Strain-dependent association between lateralization and lipopolysaccharide-induced IL-l beta 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 late ralization in a strain-dependent manner, Methods: We therefore measured pla sma levels of interleukin (IL)-1 beta and IL-6 after an intraperitoneal inj ection of lipopolysaccharide (LPS) in two strains of mice (C3H and BALB/c) that were selected for their different profiles of cytokine production. Res ults: Plasma levels of IL-1 beta and IL-6 increased after LPS injection in both strains and this increase was dependent on paw preference in BALB/c bu t not in C3H mice. Increased levels of IL-1 beta were observed in left-pawe d and ambidextrous but not in right-pawed mice. For IL-6, the LPS-induced i ncrease was higher in ambidextrous than in left- and right-pawed animals. C onclusion: Cytokines may represent one of the factors responsible for inter individual differences in brain-immune interactions. Copyright (C) 2000 S. Karger AG, Basel.