جستجوی مقالات مرتبط با کلیدواژه "y maze" در نشریات گروه "پزشکی"

Scopolamine has frequently been reported to induce a “memory deficit” in animals and humans. However, the possible role of the non-cognitive effects of the drug in these impairments is often ignored. In the present study, the effects of scopolamine on various behaviors in the radial arm maze were recorded and the ability of physostigmine to reverse them was examined. Male Long-Evans hooded rats were trained on an 8-arm radial maze to consume drops of 0.1 ml of sweetened milk from the end of each arm. Once the asymptomatic performance was achieved, the effects of scopolamine (0.25 mg/kg i.p. 20 min before testing) on(1) the number of errors (re-entries into the arms), (2) the number of rewards drops not consumed, and (3) agitation were examined. The number of errors, the number of drops left, and agitation scores were increased significantly compared to saline-treated rats. Concomitant administration of scopolamine and physostigmine (0.25 i.p. 15 min before testing) significantly reduced the agitation scores and revealed a trend toward a decrease in the number of drops left compared to scop-treated rats. However, in this experiment, scopolamine did not significantly increase the number of errors compared to the saline-treated rats. Taken together, scopolamine induced a small but inconsistent increase in the number of errors. In contrast, there were significant effects of scopolamine on agitation and milk consumption in both experiments. These non-cognitive effects of scopolamine (which were attenuated by physostigmine) may indirectly lead to an increase in errors.

In the present study, the effects of prenatal stress on spatial learning and memory deficit and its relationship with hippocampal insulin resistance were examined in male and female offspring. 

Female NMRI mice were mated with males overnight, and the 0-day of pregnancy was detected (Gestational day 0-GD0). The pregnant mice were then randomly divided into stress and control groups. The stress group received stress from the GD0 to GD10. On post natal day 30 (PND30), the offspring were divided into 4 subgroups, namely: male-control, female-control, male-stress, and female-stress. Barnes maze method was used for spatial learning evaluation. Plasma cortisol and insulin levels were measured at the beginning of the experiments. At the end of the experiments, the animals’ brains were removed, and their hippocampus was extracted. The hippocampus was homogenized, and its insulin and insulin-receptor contents were evaluated. 

The stressed animals needed more time for reaching to target hole. In addition, they spend more distance to find the target hole, which was more pronounced in the male offspring. Both plasma and hippocampal insulin content were reduced in the stressed groups. Moreover, the hippocampal insulin receptors protein was reduced in the stressed animals. There was a positive relationship between plasma and hippocampal content and memory deficit in the stressed groups.

These results indicated that prenatal stress could induce spatial learning and memory deficit in offspring, which is associated with plasma and hippocampal insulin and receptor content reduction (hippocampal insulin resistance) in these animals.

Delirium refers to acute loss of consciousness and is characterized by confused thinking and impaired orientation. It is a life-threatening, but reversible syndrome manifested by cognitive impairment, abnormal psychomotor activity and sleep disturbances. Due to high prevalence in hospitalized patients and high rate of morbidity and mortality, delirium significantly decreases the prognosis of hospitalized patients.

This experimental animal study evaluated 54 adult male Wistar rats over 2 months of age that weighed 200 to 230g. Of all, 24 rats received biperiden (40mg/kg) while the remaining 24 received 50μg/kg LPS. Induction of delirium was ensured using a Y-maze after 3 hours. The control group included 6 rats The efficacy of different doses of haloperidol for treatment of delirium was assessed 3 h after injection using the Y-maze. Data were compared using one-way ANOVA followed by Tukey’s post-hoc test via GraphPad Prism.

Haloperidol at 0.1, 0.2 and 0.5mg/kg dosage significantly increased the percentage of spontaneous alternation and improved the memory, consciousness and learning compared with biperiden and LPS groups (P<0.01). No significant difference was noted between the haloperidol groups regarding efficacy (P>0.05).

Delirium is characterized by attention deficit, impaired orientation, changes in memory, consciousness, perception and mood, and psychotic symptoms. Detection of the complete spectrum of delirium signs and symptoms in an animal that cannot talk (rat) is obviously difficult. Using of Y-maze can facilitate this problem. 

Visual information acquired through observation plays a pivotal role in learning a movement pattern and motor control.

This study aimed to analyze the effect of visual deprivation on learning in rats.

