Inhibition of prefrontal cortex and medial parietal cortex by somatosensory stimulus of Dan Tian: a NIRS study

Abstract

To evaluate a mechanism underlying Dan Tian (DT) Breathing, We investigated regional activation in the parietal and frontal cortices as assessed by changes of hemoglobin oxygenation during electrical or mechanical stimuli on (DT) using 24-channel near-infrared spectroscopy NIRS) in heathy subjeacts.During electrical stimulation of DT for 2 minutes, the levels of oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) decreased temporarily in the parietal regions near the Cz portion and the primary motor cortices. By contrast, electrical stimulation on the right forefinger elicited an increase or no change of oxyHb in the above regions. On the other hand, oxyHb concentration reduced markedly in the prefrontal cortex during mechanical stimulation of DT, though a small decrease in oxyHb was observed during mechanical stimulation of the forearm. These results suggest that DT stimulation causes active inhibition of pefrontal cortex and medial parietal part of parietal cortices. [J Physiol Sci. 2007;57 Suppl:S109]