Retrograde amnesia can occur after brain damage because this disrupts sites of storage, interrupts memory consolidation, or interferes with memory retrieval. While the retrieval failure account has been considered in several animal studies, recent work has focused mainly on memory consolidation, and the neural mechanisms responsible for reactivating memory from stored traces remain poorly under...

the aim of the present study was to evaluate the effect of melatonin as an antioxidant on spatial navigation memory in male diabetic rats. thirty-two male white wistar rats weighing 200 ± 20 g were divided into four groups, randomly: control, melatonin, diabetic and melatonin-treated diabetic. experimental diabetes was induced by intraperitoneal injection of 50 mg kg-1 streptozotocin. melatonin...

D-Serine, the endogenous coagonist of N-methyl-D-aspartate receptors (NMDARs), is considered to be an important gliotransmitter, and is essential for the induction of long-term potentiation. However, less is known about the role of D-serine in another form of synaptic plasticity, long-term depression (LTD). In this study, we found that exogenous D-serine regulated LTD in the hippocampal CA1 reg...

In the present study, the effects of morphine sensitization on morphine-induced impairment of memory formation and the state-dependent retrieval of a passive avoidance task learned under morphine influence have been investigated in mice. Pre-training administration of morphine (0.5, 2.5 and 5 mg/kg) dose dependently suppressed the learning of one-trial passive avoidance task. Pre-test administr...

Objective(s): Due to the prevalence and pervasiveness of stress in modern life and exposure to both chronic and acute stresses, it is not clear whether prior exposure to chronic stress can influence the impairing effects of acute stress on memory retrieval. This issue was tested in this study. Materials and Methods: Adult male Wistar rats were randomly assigned to the following groups: control,...

In the present study, the effects of morphine sensitization on morphine-induced impairment of memory formation and the state-dependent retrieval of a passive avoidance task learned under morphine influence have been investigated in mice. Pre-training administration of morphine (0.5, 2.5 and 5 mg/kg) dose dependently suppressed the learning of one-trial passive avoidance task. Pre-test administr...

In two experiments younger (18 ± 25 years) and older (60 ± 70 years) participants performed an information retrieval task in which they searched for the answers to questions in a hierarchical menu structure. Participants’ movement speed, spatial ability, spatial memory, working memory capacity and reasoning speed were measured. Results showed older participants to be slower than younger partici...

Age-related declines in memory for context have been linked to volume loss in the hippocampal head (HH) with age. However, it remains unclear how this volumetric decline correlates with age-related changes in whole-brain activity during context encoding, and subsequent context retrieval. In the current study we examine this. We collected functional magnetic resonance imaging data in young and o...

A computational model of how single neurons in and around the rat hippocampus support spatial navigation is reviewed. The extension of this model, to include the retrieval from human long-term memory of spatial scenes and the spatial context of events is discussed. The model explores the link between spatial and mnemonic functions by supposing that retrieval of spatial information from long-ter...

In two experiments younger (18 ± 25 years) and older (60 ± 70 years) participants performed an information retrieval task in which they searched for the answers to questions in a hierarchical menu structure. Participants’ movement speed, spatial ability, spatial memory, working memory capacity and reasoning speed were measured. Results showed older participants to be slower than younger partici...