Showing 23 results for Memory
Mohammad Reza Palizvan, Hajar Rajabian, Elahe Mirzazadeh, Yahya Jand, Ehsan Alah Ghaznavi Rad,
Volume 11, Issue 4 (12-2008)
Abstract
Background: Although the roles of steroid hormones in the activation and maintenance of reproductive function are proved well, emerging evidence indicated that these steroids influence on performance of learning and memory. These effects are complex and vary with task, gender, and age, as well as the regimens of steroid exposure. This study was carried out in order to assess the role of progesterone administration in newborns rats on Morris water maze learning ability after adolescence.
Methods and Materials : This experimental study was carried out on 36 newborns Wistar rats. Rats were divided randomly into 6 groups female progesterone, male progesterone, female sesamoide, male sesamoid rats and male and female control rats. Progesterone groups were treated with a single injection of progesterone (100 mg/kg) and sesamoid groups were received the same volume of sesamoid oil as the progesterone vehicle in day 1 or 2 after brith, 60 days later, spatial memory ability was determined in Morris water maze.
Results : The results of this study show that water maze learning can enhance by administration of sesamoid oil in newborn female pups in compared to progesterone and control groups (p<0.05). In addition, adding progesterone to sesame oil reduce water maze learning to control level.
Conclusion: The hypothesis that progesterone impaired spatial reference memory in female rats was supported by this experiment.
Mahmoud Salami, Gholam Ali Hamidi, Zahra Aghanouri, Mozhgan Dadkhah,
Volume 11, Issue 4 (12-2008)
Abstract
Background: Sensory signals and intrinsic activity of the neuronal circuits deeply influence on developing the sensory systems in early life. Light deprivation of animals is known as an established method in assessment of environmental signals in development of the nervous system. Methods and Materials: In this experimental study eighteen male rats at 75 days of postnatal age were used. The animals were divided in two groups, one reared in a cycle of 12light/12dark (light reared-LR) and the other keep in darkness since birth through experiment (Light deprived- LD). The animals were trained in a Morris water maze for spatial memory. They must navigate the maze until finding a platform hidden 1 cm below of water. Then, the time required and the distance spent to find the platform were measured for assessment of the animal behavior. Each animal was given 4 trials/day and the experiment lasted for 6 days. This stage was followed by probe and postprobe tests to evaluate how the learning is consolidated. Results: The results indicated that, compared to their LD counterparts, the LR group was superior in finding the platform where they required a noticeable shorter time to hit the platform(p<0.009). Also, animals in the LR group steered a shorter distance to find the target than did the LD animals(p<0.034). While the two groups elicited a considerable difference during the first half of the experiment both LR and LD rats demonstrated a similar behavior over the second half of the study. Conclusion: The light deprivation negatively influences the spatial navigation in water maze so that the visually deprived rats show less ability in searching the maze based on the spatial cues.
Ebrahim Nabaee, Fereshteh Motamedi, Mohammad Ali Shariat Zade, Masoomeh Nabaee,
Volume 12, Issue 2 (9-2009)
Abstract
Background: REM sleep has a role in memory processing. The period of post-learning, that REM sleep is higher than normal level and deprivation of REM sleep impairs memory, is called paradoxical sleep windows (PSW). Methods and Materials: In this experimental study, male N.M.RI rats were trained in a two-way shuttle avoidance task (100 trials/one sessions) then memory retention was tested in next week. In electrophysiology section, different sleep-memory factors were recorded in basal level and 1-4 hours after training. In behavioral section, animals that reached 70% learning criterion (learner group) were deprived of PS in the two periods of 1-4 hours and 5-8 hours after learning by Maze water technique. Results: The amount of REM sleep in group which gained 70% learning after 1-4 hours training, and group without it. In v.s of basic level, significantly increase (p0.01). Other factors were showed no significant difference between two groups before of training. In behavioral section those animals were deprived in 1-4 hr post-learning show significant memory impairment (p0.05). Conclusion: Paradoxical increased REM sleep is effective in memory consolidation after 1-4 hours training. This period can be consider as paradoxical sleep window.
