Morris Maze Test

The rat Morris maze we use consists of a circular water tank (150cm in diameter) tilled with water and maintained at 27 °C with an escape platform (15 cm in diameter) 18 cm from the perimeter always in the same position 2 cm beneath the surface of the water. The water is made opaque by addition of milk powder rendering the platform invisible. 

Twelve rats are studied per group. The test is performed blind. 

The test substance is usually evaluated at 3 doses, administered p.o. 60 minutes before the session, and compared with a vehicle control group. 

Diazepam (8mg/kg p.o.), administered under the same experimental conditions, is used as reference substance. 

The basic experiment therefore includes 5 groups. EVALUATION 

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In a passive avoidance procedure in the rat, low doses of ondansetron reversed the scopolamine-induced memory deficit, whereas tropisetron was ineffective. However, in the Morris water-maze test, tropisetron but not ondansetron counteracted the learning and memory impairment caused by scopolamine [Pitsikas and Borsini 1997]. 

In contrast to the one-trial passive avoidance procedure, the Morris maze permits the progress of learning to be evaluated within the test. Furthermore, subsequent learning can be compared with initial swimming performance. Both factors allow a clearer interpretation of drug effects. The Morris maze depends on the animal s use of extra-maze visual cues. The behavior can therefore be more readily interpreted in terms of the animal s capacity to learn to orient itself in space (spatial learning) and the effects thereon of the test substance. 

Carvacrol also improves cognitive activity. Azizi et al. [100] examined the effect of carvacrol and thymol in two rat models of dementia deficits caused by amyloid p and by scopolamine. The method they used was the Morris water maze test and they also assessed the acute toxicity of both carvacrol and thymol. The result showed that both substances could reverse and alleviate the induced cognitive impairments, for example, the escape latency and reduction in target quadrant entries. Both substances also were shown to be relative safe, with LD50s of thymol (565.7 mg/kg) and carvacrol (471.2 mg/kg) that were significantly higher than the therapeutic concentration. The authors also suggest that the antioxidative, antiinflammatory, and anti-choUnesterase activity could be involved in these activities. 

Gacar, N., Mutlu, O., Utkan, T., et al, 2011. Beneficial effects of resveratrol on scopolamine but not mecamylamine induced memory impairment in the passive avoidance and Morris water maze tests in rats. Pharmacol. Biochem. 

However, a different mouse model of CaMKIV inhibition, the forebrain-specific transgenic dn-CaMKIV mouse, yielded somewhat different results. Spatial memory was tested using the hidden platform and the visible platform versions of the Morris water maze task. Both tests showed impaired spatial memory formation in dn-CaMKIV mice compared to controls, since dn-CaMKIV mice did not remember the location of the platform as well as wild type mice (Kang et al., 2001). Tests... 

Morris water tank maze, learning set formation, multiple T-mazes and DRL learning in a Skinnerbox (refs. 34, 35, 62, 120). Although the value of apical tests is not yet clear (ref. 167), the Hebb-Williams test could serve as an example of such a test. In this test measures of activity, motivation, learning, memory and problem solving capacity can be determined in one single test situation. 

Mice with abnormally poor or abnormally good cognitive abilities may produce aberrant behavior in this test (e.g., increased or decreased social interaction, respectively). To rule out this possibility, consider testing mice in some additional memory paradigms. Memory tests, such as the Morris Water Maze and OFT habituation, may be performed to assess cognitive functions in any abnormally behaving mouse. 

Behavioural studies described age-dependent cognitive deficits assessed by using a Morris water maze. This behavioural test measures spatial reference memory. In these transgenic APP mice, both their acquisition of hidden platform locations and their retention of spatial reference information are affected (Table 1). 

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