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Background & Objective: In addition to pyramidal neurons and interneurons, the hippocampus contains Astrocytes that play important roles in regulating ion flux currents, energy production, neurotransmitter release and memory. Learning needs some instrument for information storage and information maintenances mechanisms resemble to memory. The aim of this study was determination of spatial memory effect on the number of astrocytes in rat’s hippocampus. Materials & Methods: In this experimental study, with usage of Morris Water Maze and Reference memory technique, we used 10 male albino wistar rats. 5 rats were in control group and 5 rats in Reference memory group. After histological preparation, the slides were stained with PTAH staining for showing the Astrocytes. Results: The findings of this study showed significant difference in astrocytes number in CA1, CA2 and CA3 area of hippocampus between control and reference memory group. The mean and SD of astrocytes in CA1, CA2 and CA3 of reference memory group were 118.57±25.29, 58.91±23.59 and 116.6±31.14, that they are more than control group with 49±17.29 in CA1, 48.8±25.21 in CA2 and 41.95±11.22 in CA3. Conclusion: We concluded that the number of astrocytes increased due to spatial learning (e.g. reference memory method).

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Background and Objective: In recent years many studies have reported that aspirin could have beneficial effect on learning and memory in different diseases of central nervous system. The objective of present study was to explore the effect of aspirin on learning and memory of Rats in pentylenetetrazole kindling model. Materials and Methods: In this experimental study Rats were divided randomly into six groups (n=8). Animals in three groups received aspirin (15 and 30 mg/kg, orally) and saline, one week before and during induction of kindling, respectivley. Kindling was induced in these groups by administration of pentylenetetrazole (PTZ: 40 mg/kg, ip). Two groups of animals received only aspirin 25 and 30 mg/kg orally. Other group received only saline throughout the study and served as health control group. After induction of kindling the learning and memory of Rats was tested in shuttle box. Study was divided to three stages of adaptation, acquisition and retention test. Initial Latency (IL) time before electrical shock and Step through latency (STL) time, 20 min or 24h after acquisition was evaluated as learning and memory index. Locomotor activity was also evaluated in open filed test. Results: PTZ kindling significantly decreased Initial Latency and Step through latency time, 20 min or also 24h after acquisition, and aspirin significantly increased these times in kindled animals (p<0.05). Aspirin also had no significant effect on locomotor activity of animals. Conclusion: This study showed that the administration of aspirin to kindled Rats improved learning and memory impairments induced by pentylenetetrazole kindling.

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Background and Objective: Ischemia-reperfusion invoke cell death in hippocampus. This study was carried out to investigate the effect of transforming growth factor alpha (TGF-alpha) of dentyte jyrus neurons and pyramidal cells of CA1 subfiled of hippocampus following ischemia-reperfusion in rat models. Materials and Methods: This experimental study was done on 40 male Wistar rats weighing 250-300gr. Animals were divided in four groups: control (n=7), sham (n=7), ischemia (n=14) and treatment (n=14). Sham group was just under surgical stress. In ischemia and treatment groups after induction of ischemia-reperfiusion by obstruction of carotid arteries blocked for 30 minutes, reperfusion PBS (phosphate buffer salin) and subsequently TGF-alpha (50 ng) were injected stereotaxicaly in lateral ventricle, respectively. In 12 and 72 days after treatment the brains were fixated by transcardial perfusion and stained by immunohistochemestry and nissle methods. Furthermore, morris water maze was used to evaluate the learning memory. Data were analyzed using SPSS-16 and ANOVA test. Results: Injection of TGF-alpha increased the cell number in hippocampus of treatment group compared to ischemic group. TGF-alpha increased expression of neuron in dentyte jyrus of treatment group in comparison with ischemic group (P<0.05). Also spatial memory improved in treatment group in comparison with ischemia group. Conclusion: TGF-alpha improves ischemia-induced neurodegenration and memory impairment.

