Showing 7 results for Spatial 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.
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.
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.
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.
Fatemeh Heidari Soureshjani, Majid Kheirollahi, Parichehreh Yaghmaei, Fattah Sotoodehnejadnematalahi,
Volume 23, Issue 4 (9-2020)
Abstract
Background and Aim: Alzheimer's Disease (AD) is a neurodegenerative brain disease that gradually destroys memory and cognitive skills. The disease is caused by the formation of beta-amyloid plaques, oxidative stress, dysfunctions in the cholinergic system, neuronal killing inflammation, and ultimately brain atrophy. Donepezil and hyoscyamoside have inhibitory effects on these pathogens; therefore, their impact on the learning process of Alzheimer’s rats in the Morris Water Maze was investigated.
Methods & Materials: In the present experimental study, 60 male rats of Wistar breed with approximately 7 weeks age within the control group (rats that received normal water and food), the PBS group (underwent surgery), PBS group (received solvent Aβ), the first Alzheimer›s group (animals that received beta-amyloid by Alzheimer’s surgery, second Alzheimer’s group (after Alzheimer’s surgery, they received 1 cc of normal saline daily, and treatment groups that treated the rats with beta-amyloid after Alzheimer. In the hyoscyamoside group, they received 10 mg/kg daily of hyoscyamoside for 28 days. The donepezil group received it 4 mg/kg daily for 28 days by gavage. The Morris Water Maze test was used to evaluate learning and memory. Data were analyzed by ANOVA statistical analysis and Post Hoc test.
Ethical Considerations: The Ethics Committee in Biomedical Research, Islamic Azad University, Science and Research Branch approved the research (Code: IR.IAU.SRB.REC 1397.057)
Results: Beta-amyloid injection caused extensive damage to memory. The treatment groups with hyoscyamoside and donepezil spent less time and distance with a significant level (P<0.001) than the group of Alzheimer’s patients to find the hidden platform. In the reminder phase, where the previously hidden platform was located, they spent more time, with a significant level (P<0.001) in the local quarter.
Conclusion: Treatment of rats with hyoscyamoside and donepezil improved spatial memory in Alzheimer’s rats. They appear to play a significant role in the prevention and treatment of Alzheimer’s disease.
Masoumeh Gholami, Mr Hossein Bakhtiari-Dovvombaygi, Miss Mahla Rezaei–shandiz, Dr Saeed Pazhoohan, Mehdi Sadegh,
Volume 26, Issue 3 (9-2023)
Abstract
Introduction: Maternal folate supplementation during pregnancy is associated with reduced risk of several fetal neurodevelopmental disorders. However, it is not well known that excess folate intake from diet and supplements can impair neurodevelopment and behavior in offspring. Therefore, the aim of this study is to investigate the effect of chronic and high doses of folic acid before and during pregnancy in female rats on learning and spatial and avoidance memory in male and female offspring.
Methods: 24 female Wistar rats received doses of 0.5, 1, and 2 mg folic acid by intraperitoneal injection two weeks before and during pregnancy. The control group received normal saline. Male and female offspring were divided into 8 groups. Learning behavior and spatial memory were measured by Morris blue maze test, avoidance memory by shuttle box test. The results showed that taking a dose of 2 mg folic acid before and during pregnancy causes spatial learning deficits in male offspring.
Results: While spatial memory is unchanged compared to the control. This dose of folic acid also causes a disturbance in avoidance memory in both male and female offspring.
Conclusions: Our results suggest that high doses of folic acid supplements during early life (fetal) have the potential to impair neurological functions such as memory. Although the severity of this disorder can depend on the gender of the child.