The study sample consisted of 12 male rats, divided into three groups. Group I consisted of four rats and was considered the control group. Transection of the two optic nerves was performed on rats of group II on the seventh day after birth and group III on the seventh week after birth to develop the early blind and late blind models, respectively. A T-shaped maze device was utilized to evaluate the learning behavior of rats. Rats of groups II and III were blinded by the optic nerve surgery. In total, 20 trials per day were conducted for nine consecutive days, in which the time and number of correct arm entries were recorded. The ANOVA and Kruskal-Wallis tests were employed to analyze the results in SPSS software (version 16.0). A p-value of less than 0.05 was considered statistically significant.

There was a significant difference between the three groups regarding the number of correct arm entries on days one, three, and seven (P<0.05). There was also a significant difference between the three groups regarding how long it took them to enter the target box on days two and three (P<0.05). Group III had a lower number of entries to the target box and it took them a significantly longer time to enter the target box, compared to the other groups.

According to the results, visual deprivation may affect the learning of rats during the early days; however, their learning levels increased over the following days. Moreover, the early blinded rats had a higher level of learning than the lately blinded adult rats and the same level of learning as that of the sighted adult rats.

Nowadays, exposure to electromagnetic waves has raised concerns for pregnant mothers about cognitive disorders that affect neonates. Therefore, the present study aimed to investigate the effects of electromagnetic waves and physical activity on learning, spatial memory, and levels of a brain-derived neurotrophic factor (BDNF) in the neonates of pregnant rats. Materials &

Pregnant Wistar albino female rats were randomly divided into three groups of seven animals per group (Physical activity [PA], Electromagnetic fields [EMF], and AP+EMF). All groups underwent intervention during 21 days of pregnancy period. Subsequently, 2.4 GHz frequency and swimming were selected for the intervention. After delivery, 21 neonates were kept under natural in vitro conditions for 56 days (until maturity). Eventually, the Morris Water Maze test was performed, and the hippocampus was removed to measure BDNF. Ethics code: IR.SSRI.REC.1399.919

The result of one-way ANOVA showed that the traveled distance (P=0.007) and time to reach the platform (P=0.01) in the EMF group was significantly higher, compared to the PA group. Moreover, the results of one-way ANOVA and Tukey's post hoc test showed a significant increase in the level of the hippocampal BDNF in the groups of PA and EMF+PA, compared to the EMF group (P=0.007 and P=0.02, respectively). Discussions &

Electromagnetic waves during pregnancy have a devastating effect on the memory and learning of the offspring of rats. However, physical activities, including swimming, can mitigate the destructive effects of these waves during pregnancy.

Hypericum species are known to be used in traditional therapies. H. scabrum L. is one of the Hypericum species distributed in Turkey. In this study, we evaluated the effects of Hypericum scabrum essential oil inhalation on spatial memory in scopolamine-induced amnesic rats. The essential oil was characterized by GC-FID and GC-MS system. Male wistar rats were divided into 6 groups: control; scopolamine-alone treated; diazepam-treated (positive control); tramadol-treated (positive control); scopolamine with Hypericum scabrum essential oil 1%-treated; and scopolamine with Hypericum scabrum essential oil 3%-treated group. All rats were tested behaviorally to evaluate spatial memory peformances in Y-maze task and radial-arm maze task. The most abundant component of the essential oil was identified as α-pinene (51.3%). Hypericum scabrum essential oil application significantly improved spatial memory as compared to scopolamine-alone treated rats as evidenced by increases in spontaneous alternation behavior in Y-maze task and decreases in the number of working memory errors and reference memory errors in the radial-arm maze task in this study. Hypericum scabrum essential oil inhalation could be used as a complementary therapy to reduce memory impairments in the patients with dementia and related diseases.

