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Showing 12 results for Memory
Abbas Abolghasemi, Azar Kiamarsi,
Volume 6, Issue 2 (6-2006)
Abstract
Background & Objectives: The cognitive processes such as attention, thinking, memory and recall have effective role on the child’s confrontation with daily life problems. The psychological disorders are among those impairments which may severely affect these processes. Researches have shown that schizophrenia can impair children’s cognitive processes to a great extent. The aim of this research was to compare the comprehension, lexical Knowledge, memory and recall in children with schizophrenia, conduct disorder and brain damage. Methods: The sample of this causal-comparative research consisted of 80 children (8-13 years old) suffering from schizophrenia, brain damage and conduct disorder as well as a group of healthy ones who were selected from among in and out-patients referring to psychology and neurology wards of Emam Hossein health care center in 2004 (20 subjects in each group). The instruments employed in this research were WISC-R (comprehension, vocabulary, digit span) and Recall Test of Babcoch. Results: The one way analysis of variance showed significant differences between the children with schizophrenia, conduct disorder, brain damage and non-patient in comprehension, lexical knowledge, memory and recall (p<0.01). The LSD test showed that comperhension, lexical knowledge, memory and recall in children with schizophrenia were more impaired compared to children with conduct disorder and brain damage. Moreover, comprehension, lexical knowledge and memory in children with conduct disorder were more severely impaired than children with brain damage. However, the recall was better in children with conduct disorder than those with brain damage (p<0.01). Conclusion: The results showed that schizophrenic children have comprehension, lexical knowledge, memory and recall more impaired than those suffering from conduct disorder and brain damage. The timely recognition of the cognitive abnormalities seems necessary to have a better diagnosis and choose effective treatment and remedial strategies to cope with them.
Shirin Babri , Naser Khalajy ,
Volume 6, Issue 4 (12-2006)
Abstract
Background & Objectives : Piracetam is a nootropic compound, which acts as a nervous system enhancer. Different processes are involved in memory formation and various parameters are able to disturb it. Due to increase of exposure possibility to electromagnetic fields in recent years and the effects of theses fields on memory consolidation, this investigation designed to clear the relation between these parameters and memory consolidation. Methods: In this research eleven groups of male wistar rats (ten rats in each group) with a mean weight of 275±25 gr aging 3-4 months were studied. To evaluate the effects of electromagnetic field, four groups of rats were exposed to 5mT/50HZ electromagnetic field for 1,4,6 and 8 hours respectively immediately after training. In other six groups 250mg/kg or 500 mg/kg piracetam were administered orally one hour before training. They were also exposed to electromagnetic field for 4,6,8 hours respectively immediately after training,. Retrieval test was performed 24 hours later in all groups. Results: 1 hour exposure on EMF had no meaningful effect on memory consolidation, however, in other three groups the electromagnetic fields impaired memory consolidation significantly compared to the control group (p<0.05). Piracetam administration with two mentioned doses significantly improved memory consolidation (p<0.05). Conclusions: Acute exposure to low intensity magnetic field can disturb memory consolidation and piracetam administration can prevent it.
Sana Mollahoseini , Lotfollah Khajehpour, Mahnaz Kesmati, Abdolrahman Rasekh,
Volume 12, Issue 3 (9-2012)
Abstract
Background & Objectives: Several studies have shown that Glucocorticoids affect learning and memory processes by influences on limbic structures such as amygdala. The amygdala is an important region for memory formation. Considering the existence of the muscarinic acetylcholine receptors in the basolateral amygdala (BLA), the aim of the present study was to investigate the effect of intra-BLA microinjection of pilocarpine on the effect of dexamethasone on memory retrieval . Methods: As a model of learning, using a step-through apparatus , inhibitory avoidance was used for assessment of long-term memory in 80 adult male Wistar rats . All animals were bilaterally implanted with cannulas into the BLA and were trained and tested (with 24 h interval) 7 days after surgery. Memory retrieval was evaluated by recording of the step-through latencies and the time spent in dark chamber of apparatus in the testing day. Results: Pre-test subcutaneous (s.c) administration of dexamethasone (2 mg/kg) impaired memory retrieval in animals when trained 24 h in advance. Co-pretest microinjection of different doses of pilocarpine (1 , 2 μg/rat, intra-BLA ), a muscarinic acetylcholine receptor agonist, with the dexamethasone (2 mg/kg, s.c) caused enhancement of memory retrieval. Conclusion: Results of this research indicate that impairment effect of dexamethasone on memory processes may be mediates by decrease of mechanisms of BLA muscarinic cholinergic.
