INFLUENCE OF EARLY-LIFE EVENTS ON IMMUNE REACTIVITY IN ADULT MICE

The effects of postnatal manipulations on different immune parameters were investigated in adult female mice. Postnatal stress consisted of a 15-min daily exposure to clean bedding (temperature maintained at 35 degrees C) for the first 2 weeks of life in the absence of the mother but in the presence of littermates. Controls were unhandled until wea ning. At 60 days of age, female mice stressed during postnatal develop ment showed enhanced immune reactivity as assessed by NK-cell activity and T-cell mitogenesis in comparison with unhandled mice. By contrast , B-lymphocyte proliferation induced by lipopolysaccharide (LPS) was n ot affected by alterations of postnatal environment. Furthermore, the association between immune reactivity and behavioral lateralization ob served in adult mice was not altered by postnatal stress. (C) 1994 Joh n Wiley & Sons, Inc.