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Background and Objective: Post-traumatic stress disorder (PTSD) impairs spatial learning and memory. Desmopressin acetate ameliorates the cognitive deficits induced by electroconvulsive shock. This study was designed to evaluate the protective effects of Desmopressin acetate on retention of spatial memory deficits induced by post-traumatic stress disorder in rats. Materials and Methods: In this experimental study twenty one male Wistar rats were used. Animals were trained for 5 consecutive days in Morris water maze and then were randomly assigned in three groups (Vehicle + Sham, Saline + PTSD and Desmopressin acetate + PTSD) and tested in a probe 60 sec in 24h after the last acquisition trial. The groups of PTSD+Desmopressin acetate rats and vehicle+sham, saline+PTSD were injected Desmopressin acetate (10 micro gr/kg body weight) and saline (IP), respectively. Injections performed ten minute prior to PTSD and spatial memory was tested ten minutes later. Data were analyzed using SPSS-16, One-Way ANOVA and Tukey tests. Results: The platform location latency of the Desmopressin acetate+PTSD group was significantly shorter (4.24 sec) than the control group (P<0.05) and also, had significantly smaller average proximity values (33.87 cm) compared to the saline+PTSD group (P<0.05). Desmopressin acetate + PTSD spent significantly more time (21.65%) in the target zone (P<0.05). Conclusion: This study indicated that Desmopressin acetate blocks the ability of PTSD to impair spatial memory retention.

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Background and Objective: Autism spectrum disorder is a genetic-based cognitive and neurobehavioral disorder characterized by impairment in social interaction, verbal and non-verbal communication and repetitive motor behavior. This study was done to evaluate the verbal fluency and working memory deficit in first-degree relatives of autistic children. Materials and Methods: In this case - control study, 49 first-degree relatives of autistic children from 33 families (32 mothers, 10 fathers, 6 sisters, and 1 brother) supported by Isfahan autism association were selected and compared with 51 first-degree relatives of typical children (23 mothers, 16 fathers, 7 sisters, and 5 brothers) of 27 families during 2010. The assessing tasks were phonemic and semantic verbal fluency tests to assess verbal fluency and forward and backward digiti span tests to assess low load and high load working memory. Data were analyzed using SPSS-19 and independent t-test and paired t-test. Results: Autistic relatives showed significant poor performance in phonemic (11.46±3.3 V.S. 14.08±3.8), semantic verbal fluency (16.83±3.3 V.S. 19.23±3.9), forward digiti span (5.22±0.6 V.S. 5.55±0.9) and backward digiti span (3.65±0.98 V.S. 4.14±0.8) (P<0.05) compared to healthy children of first-degree relatives. Conclusion: This study showed that parents and siblings of autistic children have a lower performance in phonemic and semantic, low and high load verbal fluency, which might be transmitted genetically.

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Background and Objective: Post-traumatic stress disorder (PTSD) is an anxiety, which is induced by exposure to life-threatening trauma and produces memory dysfunctions. This study was done to evaluate the effect of β-estradiol on traumatic memory after post-traumatic stress disorder induced by modified single-prolonged stress model in male rats. Materials and Methods: This experimental study was done on 70 male Wistar rats, weighted 200-250 grams. Initially 30 rats randomly allocated into control, shock and single prolonged stress accompanied shock (SPS&S). In SPS&S group immobilized for 2h, followed immediately with a 20 min forced swim conducted in a cylindrical filled with water. After recuperating for 15 min, animals anesthetized with ether. After 30 min recovery, stressed rats placed in the conditioned fear system (CFS). They received one 1mA, 4 second electric foot shock and remained in the chamber for another 60 second before being returned to their home cages. Shock group: Animals placed in CFS and only received the same shock as previous experiment. Naive group: Animals were removed from their home cages and exposed to chamber without receiving any foot shock. 1, 2 and 3 week later, animals in all groups were re-exposed to the shock chamber for 3 min, in order to examine conditioned fear response. In the second experiment rats were injected with β-estradiol (90 µg/kg), one and two week after training. Date were analyzed using SPSS-16, ANOVA and LSD tests. Results: SPS&S significantly induced freezing response (traumatic memory) compared with controls and shock groups (P<0.05) following three weeks. This response significantly reduced due to repetitive injection of β-estradiol in rats (P<0.05). After three weeks causes of enhanced freezing response (traumatic memory) compare with both, shock and sham groups (P<0.001). β-estradiol significantly reduced this response in rats (P<0.001). Conclusion: β-estradiol's administration following PTSD induction by modified single-prolonged stress, significantly decreased the freezing response. Therefore, β-estradiol can prevent the formation of traumatic memory.

