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...

There is considerable evidence to support the hypothesis of relationship between paradoxical sleep (PS) and learning–memory processing. It has been suggested that PS is important in memory retention at the specific time course called PS windows (PSW). The time of PSWs occurrence and duration of these PSWs following the training sessions and, the neurochemical nature of PSWs has not been well kn...

Introduction: Alzheimer’s disease (AD) is a enfeeble neurodegenerative disorder characterized by increased β-amyloid (Aβ) deposition and neuronal dysfunction leading to impaired learning and recall. Among proposed risk factors, impaired cholinergic transmission is a main cause for incidence of disease. Methods: In the present study, effects of the intracerebroventricularly administration of an ...

The primary visual cortex of rats is surrounded laterally (in Oc2L) and medially (in Oc2M) by several peristriate visual areas. Previous studies from our laboratory demonstrated that bilateral lesions in Oc2L result in visual pattern discrimination deficit, and in failure to solve a conditional discrimination which requires figure-background association. In contrast, neurotoxic lesions of the r...

Theories have proposed that the maintenance of object representations in visual working memory is aided by a spatial rehearsal mechanism. In this study, we used two different approaches to test the hypothesis that overt and covert visual-spatial attention mechanisms contribute to the maintenance of object representations in visual working memory. First, we tracked observers' eye movements while...

Spatial attention and memory were compared in young and old subjects using non-delayed and delayed matching-to-sample tests. Both young and older subjects revealed a right hemisphere superiority for spatial processing. Older subjects were as accurate as young controls in the non-delay task supporting preserved attention ability in this spatial task. However, older subjects were impaired at 3 s ...

Females of avian brood parasites, like the shiny cowbird (Molothrus bonariensis), locate host nests and on subsequent days return to parasitize them. This ecological pressure for remembering the precise location of multiple host nests may have selected for superior spatial memory abilities. We tested the hypothesis that shiny cowbirds show sex differences in spatial memory abilities associated ...

Our previous experiments showed that sleep in rats enhances consolidation of hippocampus dependent episodic-like memory, i.e. the ability to remember an event bound into specific spatio-temporal context. Here we tested the hypothesis that this enhancing effect of sleep is linked to the occurrence of slow oscillatory and spindle activity during slow wave sleep (SWS). Rats were tested on an episo...