Interleukin-1-induced sickness behavior depends on behavioral lateralization in mice

Area of Science:

• Neuroimmunology
• Behavioral Neuroscience
• Animal Models

Background:

• Individual differences in brain-immune interactions are linked to behavioral traits like lateralization.
• Lipopolysaccharide (LPS) and interleukin-1 (IL-1) are known to induce sickness behavior and immune responses.
• Behavioral lateralization in mice has been previously associated with varying responses to neurochemical and immune challenges.

Purpose of the Study:

• To investigate the influence of behavioral lateralization on sickness responses to LPS and IL-1 in mice.
• To determine if paw preference affects the behavioral outcomes of LPS and IL-1 administration.
• To explore inter-individual differences in brain-immune system reactivity.

Main Methods:

• Adult female C3H mice were selected based on paw preference in a food-reaching task.
• Mice were injected intraperitoneally with either lipopolysaccharide (LPS) or recombinant interleukin-1 beta (IL-1β).
• Sickness behaviors, including social interaction, immobility, body weight, and food intake, were assessed over 6 hours.

Main Results:

• LPS-induced sickness behavior was comparable between right- and left-pawed mice.
• IL-1β-induced sickness behavior was dependent on paw preference.
• Right-pawed mice exhibited more pronounced IL-1β-induced depression in social investigation and increased immobility compared to left-pawed mice.

Conclusions:

• Behavioral lateralization, specifically paw preference, modulates the sickness response to IL-1 but not LPS.
• Right-pawed mice demonstrate heightened sensitivity to IL-1-induced sickness, suggesting lateralization impacts neuroimmune signaling.
• These findings underscore the importance of inter-individual differences in immune system reactivity and stress responses.