Unconscious mind activates central cardiovascular network and promotes adaptation to microgravity possibly anti-aging during 1-year-long spaceflight

• Published in: Scientific reports Vol. 12; no. 1; p. 11862
• Main Authors: Otsuka, Kuniaki, Cornelissen, Germaine, Furukawa, Satoshi, Shibata, Koichi, Kubo, Yutaka, Mizuno, Koh, Aiba, Tatsuya, Ohshima, Hiroshi, Mukai, Chiaki
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.07.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 631/114; 631/181; 631/378; 631/443; 631/553; 639/33; 692/308; 692/4019; 692/617; 692/700; 704/445; Adaptation; Aging; Astrocytes; Heart rate; Humanities and Social Sciences; Microgravity; multidisciplinary; Science; Science (multidisciplinary); Space flight; Thalamus
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-14858-8

The intrinsic cardiovascular regulatory system (β, 0.00013–0.02 Hz) did not adapt to microgravity after a 6-month spaceflight. The infraslow oscillation (ISO, 0.01–0.10 Hz) coordinating brain dynamics via thalamic astrocytes plays a key role in the adaptation to novel environments. We investigate the adaptive process of a healthy astronaut during a 12-month-long spaceflight by analyzing heart rate variability (HRV) in the LF (0.01–0.05 Hz) and MF1 (0.05–0.10 Hz) bands for two consecutive days on four occasions: before launch, at 1-month (ISS01) and 11-month (ISS02) in space, and after return to Earth. Alteration of β during ISS01 improved during ISS02 ( P  = 0.0167). During ISS01, LF and MF1 bands, reflecting default mode network (DMN) activity, started to increase at night (by 43.1% and 32.0%, respectively), when suprachiasmatic astrocytes are most active, followed by a 25.9% increase in MF1-band throughout the entire day during ISS02, larger at night (47.4%) than during daytime. Magnetic declination correlated positively with β during ISS01 (r = 0.6706, P < 0.0001) and ISS02 (r = 0.3958, P  = 0.0095). Magnetic fluctuations may affect suprachiasmatic astrocytes, and the DMN involving ISOs and thalamic astrocytes may then be activated, first at night, then during the entire day, a mechanism that could perhaps promote an anti-aging effect noted in other investigations.