Epidemiological studies suggest that individuals with greater education or more cognitively demanding occupations have diminished risk of developing dementia. We wanted to test whether this effect could be recapitulated in rodents using environmental enrichment, a paradigm well documented to attenuate behavioral deficits induced by various pathological insults. Here, we demonstrate that learnin...

Given evidence that mitogen-activated protein kinase (MAPK) activation is part of the nongenomic actions of thyroid hormones, we investigated the possible consequences of hyperthyroidism for the cognitive functioning of adult rats. Young adult rats were treated with L-thyroxine or saline. Twenty rats in each group were exposed to Morris water maze testing, measuring their performance in a hidde...

In order to the neuroprotective effect of Lycium chinense fruit (LCF), the present study examined the effects of Lycium chinense fruit on learning and memory in Morris water maze task and the choline acetyltransferase (ChAT) and cyclic adenosine monophosphate (cAMP) of rats with trimethyltin (TMT)-induced neuronal and cognitive impairments. The rats were randomly divided into the following grou...

The Morris swim navigation task ("water maze") has been a primary research tool to assess hippocampal-dependent spatial learning and memory in rodents for three decades. Originally developed for rats, its application to mouse studies has been a tedious process, but nowadays there are more studies performed with the Morris swim task in mice than in rats. The task has proved to be particularly us...

Many behavioral and electrophysiological studies in animals and humans have suggested that sleep and circadian rhythms influence memory consolidation. In rodents, hippocampus-dependent memory may be particularly sensitive to sleep deprivation after training, as spatial memory in the Morris water maze is impaired by rapid eye movement sleep deprivation following training. Spatial learning in the...

Introduction: Previous studies have shown that vitamin A and its derivatives such as retinoid and all-trans retinoic acid have a crucial role in memory, learning and synaptic plasticity. The receptors of vitamin A are seen in different parts of the brain such as hippocampus, where vitamin A has an important role in learning. In this study, the effect of intrahippocampal (CA1) injection of al...

Background and Objective: A great body of evidences suggested a marked elevation of endogenous opioid levels in plasma of animals with acute cholestasis. Endogenous opioids are implicated in the pathophysiology of cholestasis. Also, many studies have shown that endogenous opioids modulate memory processes. To clarify possible role of endogenous opioid receptors in information processing in acut...

Stigmasterol, a kind of phytosterol, is present in small amounts in various foods. In the present study, we investigated the effects of stigmasterol on scopolamine-induced memory impairments using the passive avoidance and the Morris water maze tasks in mice. In addition, changes in memory-related molecules, including extracellular signal-regulated kinase (ERK) and cAMP response element-binding...