Elevated Zero Maze

The elevated zero maze (EZM) is a continuous circular runway (typically 60 cm outer diameter for mice, 100-105 cm for rats) elevated 40-70 cm above the floor and divided into four equal quadrants: two open (no walls) and two enclosed (with 25-30 cm opaque walls). Unlike the elevated plus maze, the circular design eliminates the ambiguous center junction zone, forcing every position on the track to be unambiguously classified as open or closed. This resolves the analytical complication where rodents spending time in the EPM center square are neither in open nor closed arms, inflating variance and reducing statistical power.

Primary dependent variables include time spent in open quadrants, number of open-to-closed and closed-to-open transitions (reflecting exploratory drive and risk assessment), and latency to first enter an open quadrant. The transition count is a particularly clean measure of decision-making under approach-avoidance conflict because each transition involves crossing a single boundary rather than traversing a center zone. Head dips over the edge of open quadrants and stretched-attend postures at the open-closed boundaries provide additional ethological measures of risk assessment behavior.

ConductMaze tracks the animal continuously around the circular track using overhead video with center-point detection, automatically segmenting position data into the four predefined quadrants. The system computes open quadrant time ratios, transition frequencies, and within-session time-course analysis without the need for subjective center-zone definitions. Heat maps are rendered in polar coordinates matching the circular apparatus geometry, providing intuitive visualization of spatial exploration patterns.