Increase of vagal-mediated heart rate variability and resting-state amygdala functional connectivity after short sudarshan kriya yoga practicing

• Main Authors: Ting-WeiHsu, 許庭維
• Other Authors: A-Min Huang
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/x3rq6q

碩士 === 國立成功大學 === 生理學研究所 === 107 === Sudarshan kriya yoga (SKY) consists of a unique yoga breathing technique which is practiced by more than tens of millions of people around the world. Regular practicing of SKY increases well-being and relieves emotional disorders such as anxiety and depression. There are two versions of SKY practicing: weekly “long SKY” practicing in a group and daily “short SKY” practicing at home. Recent studies have found that long SKY increases vagal-mediated heart rate variability (HRV). However, whether short SKY has similar effects on HRV is unknown. Relief of negative emotions by SKY is probably related to the activity of amygdala, which is not only an emotional center, but also affects autonomic tone. We conjectured that short SKY practicing not only changes vagal-meditated HRV but also changes the activity of amygdala and its functional connectivity (FC) with other brain regions. In this study, we have recruited 25 healthy participants who had learned SKY and regularly practice at home or in a group. Each participant underwent two days of resting-state magnetic resonance imaging (rs-fMRI) and photoplethysmographic (PPG) HRV analysis. On one day, short SKY for 35 minutes was practiced, and on the other day was 35 minutes of control video watching. Data were collected simultaneously for each participant immediately before and after interventions. HRV analysis results showed that short SKY but not video watching increased the root mean square of the successive differences (RMSSD), indicating that short SKY improves vagal-mediated HRV. Regional homogeneity (ReHo) of brain image analysis showed that the activity pattern after short SKY practicing was different from that after control video watching. Short SKY practicing especially increased the activity of the supramarginal gyrus, while the control group increased the activity of the visual cortex. However, the activity of the bilateral amygdala region did not change. FC analysis showed that if using bilateral amygdala as the seed region, FC between bilateral amygdala and the medial prefrontal cortex (mPFC), FC between left amygdala with the supramarginal gyrus, and FC between right amygdala with the temporal gyrus were all increased after short SKY practicing, suggesting that FC between the amygdala and the mood-regulating brain area after short SKY practicing. Correlation analysis showed that changed RMSSD was positively correlated with changed FC between right amygdala and right insula; changed RMSSD was also positively correlated with FC between left amygdala and thalamus, and between left amygdala with right amygdala / parahippocampal gyrus (PHG) / pons after short SKY practicing. Furthermore, using thalamus as a seed region, positive correlation was also found between changed RMSSD and changed FC between thalamus and a big cluster which includes brainstem / prefrontal gyrus / striatum / insula / thalamus / cerebellum / PHG / superior temporal gyrus / precentral gyrus/ hippocampus / claustrum / left amygdala after short SKY practicing. However, all of these positive correlations were not found in control video watching. Overall, results from this study show that the short version of SKY not only improves the vagal tone, but also the activity of brain regions involved in emotional regulation. Increase of vagal tone is related to the FC of the amygdala to regions include thalamus and brainstem.