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Background and Objective: Recent studies have shown that diabetes induced cognitive dysfunction and impairs learning and memory. Palmatine is an isoquinoline alkaloid, and has multiple pharmacological effects, including anti-diabetic and antioxidant activity. This study was conducted, to evaluate the effect of Palmatine on learning and spatial memory impairment in STZ-induced diabetic rats. Materials and Methods: This experimental study was conducted on the male Wistar rats (n=32) with approximate weight of 240±40 grams. The rats were randomly allocated and were divided into 4 groups (n=8): Control, Palmatine-treated non-diabetic, diabetic and Palmatine-treated diabetic groups. Diabetes was induced by STZ administration at the dose of 55 mg/kg through intraperitoneal route. Palmatine hydrochloride was administered subcutaneous at doses of 10 mg/kg/day 1 week after STZ injection for a period of 6 weeks. Blood samples were taken from the tail vein 1, 3, 5, 7 weeks after STZ injection to measure blood glucose levels. Behavioral tests including spatial recognition and objective recognition were performed at the end of study. Data were analyzed by using Prism-5, one way ANOVA and Tukey tests. Results: In spatial recognition test, the number of entrance in new arm of the Ymaze, in the Palmatine-treated groups significantly increased in compare to diabetic group in both sixth and seventh weeks (P<0.05). Number of rearing in new arm significantly increased in sixth and seventh weeks, compare to the diabetic group (P<0.05). The number of recognition novel objects in the Palmatine-treated diabetic group significantly increased in compare to diabetic group (P<0.05). Conclusion: Palmatine hydrochloride administration for 6 weeks improves cognitive dysfunction in streptozotocin-induced diabetic rats.

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Background and Objective: Diabetes mellitus cause learning, memory and cognitive skills disorders in the long term. This study was conducted to determine the protective effect of silymarin on the learning and memory deficiency in streptozotocin-diabetic rats. Materials and Methods: This experimental study was conducted on 40 male Wistar rats weighing 240-300 grams. The rats were randomly allocated into 5 groups: control, silymarin -treated control (100 mg/kg), diabetic, and two silymarin -treated diabetic groups (50 and 100 mg/kg). Silymarin was daily administered (i.p. and daily) ten days after streptozotocin injection for 4 weeks. Finally, initial (acquisition index) and step-through latencies (retention and recall index) were measured using passive avoidance test and alternation behavior percentage as an index of spatial memory was determined using Y maze. The level of malondialdehyde in the homogenate hippocampal tissue of the animals brains was measured. Data were analyzed using Sigma Stat-3.5, one-way and two-way ANOVA, Tukey, and Kruskall-Wallis tests. Results: A significant reduction of STL was observed in diabetic (P<0.01) and silymarin-treated (50mg/kg) diabetic (P<0.05) groups and this parameter was significantly higher in diabetic group receiving a high dose of silymarin compared to diabetic group (P<0.05). Meanwhile, alternation percentage in diabetic animals was significantly lower than control group (P<0.05) and this index did not show a significant difference in silymarin-treated diabetic groups in comparison with diabetic group. In diabetic rats, there was a significant increase in the tissue level of malondialdehyde (P<0.05) and silymarin treatment with dosage of (100 mg/kg) significantly reduced the level of MDA (P<0.05). Conclusion: This study showed that although long-term administration of silymarin at a high dose (100 mg/kg) affects the ability to store data in memory and to recall it in diabetic animals in passive avoidance test, it does not improve short-term spatial memory in diabetic animals. The beneficial effects of silymarin may be via attenuation of lipid peroxidation in hippocampus tissue.

