جستجوی مقالات مرتبط با کلیدواژه « موش کوچک آزمایشگاهی » در نشریات گروه « پزشکی »

There are numerous reports that different models of stress can cause memory loss. On the other hand, investigations determined that Cyperus rotundus rhizome can effectively improve memory and enhance recall. In the present study we assessed the possible improving effects of hydroalcoholic extract of Cyperus rotundus rhizomes on stress-induced memory retrieval impairment.

Adult male mice were divided to two  main groups, stress and non-stress, and each of these groups was divided into two subgroups: saline-receiving control and treated with Cyperus rutundus extract. First, the mice received the material by daily gavage for 7 or 21 days. One day after the last gavage, the animals were trained by step-through method. 24 hours after the training, they were exposed to elevated platform stress before the test. Step-through latency (STL) to enter dark chamber and spent time in dark chamber (STD) were recorded as measures of passive avoidance memory retrieval.

Pre-test stress significantly reduced STL and increased STD. Pre-training gavage of Cyperus rotundus extract reversed the STL and also significantly reduced the STD.

It seems that treatment with hydroalcoholic extract of Cyperus rotundus rhizomes improves ability to retrieve information from long-term memory and  ameliorates stress-induced memory impairment in a time-dependent manner.
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Today, with lifestyle changes, the tendency to use packaged food, street food, and fast food has increased, and most of them contain Acrylamide. One of the most important side effects of Acrylamide is toxicity in the reproductive system. In this study, the long-term effects of Acrylamide on in Vitro Fertilization (IVF) and sperm parameters were investigated.

Sixteen male mice (age: 6-8 weeks) were divided into two groups. The control group received normal saline (0.2ml/day) and the treatment group received Acrylamide (50mg/kg, 0.2ml/day) orally for 45 days. At the end of the term, sperms were extracted from the tail of the epididymis and fertilization process was performed in HTF + 4mgBSA medium and embryonic growth stages were studied during 120 hours of incubation. Also, sperm count, motility, viability, sperm chromatin quality, and DNA integrity were evaluated. Two proportion methods by Minitab software and T - Test by SPSS software were used for statistical analysis (p<0.05).

There was a significant decrease in the percentage of fertilization, 2 cell-embryos and blastocysts resulting from IVF and a significant increase was observed in the number of arrested embryos in treatment group by Acrylamide compared to the control group (p<0.05). Also in treatment group by Acrylamide, sperm count, motility, and viability of sperms, the number of sperms with DNA damage, abnormal morphology, and with immature nucleus showed a significant increase compared to the control group (p<0.05).

The study showed long-term oral administration of Acrylamide has negative effects on fertility potential and sperm parameters.

Propolis is a natural bee product, which has been used in folk medicine for the management of different diseases. Regarding to anti-inflammatory effects of Propolis, in this study we evaluated the analgesic effects of hydroalchoholic extract of Iranian Propolis on acute and chronic pain.

192 young adult male albino mice (25-30 g) in 24 groups (n = 8) were used. Propolis (100, 200, and 500 mg/kg), vehicle and morphine as Positive control drug (5mg/Kg) were injected intera- peritoneally 30 min before the pain evaluation tests. Acute and chronic pain was assessed by by using hot plate (HP), tail flick (TF), formalin (FT) and writhing (WR) tests.

Comapred to the control group, Propolis extract in all doeses increased pain tolerance in both the HP and TF (P<0.01). In the FT, Propolis extract decreased the reaction time in neurogenic and inflammatory phases than the control group (P<0.01). Pretreatment with the Propolis extract reduced the number and time of of abdominal writhes in the WR than the control group (P<0.01).

The above findings showed that Iranian Propolis have anti-analgesic effects in both acute and chronic models of pain.

Due to the properties of herbal remedies and their lesser side effects than chemical drugs, much attention has now beeing paid to herbal treatments. The aim of this study was done to evaluate the antinociceptive and anti-inflammatory effects of hydroalcoholic extract of aerial parts of Ruscus aculeatus.

This experimental study was performed on 80 male NMRI mice (6-8 weeks) weighing 23-25 gr. Animals were randomly allocated into 5 groups including: control group (distilled water), positive control group (morphine 10 mg/kg/bw in pain test and dexamethasone 15 mg/kg/bw in inflammatory test) and three groups receiving 75, 150 and 300 mg/kg/bw Hydroalcoholic extract of Ruscus aculeatus L. The pain was evaluated by formalin test and an investigation of inflammation conducted by xylene induced ear-edema.