Morteza Kafaee Razavi, Saeedeh Ebrahimpour, Maryam Tehranipour, Morteza Behnam Rasouli,
Volume 13, Issue 2 (6-2010)
Abstract
Background: From a physiologic point of view, memory is formed through changes in synaptic conductivity from one neuron to the next. These changes result in the formation of long-term potentiation for conducting a message. Cannabis sativa has more than 61 components that are called cannabinoid. The aim of this study was to investigate the effect of aquatic extraction of cannabis sativa seed on spatial memory consolidation in rats. Materials and Methods: First, 40 Wistar rats, each nearly 250-320g, were divided into four experimental groups and a control group. Cannabis sativa seed was extracted with Soxhlet apparatus. To consolidate spatial memory, Morris water maze (MWM) test was administered in seven sessions, four trials for each session. Experimental groups 1, 2, 3 and 4 received 50mg/kg-1, 100mg/kg-1, 150mg/kg-1, 210mg/kg-1 peritoneal injections (IP), respectively. After memory consolidation, the position of platform area was changed and MWM was repeated for five days. Results: The results show that experimental groups 1, 2, and 3 had a significant decrease in learning time in the comparison to the control group (p<0.05), whereas experimental group 4 with a 210mg/kg-1 dose did not reveal any significant difference in comparison to the control group (p<0.05). Conclusion: It is likely that this long-term potentiation is done through depolarization-induced suppression inhibition (DSI) and depolarization-induced suppression excitatory (DSE) mechanisms in the CA1 area of Hippocamp that lead to neuro-plasticity through neurotransmitter regulation.
Gholamreza Chalabianloo, Mirtaghi Garooci Farshi, Ali Akbar Malekirad, Ali Hashemzadeh,
Volume 13, Issue 2 (6-2010)
Abstract
Background: Memory is one of the main functions that is impaired by neurological disorders. Noticing the susceptibility of memory to emotions, the effect of emotional states on memory in patients with alzheimer, brain tumor, and normal individuals was investigated in this study. Materials and Methods: Through Causal-Comparative study, 26 patients with alzheimer, 38 patients with brain tumor, and 30 normal individuals were selected and tested by a memory-related computerized task on explicit recall memory and implicit memory. Results: Patients with alzheimer showed a poor performance in memory tasks. They recognized more sad and threatening words in their explicit memory. Overall, patients with alzheimer and tumor in comparison with normal individuals indicated poorer explicit/implicit memory functions, respectively. Conclusion: Cognitive processes of patients with alzheimer are influenced when they encounter simple emotional stimulus.
Roghani, Khalili, Baluchnejadmojarad, Heydari,
Volume 14, Issue 1 (3-2011)
Abstract
Background: Chronic diabetes mellitus is accompanied with disturbances in learning, memory, and cognitive skills. Noticing the existing evidence regarding the anti-diabetic potential of hesperetin, the effect of its chronic administration on learning and memory in diabetic rats was investigated. Materials and Methods: In this experimental study, 40 male Wistar rats were divided into control, hesperetin-treated control, diabetic, and hesperetin/glibenclamide-treated diabetic groups. For evaluation of learning and memory, initial (IL) and step-through latencies (STL) were determined at the end of the study using passive avoidance test, and the alternation behavior percentage was obtained using Y maze. Results: STL significantly decreased in the diabetic (p<0.01) and hesperetin-treated diabetic (p<0.05) groups in comparison to the control group however, the difference between these two groups was not significant. Alternation percentage in the diabetic group was significantly lower in comparison to the control group (p<0.05), but the hesperetin-treated diabetic group revealed a significant difference in comparison to the diabetic group (p<0.05). Conclusion: Although long-term treatment with hesperetin does not enhance the capability of retention and recall in diabetic animals on the passive avoidance test, it can improve the short-term spatial memory in diabetic animals.
Akram Eidi, Tahereh Eshraghi, Ali Haeri Rohani, Maryam Eidi, Mahsa Jolaian,
Volume 15, Issue 1 (4-2012)
Abstract
Background: It has been indicated that there is a relationship between vitamin B12 status and cognitive functioning. Measurement of serum vitamin B12 is routinely performed in patients with memory loss during initial diagnosis. Noticing the role of cholinergic system and vitamin B12 on memory, the aim of this experimental study was to examine the effect of the interactions between vitamin B12 and nicotine on memory retention in passive avoidance learning in adult male rats.
