The most significant effects measured after primary early life infection were a sharp increase in CD3+CD4negCD8neg T cells combined with virtual suppression of the production of key Th1-type cytokines like IFN-γ and IL-2; a large increase in the expression of the prototypical neurotrophin NGF; and increased pre- and post-synaptic reactivity of the ASM combined with intrinsic hyper-contractility delaying its return to resting tone. This evidence concerns the gene IFNG and infection.