The hydroalcoholic extract of Ruscus aculeatus L significantly reduced acute pain at 300 mg/kg/bw in compared to control group (P<0.05). Inhibition percent was 60% for acute pain and 85% in morphine group. Also, this plant caused significant reduction of formalin induced chronic pain at 150 and 300 mg/kg/bw doses in compared to the control group (P<0.05). At 150 and 300 mg/kg doses of Ruscus aculeatus L, inhibition of chronic pain was 71%, and 94%, respectively in compared with 97% inhibition in morphine group.

Hydroalcoholic extract of Ruscus aculeatus L at the dose of 300 mg/kg/bw reduces acute and chronic pain and at the dose of 150 mg/kg/bw reduces acute pain in laboratory animals.

Formononetin is a phytostrogen found in plants such as red clover (Trifolium pratense), which has a chemical structure similar to the estradiol hormone. The aim of this study was to investigate the effects of formononetin derived from red clover on sexual dimorphic indices in mice during neonatal life. In this experimental study, male and female neonate mice were randomly divided into the control, vehicle and 3 groups (n=8) received formonetonin subcutaneously at doses of 5, 50 and 500 mg/kg body weight on days 1-5 after birth. After examining the puberty timing, parameters of estrus cycle, anogenital distance, sexual behavior, preferred saccharin and sex hormones were also investigated. The data were analyzed by SPSS statistical software and OneWay ANOVA test. Significance was shown at p values<0.05. Puberty in females was significantly advanced by 500 mg/kg (p<0.01) and in male mice was delayed by 50 (p<0.05) and 500 mg/kg formonotonin (p<0.01). Mean duration of estrus cycle increased in 500 mg/kg formonotonin (p<0.05). Lordosis and mount numbers in 500 (p<0.001) decreased and the mean latency to the first mounts increased by 500 formonotonin (p<0.001). Percentage of saccharin preference increased by 50 (p<0.05) and 500 mg/kg formonotonin (p<0.01) in female mice. In addition, estradiol level in 50 (p<0.01) and 500 mg/kg (p<0.001) doces decreased and testosterone level in 500 formonotonin mg/kg (p<0.01) decreased, compared with controls. The results of this study show that the administration of formonotonin during the neonatal period of mice has the potential to cause development of sexual dimorphism parameters.

Many anti stress drugs have a lot of side effects on learning. The aim of this study was to compare the effect of Rosemary plant and Alprazolam on learning under stress conditions in laboratory mice. In this experimental study, 60 adult female rats were used. In order to investigate the learning capacity under stress conditions, the rats were divided into 6 groups of control, stress, alprazolam and the three experimental groups that received the hydro-alcoholic extract of rosemary plants at doses of 50, 100 and 200. In all of the samples (except the control group) 30 minutes after injection, the mice were placed in a dark box for 50 minutes for stress. Subsequently, observational behaviors of the rats were recorded by using mouse maze. The results were analyzed using SPSS software. The results showed that rosemary hydro alcoholic extract at 100 and 200 mg/kg compared to the stress and alprazolam group significantly decreased the time to reach the target box in the Maze form, which indicates a reduction on effect of stress on the learning, while the number of errors in selecting the target box (reaching the target) at a dose of 200 mg/kg shows a significant decrease with the stress and drug group. According to the results, effective compounds in rosemary extract in two doses of 100 and 200 mg/kg can increase the learning in these conditions with the effect of reducing stress.

It has been shown that the opioidergic system exerts widespread effects on cognitive functions. Interactions between opioid and serotonin receptors have been reported in some brain structures such as the dorsal hippocampus, thus a functional interaction between opioids and serotonin seems possible concerning memory control. The purpose of this study was to assess the effects of CA1 5-HT3 receptor agonist on memory acquisition deficit induced by morphine. In this study, we used 96NMRI mice. These mice were divided into twelve equal groups that received different doses of 5-HT3recepto ragonist, different doses of morphine and a combination of morphine and serotonin 5-HT3 receptor agonist. Morphine was injected into the peritoneum, while 5-HT3 receptor agonist M-Chlorophenylbiguanide (M-chl) was administered via intra-hippocampal injection. A step-down passive avoidance test was used for the evaluation of memory. Pre-training intra-peritoneal administration of morphine (5 mg/kg) induced amnesia. Moreover, pre-training intra-CA1 administration of 5-HT3 receptor agonist (M-Chl) (0.5 ng/mouse) impaired memory acquisition. Furthermore, intra-CA1 injection of M-Chl (0.005ng/mouse) reversed impairment of memory acquisition induced by morphine (5 mg/kg). The results demonstrated the existence of a synergistic effect between hippocampal 5-HT3 receptor agonists and opioidergic receptors.

