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 Introduction: It has been shown that the extract of Elaeagnus angustifolia can inhibit inflammation and pain induced by formalin in mice and rats. The aim of the present study is to reach evaluations of possible cellular and molecular mechanisms of Elaeagnus angustifolia extract in reducing pain and inflammation through examining the extract ability for inhibition of cyclooxygenase (Cox) type 1 and 2 enzymes and corticosterone release from adrenal glands in mice.

Methods:

Male Swiss Webster mice were evaluated through the injection of 2 μliters to the plantar part of right foot. Elaeagnus angustifolia extract was injected to the animals 30 minutes before formalin. In order to evaluate the mechanism of extract, naloxone and memantine were administered intrapretonealy 30 minutes before the extract administration. In separate groups, after injection of extract, blood samples were taken from animals and corticosterone concentrations were measured. In an in vitro study the effect of extract on the activity of cyclooxygenase type 1 and 2 was assessed.

Results:

the research data showed the ineffectiveness of the extract on acute phase of pain induced by formalin but it completely inhibits the chronic phase. Naloxone and Memantine administration had no effect on the efficacy of extract in the chronic phase. Also the extract administration did not increase the plasma concentration of corticosterone in mice, but in vitro inhibited Cox1 and Cox 2 enzymes.

Discussion:

These results indicate that Elaeagnus angustifolia extract probably reducesww pain and inflammation caused by formalin in mice by inhibiting cyclooxygenase type 1 and 2 enzymes.

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Introduction: The concentration of noradrenalin and corticosterone as the two nociception modulators change after fasting or stress situation. The aim of present study was to investigate the effect of food deprivation on formalin-induced nociceptive behaviours and plasma levels of noradrenalin and corticosterone in rats.

Methods:

Food was withdrawn 12, 24 and 48 h prior to performing the formalin test, but water continued to be available ad libitum. The formalin solution (50 μL, 2%) was injected into plantar surface of hind paw. The nociception responses of the animals during the first phase (1-7 minutes), the inter-phase (8-14), the phase 2A (15-60) and the phase 2B (61-90) was separately evaluated. The plasma concentrations of noradrenalin and corticosterone were measured using specific ELISA and IRA kits, according to manufacturer's instructions.

Results:

In contrast to the increasing of 48 h food deprived animals during phase 2, the nociceptive behaviours of 12 and 24 h groups decreased through the interphase, phase 2A and phase 2B. The injection of formalin in the normal male rats significantly decreased the plasma level of noradrenalin and corticosterone. Food deprivation for 12 and 24 h increased noradrenalin level significantly in comparison with control group which has caused by fasting induced antinociceptive behaviours. There was no significant change in food deprivation for 48 h group. Food deprivation for 12, 24 and 48 h had no effect on corticosterone level in male rats.

Discussion:

The present study emphasizes that the acute food deprivation diminished the nociceptive behaviours in the formalin test and show a correlation with increase in plasma noradrenalin level.

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Introduction: Brain-Derived Neurotrophic Factor (BDNF) and its receptor, TrkB, in the hippocampus are targets for adverse effects of stress paradigms in addition, BDNF and its receptor play key role in the pathology of brain diseases like depression. In the present study, we evaluated the possible role of hippocampal BDNF in depression during pregnancy, Methods: To achieve the purpose, repeated restrain stress (1 or 3 hours daily for 7 days) during the last week of pregnancy was used and alteration in the gene expression of hippocampal BDNF and TrkB evaluated by semi-quantitative PCR. Results: The results showed that in stress group the level of ACTH and Corticosterone is increased showing that our model was efficient in inducing psychological stress we also found that BDNF and TrkB expression are decreased in 3 hours stress group but not in 1 hour stress compared to control group. Discussion: Our results imply that decrease in BDNF and its receptor could contribute in some adverse effects of stress during pregnancy such as elevation of depressive like behavior.

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Introduction: Celastrus paniculatus seed oil, commonly known as Malkangni or Jyotishmati, was in use from time immemorial to treat brain related disorders. Celastrus paniculatus seed oil has significant antidepressant-like activity in chronic unpredictable stressed mice. The present study was undertaken to evaluate the antidepressant-like effect of Celastrus paniculatus seed oil in unstressed mice and to explore its mechanism of action.
Methods: The seed oil (50, 100, and 200 mg/kg, PO) and fluoxetine per se were administered for 14 successive days to Swiss young albino mice. On the 14th day, 60 min after drug administration, animals were subjected to Tail Suspension Test (TST) and Forced Swim Test (FST). The mechanism of action was also studied.
Results: The oil significantly decreased immobility period of mice in both tail suspension test and forced swim test, indicating its significant antidepressant-like activity. The efficacy was found to be comparable to fluoxetine (P<0.0001). ED50 value of celastrus seed oil using FST and TST were 17.38 and 31.62 mg/kg, respectively. The oil did not show any significant effect on locomotor activity. It significantly inhibited brain MAO‒A activity and decreased plasma corticosterone levels. Sulpiride
(selective D2-receptor antagonist), p-CPA (tryptophan hydroxylase inhibitor), and baclofen (GABAB agonist) significantly attenuated the oil-induced antidepressant-like effect, when assessed during TST. 

