Object-Place Recognition

The object-place recognition (OPR) test evaluates the ability to bind object identity with spatial location, a core component of episodic-like memory in rodents. During the sample phase, the subject encounters two distinct objects in fixed positions within an arena. In the test phase, one object is displaced to a novel location while the other remains stationary. Successful performance requires intact hippocampal function, as the CA1 subfield and dorsal hippocampus integrate spatial and object information through place cell-object associations.

The spatial displacement discrimination index is calculated as (time exploring displaced object minus time exploring stationary object) divided by total exploration. Intact subjects preferentially explore the displaced object because the object-place conjunction is novel even though both individual objects are familiar. This paradigm is more hippocampally dependent than standard NOR because it taxes spatial relational memory. Locomotor activity and total exploration serve as control variables to rule out non-mnemonic confounds.

ConductMaze defines object-location zones for both sample and test configurations, automatically detecting displacement events and scoring interactions with positional accuracy. The system captures moment-by-moment proximity data to each object, enabling fine-grained analysis of exploration bout dynamics and approach trajectories. Spatial heatmaps overlay object positions across phases, providing visual confirmation of displacement-driven exploration shifts. Counterbalanced location assignments are managed through the protocol editor.