introduction: alzheimer disease is a progressive and irreversible neuropsychiatric disorder. melissa officinalis improves anxiety and clinical dementia symptoms caused by ad therefore, the purpose of the present study was to evaluate the effect of mellisa extract on spatial memory deficit induced by stz in mwm examination of male wistar rats. methods: in the present study, 112 male wistar rats ...

objective(s):  the cholinergic system plays an important role in learning and memory. this study investigated the effects of curcumin (turmeric extract) and the cholinergic system and their interaction on memory retention of passive avoidance learning in adult male wistar rats. materials and methods: at first, an injection cannula was implanted in right ventricles of the animals. one week after...

If information is stored as distributed patterns of synaptic weights in the hippocampal formation, retention should be vulnerable to electrically induced long-term potentiation (LTP) of hippocampal synapses after learning. This prediction was tested by training animals in a spatial water maze task and then delivering bursts of high-frequency (HF) or control stimulation to the perforant path in ...

background: different stressors induce learning and memory impairment and physical activity influence learning and memory enhancement. in this research, we investigated the effect of synchronized running activity with stress on acquisition and retention time of passive avoidance test. methods: male wistar rats were randomly divided into five groups as follows: control (co), sham (sh), exercise ...

Two experiments examined the effects of perirhinal cortex and hippocampal neurotoxic lesions on the retention of allocentric information. Perirhinal (Expt. 1) and hippocampal rats (Expt. 2) were trained on an allocentric task until they reached a performance equal to that of the control groups. Results showed that 24 days after acquisition, during a retraining period, only the hippocampal rats ...

The use of cognitive subtraction to study the neural substrates of the maintenance component of spatial working memory in humans relies upon the assumptions of the pure insertion of cognitive processes and a linear transform of neural activity to neuroimaging signal. Here, functional changes attributable to the memory requiring phase (referred to as the retention delay) of a spatial working mem...

background: this study was planned to examine the effects of whole-body exposure to gsm-950 mhz electromagnetic fields (emfs) on acquisition and consolidation of spatial memory in rats using a water maze task. materials and methods: in experiment 1, the animals were given two blocks of five trials per day for three consecutive days in a water maze task. the interval between blocks was 4h. befor...

Estrogen's (E) involvement in cognition has been difficult to characterize; numerous studies show that E can both enhance and impair learning and memory. One difficulty may be that experimental paradigms often examine only a single aspect of E's involvement in cognition, for example, the role E plays in the expression of memory after learning has taken place. In addition, the effect of aversive...

The golden hamster's (Mesocricetus auratus) performance on radial maze tasks has not been studied a lot. Here we report the results of a spatial memory task that involved eight food stations equidistant from the center of a circular platform. Each of six male hamsters depleted the food stations along successive choices. After each choice and a 5-s retention delay, the hamster was brought back t...

Diet and exercise have a profound impact on brain function. In particular, natural nutrients found in plants may influence neuronal survival and plasticity. Here, we tested whether consumption of a plant-derived flavanol, (-)epicatechin, enhances cognition in sedentary or wheel-running female C57BL/6 mice. Retention of spatial memory in the water maze was enhanced by ingestion of (-)epicatechin...