Task optimization and ontogenetic profile of the object-in-Place task in mice

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Animal Cognition

Background:

• Spatial memory, including object-place associations, is vital for animal survival and exploration.
• Object-in-place (OiP) tasks are standard for assessing spatial memory in rats, but less established in mice.
• Mice are increasingly important models in neuroscience, necessitating robust behavioral assays.

Purpose of the Study:

• To adapt and validate spontaneous object-in-place (OiP) preference tasks for mice.
• To compare OiP task performance across different mouse strains and experimental designs.
• To determine the developmental emergence of OiP in a specific mouse strain.

Main Methods:

• Tested three spontaneous OiP preference task designs in adult C57/129/6J and C57BL/6J mice.
• Evaluated performance in two-object and four-object OiP tasks with varying retention intervals.
• Assessed the ontogeny of the two-object OiP task in C57/129/6J mice from postnatal day 25 to 28.

Main Results:

• C57BL/6J mice, but not C57/129/6J mice, showed a preference in the four-object OiP task.
• Both mouse strains successfully performed the two-object OiP task with 5-minute and 1-hour retention intervals.
• Two-object OiP preference emerged in C57/129/6J mice between postnatal days 25 and 28.

Conclusions:

• Established effective object-in-place task designs for assessing spatial memory in mice.
• Provided strain-specific performance data and developmental timelines for OiP tasks in mice.
• Expanded the behavioral toolkit for spatial memory research using mice as a model organism.