Development of visual-stimulus reversal learning-memory in mice is dependent on social interaction

Area of Science:

• Neuroscience
• Animal Behavior
• Cognitive Science

Background:

• Flexible learning, involving adapting to changing rules, is crucial for survival.
• Visual discrimination and reversal learning tasks are common methods to study cognitive flexibility in rodents.
• Developmental and social factors can significantly influence cognitive abilities in young mammals.

Purpose of the Study:

• To investigate the impact of age and social isolation on flexible learning and memory in male mice.
• To examine how cognitive flexibility, specifically rule reversal learning, changes during development (6-12 weeks).
• To compare the effects of same-day (working memory) versus consecutive-day (long-term memory) testing on reversal learning in socially reared versus isolated mice.

Main Methods:

• Male mice (6-12 weeks old) were trained on a compound discrimination (CD) task, followed by a rule reversal (CDR) task.
• Mice were tested at different ages (weekly) to assess developmental effects.
• Socially reared (SR) and socially isolated (SI) mice were compared under working memory and long-term memory conditions.

Main Results:

• All ages showed more errors during rule reversal (CDR) than initial learning (CD).
• Younger mice (6 weeks) made fewer CDR errors, suggesting immature long-term memory.
• Socially isolated mice exhibited preserved long-term memory reversal learning compared to socially reared mice, indicating prolonged immature long-term memory.

Conclusions:

• Cognitive flexibility, particularly rule reversal, is influenced by both age-related memory development and social experience.
• Social isolation in mice may prolong a state of immature long-term memory, facilitating reversal learning.
• These findings highlight the critical role of early social environment in shaping cognitive development and learning.