A balanced brain asymmetry modulates T cell-mediated events.

Partial ablation of the left fronto-parietal cerebral cortex decreases the number of spleen T cells, impairs IgG-alpha SRBC and T mitogen-induced responses, and delays the response to alloantigens. In contrast, these events are increased following a symmetric lesion of the right neocortex. The findings extend previous results showing that the neocortex modulates NK activity and the efficacy of T cell-specific serum factors. B cells and macrophages are not affected. In these assays, mice subjected to ablation of one lateral cerebral neocortex serve as controls for symmetrically lesioned mice, in addition to no surgery or sham-operated controls. The findings suggest that brain lateralization for cognitive processes should be extended to T cell immune recognition. The phenomenon is present at a population level.