Discussion: Celastrus paniculatus seed oil produced significant antidepressant-like effect in mice possibly through interaction with dopamine D2, serotonergic, and GABAB receptors as well as inhibition of MAO‒A activity and decrease in plasma corticosterone levels.

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Introduction: Depression is one of the most frequent psychiatric disorders in the world with occurs with higher incidence in women. In the present study, the effect of water-alcoholic extract of Papaver rhoeas L. on forced swimming test (FST) in Swiss-Webster mice were examined.
Methods: We used Swiss-Webster mice (20-25 g) to execute FST on them. The plant extract (1, 10, 30, and 100 mg/kg) was injected to the animals 30 minutes before each session. Fluoxetine (20 mg/kg) was used as standard antidepressant drug. In another group of animals, 30 minutes after extract administration, blood samples were taken from retro-orbital sinus for corticosterone assay. Yet in third group, the drugs were injected to the animals and 30 minutes later, their activities were tested in an open field apparatus.
Results: Our experiments showed that the extract efficiently reduced FST time both in male and female mice dose-dependently. This effect was comparable with fluoxetine. In addition, corticosterone assay indicated that plasma corticosterone in animals which received extract was higher than those amounts in fluoxetine and saline controls. Moreover, the animals did not show any motor activity deficit in all doses of the extract and fluoxetine compared to saline control.
Conclusion: The extract of Papaver rhoeas can reduce immobility time which is comparable to the effect of fluoxetine. Also the effect of the extract is contrary to its effects on plasma corticosterone level and or animals’ activity.

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Introduction: The role of different parts of the extended amygdala in metabolic signs of stress is not well understood. In the present study, we decided to evaluate the impact of the shell part of nucleus accumbens (NAc) on metabolic disturbance induced by electro foot shock stress using transient inactivation method in the rat. 
Methods: Male Wistar rats (W: 230-250 g) were canuulated unilaterally in the shell part of nucleus accumbens and left one week for recovery. Five minutes before each stress session, the animals either received sterile saline (0.25 µl/side) (control) or lidocaine 2% (0.25 µl/side) (experiment). Blood samples were taken from rats’ retro-orbital sinus for plasma corticosterone measurements. In addition, animals’ weight gain, food and water intake, locomotor activity, and rearing were recorded. 
Results: Stress reduced weight gain and food intake, increased water intake and plasma corticosterone level, and reduces locomotor activity and rearing. Transient inactivation of the right side of the NAc inhibits the stress effect on weight gain, water intake and plasma corticosterone level, but not food intake. However, when the left side of the NAc was inactivated, only weight gain was affected and other parameters were not differing from stress group. Even thought, the plasma corticosterone level was elevated. 
Conclusion: In conclusion, our data indicated that right side of shell part of NAc transient inactivation leads to reduction in metabolic signs of stress but left side of shell part of the NAc inactivation even exacerbates stress signs.

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Introduction: of the study: Post-training administration of glucocorticoids enhance memory consolidation of inhibitory avoidance learning. Given the involvement of 5-HT6 receptors in memory processing and the interaction of glucocorticoids with the brain serotonergic system in modulating memory processing, we investigated whether the effect of glucocorticoids on the consolidation of emotionally arousing training depends on hippocampal 5-HT6 receptors. 
Methods: Rats were trained in an inhibitory avoidance task and immediately received the systemic injections of corticosterone (CORT) as well as the intra-hippocampal injections of 5-HT receptors agonist or antagonist. The memory retention test was done 48 hours after training and immediately after the behavioral test, the animals were sacrificed and the hippocampi (left and right) rapidly dissected out for molecular studies.
Results: Post-training injections of different doses of CORT (1.25, 2.5, 5, and 10 mg/kg) enhanced memory retention in a dose-dependent manner. The CORT-induced enhancement of memory consolidation was blocked by bilateral intra-hippocampal injections of 5-HT6 receptor antagonist SB271046 (5 or 10 ng/per side), but not agonist EMD386088 (5 or 10 ng/per side). Furthermore, systemic CORT reduced 5-HT6 receptor mRNA and protein expression in the hippocampus. Both doses of 5-HT6 receptor agonist and antagonist significantly enhanced and reduced the expression of the 5-HT6 receptor, respectively, and both ligands at the higher dose (10 ng) enhanced memory consolidation. Moreover, CORT injection attenuated and enhanced, respectively, the effects of agonist and antagonist on 5-HT6 receptor expression. 
Conclusion: These behavioral and molecular findings indicated an interaction between glucocorticoids and hippocampal 5-HT6 receptors in the consolidation of emotionally arousing experiences. 

