Sae Goto1, Yoshiro Fujisawa1, Jun-Ichi Uemura2, Sumio Yamada2, Minoru Hoshiyama2, Masaaki Hirayama3. 1. Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan. 2. Department of Physical and Occupational Therapy, Nagoya University Graduate School of Medicine, Nagoya, Japan. 3. Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan. Electronic address: hirasan@med.nagoya-u.ac.jp.
Abstract
OBJECTIVE: The aim of the study was to investigate the functional differences between N20m and P30m components of somatosensory-evoked magnetic cortical field (SEF) in young and senior subjects. METHODS:Twenty-nine healthy subjects, 13 younger (mean age: 21.8years) and 16 senior (63.8 years), participated. Magnetic fields were measured using a 160-channel, whole head MEG. Single- and paired-pulse stimulations of 200 artifact-free MEG signal epochs were averaged separately. We calculated how aging affects recovery function of SEFs. RESULTS: The senior showed a prolonged N20m peak latency compared to the younger, although the P30m peak latency was not significantly different between groups. The N20m ratios at 60 and 80 ms in the senior were significantly increased compared to the ratios in the younger (60 ms: P<0.05, 80 ms: P<0.001). The P30m ratios at inter-stimulus interval (ISI) of 80 and 100 ms showed even disinhibition in the senior than in the younger (P<0.05). The younger also showed a significantly negative correlation between P30m and N20m components' recovery curves (R=0.72, P<0.05). CONCLUSION: Aging-related changes that occurred in recovery functioning were the decrease in N20m component suppression and the increase in P30m component recovery, indicating that the N20m and P30m components have different functions in aging-related recovery changes. SIGNIFICANCE: Our results show that the N20m ratio at an ISI of 80 ms was significantly increased in the senior group, indicating that the second stimulus-evoked SEF was less inhibited by the initial stimulus at this ISI, suggesting less refractory effect or increased disinhibition.
RCT Entities:
OBJECTIVE: The aim of the study was to investigate the functional differences between N20m and P30m components of somatosensory-evoked magnetic cortical field (SEF) in young and senior subjects. METHODS: Twenty-nine healthy subjects, 13 younger (mean age: 21.8years) and 16 senior (63.8 years), participated. Magnetic fields were measured using a 160-channel, whole head MEG. Single- and paired-pulse stimulations of 200 artifact-free MEG signal epochs were averaged separately. We calculated how aging affects recovery function of SEFs. RESULTS: The senior showed a prolonged N20m peak latency compared to the younger, although the P30m peak latency was not significantly different between groups. The N20m ratios at 60 and 80 ms in the senior were significantly increased compared to the ratios in the younger (60 ms: P<0.05, 80 ms: P<0.001). The P30m ratios at inter-stimulus interval (ISI) of 80 and 100 ms showed even disinhibition in the senior than in the younger (P<0.05). The younger also showed a significantly negative correlation between P30m and N20m components' recovery curves (R=0.72, P<0.05). CONCLUSION: Aging-related changes that occurred in recovery functioning were the decrease in N20m component suppression and the increase in P30m component recovery, indicating that the N20m and P30m components have different functions in aging-related recovery changes. SIGNIFICANCE: Our results show that the N20m ratio at an ISI of 80 ms was significantly increased in the senior group, indicating that the second stimulus-evoked SEF was less inhibited by the initial stimulus at this ISI, suggesting less refractory effect or increased disinhibition.
Authors: Rachel K Spooner; Alex I Wiesman; Amy L Proskovec; Elizabeth Heinrichs-Graham; Tony W Wilson Journal: Cereb Cortex Date: 2019-02-01 Impact factor: 5.357
Authors: Jan H Bettmann; Christine H Meyer-Frießem; Lauren M Schweizer; Lara Schlaffke; Peter K Zahn; Martin Tegenthoff; Oliver Höffken Journal: Sci Rep Date: 2020-12-15 Impact factor: 4.379