Showing 9 results for Learning
Aa Vafaei, A Rashidy-Pour ,
Volume 12, Issue 1 (4-2004)
Abstract
Introduction: Many evidences have suggested that the Basolateral Amygdala (BLA) are probably involved in emotional learning and modulation of spatial memory processes. The aim of this present study was assessment of the effect of reversible abolition of BLA on spatial memory processes in a place avoidance learning model in a stable environment.
Methods and Materials: Long-Evans strain rats (280-320 gr.) were selected and cannulae aimed at the BLA were surgically implanted bilaterally. The mice were trained to avoid a 60° segment of the arena by punishing with a mild foot shock upon entering the area. The punished sector was defined by room cues during the place avoidance training, which occurred in a single 30-min session and the avoidance memory was assessed during a 30-min extinction trial after 24 hours. The time of the first entry and the number of entrances into the punished sector during extinction were used to measure the place avoidance memory. Bilateral injections of Tetrodotoxin (5ng/0.6ml per side) were used to inactivate the BLA 60 min before acquisition, immediately, 60 and 120 min after training, or 60 min before the retrieval test. Control mice were injected saline at the same time.
Results : The results indicated that acquisition, consolidation (immediately, 60 min after training) and retrieval of spatial memory in stable arena were impaired (p<0.01). Injection of TTX 120 min after training had no significant effect. (p value>0.05).
Conclusion: We conclude that the Basolateral Amygdala (BLA) modulate spatial memory processes in place avoidance learning model in stable arena and this effect in regard to consolidation is time dependent.
Z Zamani, P Reisi, H Alaei, Aa Pilehvarian,
Volume 20, Issue 2 (6-2012)
Abstract
Introduction: Studies have proposed that royal jelly(RJ) has various biological activities in different cells and tissues. Since it has been demonstrated that RJ contains compounds having desirable effects on central neurons system and neural functions, the present study aimed to investigate the effect of royal jelly on learning and memory in rats.
Methods: Male wistar rats were divided into two groups, the royal jelly and the control. In the RJ group, the rats received a food that contained 3% RJ instead of regular food for 10 days. Then learning and memory were investigated in these animals through both passive avoidance learning test(1 day and 1 week after receiving electrical shock) and Morris water maze test(1 day and 1 week after a 4-day learning period).
Results: The study results indicated that the food containing RJ in the RJ group significantly increased the time of the first entrance to the dark room one week after the electrical shock in passive avoidance learning test. In other words, the findings suggest an improvement of learning and memory in RJ group. In the acquisition phase of Morris water maze test, rats receiving RJ found the underwater escape plate during less time and distance comparing with the control group. Furthermore, one week after the acquisition phase, in the retention phase, rats spent more time in the quadrant in which the escape plate was previously located.
Conclusion: The present study findings propose that Royal Jelly can improve cognitive processes through positive effects on neural functions and probably has a significant influence on prevention and therapy of some neuronal disorders.
L Ghasemi Abhari, Mh Esmaeili, M Benanaj,
Volume 23, Issue 1 (4-2015)
Abstract
Background and objective: Insulin and its receptor are located in the central nervous system where it regulates many important processes such as neural proliferation, apoptosis, synaptic transmission, neuronal survival, synaptic plasticity, learning and memory. Alzheimer's disease (AD) is characterized by the accumulation of extracellular amyloid-β (Aβ) plaques, and intracellular aggregation of hyperphosphorylated Tau protein. Currently there is widening recognition that AD is closely associated with impaired insulin signaling and glucose metabolism in brain, suggesting it to be a brain-specific form of diabetes and so also termed as "type 3 diabetes". Insulin has been shown to affect both Aβ levels and Tau phosphorylation. Experimental evidence suggests a link between type 2 diabetes and AD. Insulin modulates metabolism of beta-amyloid precursor protein (APP) in neurons, decreasing the intracellular accumulation of Aβ. Therefore investigating the role of agents that could improve neuronal insulin resistance merit attention in AD therapeutics. In present study, we aimed to investigate the therapeutic efficacy of intra ventricular injection of metformin on spatial learning and memory of streptozotocin(STZ) Rat Model of AD Materials and Methods: 48 Female wistar rate (200-250gr) were divided into 6 groups(n=6): control, STZ, STZ+Salin(5ul), STZ+Metformin(50,100,200ug/kg, i.c.v. for 10 day). For induction of AD, STZ (3 mg/kg, i.c.v, 10 μl each) were administered bilaterally into latral ventricles. All rates were tested spatial learning and memory in the Morris water maze. Results : We observed that pre-training microinjection of Metformin in to lateral ventricle for 10 day improves spatial learning and memory in STZ Rat Model of AD in a dose dependent manner, so that rats of these groups found platform in less time and with less distance traveled, in comparison with STZ+Salin group, in the radial maze. Conclusion: The results demonstrate possible therapeutic efficacy of metformin in AD by its ability to sensitize neuronal insulin resistance and also show that metformin is useful for AD treatment.