Materials and Methods: The present study was an experimental one. Drugs, including vitamin B12 (0.01, 0.02, 0.03, 0.05, 0.1, and 1 µg/rat) and nicotine (0.1, 0.5, and 1 µg/rat) were administrated after training session intracerebroventriculary (i.c.v.). The drugs were used (i.c.v.) in a volume of 1µl/rat immediately after the training session. The level of memory retention was evaluated by passive avoidance learning. Twenty-four hours after training, a retention test was performed to determine long-term memory. Statistical analysis was carried out using one-way ANOVA test.
Results: The results showed that the administration of vitamin B12 and nicotine significantly increased memory retention in rats. Nicotine significantly increased the response to vitamin B12 in memory retention process.
Conclusion: Vitamin B12 through interaction with cholinergic system acts in memory retention process.
Mozhgan Torabi, Mahdi Firoozan , Mahnaz Kesmati,
Volume 16, Issue 12 (3-2014)
Abstract
Background: Studies have shown that central cholinergic system can be effective on animal memory in objects emplacement, but there were no sufficient information about the consumption of effective substances on this system during pregnancy in novel object recognition in compared to old object and its effect on the fetus. The aim of this study is investigation of lecithin (as a source of choline) effect during pregnancy and lactation on object recognition behavior as a marker of cognitive memory in male and female rat offspring.
Materials and Methods: In the present experimental study, female rats with an average weight of 160±10 g were gavaged of pregnancy (22 days) until 21 days after the parturition by different amounts of lecithin or its vehicle. The groups were: control (without receiving any medications), vehicle and receiving lecithin with amounts 120 and 240 mg/kg. After gender segregation, at 36 days of birth offspring were trained to evaluate the recognition memory. The number of offspring in each group for each sex was 7.
Results: Results showed that consumption of lecithin 240mg/kg in female offspring was lead to increase in percentage of time spent in near of novel object in compared with vehicle group (p<0.05). While in other groups there was no difference between offspring.
Conclusion: Lecithin consumption during mother pregnancy and lactating lead to change in precognitive memory of female offspring and also sex can cause different effects of this compound in the body of an animal.
Ameneh Rezayof, Mohammad Reza Zarrindast, Niloufar Darbandi,
Volume 17, Issue 6 (9-2014)
Abstract
Background: It is well known that morphine influence learning and memory processes. The Nucleus accumbens (N.ac) which has an important role in reward participates in morphine-induced impairment of memory retention. Considering the cholinergic system is involved in the effects of morphine on learning and memory, in the present study, the effects of intra-N.ac injections of acetylcholine receptor antagonists alone or with morphine on memory retention and morphine-induced memory has been investigated in rats.
Materials and Methods: In this original research animals were bilaterally cannulated in the N.ac and a step-through passive avoidance task was used for the assessment of memory retention .
Results: Post-training subcutaneous administration of morphine dose dependently decreased the learning and induced amnesia. The administration of the same dose of morphine as pre-test treatment induced state-dependent learning. Pre-test intra- N.ac administration of atropine, scopolamine and mecamylamine in different doses alone cannot affect on memory retention. While, pretest intra- N.ac injection of these drugs before the administration of morphine dose dependently inhibited morphine state-dependent learning. The level of statistical significance was set at p<0.05 .
Conclusion: The processes of learning in animals can be affected by morphine and the opioids produce state-dependent learning. Moreover, it can be concluded that inactivation of the muscarinic and nicotinic acethylcoline receptors in the N.ac are involved in mediating morphine state-dependent learning.
Zeinab Sargholi Nootarki, Mahnaz Kesmati, Mahdai Poormehdi Borujeni,
Volume 18, Issue 7 (10-2015)
Abstract
Background: Failure to pass the blood-brain barrier is a serious challenge to the use of magnesium in the treatment of neurologic disorders. But , recently, applying magnesium oxide nanoparticles that is capable of crossing biological barriers has created new hopes. According to the reinforcing effects of magnesium oxide nanoparticles on memory and ambiguity in the best time of application and duration of its effects, the aim of the present study was to compare effects of pre-and post-training administration of different doses of magnesium oxide nanoparticles on long-term memory.
