Learning, memory, and glial cell changes following recovery from chronic unpredictable stress

Area of Science:

• Neuroscience
• Stress Research
• Neuroinflammation

Background:

• Chronic stress is linked to inflammation, cognitive decline, and glial cell alterations.
• The reversibility of these stress-induced changes after recovery remains largely unknown.

Purpose of the Study:

• To investigate the impact of recovery from chronic unpredictable stress (CUS) on spatial learning, memory, and neurobiological markers.
• To assess the reversibility of CUS-induced changes in microglia, astrocytes, IL-1β, and GDNF.

Main Methods:

• Mice were subjected to 40 days of CUS, followed by a 40-day recovery period for the recovery group.
• Spatial learning and memory were evaluated using the Morris water maze.
• Immunohistochemistry and Western blot analyses were employed to assess glial cell changes and protein levels (IL-1β, GDNF).

Main Results:

• CUS-induced spatial learning and memory impairments were reversible after the recovery period.
• Microglial alterations in the hippocampus (CA3) and prelimbic areas normalized during recovery.
• Astrocyte activation in the CA3 region and elevated hippocampal GDNF levels persisted post-recovery, while IL-1β levels decreased.

Conclusions:

• Recovery from CUS can reverse learning and memory deficits.
• Sustained astrocyte activation and increased GDNF levels post-recovery suggest their crucial role in brain adaptation and repair following chronic stress.