Elevated corticosterone after fear learning impairs remote auditory memory retrieval and alters brain network...

Area of Science:

• Neuroscience
• Behavioral Science
• Molecular Biology

Background:

• Glucocorticoids are key regulators of memory, influencing behavior adaptively or maladaptively.
• While their role in recent memory is known, glucocorticoids' impact on remote memory remains unclear.

Purpose of the Study:

• To investigate the effect of corticosterone (CORT) administration after learning on remote fear memory.
• To explore the neural mechanisms underlying CORT's influence on long-term memory consolidation and retrieval.

Main Methods:

• Mice underwent auditory fear conditioning followed by a 2 mg/kg CORT injection.
• Remote memory was assessed after 28 days.
• Neuronal activation was measured using c-Fos immunohistochemistry, and brain region coactivation was analyzed via correlation matrices.

Main Results:

• CORT-treated mice showed significantly impaired remote auditory memory retrieval.
• Despite similar net brain activity, CORT altered correlated activity between brain regions.
• Reduced connectivity was observed between the lateral amygdala, basal amygdala, and dorsal dentate gyrus in CORT-treated mice.

Conclusions:

• Post-learning corticosterone administration impairs remote fear memory in mice.
• Disrupted network connectivity within the amygdala and hippocampus may underlie this memory impairment.
• Understanding these pathways offers insights into stress effects on memory and potential therapeutic targets.