Differences in active avoidance behaviour of hypoactive and hyperactive rats subjected to immobilisation stress

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Psychopharmacology

Background:

• Open field activity distinguishes Wistar rats into hypoactive and hyperactive groups based on ambulatory and rearing behaviors.
• Investigating the impact of activity levels on cognitive functions like avoidance learning is crucial for understanding behavioral variations.

Purpose of the Study:

• To compare the active avoidance learning capabilities of hypoactive and hyperactive Wistar rats.
• To examine the effects of domperidone and immobilization stress on avoidance learning in both activity groups.

Main Methods:

• Wistar rats were categorized as hypoactive or hyperactive based on open field activity.
• Active avoidance learning was assessed using a shuttle box paradigm.
• The influence of domperidone and immobilization stress on learning was evaluated.

Main Results:

• Hyperactive rats demonstrated significantly better acquisition of active avoidance learning than hypoactive rats.
• Domperidone impaired learning in both hypoactive and hyperactive rats.
• Immobilization stress facilitated avoidance learning exclusively in the hypoactive group.

Conclusions:

• Activity levels influence avoidance learning, with hyperactivity being associated with better performance.
• Immobilization stress selectively enhances avoidance learning in hypoactive rats, potentially through dopaminergic pathways.
• These findings highlight the complex interplay between stress, dopamine, and learning in different behavioral phenotypes.