F Gholampoor Fard, N Heydarieh, Mohamad Moghaddami Rad,
Volume 24, Issue 5 (8-2016)
Abstract
Introduction: Epilepsy is the most common disorder of the central nerves system. Patients suffering from epilepsy can experience a wide range of neuropsychological disorders such as impaired memory, disturbances in attention and information processing. Due to the effect of anticonvulsant carbamazepine and its effect on the memory and learning, the aim of this study was investigating the effect of Carbamazepine on passive avoidance learning in male rats seizure model.
Methods: 30 male Wistar rats with an average weight of 230±20 g were used in the study. Animals were randomly divided into 5 groups. Seizure was induced by administration of pentylenetetrazole (PTZ: 60 mg/kg, ip). After induction of seizure the learning and memory of rats was tested in shuttle box. Latency to enter the dark room memory was evaluated as indicators of learning and memory. The data were analyzed by one way variance analysis and Tukey’s test using SPSS.
Results: Pentylenetetrazole-induced seizures (PTZ) in acquisition group significantly reduced the latency to enter the dark room (P<0.01). Carbamazepine significantly reduce the entrance time in intact rats and kindled rats by PTZ (P<0.05, P<0.01).
Conclusion: This study showed that the administration of Carbamazepine in seizure rats can cause the increasing learning and memory impairments in rats by Pentylenetetrazole.
M Ghaneian , H Kazemi-Zahrani ,
Volume 24, Issue 6 (9-2016)
Abstract
Introduction: The prevalence of sleep disorders is different in international studies. Sleep disorders with the increasing prevalence among children is common. Cognitive problems are the most serious complication of sleep disorders in children. The present study, the prevalence of sleep problems and neuropsychological learning disabilities were evaluated on pre-school children (4-6 years old) in Isfahan in the year of (1393-1394).
Methods: This descriptive study was conducted on 350 pre-school children in 1393-1394. They have been selected for cluster sampling method. The sleep disturbances scale questionnaire for children (SDSC) and Conners neuropsychological questionnaire were given to the mothers of pre-school children.
Results: The results showed 144 (41.14%) pre-school children were prone to sleep disturbances, out of 280 pre-school children, 92 people (32.85%) had neuropsychological learning disabilities, 31 children, disorders of initiating and maintaining sleep (8.85%), 15 children, sleep disordered breathing (4.28%), 53 children, excessive sleepiness disorder (15.14%), 74 children, sleep wake disorders (21.14%), 32 children, 32 children, arousal disorder (9.14%), 43 children, sleep hyperhidrosis (12.28%), 62 children, attention problems (22.14%), 1 children, impaired sensory function (0.7%), 4 children, language dysfunction (1.42%), 7 children, general learning and memory impairment (2.5%), 14 children, executive dysfunction (6.42%).
Conclusion: The prevalence of sleep and attention problems could indicate the importance of sleep and attention problems, furthermore, it could be awareness as regards patterns of the healthy sleep and neuropsychological learning disabilities in order to enhance the awareness of parents and health care providers.
F Delrobaei, M Bahmani, F Ayoobi, A Shamsizadeh, I Fatemi, M Allahtavakoli,
Volume 25, Issue 3 (6-2017)
Abstract
Introduction: Estrogen regulates many processes in the brain such as synaptic formation, learning, and memory. Empirical evidence shows that there is a correlation among menopause, memory impairment, and anxiety due to Estrogen deficiency. In this study, we tested the effect of Metformin (Met) with antioxidant effect, which can improve the impairment of tactile learning and anxiety-like behavior in ovarectomized mice.
Methods: Thirty-two female mice weighting 20±5 g were randomly divided into four groups of eight, including sham group, ovariectomy, ovariectomy with doses 7 and 15 mg/kg of Met. At first, mice were ovariectomized and then they were treated with the doses of the Met or water for 21 days. Then, tactile learning (by Novel Object Recognition Test) and anxiety like-behavior (by Elevated Plus-maze) were determined.
Results: Met at the doses of 7 or 15 mg/kg significantly improved tactile learning compared to the ovariectomy group. Met at the doses of 7 or 15 mg/kg significantly increased Open Arm Time (%OAT) and Open Arm Entries (%OAE) compared to the ovariectomy group.
Conclusion: Met especially at the dose of 7 mg/kg showed a significant role in improving the anxiety and tactile learning in the ovariectomized mice.
Marzieh Karimi Arab , Nasrin Heidarieh , Fatemeh Jamalloo ,
Volume 25, Issue 5 (8-2017)
Abstract
Introduction: Learning and memory is characteristically human to survive; reducing sexual hormones in aging and the side effects of chemical drugs are factors that can cause memory and learning disruption. In this study the effect of hydroalchoholic extract sumac (Rhus coriaria L.) on expression passive avoidance learning in gonadectomized male rats was studied.