Zahra Kiasalari , Mehrdad Roghani, Tourandokht Baluchnejadmojarad, Mohammad Javad Hasas ,
Volume 14, Issue 3 (10-2014)
Abstract
Background & objectives : Epileptic seizures accompany disturbances in learning, memory, and cognitive skills. With regard to antiepileptic potential of curcumin and its beneficial effect on memory, the effect of its administration on learning and memory in kainate-epileptic rats was investigated. Methods: Forty male rats were divided into sham, positive control ( valproate-treated epileptic), epileptic, and two curcumin-treated epileptic groups. Rat model of epilepsy was induced by unilateral intrahippocampal administration of 4 μg of kainate per rat. Rats received intraperitoneal injection of curcumin (50 and 100 mg/kg) daily for 1 week before surgery. For evaluation of learning and memory, initial (IL) and step-through latencies (STL) were determined using passive avoidance test and alternation behavior percentage was obtained according to Y maze test. Results: Regarding IL, there was no significant difference between the groups. In contrast, STL significantly decreased in curcumin-50-treated epileptic group (p<0.05) (a change from 263.1 to 184.5 s). However, this parameter significantly increased in curcumin-100-treated epileptic group as compared to epileptic group (p<0.01) (a change from 263.1 to 220.3 s). In addition, STL was also significantly higher in valproic acid-treated epileptic group versus epileptic group (p<0.05) (a change from 145.7 to 210.3 s). Alternation percentage was also significantly higher in curcumin-50- and curcumin-100-treated epileptic groups relative to epileptic group (p<0.05) (a change from 60.5 to 77.6 and 80.3%). Conclusion: Curcumin could dose-dependently enhance the consolidation and recall in epileptic animals and could improve spatial memory in such animals.
Shima Abtin, Lotfollah Khajehpour, Mahnaz Kesmati, Hosein Najafzadeh,
Volume 15, Issue 4 (1-2015)
Abstract
Background & objectives: Salvia officinalis is one of the memory-enhancing herbs that were used in the past. On the other hand, iron oxide nanoparticles which are widely used in medicine and industry may impair the brain process related to memory. In this investigation, the effect of hydro-alcoholic extract of Salvia officinalis on iron oxide nanoparticle induced memory impairment and the role of beta-adrenergic receptors in this effect were studied.
Methods: To assess the inhibitory avoidance memory, animals were trained in the step-down task and drugs (saline, hydro-alcoholic extract of sage leaves, nanoparticles of iron oxide and propranolol) were injected immediately after training by intraperitoneal (ip) injections. Long-term memory was tested 24 hours later and step-down latencies were recorded.
Results: Administration of iron oxide nanoparticles (5 mg/kg, ip) impaired memory retrieval. Salvia officinalis extract (40 mg/kg, ip) also prevented iron oxide nanoparticle induced long-term memory impairment. On the other hand, administration of propranolol (5, 10 mg/kg, ip) before Salvia officinalis extract (40 mg/kg, ip) and iron oxide nanoparticles (5 mg/kg, ip) attenuated the effect of Salvia officinalis extract.
Conclusion: It seems that extract of Salvia officinalis leaves decreases iron oxide nanoparticle induced memory impairment. Beta-adrenergic mechanisms are possibly involved in these effects of Salvia officinalis extract.
Bahador Karimi, Zohreh Ghotbeddin, Seyed Reza Fatemi Tabatabaei ,
Volume 16, Issue 4 (1-2016)
Abstract
Background & objectives: Zinc as one of the most important trace elements is needed for proper functioning of the nervous system and homeostasis. Many studies show that stress causes memory impairment through various mechanisms, including oxidative stress induction and some mechanisms which are directly effecting brain function. So, in this work we assessed the effect of zinc chloride on passive avoidance memory and oxidative stress following acute stress in male rats.
Methods: In this study, 50 male Wistar rats were used in five groups: control, sham, stress, zinc chloride treatment and zinc chloride treatment before stress induction. For stress induction, rats were restrained (not immobilized) for 6 h/day, 7 days in a Plexiglas restrainer, and treated rats received an oral dose of zinc chloride 32 mg/kg/day by gavage for 6 days. At the end of the experiment, passive avoidance memory was avaluated by shuttle box and some oxidative damage markers were determined in all groups.
Results: Results of this study showed that animals which were exposed to stress showed a significant decrease in passive avoidance memory compared to control group (p<0.01) and the oxidative stress parameters in this group showed significant changes compared to the control group (p<0.05). While passive avoidance memory and oxidative stress parameters in group treated with zinc chloride were nearly closed to control group.
Conclusion: According to our results, zinc chloride with antioxidant properties can have a protective effect on memory impairment and oxidative stress induced by stress.