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Introduction: Previous studies demonstrated that forced and voluntary exercise had ameliorative effects on behavioral tasks followed by Sleep Deprivation (SD) in intact female rats. The main goal of this research was evaluating the impact of voluntary exercise on cognitive functions while SD and ovariectomization is induced in female wistar rats.
Methods: The rats were anesthesized combining dosage of ketamine and xylazine. Then, both ovaries were eliminated and 3 weeks after surgery the animals entered the study. The exercise protocol took 4 weeks of voluntary exercise in a wheel which was connected to home cage. For inducing a 72 hours deprivation the multiple platforms was applied. The cognitive functions were studied by exploiting the Morris Water Maze (MWM) and Novel object recognition tests. Anxiety was evaluated by open field test and corticostrone measurement was carried out by ELISA method. One-way and two-way ANOVA and repeated measures were utilized for data analysis and P<0.05 was considered statistically significant.
Results: We observed significant spatial and recognition learning and memory impairments in OVX sleep-deprived rats compared to the control group and voluntary exercise alleviated the SD-induced learning and memory defects.
Conclusion: We concluded that voluntary exercise can improve cognitive impairments followed by SD in OVX female rats.

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Introduction: The lack of social communication is associated with the primary risk of proper brain functions. It is reported that crocin helps relieve this problem. The present study examined the protective effect of two doses of crocin on Long-term potentiation (LTP) of hippocampal cornu ammonis 1 (CA1) area as a cellular mechanism in rats exposed to chronic social isolated stress.
Methods: Rats were assigned to the control, sham, isolation stress, and two stress groups (receiving 30 and 60 mg/kg crocin). Chronic isolation stress (CIS) was induced 6 h/d, and crocin was administrated for 21 days. The field excitatory postsynaptic potential (fEPSP) slope and amplitude were measured by input/output functions and LTP induction in the CA1 area of the hippocampus. Also, the corticosterone and glucose levels were assayed in the hippocampus and frontal cortex.
Results: The slope and amplitude of fEPSP severity were impaired in both input/output and LTP responses in the CIS group. Crocin at a dose of 30 and particularly 60 mg/kg improved input/output and LTP responses in the CIS group. Also, the corticosterone levels significantly increased in the frontal cortex and especially the hippocampus. In contrast, only a high dose of crocin decreased hippocampal corticosterone levels in the CIS condition. Finally, the glucose levels did not change in the hippocampus and frontal cortex in all experimental groups. 
Conclusion: The chronic isolation stress impaired neural excitability and Long-term plasticity in the CA1 area due to elevated corticosterone in the hippocampus and probably the frontal cortex. The low and high doses of crocin improved excitability and Long-term plasticity in the chronic isolation stress group by only decreasing corticosterone levels in the hippocampus, but not the frontal cortex. 

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Introduction: Psychological stress impairs cognitive performance and affects mood states. This study compares the effect of four types of psychological stress (crowding, relocation, isolation, and restraint) on locomotor activity, learning, and memory, as well as anxiety-like behaviors performed by the open field, elevated plus maze, and passive avoidance tests.
Methods: Wistar rats were randomly assigned to different groups of crowding, relocation, isolation, and restraint stress, and control. The stress induction was administered for 21 consecutive days (6 h/day). To evaluate various types of behaviors, the open field, elevated plus maze, and passive avoidance tests were employed.
Results: According to the PA test results, the latency to enter the darkroom decreased significantly in all stress groups, especially in the crowding and isolation stress groups. However, it had an inverse relationship with serum corticosterone (CORT) levels. The total dark stay time increased significantly in the restraint and crowding stress groups, and also particularly, in the isolation stress group. In the isolation stress group, the number of darkroom entries decreased significantly. All stress groups spent a significantly shorter time in the open arms of the EPM apparatus. Finally, the total distance traveled, in the open field test was significantly lower in all stress groups, particularly in the isolation stress group.
Conclusion: Crowding and social isolation were the two stress types that had the most adverse effect on cognitive performance, as they induced stress-driven anxiety-like behaviors, probably due to increased CORT secretion. A high or low population of social density may create a condition, in which the nervous system could not efficiently manage stress, particularly at chronic levels.