Methods: In this experimental study, 32 adult Wistar rats with a weight of 230±20 were put in four groups (8 rats per group), including: received healthy solvent extract Dimethyl sulfoxide (DMSO), gonadectomized received of DMSO and doses of 25 and 50 mg/ kg extract sumac . Firstly, , rats injected intraperitoneally with ketamine (75 mg/kg) and xylazine (10 mg/kg) anesthesia, gonads removed after 15 days recovery period, extensive testing. Passive avoidance test by the Shuttle box device after treatment by the same conditions was performed for all groups. All treatment was performed intraperitoneally and a half hours before the test on the second day (check expression).The data were analyzed by the one-way ANOVA and Tukey test (P<0.05).
Results: Results showed that in the gonadectomized group received solvent extract (DMSO) (3/0 cc) a significant reduced was found in latency to enter the dark room compared to DMSO control groups (P <0.001). The groups The groups receiving the extract sumac(Rhus coriaria L.) at a doses of 50 and 25 mg / kg showed a significant increase in latency in the dark room compared with the group receiving the gonadectomy receiving DMSO(P<0.05).
Conclusion: Results show that the gonadectomy reduces the incidence of avoidance learning and In gonadectomized rats, hydroalcoholic extract of sumac increases the incidence of passive avoidance learning.
Fatemeh Sanjarani , Mansour Esmaeilidehaj, Fatemeh Zareh-Mehrjardi, Tayebe Eghbali , Mohammad Ebrahim Rezvani,
Volume 25, Issue 12 (3-2018)
Abstract
Introduction: Effects of many flavonoids have been studied on memory, learning and improvement of Alzheimer. Many flavonoids are effective in the improvement of Alzheimer. Since no study has been conducted on the effect of salvigenin on memory and learning, our aim was to examine the effect of this flavonoid.
Methods: Intraperitoneal injection of D-galactose at a dose of 120 mg / kg was used for 45 for creation of Alzheimer disease model. In this experimental study, 28 male wistar rats weighing approximately 200-250 grams were divided into 4 groups with 7 members, including: normal group: rats that received no drugs, control group: alzheimer disease model rat, which had been stricken to Alzheimer by intraperitoneal injection of D-galactose at a dose of 120 mg/kg and 1, 2 salvigenin groups: in which each group was the same as the control group. Furthermore, they received daily 10 or 20 mg/kg of salvigenin by gavage. In order to evaluate memory, shuttle box and passive avoidance learning was used 2 and 7 days after learning. To assess the mRNA expression rate of BDNF, the entire RNA of hippocampus was isolated and after synthesis of Complementary DNA (cDNA), real time and PCR were done and relative expression of mRNA was evaluated.
Results: The results showed that daily administration of different doses of salvigenin can slow down Alzheimer's induction. The delay duration in entering the dark compartment in trained rats in the treated group was significantly more than the control group. mRNA expression rate of BDNF in salvigenin receiving groups was more than control group.
Conclusion: Generally it can be concluded that salvigenin can improve the memory caused by Alzheimer and also increase mRNA expression rate of BDNF in Alzheimer's rats.
Jamal Zarepour Ahmadabadi, Fatemeh Zare Mehrjardi, Mahdieh Ghanbary, Masoud Mirzaei,
Volume 32, Issue 7 (10-2024)
Abstract
Introduction: Ischemic heart diseases are one of the most common diseases that cause high mortality worldwide. This article has identified various factors affecting heart disease and identified susceptible people using various machine learning methods.
Methods: The current research was conducted on the Yazd Health Study (YaHS) database. YaHS was conducted on adults aged 20-70 years who were residents of Yazd Greater Area and collected information on the health and various diseases of nearly 10,000 people in the form of a questionnaire with 300 different questions. In this research, by using the correlation of questions with heart disease, the most important factors of heart disease have been identified. By using the identified factors and machine learning algorithms, susceptible people with heart disease have been identified.
Results: The results of the evaluations have shown that factors such as age, family history of heart disease, blood pressure, diabetes, blood cholesterol, stress, anxiety, depression, quality of life, quality of sleep, physical activity, smoking, and diet have an effect on heart disease. Likewise, among the different machine learning methods, the nearest neighbor method, the deep neural network method, and the multi-layer perceptron method with a recall criterion of 99.94%, 99.88%, and 99.11% have performed the best in the identifying sick people, respectively.
Conclusion: According to the findings of the research, it can be understood that by controlling factors such as blood pressure, diabetes, blood cholesterol, stress, anxiety, and depression, changing factors such as quality of life, sleep status, physical activity, and eating patterns of people and quitting smoking, it is possible to move towards improving the health of society. On the other hand, the identification of people prone to heart disease using machine learning methods is done faster and at a lower cost than the traditional methods that are done by referring to medical centers and doctors and performing various tests.
