Ketamine, a non-selective inhibitor of NMDA (N-methyl-D-aspartate) channels is used in anesthetic or sub-anesthetic doses to induce analgesia, amnesia, to suppress fear, anxiety and depression. Although the ketamine's effect on memory acquisition is known, its effects on other aspects of memory are controversial. Morris water maze is a task which assesses spatial learning and memory. This study...

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...

We tested whether indomethacin or rosiglitazone treatment could rejuvenate spatial ability and hippocampal neurogenesis in aging rats. Young (4 mo; n = 30), middle-aged (12 mo; n = 31), and aged (18 mo; n = 31) male Fischer 344 rats were trained and then tested in a rapid acquisition water maze task and then fed vehicle (500 μl strawberry milk), indomethacin (2.0 mg/ml), or rosiglitazone (8.0 m...

The authors sought to determine how different elements of enrichment, for example, cognitive stimulation and voluntary exercise, differ in their ability to improve memory throughout the lifespan. Young, middle-aged, and aged female C57BL/6 mice received 24-hr exposure in their home cages to toys alone (cognitive stimulation), running wheels alone (exercise), or both toys and running wheels (com...

Chronic stress and spatial training have been proposed to affect hippocampal structure and function in opposite ways. Previous morphological studies that addressed structural changes after chronic restraint stress and spatial training were based on two-dimensional morphometry which does not allow a complete morphometric characterisation of synaptic features. Here, for the first time in such stu...

In the present study, F-344 rats throughout 1.5 to 26 months of age were tested in the reference memory version, a moving-platform repeated acquisition version, and in a cued platform version of the Morris water maze. The results suggest that: (1) performance in the water maze declines continuously, beginning at the earliest age, and very closely fits a linear function; (2) there are robust, re...

BACKGROUND Reports on agmatine are controversial showing that it may improve memory, it can deteriorate memory and some did not notice any interference with learning and memory. In the present study, the effect of directly intra-CA1 agmatine microinjection on water maze learning and memory has been assessed. METHODS The cannuls were implanted in hippocampal CA1 regions of rats in a sterotaxic...

The Morris water maze is a spatial abilities test adapted from the animal spatial cognition literature and has been studied in the context of sex differences in humans. This is because its standard design, which manipulates proximal (close) and distal (far) cues, applies to human navigation. However, virtual Morris water mazes test navigation skills on a scale that is vastly smaller than natura...

Chronic stress and spatial training have been proposed to affect hippocampal structure and function in opposite ways. Previous morphological studies that addressed structural changes after chronic restraint stress and spatial training were based on two-dimensional morphometry which does not allow a complete morphometric characterisation of synaptic features. Here, for the first time in such stu...

Previous studies have shown that physical activity improves learning and memory. Present study was performed to determine the effects of acute, chronic and continuous exercise with different periods on spatial learning and memory recorded as the latency and length of swim path in the Morris water maze testing in subsequent 8 days. Four rat groups were included as follows: 1- Group C (controls w...