Mammillary bodies and the mammillothalamic tract are parts of a classic neural circuitry that has been implicated in severe memory disturbances accompanying Korsakoff's syndrome. However, the specific role of mammillary bodies in memory functions remains controversial, often being considered as just an extension of the hippocampal memory system. To study this issue we used mutant mice with a ta...

introduction: it has been reported that acute administration of morphine impairs learning and memory processes in rats. furthermore, recent studies showed that saffron extract improved ethanol-induced impairments of learning behaviors in mice, and also prevented ethanol-induced inhibition of hippocampal long-term potentiation. it can be postulated that there are some common mechanisms responsib...

introduction: ascorbic acid (aa) acts as an antioxidant in the central nervous system (cns) of the mammalians. it is released from the some nerve ending together with neurotransmitters. the results have shown that ascorbic acid could affect learning as well as memory. in this study, we examined the effect of icv injection of ascorbic acid on learning and memory by morris water maze. method: in ...

A parieto-medial temporal pathway is thought to underlie spatial navigation in humans. fMRI was used to assess the role of this pathway, including the hippocampus, in the cognitive processes likely to underlie navigation based on environmental cues. Participants completed a short-term spatial memory task in virtual space, which required no navigation but involved the recognition of a target loc...

introduction: the n-methyl-d-aspartate (nmda) receptors, which have been implicated in memory formation, could be noncompetitively blocked by ketamine. the present study examines the short term effect of ketamine on induction of anterograde and retrograde amnesia in male rats using morris water maze (mwm). methods: male n-mri rats were randomly divided into nine experimental groups. mwm studies...

Age-related declines in spatial navigation are well-known in human and non-human species. Studies in non-human species suggest that alteration in hippocampal and other neural circuitry may underlie behavioral deficits associated with aging but little is known about the neural mechanisms of human age-related decline in spatial navigation. The purpose of the present study was to examine age diffe...

Spatial navigation attracts the attention of neuroscientists as an animal analogue of human declarative memory. The Carousel maze is a dry-land navigational paradigm, which proved to be useful in studying neurobiological substrates of learning. The task involves avoidance of a stable sector on a rotating arena and is highly dependent upon the hippocampus. The present study aims at testing hypot...

This study used computer-generated (“virtual”) mazes to investigate sex differences in the efficiency of spatial route learning in humans. Correlations between maze performance and traditional psychometric measures of spatial ability also were examined. Male and female subjects completed a total of five learning trials on each of two spatial mazes and completed a battery of spatial and verbal c...

Degeneration of cholinergic cells in the basal forebrain correlates with the cognitive impairment seen in Alzheimer’s disease (AD), but so far the cognitive improvement of AD patients receiving cholinergic therapy has only been modest at best. In addition, degeneration of glutamate-containing cells has been observed in AD, thus suggesting that dysfunction of glutamatergic receptors may contribu...

The hippocampus and parahippocampal cortices exhibit theta oscillations during spatial navigation in animals and humans, and in the former are thought to mediate spatial memory formation. Functional specificity of human hippocampal theta, however, is unclear. Neuromagnetic activity was recorded with a whole-head 275-channel magnetoencephalographic (MEG) system as healthy participants navigated ...