Strain-dependent modulation of memory by stress in mice

Area of Science:

• Neuroscience
• Behavioral Science
• Genetics

Background:

• Stress significantly impacts cognitive functions, including memory.
• Genetic variations among mouse strains can influence responses to stressors.
• Endogenous opioids and stress hormones are implicated in memory modulation.

Purpose of the Study:

• To investigate the effects of immobilization stress on memory retention in different mouse strains.
• To determine the duration of stress-induced memory modulation.
• To explore the role of naloxone in antagonizing these effects.

Main Methods:

• Utilized a passive avoidance task to assess memory retention.
• Applied immobilization stress immediately or 2 hours post-training.
• Tested memory recall at various time points up to 14 days.
• Administered naloxone to evaluate its antagonistic effects.

Main Results:

• Immobilization stress immediately after training impaired memory in Swiss Webster (Swiss) and DBA/2 (DBA) mice.
• C57BL/6 (C57) mice showed improved memory retention following immediate immobilization stress.
• Memory effects persisted longer in C57 mice (14 days) compared to DBA and Swiss mice (<7 days).
• Naloxone administration antagonized the observed stress-induced memory modulations.

Conclusions:

• Genetic background critically influences stress-induced memory modulation in mice.
• Endogenous opioid systems may play a role in mediating these stress effects on memory.
• Stress-induced memory changes are time-dependent and strain-specific.