Morris Water Maze Working Memory

The Morris water maze working memory protocol, also known as the delayed matching-to-place (DMP) task, tests rapid one-trial spatial learning by relocating the hidden platform to a new position each day. Animals receive multiple trials per day to the same platform location, with trial 1 serving as the information-encoding trial (the animal must search for the novel location) and trial 2 serving as the memory test (the animal should swim directly to the location found on trial 1). The savings between trial 1 and trial 2 latencies—the within-day improvement—provides a pure measure of one-trial spatial learning that is highly sensitive to hippocampal NMDA receptor function.

This protocol dissects a distinct form of spatial memory from the multi-day reference memory task: whereas the standard acquisition protocol measures gradual, incremental learning over days, DMP measures the ability to form and use a new spatial representation within a single session. The inter-trial interval between trial 1 and trial 2 can be parametrically varied to probe the persistence of this rapidly formed memory trace. The DMP task was famously used to demonstrate that hippocampal NMDA receptors are required for encoding new spatial memories but not for expressing previously learned ones.

ConductMaze supports the DMP protocol by allowing experimenters to define daily platform positions from a library of pre-calibrated locations. The software automatically switches target zones between days, computes trial 1-to-trial 2 savings ratios, and generates within-session learning curves. Inter-trial interval management, path analysis, and search strategy classification are all automated, and the daily platform position sequence can be exported for replication across cohorts.