Materials and Methods: In this experimental study, fifty- six adult male NMRI mice in the control group and receiving magnesium oxide nanoparticles group at doses of 1, 2.5 and 5 mg/kg (I.P) before and after training were used. Long-term memory of mice in a week on days 1,3and7 days after training (shock) by using step-down device and passive avoidance learning method was assessed. Time latency in coming down the secure platform was considered as the memory assessment scale.
Results: The results showed that injection of nano-magnesium oxide in both the 2.5 and 5 mg/kg improved memory through increasing the latency in coming down the secure platform during a week (p< 0.001), without any changes in locomotor activity, whereas, it had no effect at 1 mg dose. Pre-training injection of magnesium oxide nanoparticles increased memory relatively, it wasn't statistically significant compared to the control group.
Conclusion: According to the above results, magnesium oxide nanoprticles improves long term memory, and it is possible when the training and the acquisition has occurred, otherwise it will not make a significant impact .
Elham Soleimani, Iran Goudarzi, Kataneh Abrari, Taghi Lashkarbolouki,
Volume 19, Issue 2 (5-2016)
Abstract
Background: Few studies have investigated the possible ways to prevent lead induced defects during gestation and lactation. The aim of this study was to investigate the effect of melatonin as a hormone with antioxidant properties on oxidative stress in the hippocampus and learning and memory impairment induced by administration of lead.
Materials and Methods: Pregnant rats were exposed to treatments of control, lead acetate (0.2% solution in water), lead acetate + melatonin and melatonin (10 mg / kg by oral gavage) from gestation day 6 until weaning. 21 days after birth, the activities of several antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) as well as malondialdehyde levels in hippocampus of 23 male offspring rats were assayed. To behavioral studies, on postnatal day 30, 57 rats were trained 6 days in the Morris water maze and the probe test was performed 24 h later.
Results: The results showed that administration of lead during pregnancy and lactation could increase MDA levels and decrease glutathione peroxidase, superoxide dismutase and catalase antioxidant enzymes activities in the hippocampus of male offspring. Also, this treatment significantly disrupted performance of the Morris water maze test and impaired learning and spatial memory in male offspring compared with control. Administration of melatonin attenuated lipid peroxidation and could improve learning and spatial memory deficits and the activity of antioxidant enzymes in lead exposure group.
Conclusion: Melatonin as a neuropotective drug can protect the hippocampus against the complications of lead exposure, in the course of development.
Mahbobe Ebadi, Fatemeh Hoseini, Fateme Pahlevan, Mohammad Esmaeilzade Akhoundi, Vahid Farhadi, Roqaye Asqari,
Volume 20, Issue 5 (8-2017)
Abstract
Abstract
Background: The aim of this study was to evaluate the effectiveness of of transcranial direct current stimulation (tDCS) on working memory in patients with major depression.
Materials and Methods: The research method was quasi-experimental with pretest and post-test and follow-up with control group. The research population comprised female outpatient referrals to private psychiatric centers and psychological counseling centers in Tehran in the first half of 2016, They had received a diagnosis of depression by a psychiatrist at least once. Of these, 30 females were selected as a sample group with convenience sampling method and based on the criteria of inclusion and exclusion and were divided randomly into two groups , experimental (n = 15) and control (n = 15) group. The experimental group received transcranial direct current stimulation (tDCS) in 10 sessions, While this intervention was not provided to the control group. The data were collected by N-BACK. Analysis of variance with repeated measurments was used to test the research hypothesis.
Results: The results showed that transcranial direct current stimulation (tDCS) had a significant effect on increasing working memory and the impact will continue to follow up.
Conclusion: Therefore, this approach can be used to improve working memory in people with major depression.