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Background and Objective: Attention deficit / hyperactivity disorder (ADHD) is a neurodevelopment abnormality. Inattentive behavior is considered a core and pervasive feature of ADHD. This study was done to compare the executive function and working memory in attention deficit / hyperactivity disorder and healthy children. Materials and Methods: This case – control study was done on 50 children with ADHD as cases and 40 healthy children as controls. The disorder was diagnosed by applying Kanerz teacher test and confirmed by a psychiatrist. Stroop test, Wisconsin Card Sorting Test (WCST), Continuous Performance Test (CPT) and n-back test were used to assess the executive function and working memory. Results: There was a significant difference between case and control groups in regard to executive function and working memory (P<0.05). Error omission was 16.98±8.157 and 7.3±3.824 in cases and controls, respectively (P<0.05). Conclusion: Attention deficit / hyperactivity disorder reduces executive function and working memory in children.

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Background and Objective: Diabetes mellitus is common endocrine disease cause learning and memory impairment. This study was done to evaluate the effect of quercetin on learning and memory in STZ-induced diabetic rats was investigated. Methods: In this experimental study, 40 male Wistar rats were randomly allocated into five groups: control, quercetin - treated control, diabetic and quercetin - treated diabetic (10 and 20 mg/kg/bw, intraperitoneally) for 14 days. Induction of diabetes was performed using 60 mg/kg/bw of streptozotosin, interapritonally. Passive avoidance and Y-maze tests were used for the evaluation of learning and memory. Results: In passive avoidance learning, there was no significant difference in initial latency between diabetic and treated - diabetic groups. The mean of step latency in control group (383.57±19.26) significantly reduced to 128.86±10.38 in diabetic group (P<0.05). The mean of step latency in the treated diabetic group significantly increased in compare to the diabetic group (P<0.05). Step latency in quercetin - treated diabetic (10 mg/kg/bw) and (20 mg/kg/bw) groups increased to 316.67±23.76 and 397.50±31.21, respectively. The alternative percentage in diabetic group was significantly lower than control group (P<0.05), but in quercetin -treated diabetic groups it was higher than the diabetic group (P<0.05). Conclusion: Administration of quercetin for 14 days enhances the capability of the memory storage, recall and improves short-term spatial memory in STZ-induced diabetic rats.

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Background and Objective: Stem cells are a suitable treatment method for improvement of central nervous system diseases. Neuron regeneration is occure in damaged region using stem cell transplantation. This study was done to determine the effect of bone marrow mesenchymal stem cells on memory and neuronal cells graft number in the trimethyltin chloride damaged hippocampus. Methods: In this experimental study, 28 wistar male rats were allocated into four groups including control, model, Vehicle and treatment groups. Animals were received 8 mg/kg/bw of neurotoxin trimethyltin chloride by the intraperitoneal injection for causing damaged in hippocampus. One week after intraperitoneal injection of trimethyltin chloride, stem cells was injected by stereotaxy method. Six weeks after stem cells injection, the spatial memory was assessed by Morris water maze and histological studies were done by Nissl staining and normal cells count by Olysia bio report software. Results: After bone marrow mesenchymal stem cells graft, the number of normal cells were more in the treatment group (74±15.190) in compared to the Vehicle (44.67±12.971) and Model (48.56±18.105) groups (P<0.05). Also in Morris water maze test, the treatment group (387.35±189.18), (31.30±13.67) spent shorter distance and escape latency to reach the hidden platform, but this reduced non significantly in compared to Vehicle (438.18±192.56), (40.14±14.89) and model (407.98±225.44), (37.68±17.15) groups. The model and Vehicle groups spent longer distance to reach the hidden platform in comparision with the control (275.45±165.10) group (P<0.05). Also the traveled distance in target quarter had significant increased in the treatment groups (799.80±125.91) in compared to model (588.51±136.94) and Vehicle (546.48±86.47) groups (P<0.05). Conclusion: Using the bone marrow mesenchymal stem cells leads to reduce hippocampal lesions and increase the number of pyramidal neurons and improving memory in damaged hippocampus in animal model.

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Background and Objective: Tamoxifen is one of the selective estrogen receptor modulators that exerts estrogen / anti-estrogen effects in various tissues. This study was done to evaluate the effect of chronic administration of tamoxifen on spatial memory and passive avoidance task in adult male Wistar rats.

Methods: In this experimental study, 48 adult male Wistar rats were randomly divided into control, sham and tamoxifen groups. Animals in sham and tamoxifen groups were received tamoxifen solution and tamoxifen (400mg/kg/day) orally for 35 consecutive days. At the end of treatment, spatial learning and memory of animals was assessed using the Morris water maze task and passive avoidance memory was examined using the shuttle box.

