce hypoxia, pregnant rats were placed in a hypoxia box. In crocin group, rat offspring received 30 mg/kg crocin via IP injection at P14-28. Control group also received saline injection at the same time. Finally, balance and motor activity in offspring were measured respectively by rotarod and open-field devices. Results showed that motor activity significantly decreased in hypoxia-ɪɪɪ group as compared with sham group (p < 0.01). Balance in hypoxia-ɪɪɪ group significantly decreased as compared with sham group (p < 0.05). As a result, crocin treatment improved all these changes. The results of this study implied that both hypoxia duration and intensity have profound effects on motor activities impairments.

Ca2+ Channels Involvement in Low-Frequency Stimulation-Mediated Suppression of Intrinsic Excitability of Hippocampal CA1 Pyramidal Cells in a Rat Amygdala Kindling Model.

Low-frequency stimulation has demonstrated promising seizure suppression in animal models of epilepsy, while the mechanism of the effect is still debated. Changes in intrinsic properties have been recognized as a prominent pathophysiologically relevant feature of numerous neurological disorders including epilepsy. Here, it was evaluated whether LFS can preserve the intrinsic neuronal electrophysiological properties in a rat model of epilepsy, focusing on the possible involvement of voltage-gated Ca2+ channels. The amygdala kindling model was induced by 3 s monophasic square wave pulses (50 Hz, 1 ms duration, 12times/day at 5 min intervals). Both LFS alone and kindled plus LFS (KLFS) groups received four packages of LFS (each consisting of 200 monophasic square pulses, 0.1 ms pulse duration at 1 Hz with the after discharge threshold intensity), which in KLFS rats was applied immediately after kindling induction. Whole-cell patch-clamp recordings were made in the presence of fast synaptic blockers 24 h after the last kindling stimulations or following kindling stimulations plus LFS application. In the KLFS group, both the rebound excitation and kindling-induced intrinsic hyperexcitability were decreased, associated with a regular intrinsic firing as indicated by a lower coefficient of variation. The amplitude of afterdepolarization (ADP) and its area under the curve were both decreased in the KLFS group compared to the kindled group. LFS prevented the increasing effect of kindling on Ca2+ currents in the KLFS group. Findings provided evidence for a novel form of epileptiform activity suppression by LFS in the presence of synaptic blockade possibly by decreasing Ca2+ currents.

Quantitative Analysis of the Antiepileptogenic Effects of Low Frequency Stimulation Applied Prior or After Kindling Stimulation in Rats.

Background and Objective: Developing quantitative measures based on spectral analysis of electroencephalograph (EEG) recordings of neural activities plays an important role in developing efficient treatments for epilepsy. Such biomarkers can be used for developing open or closed loop approaches for seizure prediction or prevention. This study aims to quantitatively evaluate antiepileptogenic effects of low frequency stimulation (LFS) applied immediately before or after kindling stimulations using spectral power analysis of extracellular EEG in rat. Methods: Nineteen adult rats were used: seven for kindle, six for LFS+Kindle (LFSK) and six for Kindle+LFS (KLFS). Four packages of LFS (1Hz) were applied immediately before or after rapid kindling stimulations. The power spectral densities of afterdischarge (AD) sections of EEG corresponding to different stages of kindling for delta (0-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-28 Hz), gamma (28-40 Hz) sub-bands, and theta/alpha ratio were comparatively investigated. Moreover, correlation between AD duration (ADD) and its different frequency components was calculated. Results: Both LFSK and KLFS significantly increased delta and reduced beta and gamma oscillations, compared with kindle group. However, just the reduction in LFSK group was significant. Both protocols increased theta/alpha ratio, but just LFSK showed significant increase (p < 0.05). Although LFSK enhanced theta/alpha ratio more than KLFS, the difference was not statistically significant. Furthermore, strong correlation between each frequency sub band and ADD was not observed in kindle and LFS treated groups (both LFSK and KLFS). Conclusion: Although behavioral assessments showed relatively the same level of antiepileptogenic effects for KLFS and LFSK, quantitative assessments showed more significant differences in the quantitative measures between the two protocols. Developing more quantitative EEG based measures correlated with LFS-induced effects can facilitate developing open or closed loop seizure prevention modalities.

Improving cognitive task in kindled rats by using low frequency stimulation during epileptogenesis.