Nematollah Gheibi , Javad Shahbazi, Zahra Zarmohammadi , Mahmoud Alipoor Heydari , Eftekhar Kakaeie, Mohammad Sofiabadi ,
Volume 17, Issue 1 (4-2017)
Abstract
Background & objectives: Propolis is a natural product with powerful antioxidant and therapeutic effects. The aim of this study was to investigate the effect of propolis on passive avoidance memory in adult male mice.
Methods: In this study, 40 adult male mice were divided into 8 groups, including control, sham (solvent) and 3 treatment groups orally treated with 50, 100 and 200 mg/kg of propolis, respectively for two weeks before and one week after treatment. Then, passive avoidance learning and memory were recorded in timescales of 24 and 48 hours, 4 days and a week after shock by the shuttle box. Data were analyzed by ANOVA and Dunnett’s post hoc tests, and p<0.05 was considered significant.
Results: Administration of propolis (50 mg/kg) significantly increased the dark chamber entering time at intervals of 24 and 48 hours (p<0.001) and at concentrations of 100 and 200 mg/kg in all time periods after the shock (p<0.001).
Conclusion: Oral administrations of propolis can improve learning and memory dose-dependently in adult male mice.
Mohammad Sofiabadi, Mohammadhousein Esmaeili, Hashem Haghdoost-Yazdi , Moustafa Aali,
Volume 17, Issue 3 (10-2017)
Abstract
Background & objectives: Diabetes mellitus cause cognitive defects. Royal Jelly has been claimed to improve the neurological damage caused by diabetes. In this study, the effect of oral administration of royal jelly on memory and passive avoidance learning was studied in diabetic male rats.
Methods: This experimental study was conducted in Qazvin University of Medical Sciences on 48 male Wistar rats. The animals were divided into control, diabetic without treatment, diabetic recipient of glibenclamide (600 μg/kg) and three diabetic groups treated with 50, 100 and 200 mg/kg royal jelly (n=8). Diabetes was induced in the animals by intraperitoneal injection of streptozotocin (60mg/kg/ip). Treatment in the groups performed by gavage from the onset of hyperglycemia for 30 days. At the end of the test, the passive avoidance learning and memory and blood glucose were measured. Data were analyzed by by SPSS software using ANOVA and post-hoc LSD tests, and p<0.05 was considered significant.
Results: Diabetes reduced the latency time of dark room entering. Royal jelly treatment delayed the entrance to the dark room significantly at 24 h, 48 h and 2 weeks after the shock, especially at doses of 100 (p<0.05) and 200 mg/kg (p<0.01) compared to untreated diabetic animals.
Conclusion: According to the results, diabetes causes memory impairment, and royal jelly administration can reduce the memory impairment due to diabetes.
Mohammad Hossein Esmaeili, Zohrea Rozbahani,
Volume 18, Issue 3 (10-2018)
Abstract
Background & objectives: Epidemiological Studies have shown that diabetes increase the risk of developing Alzheimer’s disease (AD).also several studies have confirmed that long term use of Metformin (Met) improves cognitive function in diabetic patients. The aim of the present study was to investigate the effects of Met on learning and memory in diabetic and non-diabetic rats.
Methods: Animals were divided into 2 groups including healthy and diabetic group. In healthy group, normal rats subdivided into control, saline and Met groups which received saline or Met (500mg/kg) and in diabetic group including DM, DM+saline and DM+Met subgroups, diabetic rats received saline or Met (100, and 200mg/kg) for 20 days. Diabetes was induced by intraperitoneal injection (ip) of streptozotocin (STZ).
Results: Our results showed that Met (500mg/kg, ip) impaired spatial learning but improved spatial memory in normal rats. The results also showed that Met improved learning and memory in diabetic rats in a dose dependent manner, so that the rats of DM+Met group compared to DM+saline group found platform in less time and with less distance traveled. Met also increased the percentage of time elapsed and the distance swum in the target quadrant in diabetic rats during the probe trial.
Conclusion: An intraperitoneal injection of STZ resulted in a significant decline in learning and memory and treatment with Met can enhance learning and memory in a dose dependent manner, therefore, it is useful for treatment of cognitive impairment in diabetic patients.
Mr. Ahmad Fazeli Sani, Dr. Hasan Matin Homaee, Dr. Abdolali Banaeifar,
Volume 20, Issue 3 (10-2020)
Abstract
Background & objectives: Mitochondrial dysfunction is one of the main risk factors for neurological diseases which are associated with aging. On the other hand, aerobic exercise has beneficial effects on the brain health and cognitive function, and also improves mitochondrial dynamics. Therefore, the aim of the present study was to investigate the effect of 4 weeks of aerobic exercise on spatial learning, memory performance and mitochondrial dynamics in the hippocampal tissue of old rats.