Results: The time spent and distance moved to reach the platform, significantly increased in tamoxifen group compared to controls (P<0.05). In addition, the time spent and distance moved in the target quadrant (in the probe test) significantly reduced in tamoxifen group in compared to controls (P<0.05). In passive avoidance task, tamoxifen significantly decreased the time of the entrance to the dark room compared to control animals (P<0.05).

Conclusion: Long-term administration of tamoxifen impairs spatial learning and memory and passive avoidance memory in rats.

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Background and Objective: Ducrosia anethifolia (Dc.) is a medicinal odor plant contains CNS effective compounds which has been used in Iranian traditional medicine. This study was done to determine the effect of Ducrosia anethifolia (Dc.) Boiss essential oil on spatial learning and memory in adult male rats.

Methods: In this experimental study, 35 wistar adult male rats were randomly allocated into the five groups (n=7) including: control, sham (injected vehicle) and Ducrosia anethifolia (Dc.) Boiss essential oil groups 0.125, 0.25 and 0.5ml/kg/bw, intraperitonally during four days. Morris water maze test was used to assess learning and memory.

Results: Ducrosia anethifolia (Dc.) Boiss essential oil (0.5 ml/kg/bw) was significantly increased escape latency in the second and third (P<0.05) as well as forth (P<0.05) days of acquisition test in compare to control group. In addition latency to find the hidden platform was significantly decreased with 0.25 essential oil in all days except first day (P<0.05) and in essential oil- treated rats at 0.125 ml/kg/bw in the second and third days (P<0.05) in compare to the control group.  Time spent and distance travelled in target zone were significantly increased in Ducrosia anethifolia (Dc.) Boiss essential oil -treated rats (0.5ml/kg/bw) in compare to control group (P<0.05).

Conclusion: Intraperental administration of the Ducrosia anethifolia (Dc.) Boiss essential oil at doses of 0.5 and 0.25 ml/kg/bw during four days can improves spatial learning and memory in adult male rats.

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Background and Objective: Oxidative stress causes disorder in the brain processes including memory. Pistacia atlantica kurdica (pistachio) contains antioxidant compounds, oleic and linoleic acid. Fluvoxamine is an antidepressant medicine which inhibits serotonin reuptake. This study was done to determine the effect of hydroalcoholic extract of pistachio and fluvoxamine on spatial memory of male rats under immobilization stress.
Methods: This experimental study was done on 30 adult male Wistar rats in 5 groups (n=6). The control group was not under immobilization stress. Animals in the stress group were just under immobilization stress. Animals in the pistachio group were under immobilization stress and were received 400 mg/kg/bw hydroalcoholic extract of pistachio. Animals in the fluvoxamine group under immobilization stress were received 120 mg/kg/bw fluvoxamine. Animals under immobilization stress, in the pistachio plus fluvoxamine group were received 400 mg/kg/bw hydroalcoholic extract of pistachio and fluvoxamine 120 mg/kg/bw. The radial arm maze test was used for evaluation of spatial memory. After the animals’ decapitation, the malondialdehyde and catalase level in hippocampus and the serum level of corticosterone and blood glucose were measured.
Results: The stress significantly increased the time of reaching to target, malondialdehyde, corticoestron and blood glucose level, and reduced the catalase in stress group in comprasion with controls (P<0.05). In the pistachio and the pistachio+fluvoxamine treated groups, the time of reaching to target, malondialdehyde, corticoestron and blood glucose level significantly reduced and the catalase level significantly increased in comprasion with stress group (P<0.05) but fluvoxamine significantly increased the time of reaching to target, malondialdehyde and blood glucose, and reduced the corticoestron and catalase in compared to controls (P<0.05).
Conclusion: The immobilization stress led to attenuation of spatial memory and the fluvoxamine administration as an antidepressant drug caused to deterioration of memory,while the treatment with pistachio extract lead to improve the memory.