Numerous studies indicate that one of the bad effects of epilepsy is cognitive impairment. In this study we focused on the effect of LFS as a potential anticonvulsant agent, during epileptogenesis on cognitive impairments induced by amygdala kindling in rat. Twenty-one adult rats were divided into 3 groups including control (n = 7), kindled (n = 7), and Kindled+LFS (KLFS) (n = 7). Animals in the kindled group received kindling stimulation in a rapid kindling manner (a 3 s train of 50 Hz monophasic pulses of 1 ms duration, 12 times a day) in amygdala whereas control animals had no stimulation. Four packages of LFS (each package consisting of 200 monophasic square pulses, 0.1 ms pulse duration at 1 Hz) were applied daily after termination of kindling stimulation in KLFS group. Spatial memory of all animals was tested using radial arm maze after termination of stimulation on acquisition trial days and 14 days after the final acquisition trial test. Epileptogenesis process significantly increased working and reference memory error compared to control groups whereas application of LFS immediately after kindling stimulation prevented this impairment in 8 arm radial maze and there was no significant difference between KLS and control groups. Our results indicated that application of LFS during kindling acquisition suppresses memory impairment in epileptogenesis by kindling stimulation.

Quantitative assessments of extracellular EEG to classify specific features of main phases of seizure acquisition based on kindling model in Rat.

OBJECTIVE: Quantitative assessments of extracellular EEG to identify specific features of three main phases of seizure acquisition based on kindling model in Rat. METHODS: Male rats were divided into 2 groups including kindled (n=10) and sham (n=7) and respectively underwent an amygdala rapid kindling and placebo kindling. EEG signals in stages 1-2 (initial seizure stages (ISSs)), 3 (localized seizure stage (LSS)), and 4-5 generalized seizure stages (GSSs) were divided into 5 bands: delta (0-4Hz), theta (4-8Hz), alpha (8-12Hz), beta (12-28Hz), and gamma (28-40Hz). Spectral power of the sub bands and the ratios of theta/alpha and delta/beta were compared in the three phases and between the sham and kindling groups. RESULTS: Beta power significantly increased during kindling acquisition, though it was significantly lower than sham. Delta oscillation in ISSs was higher than LSS and GSSs, but the difference was significant only with LSS. Moreover, delta power was higher in all stages of kindling than sham. Gamma power in all stages of kindling was significantly lower than sham. Alpha power was significantly reduced in ISSs, compared with sham, but gradually increased during epileptogenesis. Theta/alpha and delta/beta increased in all stages, compared with sham (p<0.05). Theta/alpha significantly decreased in LSS and GSSs, compared with ISSs (p<0.05). Delta/beta decreased during kindling, but it was significantly different only between ISSs and LSS (P<0.05). CONCLUSION: Beta and alpha oscillations at ISSs significantly decreased, but gradually increased along with kindling progression. Furthermore, delta power significantly increased during kindling process.

Low Frequency Electrical Stimulation Either Prior to Or after Rapid Kindling Stimulation Inhibits the Kindling-Induced Epileptogenesis.

Objective. Studies are ongoing to find appropriate low frequency stimulation (LFS) protocol for treatment of epilepsy. The present study aimed at assessing the antiepileptogenesis effects of LFS with the same protocol applied either just before or immediately after kindling stimulations. Method. This experimental animal study was conducted on adult Wistar rats (200 ± 20 g) randomly divided into kindle (n = 7), LFS + Kindle (n = 6), and Kindle + LFS groups (n = 6). All animals underwent rapid kindling procedure and four packages of LFS (1 Hz) with 5 min interval were applied either immediately before (LFS-K) or after kindling stimulation (K-LFS). The after discharge duration (ADD), daily stages of kindling, and kindling seizure stage and number of stimulations required to reach each stage were compared between the three groups using two-way analysis of variance (ANOVA) followed by Tukey post hoc and one-way ANOVA, and Kruskal-Wallis test, respectively. Results. LFS in both protocols significantly decreased the ADD (p < 0.05) and daily seizure stages (p < 0.05) and increased the number of stimulations required to achieve stage 3 and stages 4 and 5 of kindling compared with the kindle group (stage 2: p > 0.05, stages 3 to 5: p < 0.05). Conclusion. Although LFS-K showed more inhibiting effect than K-LFS, the difference was not statistically significant.