PET imaging for altered brain function evoked by exercise: measurements of changes in cerebral blood flow and neurotransmitters

Abstract

Epidemiologic and clinical studies have suggested that exercise intervention has an important role to improve and maintain brain function. To elucidate how exercise influences physiological aspects related with brain function, we investigated changes in regional cerebral blood flow (rCBF) and μ-opioidergic receptor system in brain. As a result of a PET study using ¹⁵O-H₂O, we explored that during aerobic exercise rCBF increased in broad areas including the primary sensorimotor cortex, cerebellum and insular cortex. This alteration in rCBF may attributable to the possible underlying mechanism for exercise-induced plasticity via the enhanced regional neural activity and influence to neurotransmitters as well. Another PET study using ¹¹C-Carfentanil suggested that positive alteration in mood status following aerobic exercise and fatigue caused by severe-intensity exercise had associated with μ-opioidergic receptor system in the limbic system and pituitary. This change in μ-opioidergic receptor system was influenced by exercise intensity and the inter-individual difference in the altered mood. Neuroimaging studies using PET is a useful method to elucidate changes in rCBF and neurotransmitter systems evoked by exercise, which may related with the underlying mechanisms for exercise-induced altered brain function.