Strain-dependent association between lateralization and lipopolysaccharide- induced IL-1beta and IL-6 production in mice.

OBJECTIVE

The brain modulates the immune system in an asymmetrical way, as shown by the association between paw preference and immune response in the mouse. We predicted that the production of cytokines, which are one of the molecular pathways for brain-immune interactions, should be linked to lateralization in a strain-dependent manner.

METHODS

We therefore measured plasma levels of interleukin (IL)-1beta and IL-6 after an intraperitoneal injection of lipopolysaccharide (LPS) in two strains of mice (C3H and BALB/c) that were selected for their different profiles of cytokine production.

RESULTS

Plasma levels of IL-1beta and IL-6 increased after LPS injection in both strains and this increase was dependent on paw preference in BALB/c but not in C3H mice. Increased levels of IL-1beta were observed in left-pawed and ambidextrous but not in right-pawed mice. For IL-6, the LPS-induced increase was higher in ambidextrous than in left- and right-pawed animals.

CONCLUSION

Cytokines may represent one of the factors responsible for interindividual differences in brain-immune interactions.