Related Experiment Videos
Chronic administration of corticosterone impairs spatial reference memory before spatial working memory in rats.
P S Coburn-Litvak1, K Pothakos, D A Tata
1Program in Neurobiology, SUNY Stony Brook, Stony Brook, NY 11790-5230, USA.
Neurobiology of Learning and Memory
|May 10, 2003
Summary
Elevated corticosterone (CORT) for 21 days impairs long-term spatial memory formation but not working memory in rats. Longer CORT exposure (56 days) is needed to affect spatial working memory.
Area of Science:
- Neuroscience
- Endocrinology
- Behavioral Science
Background:
- Corticosterone (CORT) is the primary glucocorticoid in rodents.
- Elevated CORT levels over 21 days are known to damage the hippocampal CA3 subregion.
- The hippocampus is critical for spatial memory functions.
Purpose of the Study:
- To investigate the effects of chronic CORT elevation on spatial memory in rats.
- To test the hypothesis that CORT impairs hippocampal-dependent spatial memory.
Main Methods:
- Rats received daily subcutaneous injections of CORT (26.8 mg/kg) or vehicle (sesame oil) for 21 or 56 days.
- Behavioral testing included the Y-maze and Barnes maze, focusing on spatial working and reference memory.
- Testing commenced 24 hours after the final injection to avoid acute stress effects.
Main Results:
- CORT administration for 21 days did not impair spatial working memory in the Y-maze or Barnes maze.
- Spatial working memory was impaired after 56 days of CORT administration in the Y-maze.
- While the vehicle group improved on reference memory tasks, the CORT group did not, indicating impaired long-term memory formation.
Conclusions:
- Short-term CORT elevation (21 days) impairs the formation of long-term spatial memory (reference memory) but not spatial working memory.
- Impairments in spatial working memory require longer durations of CORT exposure (≥56 days).
- These findings highlight the differential impact of chronic CORT on distinct types of spatial memory.