Damage to the hippocampus typically produces temporally graded retrograde amnesia, whereby memories acquired recently are impaired more than memories acquired remotely. This phenomenon has been demonstrated repeatedly in a variety of species and tasks. It has also figured prominently in theoretical treatments of memory and hippocampal function. Yet temporally graded retrograde amnesia has not b...

Introduction: Previous studies have indicated that stress levels of glucocorticoid hormones induce impairment of long term memory retrieval, but the underlying mechanisms (genomic or non-genomic) are not clear. To clarify this issue, we investigated the involvement of brain corticosteroid receptors and protein synthesis in the glucocorticoid-induced impairment of memory retrieval. Methods: 140 ...

Glucocorticoid hormones enhance memory consolidation of hippocampus-dependent spatial/contextual learning, but little is known about their possible influence on the consolidation of procedural/implicit memory. Therefore, in this study we examined the effect of corticosterone (2, 5, or 10 ng) infused into the dorsal striatum of male Wistar rats immediately after training on either a cued or spat...

The performance of 4 seed-caching corvid species was tested using 2 different operant nonmatching tasks. These species differ in their dependence on stored food, and differences in spatial memory tests have been correlated with better performance by the more cache-dependent species. Acquisition and retention of a color non-matching-to-sample task was tested in Experiment 1. Acquisition of the c...

The spatial water maze is routinely used to investigate hippocampal-dependent spatial memory and the biological mechanisms that underlie variability in cognitive decline during aging. The utility of the task for repeated testing in order to examine the trajectory of cognitive decline and to prescreen animals prior to therapeutic interventions maybe limited due to carryover effects of repeated t...

Three experiments were conducted to dissociate movement planning costs and movement execution costs in working memory (WM). The aim of the study was to clarify what kind of WM processes (verbal, spatial, or both) are recruited during movement planning and movement execution. Therefore, a WM task (verbal and spatial versions) was combined with a high-precision manual action. Participants initial...

Objective(s): Auraptene (7-geranyloxycoumarin) (AUR), from Citrus species has shown anti-inflammatory, neuroprotective, and acetylcholinesterase (AChE) and beta-secretase inhibitory effects. Scopolamine is a nonselective muscarinic receptor antagonist which causes short-term memory impairments and is used for inducing animal model of Alzheimer’s disease (AD). This research aimed to investigate ...