Matricaria recutit (MAT) has a series of flavonoid compounds with benzodiazepine-like properties. So, it may be effective in the treatment of epilepsy and seizures. This study aimed at examining the effect of intraperitoneal injection of the hydro-alcoholic extract of Matricaria recutita on seizures induced by pentylenetetrazole (PTZ) in mice. In this study, 56 male mice (25-30 g) were divided into seven groups (n=8): 1-control (saline), 2-control (PTZ), 3-MAT (50mg/kg), 4-MAT (100 mg/kg), 5- MAT (200 mg/kg), 6- diazepam (1mg/kg) and 7- MAT (50 mg/kg)+diazepam (0.25 mg/kg). After 10 days of treatment in different groups, the PTZ-induced seizure threshold was assessed and nitric oxide (NOX) metabolites in the brain tissue were measured by the Greiss method. The chamomile hydro-alcoholic extract (200 mg/kg), and diazepam (1 mg/kg) significantly increased the seizure threshold (P<0.001). The chamomile hydro-alcoholic extract (50, and 100 mg/kg) did not show anticonvulsant activity. The concentrations of NOX in the diazepam (1 mg/kg), MAT 100 mg/kg, and MAT 200 mg/kg groups were significantly lower than those in the control (PTZ) group and co-administration of MAT (50 mg/kg) with diazepam (0.25) decreased the NOX concentration. The hydro-alcoholic extract of MAT (50 mg/kg) had no significant effect on the NOX concentration. According to the results of this study, the chamomile hydro-alcoholic extract has an inhibitory effect on the PTZ-induced seizure and NOX in male mice.

Increase in the consumption of nano zinc oxide in medicine, manufacturing cosmetic products, and in research has raised the questions about their toxicity. Because of the small size of nano materials its absorption by the digestive system is simple. In this study, the effects of nano zinc oxide have been investigated in vivo on the ileum tissue of adult NMRI male mice.
In this experimental study, male mice were randomly divided into five groups, including control, sham, and three experimental groups. 10-30 nm-sized zinc oxide (ZnO) nanoparticles were injected intraperitoneally in three concentrations, 100-300-500mg/kg for 21 days. Histological changes including; height and width of the ileum villus, the thickness of the muscle tissue and epithelium tissue, width of connective tissue, diameter of crypts, and goblet cell numbers were studied by One Way ANOVA and Tukey-Kramer posttest, after treatments.
Findings: The results showed that nano zinc oxide had no effect on the height and the width of villi and diameter of crypts, but reduced the width of lamina propria and goblet cells of and increased the width of epithelium and muscle tissue ileum (P Discussion & The height and the width of villi and crypts diameter in the experimental groups had no significant difference compared to the sham and control groups. However, the width of the lamina propria and the number of goblet cells decreased significantly in all experimental groups, which indicated low toxicity of nano zinc oxide in these doses. A significant increase was observed in epithelium and muscle tissue compared to the control and sham groups. It seems that nano zinc oxide could be increase the growth of epithelial cells. Due to changes in the intestinal epithelium tissue in adjacent to nano zinc oxide, the long- term use of this material should be avoided.

Glycyrrhiza glabra L. (licorice) is a very sweet and soothing herb with anti-inflammatory property and hormonal effects, and in the high importance to the pharmaceutical and food industries. The aim of this study was to investigate the Anti-inflammatory and analgesic effects of extract containing and without Glycyrrhizic acid of licorice rhizome on small laboratory mice.
In this experimental study, 126 male NMRI mice randomly divided into 18 groups (n=7). Xylene and Formalin Tests used for demonstrating anti-inflammatory and antinociceptive effects. The normal saline control group and the positive control group in the inflammation test were injected dexamethasone, and morphine was injected in the pain test. Experimental groups received extract with and without Glycyrrhizic acid of licorice rhizome at doses of 20, 40, 60, 90 and 120 mg/kg. Statistical analysis was performed using Graph pad Prism software, one and two way ANOVA and Tukey’s post-hoc tests (P The results of inflammation test showed that all doses of extract with glycyrrhizin contain anti-inflammatory effect in inhibiting the xelen-induced inflammation compared with the control group. Results of formalin test showed that the extract with glycyrrhizin has more analgesic effect than without glycyrrhizin extract. Analgesic effects of two extracts in both acute and chronic pain were observed which the pain score dropped significantly in chronic pain.
Findings of this study showed that licorice root extract has analgesic and anti-inflammatory effects so that major part of these effects is probably related to Glycyrrhizic acid.