Azam Alinaghipour, Marziyeh Tavassoli, Elahe Seyed Hosseini, Abolfazl Ardjmand,
Volume 20, Issue 7 (10-2017)
Abstract
Abstract
Background: Neuronal damage following seizures and epilepsy is one of the main causes of disabilities and mortality worldwide. In recent years, preconditioning has been introduced as a novel strategy for the prevention of brain damage. Preconditioning is a phenomenon in which a minor noxious stimulus protects from a subsequent more severe insult. The aim of present study was to examine the effect of ethanol (Eth) preconditioning on pentylenetetrazole (PTZ)-induced impairment memory in the inhibitory avoidance model.
Material and Methods: This study was carried out on 45 adult male Wistar rats (180-200 g). Animals were assigned into five groups: Control, Eth 0.25, Eth 0.5, PTZ and Eth (0.5) +PTZ (n=9, for all groups). Eth-preconditioning was induced 6 days before the injection of PTZ. The animals were tested in a single trial step-through inhibitory test in two sessions (train and test). Then locomotor activity of rats was recorded in the open-field apparatus and NR1 mRNA expression in the hippocampus was measured by real-time PCR technique.
Results: One-way ANOVA revealed that the Ethanol preconditioning did not impair inhibitory memory. Further, post-test analyses showed that Ethanol preconditioning significantly prevented from PTZ-induced memory impairment, and increased NR1 subunit mRNA expression in PTZ-induced memory impairment group. In addition, one-way ANOVA for the locomotor activity showed no significant difference between the groups.
Conclusion: Our results showed that a pre-conditioning treatment with Ethanol
(0.5g/kg/day), 6 days before PTZ-induced memory impairment may provide a kind of neuroprotection in rats.
Javad Sohrabi Asadabad, Zohreh Ghotbeddin, Mohammad Reza Tabandeh,
Volume 20, Issue 9 (12-2017)
Abstract
Abstract
Background: A lot of studies indicate that cancer chemotherapy drugs such as doxorubicin results in memory impairment. On the other hand, crocin as the chemical constituent isolated from the Saffron is effective on memory and motor enhancement. So, in this work, we have studied the co-administration effect of crocin and doxorubicin on avoidance memory and motor activity in adult male rat.
Material and Methods: In this study, 50 male rats were divided into 5 groups: control, sham, doxorubicin, crocin and treated rats with coadministration of doxorubicin and crocin. In crocin group, crocin injected 30mg/kg for 21 days and each rat in the chemotherapy group was treated once a week for 3 weeks with doxorubicin (5mg/kg). Treatment group, received doxorubicin and crocin at the same time. Sham groups administrated with saline. All drugs were injected intraperitoneally. After these procure passive avoidance memory, balance and exploratory behaviors were assessed respectively by shuttle box, rotarod and open field instruments.
Results: Memory in rats which have consumed doxorubicin significantly was decreased compared to other groups (p<0.001). Crocin treatment improved memory impairment following doxorubicin injection (p<0.001). Motor activity in open field and rotarod tests in treatment group showed significantly increased compared to doxorubicin group (p<0.001).
Conclusion: Crocin consumption beside of anticancer drugs such as doxorubicin has protective effect on the bad effects of chemotherapy drugs on memory and movement.
Niloufar Darbandi, Hamidreza Momeni, Mahshid Tajiani,
Volume 20, Issue 10 (1-2018)
Abstract
Abstract
Background: Alzheimer is a neurodegenerative disease wich caused memory impairment, reduced cognitive functions, intellectual ability and behavior changes. In this study, the effect of N-acetyl-cysteine (NAC) as a strong antioxidant on memory deficiency and number of CA1 pyramidal neurons in Streptozotocine (STZ) - induced Alzheimeric rats were studied.
Materials and Methods: 32 Male Wistar rats were divided into four groups: sham group, streptozotocin group, treated group with streptozotocin plus N-acetyl-cysteine, and treated group with N-acetyl-cysteine alone. Intracerebroventricular (ICV) administration of STZ was done in the first and the third day of surgery and i.p injection of N-acetyl-cysteine was done in the fourth of surgery. After the memory test, the animals were killed and their brains were fixed and density of intact neurons in the CA1 area of the hippocampus was investigated. Statistical analysis was performed with software SPSS, ANOVA and Prisme software. The level of statistical significance was set at p < 0.05.
