Conditioned enhancement of antibody production is disrupted by insular cortex and amygdala but not hippocampal lesions

Pavlovian conditioning procedures can be used to activate the immune system. A reliable conditioned increase of antibody production can be obtained in rats that have previously received a gustative or odor stimulus as the conditioned stimulus paired with an antigen, by exposing the animals to the conditioned stimulus alone. We showed evidence that an excitotoxic lesion bilaterally applied into the insular cortex or the amygdala, but not into the dorsal hippocampus, impaired the acquisition of both odor and gustatory conditioned immune enhancement. We found no effects of lesions on normal antibody production. These results suggest that the amygdala and the insular cortex are involved in the neural-immune interactions: that mediate conditioned immunity. (C) 1999 Academic Press.