IntroductionGiardia lamblia is one of the most prevalent flagellate protozoa in human with the world-wide distribution. Millions of people are affected by Giardiasis annually. Today, many treatments are available for giardiasis that associated with some side effects. This study is aimed to evaluate the antigiardial activity of Lavandula angustifolia in vivo.
Materials and Methods In this study 25 mice are categorized in 5 groups include; Control group (without any treatment), Positive control (treatment by Metronidazole) and other three groups (treatment by 100, 200 and 400 mg/ml of Plant extracts). Then, after 10 days, the effects of each group are evaluated on the Giardia lamblia. The statistical methods used were based on one-way variance analysis and paired t-comparison that were used in the usual way for normal values in the Bootstrap method for values that were not distributed normalized according to the low sample size.
Results In this study, the body weights of treated mice with different extracts were more than the positive control and less than the negative control. Also, the live cysts were decreased 77.7, 83.4 and 95.1% by the use of 100, 200 and 400 mg/ml of plant extracts.
Conclusion The results of the current study indicated that Lavandula angustifolia has conceivable effects in vivo and it will be a suitable alternative for treatment of Giardiasis.

In traditional medicine, the different parts of hops with the scientific name Humulus lupulus (Hops) are used for the treatment of various diseases including reproductive disorders. In addition, having a healthy child with the desired sex is ideal for most couples. Therefore, the study aimed to investigate the effect of alcoholic extract of hops flower plant on sex ratio of Syrian newborn mice.
In the experimental study, 80 mice weighing approximately 35 to 30 gr in the control, sham and experimental groups of male and female Syrian mice were studied. Each control group consisted of 8 mice; the experimental groups of male and female each consisting of 40 mice that were divided into three different experimental of eight 1, 2 and 3, respectively. Experimental groups received doses of 50, 100 and 150 mg/kg alcoholic extract of hops flowers every day for 35 days by gavage. On the last prescribing day, the male and female mice mate together from different groups and after the offspring birth, their sex ratio was evaluated by the chi square test.
The findings showed that consumption of alcoholic extract of hops flowers significantly increases the proportion of male infants than female infants.
Hops flowers extract might increase the serum levels of minerals such as potassium which in turn might lead to increased male to female ratio in infants possibly through altering the PH of the vagina area.

Diabetes mellitus is a metabolic disease which causes congenital anomalies and misabortion in females. Decrease in follicle growth and maturation and quality of oocytes occur in type 1 diabetes. The antidiabetic effect of Aloe vera is reported by several investigators. In this study, the effects of Aloe vera gel on diabetic mice oocyte were examined.
First, 25 mice were randomly divided into five groups including: control group (normal saline), Aloe vera group (350 mg/kg/day, by gavage), diabetic group (single dose of 190 mg/kg streptozotocin, IP), diabetic receiving Aloe vera (350 mg/kg/day, by gavage), and diabetic receiving insulin (1 IU/day, SC). All animals were superovulated after 3 weeks. Ovulated oocytes were collected from oviduct. Oocyte nuclear maturation and mitochondrial redistribution were investigated by microscopy and immunocytochemical methods.
Diabetes led to a significant increase in spindle defects, chromosome misalignmentm, and mitochondrial redistribution changes (P˂0.05). Aloe vera and insulin administration decreased these defects significantly (P˂0.05). Maturation rate decreased in diabetic mice, but Aloe vera and insulin administration prevented the decrease significantly (P˂0.05).
The results show that diabetes damages oocyte maturation process and reduces maturation rate and oocyte quality which can cause infertility or subfertility, but Aloe vera administration reduced these defects significantly.

