Cerebral correlates of autonomic cardiovascular arousal: a functional neuroimaging investigation in humans

1. States of peripheral autonomic arousal accompany emotional behaviour, ph ysical exercise and cognitive effort, and their central representation may influence decision making and the regulation of social and emotional behavi ours. However, the cerebral functional neuroanatomy representing and mediat ing peripheral autonomic responses in humans is poorly understood. 2. Six healthy volunteer subjects underwent (H2O)-O-15 positron emission to mography (PET) scanning while performing isometric exercise and mental arit hmetic stressor tasks, and during corresponding control tasks. Mean arteria l blood pressure (MAP) and heart rate (HR) were monitored during scanning. 3. Data were analysed using statistical parametric mapping (SPM99). Conjunc tion analyses were used to determine significant changes in regional cerebr al blood flow (rCBF) during states of cardiovascular arousal common to both exercise and mental stressor tasks. 4. Exercise and mental stressor tasks, relative to their control tasks, wer e associated with significantly (P < 0.001) increased MAP and HR. Significa nt common activations (increased rCBF) were observed in cerebellar vermis, brainstem and right anterior cingulate. In both exercise and mental stress tasks, increased rCBF in cerebellar vermis, right anterior cingulate and ri ght insula covaried with MAP; rCBF in pens, cerebellum and right insula cov aried with HR. Cardiovascular arousal in both categorical and covariance an alyses was associated with decreased rCBF in prefrontal and medial temporal regions. 5. Neural responses in discrete brain regions accompany peripheral cardiova scular arousal. We provide evidence for the involvement of areas previously implicated in cognitive and emotional behaviours in the representation of peripheral autonomic states, consistent with a functional organization that produces integrated cardiovascular response patterns in the service of vol itional and emotional behaviours.