By Meghan Bialt-DeCelie ’19
Scientists have reported that they have developed an analogous rodent test that could aid in Alzheimer research for humans. The Morris Maze Test assesses the ability of rodents with Alzheimer’s disease to reach a pedestal in a water-filled arena. During the assessment, rodents attempt to reach the pedestal in a number of trials. In the first trial, the pedestal is shown to them just above the waterline. To avoid drowning, the rat must swim to the platform. In further trials, the experimenter manipulates the rodent’s surroundings by raising the water level above the platform and making the water opaque. The rodents then perform this task again with the unmoved pedestal hidden underwater. Previous tests suggested that rats with symptoms of Alzheimer’s disease did not perform as well when locating the platform. Because of ethical issues when placing Alzheimer patients into a tank for survival, researchers felt a need to develop a different type of test.
A team led by Dr. Katherine Possin of the University of California, San Francisco created a human test that mimics the properties of a Morris Maze without the dangers of participants drowning. Participants begin the test by navigating a virtual world with landmarks to a marked location. They are then moved to a different part of the virtual world and have to return to the marked location without it being marked. This test is better for assessing Alzheimer in humans especially after testing new treatments from rodent studies. Human tests differed from the rodents’ in that they often involved memory tasks such as retelling stories and recalling a list of words.
The researchers analyzed the results from the rodent’s Morris Maze Tests and compared it to their experiment with humans. In the study, the humans and the rodents improved in finding the marked location over the course of 10 to 12 trials. The healthy humans and rodents located the target more easily than the afflicted group with Alzheimer symptoms. This study proved that the Morris Maze Test was a useful tool to compare the two species. Eventually, the Morris Maze Test will be able to help researchers test drugs and other therapies on the mouse models before administering it to humans.
- Image acquired from: https://www.sketchport.com/drawing/5627408103243776/a-maze-me
- K.L. Possin, et al., Cross-species translation of the Morris maze for Alzheimer’s disease. The Journal of Clinical Investigation. (2016).
- Shultz, Virtual landscape makes you feel like a rat in a maze, could aid Alzheimer’s research. Science News (2016).