Barnes Maze Probe Trial

The Barnes maze probe trial assesses the precision and strength of spatial reference memory after the animal has learned the location of the escape hole over multiple acquisition sessions on an elevated circular platform with 20 equally spaced holes around the perimeter. During the probe trial, the target escape hole is blocked or covered, and the animal is placed on the brightly lit platform for 90 seconds while its search behavior is recorded. An animal with strong spatial memory will concentrate its search around the former target location, making more nose pokes and spending more time near the target hole than at other locations around the perimeter.

Key performance measures include primary latency (time to first visit the target hole), primary errors (number of non-target holes investigated before reaching the target), target zone time, and the spatial distribution of hole investigations. Search strategy classification distinguishes spatial (direct path to target zone), serial (systematic clockwise or counterclockwise search), and random (unsystematic hole investigation) strategies. The Barnes maze is an increasingly popular alternative to the Morris water maze because it avoids the confounds of forced swimming, hypothermia, and stress-induced corticosterone elevation, making it particularly suitable for aged animals, immunocompromised strains, or studies where stress hormones are a variable.

ConductMaze provides automated Barnes maze analysis through overhead camera tracking combined with infrared nose-poke sensors at each hole. The software records every hole investigation with timestamp precision, classifies search strategies using published algorithms, and generates polar plots showing the spatial distribution of search behavior. Heat maps of platform occupancy and hole investigation frequency are generated automatically, and the deviation score (mean distance of investigated holes from the target) is computed as a continuous measure of search accuracy.