In traditional medicine, Boswellia serrata (Burseraceae family) has been used for its various effects such as enhancing learning and memory. However, some side effects have been mentioned with emphasizing on a probability for abortion. Therefore, the aim of this study was to evaluate Boswellia serrata abortive effect in mice. In this experimental study, virgin young female mice (balb/c) with a 25-30 gr weight were used in three different time periods: before fertilization, pre-implantation period (days 1-5 of gestation) and during implantation (days 5-7 of gestation). In each study four groups (n=8) were used including experimental groups who received 50, 100 and 200 mg/kg of Boswellia extract (IP), respectively and a control group (received 0.3 ml distilled water (IP). Animals were sacrificed on days 11-13 of pregnancy and the number of implantation sites were counted. The average number of implantation sites in control and 50, 100 and 200mg/kg concentrations of extract in the pre-fertilization period were 9.83±1.17, 6.5±1.76, 6.5±1.22 and 6.67±2.07, respectively (P=0.003). In the pre-implantation period they were 8.5±0.91 6±1.31, 5±1.16 and 3.29±1.27, respectively (P=0.032), and during implantation were 9.38±2.77, 6.38±3.1, 5.25±2.25 and 3.57±2.17, respectively (P=0.035). Reductions in the number of implantation sites were found to be dose-dependent in preimplantation and implantation periods. Our findings showed that Boswellia exert has abortive effects in mice and the stronger effect was observed with higher doses during preimplantation and implantation periods.

Crocin is one of the main components of saffron. The effect of saffron on birth abortion has been established. So, the possible effect of crocin on abortion was evaluated in this study. Pregnant mice were divided into 8 groups. Each group received crocin (0 or 10 or 50 or 100 mg/kg, i.p.) from the first to the fifth day of pregnancy. Then, the first four groups were sacrificed on the seventh day to evaluate the implantation sites. The other four groups were sacrificed on the 20th day and the number of embryos was counted. Data were analyzed by ANOVA. Administration of crocin (50 and 100 mg/kg) significantly reduced the mean number of implantation sites and embryos compared to the control group (P<0.05). Administration of high doses of crocin in the first week of pregnancy reduced the number of implantation places and embryos in mice.

Resistance of microorganisms to chemical drugs makes the medicinal plants to be considered in folk medicine. Antidepressants، antimicrobials، antinociceptives and antioxidants effects of Salvia officinalis L. have been evaluated. In this study، the anti-inflammatory like effect of Salvia officinalis L. hydroalcoholic extract was studied on the inflammation induced byxylene in the right ear of male mice. In the experimental groups، 0. 03ml of xylene was injected subcutaneously in the right ear of mice weighing 20-25 g. 30 minutes before xylene injection، Salvia officinalis L. extracts in doses of 10، 50، 100، 150 mg / kg and dexamethasone 15mg/ kg were administered intraperitoneally. The inflammation was measured according to the weight difference of a plug with 6mm of thickness in treated and non- treated ears of mice. After treatments، white blood cells of animal’s serum were counted. The results showed that Salvia officinalis L. hydroalcoholic extract reduces inflammation comparable with dexamethasone effect. The hydroalcoholic extract of Salvia officinalis L. has anti-inflammatory effect and this effect may be due to flavonoid and terpene components in plant.

Medicinal herb of Silybum Marianum usually grows in different parts of Iran. For many years it is experimentally used for treatment of various diseases, such as heal wounds, however, little research has been done on it. The purpose of this study was to investigate the effect of hydralcoholic extract of Silybum Marianum on cutaneous wound healing. This study was performed on 36 rats weighting 200-220g that were divided into 6 groups. All parts of the plant were collected and dried. Hydralcoholic extract of Silybum Marianum was prepared by maceration method. Full thickness wound (2x2) in left flank of the animals was made. The first group was left without treatment, the second was treated with Eucerin, in third group phenytoin cream 1% was used and in the other groups, different concentrations of hydroalcoholic extract of Silybum marianum (20%, 40%, 60% w/w) combined with Eucerin base were administrated 2 times daily. The areas of wounds were measured daily and healing percentage during all the days was compared. For histopathological studies, some biopsies were taken on the 7th and 21st day. In no treatment and Eucerin groups, the healing was completed in 21 days. In Phenytoin %1group, the healing time was 19days and in Silybummarianum groups of 20%, 40% and 60% the complete wound closure was observed in 18, 16 and 14 days respectively. Statistically all the treated groups and the control group had significant difference with negative control and control group (p<0.05). In histological study the group treated with hydralcoholic extract of Silybum Marianum, symptoms and improvement of skin tissues were more perfect. Results showed that the extract of Silybum Marianum significantly causes increasing in open wound healing.