Methods: For this purpose, 14 male Wistar rats at 20 months of age were randomly divided into 2 groups: aerobic exercise (n=7) and control group (n=7). The exercise group performed 4 weeks of treadmill training (5 days per week at a speed of 10 to 15 m/min). Forty-eight hours after the last training session, the animals underwent behavioral tests. Twenty-four hours after the behavioral test, all rats were killed and hippocampal tissue was extracted. The mRNA expression of OPA1, Mfn2 and Drp1 genes were assayed using Real Time-PCR. The Independent t test was used for statistical analysis.
Conclusion: Aerobic exercise in old animals improved spatial learning and memory performance, increased hippocampal OPA1 gene expression, and decreased Drp1 gene expression compared to the control group (p≤0.01).
Conclusion: It seems that aerobic exercise can improve the function of brain mitochondria by modulating fusion and fission processes and it can be considered as an effective non-pharmacological method to deal with aging-related learning and memory perturbations.
Ensieh Ahmadpour, Maghsoud Piri, Mohammad Ali Azarbijani,
Volume 21, Issue 4 (1-2022)
Abstract
Background & objective: Alzheimer's disease (AD) is the most common cause of dementia among the elderly, threatening their quality of life. On the other hand, regular exercise is associated with improved brain health and cognitive function. However, the mechanisms of these benefits have not yet been fully elucidated. Therefore, the aim of this study was to investigate the effect of 4 weeks of moderate intensity interval aerobic training on cognitive function and expression level of PGC1α and VEGF genes in the hippocampus of old rats with AD.
Methods: For this purpose, 20-month-old male Wistar rats were divided into three groups of AD (n=8), AD+exercise training (n=8) and control (n=8). Intra-hippocampal injection of Aβ42 was used to induce AD. The animals in the exercise group performed moderate-intensity interval aerobic exercise for 4 weeks, 5 days a week. To assess spatial learning and memory, the animals underwent the Morris water maze test 48 hours following the last training session. Then, the animals were killed and hippocampal tissue was extracted. Real time-PCR method was used to measure gene expression. Statistical analysis was performed using one-way analysis of variance and Pearson correlation coefficient at the significance level of p£0.05.
Results: The results showed that Aβ42 injection impaired spatial learning and memory function and reduced the expression level of PGC1α and VEGF genes in hippocampal tissue (p£0.05). Aerobic exercise improved spatial learning and memory function and increased PGC1α and VEGF genes expression (p£0.01). Also, a significant positive relationship was observed between the PGC1α and VEGF gene expression levels in the hippocampus (r= 0.859, p≤0.01). In addition, there was a significant inverse relationship between PGC1α and VEGF genes expression and the mean time spent to find the platform (r= -0.9, p£0.01 and r= -0.750, p£0.01, respectively), and a significant positive relationship with the time spent in the target quadrant (r= -0.794, p£0.01 and r= -0.632, p£0.01, respectively).
Conclusion: In general, aerobic training improves spatial learning and memory performance in old animals with AD; up-regulation of the exercise-induced PGC1α/VEGF pathway in the brain, at least in part, appears to be involved in this adaptation.
Adele Naseri, Mohammad Shariatzadeh Joneydi, Arefe Naseri,
Volume 22, Issue 2 (7-2022)
Abstract
Background & objectives: Brain trauma is one of the most common causes of damage to the central nervous system which can lead to death and long-term disability. The present study aimed at investigating the effect of 8 weeks of swimming exercise on the level of memory and interleukin 10 (IL-10) in the hippocampus and prefrontal cortex of mice with brain trauma.
Methods: 40 male NMRI mice were randomly divided into four groups (control, swimming, trauma, swimming + trauma). After completing the exercise protocol, induction of trauma was performed by the weight -drop method. Ten days after trauma induction, the mice were evaluated for spatial memory with Y-maze test. The IL- 10 level was measured using ELISA technique. One-way analysis of variance and Tukey post hoc test were used for statistical analysis at a significance level of p<0.05 and using SPSS software version 26.
Results: The study results indicated that eight weeks of swimming exercise significantly increase memory in mice with brain trauma (p=0.001). Furthermore, eight weeks of swimming exercise significantly increase the level of IL-10 in the hippocampus of mice with brain trauma (p=0.001). However, this increase was not significant in the prefrontal cortex (p=0.126).
Conclusion: The results of the present study showed that swimming exercise before induction of brain trauma reduces inflammation and memory disorders and facilitates recovery after injury. Previous exercise training can probably reduce inflammation by increasing the amount of anti-inflammatory cytokines, including interleukin-10, and limit secondary damage with its protective effect.
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