Morris water maze: This test involves placing the gerbil in a circular pool of water with a hidden platform submerged just below the surface. The gerbil must learn to use visual cues around the room to locate the platform. Over multiple trials, the gerbil's latency to find the platform decreases, indicating memory improvement.
Radial arm maze: This test involves a central platform connected to several arms radiating outward. Each arm contains a food reward at the end. The gerbil is allowed to explore the maze and retrieve the rewards. Over multiple trials, the gerbil remembers which arms it has already visited and avoids revisiting them, demonstrating spatial memory.
Object recognition test: This test involves presenting the gerbil with two objects, one of which is familiar and one of which is novel. The gerbil is allowed to explore the objects, and its preference for the novel object is measured. A longer exploration time for the novel object indicates that the gerbil remembers the familiar object.
Associative learning: This test involves pairing a neutral stimulus (e.g., a light) with a meaningful stimulus (e.g., a mild electric shock). Over multiple pairings, the gerbil learns to associate the neutral stimulus with the meaningful stimulus and exhibits a fear response to the neutral stimulus alone. This demonstrates associative memory.
Novelty preference test: This test involves presenting the gerbil with two identical environments, one of which contains a novel object. The gerbil is allowed to explore both environments, and its preference for the novel environment is measured. A longer exploration time for the novel environment suggests that the gerbil remembers the familiar environment.
In summary, to test a gerbil's memory, researchers can use different behavioral tasks like the Morris water maze, radial arm maze, object recognition tests, and associative learning tasks.