Herbal medicine has been used to relieve pain around the world for many years. The aim of this study was to evaluate the analgesic effect of ethanol extract on the aerial parts of Salvia aethiopis in NMRI mice. In the present experimental study, 126 mice (NMRI) were randomly selected and used for formalin, hot plate and acetic acid test. In every experiment there were seven groups of six mice.The rats were administrated with Salvia aethiopis extract at concentrations of (1, 10, 50 and 100 mg/kg body wt.) or morphine at concentration of (10 mg/kg body wt.) as the standard drug. The intact animals were used as controls and the control group was treated with saline. In the formalin test, formalin was injected into the dorsal surface of the right paw. The animals were observed for 45 min after injection of formalin and pain scores were recorded. After formalin injection, the pain rated from 0 to 5 min (early phase) and 15-45 min (second phase) were counted. In hot plate test, rats were placed on an aluminum hot plate kept at a temperature of 55 ± 0.5°C for a maximum time of 30 s. Reaction time was recorded when the animals licked their fore and hind paws and jumped at 0 and 15, 30, 45 and 60 min after intraperitoneal administration of the extract. In acetic acid experiment, the induced pain was counted by acetic acid administration. The number of abdominal constrictions induced by acetic acid were subsequently counted. The analgesic activity of the abdominal contractions were inhibited. The data were expressed as mean values ± SEM and tested, using analysis of one-way ANOVA test. The results showed that the extract decreased only the second phase of formalin-induced pain (p<0.05). the extract reduced the cramps induced by acetic acid (p<0.05). In the hot plate test, the ethanolic extract was able to increase the pain threshold during 60 min. The present data indicated that this plant had an antinociceptive effect on the mice, but more research is needed to clarify the mechanism of action of the analgesic effect of ethanolic extract of Salvia aethiopis.

Chamomile (matricaria chamomilla L.) is a well–known medicinal plants species from the Asreraceas family. Nowadays، chamomile is a highly favored and much used medicinal plant in Folk and traditional medicine through the world، and can therefore be considered as an important medicinal species. Chamomile is an important medicinal plant، whose multitherapeutic cosmetic، and nutritional values have been established through years of Traditional and scientific use and research. chamomile has bee reported to exhibit antiseptic، healding، stimulative، carminative، spasmolytic and sedative activities. since chamomile has been Recommended in the literature as a remedy for the alleviating of pain، it was considered Worthwhile to investigate the antinociceptive affects of chamomile ethanolic extract in adult Male NMRI mice.

antiniciceptive activity was done using by formalin،hopt plate and writhing tests. the chamoline ethanolic extract (5،10 and 50 mg/kg body wt.) was injectedIntraperitoneally. the control group was administrated with saline.

the results showd that the chamoline ethanolic extract decreased only second phase of formaline induced pain. in hot plate Ethanolic extract exhibited antinociceptive activity against writhing-induced by acetic acid.

the Present data indicated that the plant has antinociceptive effect on mice and the plant should be considered in future therapeutic researches.

Nitric oxide and mecamylamine have an important role in anxiety-like behavior. Determining the site of action in the brain and interaction between these agents need to be investigated. Therefore، this study aimed to investigate the possible interaction between mecamylamine and nitric oxide in dorsal hippocampus using the elevated plus-maze test of anxiety. This experimental study was performed on 180 male NMRI mice. Mice were anaesthetized with ketamine and xylazine and two cannuale were inserted stereotaxically into the CA1 region of the dorsal hippocampus. All animals were allowed to recover for 1 week before the beginning of the behavioral testing. The elevated plus-maze was used to test the anxiety-like behavior. Bilateral intra-dorsal hippocampal injections of mecamylamine، L-arginine or L-NAME induced the anxiogenic effects. Intra-dorsal hippocampal injection of ineffective dose of mecamylamine before different doses of L-arginine or L-NAME potentiated the anxiogenic effects of L-arginine or L-NAME. Results reveal that both nitric oxide and mecamylamine not only play a part in the modulation of anxiety in the dorsal hippocampus of mouse but also have demonstrated a complex interaction as well.