HUMAN CENTRAL AUTONOMIC CARDIOVASCULAR REGULATION DURING EXERCISE: BRAIN REGIONS INVOLVED WITH CENTRAL COMMAND

Abstract

Background: Isometric handgrip (IHG) exercise increases heart rate (HR) and mean arterial pressure (MAP); MAP can be sustained after exercise via post-exercise ischemia (PEI). HR and MAP responses are mediated by feed-forward cortical signals (central command, CC) and neural feedback from active muscles (exercise pressor reflex, EPR). Purpose: Differentiate between cortical regions involved with CC versus the EPR via changes in alpha (8-12Hz) and beta (13-30Hz) power using magnetoencephalography (MEG). Methods: Participants (n=11, 22 ± 2 years) completed a repeated IHG and PEI protocol at 5% (control) and 40% maximum force. Results: HR and MAP increased (p<0.04) early during IHG (CC only), while MAP increased further (p=0.03) as IHG continued (CC & EPR). The MAP response persisted during PEI (EPR, p=0.07). During IHG, alpha and beta power decreased within the contralateral sensorimotor cortex. Power increased within MEG sensors associated with the ipsilateral (IHG-alpha) and contralateral (IHG-beta and PEI-beta) insular cortex.