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Background and Objective: Dysfunction and loss of basal forebrain cholinergic neurons and their cortical projections are the earliest pathological events in the pathogenesis of alzheimer disease (AD). This study was done to evaluate the effect of donepezil hydrochloride on reference and working memory caused by mutual electrical lesion of the nucleus basalis magnocellularis (NBM) in animal model of AD.
Methods: In this experimental study, 56 adult male Wistar rats were allocated into 8 group (n=7) including: control (intact), NBM lesion group, which received electrically- induced lesion (0.5 m A, 3s) in NBM, Sham group (the electrode was impaled in to the NBM with no lesion), donepezil groups (lesion + 0.1, 1, 5, 10 mg/kg/bw of donepezil hydrochloride) and vehicle group (NBM lesion+ saline). Acquisition and retention testing were done by using an eight-radial arm maze, in which, the patterns of arm entries in each group was recorded for calculating correct choice, working memory errors, reference memory error and latency.
Results: The spatial learning of animals in the lesion of NBM group significantly reduced in compared to controls (P<0.05). Moreover, no effect on spatial learning was seen in the sham group compared with the lesion group. The post-lesion treatment with donepezil hydrochloride in dose-dependent manner improved the parameters of spatial memory errors in the acquisition and retention tasks in comparision with the lesion group (P<0.05).
Conclusion: Treatment with donepezil hydrochloride, dose-dependently improves cognitive impairment induced by the destruction of the nucleus basalis magnocellularis.

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Background and Objective: Learning is the acquisition of information that makes this possible, and memory is meant to store this information. Millet contains proteins, minerals, vitamins and antioxidants needed to preserve the life and health of mammalian cells. This study was conducted to determine the effect of alcoholic extracts of seed of millet (Panicum miliaceum L.) on spatial memory in mice.
Methods: In this experimental study, 24 male rats were randomly allocated into 4 groups. Hydrochloric extract of Prossu millet was prepared by Soxhlet method and injected into three treatment groups with doses of 25, 50 and 75 mg/kg/bw by intraperitoneal injection for 21 days. Animals in control group were received normal saline. After one month from the first injection, learning behaviors and memory tests were performed. Mauritius water maze was used to evaluate the spatial memory. Also, shuttle box method was used to determine passive avoidance of spatial memory.
Results: The results showed that the mean time for finding the platform between the control group and alcoholic treatments in doses of (75 mg/kg/bw) was significantly different (P<0.05). Also, the mean time of training and test time in control and treatment groups receiving alcoholic extract showed a significant difference, indicating that this extract had a significant effect.
Conclusion: Alcoholic extract of millet seed with dosage of 75 mg/kg/bw improves the learning and spatial memory of male mice.

 

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Background and Objective: Atorvastatin is a member of the statin family with lipophilic character and anti-hyperlipidemic effect. There is many evidence that atorvastatin has protective effect on cognitive function. This study was done to evaluate the effect of atorvastatin on spatial memory in rats following a high-fat diet.
Methods: This experimental study was performed on 35 male Wistar male rats. Animals were randomly allocated into 5 groups including control, control plus atorvastatin and sham (received high-fat diet for 4 weeks) and high-fat diet plus atorvastatin (10 and 50 mg/kg, for 4 weeks). Learning and spatial memory were measured using Morris water maze for a 6-day period including 5 days training and the last day, test day (probe day).
Results: High-fat diet reduced learning and poor memory performance during training and probe compared to the control group, and also on the probe day, the high-fat group spent less time in the target quarter (P<0.05). Administration of atorvastatin after a high-fat diet improvement spatial memory in compared to high-fat group (P<0.05).
Conclusion: Short-term treatment (4 weeks) with atorvastatin in high-fat dietary rats can improve spatial memory.

