Resting cerebral metabolism correlates with skin conductance and functional brain activation during fear conditioning

We investigated whether resting brain metabolism can be used to predict autonomic and neuronal responses during fear conditioning in 20 healthy humans. Regional cerebral metabolic rate for glucose was measured via positron emission tomography at rest. During conditioning, autonomic responses were measured via skin conductance, and blood oxygen level dependent signal was measured via functional magnetic resonance imaging. Resting dorsal anterior cingulate metabolism positively predicted differentially conditioned skin conductance responses. Midbrain and insula resting metabolism negatively predicted midbrain and insula functional reactivity, while dorsal anterior cingulate resting metabolism positively predicted midbrain functional reactivity. We conclude that resting metabolism in limbic areas can predict some aspects of psychophysiological and neuronal reactivity during fear learning.

► Resting FDG PET, skin conductance and fMRI of classical conditioning in 20 subjects.
► Mid-cingulate metabolism correlates to autonomic fear conditioning.
► Anterior insula and midbrain metabolism correlate negatively to their BOLD response.
► Mid-cingulate metabolism predicted midbrain BOLD reactivity.
► Results indicate a complex relationship between resting metabolism and BOLD signal.