NEUROVISCERAL COUPLING DURING EMOTIONAL RESPONDING IN MAN

Assessment of defensive behavior in the cardiovascular system is based on the presentation of an intense aversive unexpected stimulus that prompts a specific phasic cardiovascular reactivity pattern (usually HR and arterial BP reactivity) coined as the cardiac defense response (CDR). The CDR indexes activity of the defensive motivational system and behavioral coping programs. Using the CDR as a model of defensive behavior, the aim was to analyze putative contribution of brain oscillations into central mechanisms of enhanced cardiovascular stress reactivity in arterial hypertension patients. To address this issue the CDR was elicited in controls (n=19) and naive unmedicated hypertensives (n=17). Heart rate (HR) and arterial blood pressure (BP), based on the beat-by-beat technology (Finometer®) along with 64-channel EEG were simultaneously recorded while the 3 CDR were sequentially evoked. As for the neurophysiological analysis of the CDR’s time-course the event-related synchronization/desynchronization (ERD/ERS) of EEG in different frequency bands was calculated throughout the all recorded CDRs. It was revealed that long-latency BP increases in hypertensives were marked by lack of the alpha-2 (10-12 Hz) ERS over the central and centro-parietal cortex bilaterally. On the contrary, the controls manifested alpha-2 ERS over these regions which was concomitant to the lowered long-latency BP reactivity. High frequency brain alpha oscillations of the centro-parietal cortex are involved into the top-down inhibitory control of BP stress reactivity, and arterial hypertension may be associated with the deficiency of this mechanism.