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Background and Objective: Multiple Sclerosis (MS) is a neurologic necrotic and chronic illness that causes by demyelination in CNS. One of the common clinical symptoms in MS is cognitive disorders. The most common cognitive defects in patients with MS are reduction of memory and information processing rate hippocampus functions in brain are memory and learning. This study was done to determine the function mechanism of memory discover by study on hippocampus. Nowadays tendency of herbal therapy is increased because of drug's side effects. This study's purpose that is from experimental typ effect of compaind extract of Portulaca olerace, Urtica dioica and Boswellia serrata on memory and number of neurons in CA1 area of hippocampus in induced multiple sclerosis rats.
Methods: In this experimental study 30 male adult rats were randomly allocated into control group, sham group (salin injection), (MS + salin) group, (MS + mixture extract, dose of 200 mg/kg), (MS + mixture extract, dose of 400 mg/kg). MS model was induced by intra hippocampal injection a single dose of ethidium bromide (0.01% ethidium bromide sulotion in 0.9% salin) and in 3 microlitre volume with 1 microlitre in minute rate intraperitoneally. Compaind extract of Portulaca olerace, Urtica dioica and Boswellia serrata were injected as the treatment for 21 days. The shuttle box test was used for evaluation of memory. Dissector method was used for neural density in CA1 of hippocampus. Histopathology method was used for evaluation of the alteration of cells.
Results: Neural density in MS induced group was singnificantly reduced in comparison with control and sham groups (P<0.05). Neural density was singnificantly increased in treatment groups in comparison with MS induced group (P<0.05). Histological results showed that induction of MS caused the disrution of neuron cells in compare to controls, but intraperitonal injection of compaind extract cause neurogenesis in tertment groups. Memory in MS induced group was singnificantly reduced in comparison with control and sham groups (P<0.05), but memory was singnificantly increased in treatment groups in comparison with MS induced group (P<0.05).
Conclusion: Compaind extract of Portulaca olerace, Urtica dioica and Boswellia serrata with dosages of 200 and 400 mg/kg/bw due to neurogenesis and amilioration can effective in memory recovery and neural necrosis in MS disease.

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Background and Objective: Alzheimer is the most common form of dementia in elderly persons. Oxidative stress is one of the main pathological factors in Alzheimer’s disease. This study was done to investigate the effect of crosin on histological changes of hippocampus and memory impairment which induced by scopolamine in the male rats.
Methods: In this experimental study, 30 male rats were randomly allocated into 3 groups including: control, scopolamine and scopolamine with crosin treated groups. Scopolamine with dose of 3 mg/kg/bw for one week and crocin with dose of 30mg/kg for two weeks were administered, intraperitoneally. The learning and spatial memory parameters were evaluated by Morris water maze test. Then the animals were sacrificed and their hippocampi were removed immediately for histological evaluation.
Results: Scopolamine injection causes significantly increased the number of dark cells in CA1 region of hippocampus in compared to control group (P<0.05). Treatment with crocin decreased dark cells and increased light cells number in CA1 region of hippocampus (P<0.05). Also treatment with crocin decreased memory impairment that induced by scopolamine in rats (P<0.05).
Conclusion: It seems that treatment with crocin has protective effects against neuronal damage of CA1 region of hippocampus and memory impairment that induced by scopolamine.

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Background and Objective: Food restriction may have beneficial or detrimental effects on the brain functions such as learning and memory. Also, dopamine receptors are involved in learning and information retrieval. This study was performed to determine the simultaneous effect of food restriction and dopamine D2 receptor inhibition on spatial memory of rats.
Methods: In this experimental study, 60 male Wistar rats were allocated into 6 groups including controls, 25%, 50% and 75%, food restriction, sulpiride (D2 receptor antagonist, 4 mg/kg/day, ip), 75% food restriction and sulpiride and treated for 21 days. To evaluate the memory, an eight-point radial arm maze was used. Then, the catalase and malondialdehyde level of the hippocampus were measured.
Results: Twenty-five percent food restriction caused to 11.8 percent decrease in spending time to find the food compared to control group (P<0.05). The 75% food restriction and or sulpiride injection significantly increased that time by 24.4% and 18.3%, respectively (P<0.05). The group with 75% food restriction were received sulpiride showed the most increase in the time of food finding compared to all groups (P<0.05). Catalase activity was only significantly reduced in the 75% restricted groups to 17.6% and 22.2%, respectively (P<0.05). Malondialdehyde production was significantly increased in the 75% food restricted groups to 50.2% and 59.3, respectively and sulpiride-received group to 31.2% compared to the control group (P<0.05).
Conclusion: Simultaneous applying of food restriction and inhibition of dopamine D2 receptors resulted in increased hippocampal prooxidant levels and exacerbated memory impairment.