Results: The ICV injections of STZ significantly reduced memory retention and intact pyramidal cells compared to the sham group (p<0.001). Administration of N-acetyl-cysteine improved STZ-induced effects on memory retrieval and increased intact neurons in hippocampal CA1 area compared to the STZ group (p<0.001). N-acetyl-cysteine alone doesn’t have any significant effect on memory retrieval and the number of intact neurons in hippocampal CA1 area compared to the sham group (p>0.05).
Conclusion: N-acetyl-cysteine improved memory retrieval and hippocampal CA1 area intact neurons in streptozotocin-induced Alzheimeric male rats.
Malahat Amani, Hossein Alizade, Esmaeil Shiri,
Volume 20, Issue 10 (1-2018)
Abstract
Abstract
Background: The exact diagnosis of schizophrenic disorder from schizoaffective disorder has always been a challenge for therapists due to the comorbidity of many signs and symptoms. The purpose of this study is to investigate the differential diagnosis of schizophrenia disorder from schizoaffective disorder, focusing on the emotional content of their memories.
Materials and Methods: The present study is a causal-comparative study on 23 male and female patients with schizophrenia and schizoaffective disorder (without any comorbid diagnosis). Using a clinical interview, the emotional events and memories of their lives, as well as the amount of affective and emotional words used by these patients in expressing their memories, have been assessed. To determine the differences between the two groups, the data were analyzed by Chi-square test.
Results: Results showed that men with schizophrenia had a significant difference in expressing the amount of emotional events in their lives, as well as in expressing affective and emotional words compared to schizoaffective men. But, this difference was not observed in schizophrenic and schizoaffective women.
Conclusion: The findings of this study suggest that differential diagnosis of schizophrenia and schizoaffective disorder can be made with emphasis on the emotional content of memories, especially in men.
Fatemeh Jalalvand, Masoumeh Asle-Rousta,
Volume 21, Issue 3 (6-2018)
Abstract
Background and Aim: Chronic restraint stress impairs spatial learning and memory. Myrtle (Myrtus communis) has antioxidant, antidiabetic, hepatoprotective and neuroprotective properties. The aim of this study was to investigate the effect of myrtle hydroalcoholic extract on chronic restraint stress-induced spatial learning and memory deficit in adult male Wistar rats.
Materials and Methods: In this experimental study, 80 adult male Wistar rats were allocated to eight groups (10 in each) included control group (intact), myrtle0.75, myrtle1.5, myrtle3 groups (were gavaged with hydroalcoholic extract of myrtle at 0.75, 1.5 and 3 mg/ kg bw doses), stress group (restrained in restrainers for 6 hours per day for 21 consecutive days), stress- myrtle0.75, stress-myrtle1.5 and stress- myrtle3 groups (received myrtle extract at 0.75, 1.5 and 3 mg/ kg bw doses and exposed to chronic immobility stress). Spatial learning and memory were examined through the Morris water maze test.
Findings: Chronic immobilization stress caused spatial learning and memory impairment. Consuming doses 1.5 and 3 of Myrtle extract to stressed animals caused significant decrease in spent time and swam distance to reach the hidden platform (p<0.05) and increased time lapsed in target quadrant comparing with stress group (p<0.05).
Conclusion: It has been concluded that myrtle extract can improve spatial learning and memory in rats exposed to stress in a dose dependent manner.
Asma Mahmoodi, Farhad Ghadiri, Ali Rashidi-Pour,
Volume 21, Issue 4 (8-2018)
Abstract
Background and Aim: Stress is a powerful modulator of memory performance. Emotional arousal affects the various aspects of learning and memory through stimulation of the amygdala or the hippocampus. The aim of the present study was to investigate the effects of stress related acute exercise on reconsolidation of dart throwing task learned with errorless method.
Materials and Methods: Participants of the study included 60 girls with an average age of 20.5 who were randomly assigned to three groups including: target (n = 20), control (n=20), and control 2 (n = 20). On the first day, all three groups under the same conditions acquired the skill of throwing darts in an errorless method and immediately after that performed the immediate retrieval. On the second day, after memory reactivation, the target group was exposed to stress resulting of acute exercise while the control 1 group did rest. The acute stress was presented to control 2 group without memory reactivation. During the experiment, changes in salivary cortisol were measured. On the third day, the delayed memory retrieval for each of the three groups was implemented.