Alzheimer’s disease (AD) is a multifactorial and debilitating condition without precise etiology and definite cure burdened with highmonetaryandhumanresources to the societyaroundthe globe. Given that Iranian traditional medicine has a valuable treasure of medicinal plants with multi-dimensional effects, we designed this study to examine one week daily low single-dose treatment protocol of 3 mg/kg Teucrium polium (TP) hydro-alcoholic extract effects on rat’s spatial memory performance and CA1 hippocampal neuronal count in rat A25-35 as an AD model. Animals were bilaterally microinjected with single 10 g/2 g intrahippocampal A25-35 fragment for the AD induction. After a two-week recovery period, daily intraperitoneal injection of TP for a week was initiated in A-received TP-treated (treated) and TP-received animals (control). Spatial memory performance and CA1 neuronal count were evaluated. TP significantly reduced time latency and distance swum during the first three days of the training protocol compared with A-received rats (sham). Probe reference test findings, however, were not statistically different in treated, sham, and control groups. Intact CA1 hippocampal neuronal count showed a significant increase in A-received TP-treated (case) rats in comparison with A-received (sham) animals. It seems that the least reported low dose TP has the active chemical components capable of memory enhancing effects in Morris water maze (MWM) setting and potential neuronal survival property in hippocampal tissue. In spite of myriad claims against TP use, we should reconsider the matter and domore research to find the exact active ingredients of various species of the plant plus possible underlying mechanisms for ensuring potential use for human clinical trials in AD and other central nervous system-related diseases.

In recent years, Crocin has been used for its pharmacological functions, such as memory and learning enhancement. The aim of the present study was to assess the effect of Crocin on total sleep deprivation (TSD)-induced amnesia in male Wistar rats. The water box apparatus was used to induce sleep deprivation followed by Y- maze task as an index of learning and memory (the percentage of time in the novel arm during the retention phase was reported as an index of memory performances). The rats were divided into 12 groups, 8 rats in each group, including four control groups, four sham groups, and four TSD groups. Each group received saline and Crocin at doses of 1, 5 or 15 mg/kg twice a day. The findings revealed that TSD for 24 h impaired memory function. In addition, the intra-peritoneal injection of Crocin at all doses (1, 5 and 15 mg/kg) did not change the percentage of time spent in the novel arm of Y-maze in sham of TSD, whereas it abolished the responses induced by the TSD groups. The findings showed a close interaction between the Crocin and SD. Based on the findings, Crocin seems to possess a modulatory effect on SD-induced amnesia.

In temporal lobe epilepsy (TLE), recurrent seizures accompany with cognitive deficit. In some patients, the current medications cannot provide satisfactory control of seizures, therefore new drugs that act through different mechanisms are required. In the present study, the useful effect of dipeptidyl peptidase-4 inhibitor was evaluated in experimental model of temporal lobe epilepsy in male rats.
In this study, the effects of administration of dipeptidyl peptidase-4 inhibitor, linagliptin, on seizures score according to Racine’s scores and learning and memory impairment induced by intrahippocampal injection of kainic acid (4 g) using Y-maze and passive avoidance test were studied in rats. Linagliptin thirty minutes before kainic acid injection was administrated intracerebroventricularly.
In this study, the kainic acid-induced recurrent seizures, reduced alternation level in Y-maze test (p The obtained data indicate that linagliptin in kainate rats mitigates seizure severity and develops short-term memory.

Diabetes as a metabolic disorder can cause memory and learning impairment. In recent years, the effect of plant extracts on the treatment of diabetes mellitus has been raised. The purpose of this study was to determine the effect of isorhmnetin administration on learning and memory disability in an experimental model of streptozotocin-induced diabetes mellitus in rats.
In the present study, for inducing diabetes, streptozotocin was administered at a dose of 60 mg/kg (intraperitoneal) in male rats. Intraperitoneal injection of isorhmnetin (10 mg/kg) was performed after induction of diabetes (10 mg/kg) for 12 weeks. Control groups also received relevant doses. Y-maze and passive avoidance tests were used for assessing of learning and memory ability. The serum glucose and body weight were determined before and 12 weeks after diabetic development.
Behavior data showed that compared to control rats, alternation percentage in Y-maze task (p
This study reveals that isorhmnetin administration to diabetic rats attenuates learning and memory impairment.

Epilepsy as a chronic neurological disorder causes inherent seizures and learning and memory failure. Since there is no acceptable control of seizures in some patients with the current recommended drug therapy, new medications with different mechanisms of action are needed. Here, the beneficial effect of hepatocyte growth factor (HGF) was evaluated in an experimental model of temporal lobe epilepsy in male rats.
In the present study, effects of intracerebroventricular administration of HGF (6 µg) thirty minutes before intrahippocampal injection of kainic acid (4 µg) on spontaneous seizures and learning and memory impairment were assessed in rats. As positive control group, valproic acid (200 mg/kg) was injected intraperitoneally.
Behavior data showed that the kainate rats exhibited spontaneous seizures, lower spontaneous alternation score in Y-maze task (p
This study revealed that HGF administration to kainate-injected rats attenuates seizure scores and improves learning and memory.