Y-Maze Forced Alternation

The Y-maze forced alternation test is a two-trial procedure that evaluates spatial working memory by constraining the animal to a single arm during a sample phase and then allowing free choice after a defined inter-trial interval. During the sample phase, one arm is blocked by a removable guillotine door, forcing the animal to explore only two of the three arms. After a delay ranging from seconds to hours, the animal is returned to the maze with all three arms open for the choice phase. The innate preference for novelty drives rodents to preferentially explore the previously blocked arm, and this preference diminishes in proportion to memory impairment.

The principal dependent measure is the percentage of time spent in the novel (previously blocked) arm during the choice phase, with chance performance set at 33.3%. Additional metrics include the latency to first enter the novel arm, the number of entries into each arm, and the discrimination ratio calculated from time in novel versus familiar arms. This protocol is more sensitive to hippocampal lesions than spontaneous alternation because the imposed delay between sample and choice phases places greater demands on spatial working memory consolidation.

ConductMaze automates both phases through programmable guillotine door control integrated with overhead video tracking. The software manages inter-trial intervals, triggers door open/close sequences, and records all positional data from both sample and choice phases. Automated zone definitions ensure consistent arm entry criteria across subjects, while real-time alerts notify experimenters of equipment malfunctions or animal inactivity during critical phases.