Findings: the results showed that while the control 1 and control 2 groups did not show enhancement of dart throwing learning across delayed memory retrieval than immediate retrieval, the target group showed substantial enhancement across the same time (p<0.05).
Conclusion: Our findings indicate that acute stress after memory reactivation can facilitate the implicit motor memory reconsolidation in women.
Mohammad Amin Edalatmanesh, Habibollah Khodabandeh, Nooshin Yazdani, Samaneh Rafiei,
Volume 21, Issue 6 (12-2018)
Abstract
Background and Aim: Neuropathy is the most common abnormality in diabetes mellitus which characterized with cerebral damages especially in hippocampus. This study evaluates the effect of Cinnamomum Zeylanicum extract (CZE) on memory, hippocampal neuron damage and antioxidant enzymes levels in animal model of diabetes.
Materials and Methods: 50 adult Sprague dawley rats were randomly divided into 5 groups: Control, STZ (Streptozotocin, 50 mg/kg; i.p.), and STZ + CZE100, STZ + CZE200 and STZ + CZE400 which were treated with CZE in 100, 200 and 400 mg/kg, respectively. CZE was administered in 14 days, orally. After evaluation of working and spatial memory, activity of catalase (CAT) and glutathione peroxidase (GPx) enzymes was assessed by ELISA. Then, histopathological assessment of hippocampus was done.
Findings: In comparison with the controls, STZ group showed an increase in latency time and distance to the hidden platform in MWM, a decrease in alteration behaviors, cell density and activity of CAT and GPx enzymes in hippocampus (p˂0.05). In addition, treatment with CZE decreased latency time and distance in MWM and increased alteration behavior, hippocampal cell density and activity of antioxidant enzymes in comparison with the STZ group (p˂0.05).
Conclusion: Diabetes with reduction of neuronal density and activity of antioxidant enzymes in the hippocampus causes deficits in spatial and working memory. However, Administration of CZE ameliorates these neuropathologic disorders.
Maryam Rahimi Tesiye, Farhad Valizadegan, Shahrbanoo Oryan,
Volume 22, Issue 1 (4-2019)
Abstract
Background and Aim: Working memory is a dynamic neural system for temporarily maintaining and processing of information. Prefrontal cortex (PFC) is the main processing center of Working memory by using different neurotransmitter systems communicate with other brain structures such as Basolateral Amygdala (BLA). In this study, we investigated the role of Opioidergic system in medial PFC and Dopaminergic system of BLA nucleus in working memory based on RAM test.
Materials and Methods: In this study, The male Wistar rats were used. Rats were cannulated with stereotaxic surgery in mPFC and BLA sites. After a recovery period, they were microinjected. Parameters such as working and reference memory errors were calculated with DSWS protocol.
Ethical Considerations: This study with research ethics code IR.UMZ.REC.1397.23 has been approved by Bioethics Committee at Mazandaran University, Iran.
Findings: High doses of Morphine (2 µg/rat) intra mPFC and Chloropromazine (2 µg/rat) intra BLA have improving effects on working and reference memory (p≤0.05). Low (0.005 µg/rat) and high dose (0.5 µg/rat) of Apomorphine had improving {(p≤0.05), (p≤0.01)} and the moderate dose (0.05 µg/rat) of it had decreasing effect on working and reference memory (p≤0.01). Microinjection of Morphine (0.5 µg/rat) with triple doses of Chloropromazine had no significant change on working and reference memory errors. Interaction of Morphine (0.5 µg/rat) with different doses of Apomorphine could change Apomorphine different effects. Coadministration of different doses of Apomorphine with effective dose of Chloropromazine (2 µg/rat) and Morphine (2 µg/rat) decreased the working and reference memory errors.
Conclusion: Our findings showed that in processing of working and reference memory, opioidergic system in mPFC and dopaminergic system in BLA, are interacting reciprocally.
