Source Paper
Accumulation of Hippocampal Place Fields at the Goal Location in an Annular Watermaze Task
Stig A. Hollup, Sturla Molden, James G. Donnett, May-Britt Moser, Edvard I. Moser
Journal of Neuroscience • 2001
Probe Trial
Objective: Assess hippocampal place field accumulation at goal location independent of immediate escape behavior by conducting probe trials without an escape platform
Protocol Steps
Train rats on watermaze task
Train rats to find hidden platform at constant location in annular watermaze
Note: Platform location remains constant throughout training
View evidence from paper
“rats trained to find a hidden platform at a constant location in a hippocampal-dependent annular watermaze task”
Conduct probe trial
Conduct probe trial without escape platform to assess place field accumulation independent of immediate escape behavior
Note: No platform present during probe trial; allows assessment of spatial representation without motor escape component
View evidence from paper
“probe trials without immediate escape”
Record single-unit activity
Make multiple single-unit recordings from hippocampal pyramidal neurons during probe trial
Note: Record place-related firing patterns of hippocampal cells
View evidence from paper
“we made multiple single-unit recordings in rats trained to find a hidden platform”
Analyze place field distribution
Analyze accumulation of place fields near platform location and compare to other arena regions
Note: Determine percentage of cells with peak activity around hidden platform location versus equally large areas elsewhere
View evidence from paper
“Place fields tended to accumulate near the platform, even in probe trials without immediate escape”