Miyazaki, J. | Search bioRxiv

bioRxiv2025

Discovery of a chemosynthetic community at the serpentinite-hosted seep on the Quaker Seamount, Mariana Forearc

Deep-sea chemosynthesis-based ecosystems in the Mariana Region include hydrothermal vents on the Mariana Arc and in the Mariana Back-Arc, and serpentinite-hosted seeps on the Mariana Forearc - with the latter being by far the least studied. Here, we surveyed the biodiversity of the serpentine seep on the Quaker Seamount. At first glance, the area appears to be devoid of megafauna, but examination of the carbonates revealed dense aggregations of animals dominated by the limpets Bathyacmaea and Pyropelta on brucite-carbonate chimney structures exhibiting visible fluid venting. Sorting of recovered material yielded a total of 14 species and together with an observation of a Munidopsis squat lobster we report a total of 15 species; six of these are considered endemics of chemosynthetic ecosystems. The occurrence of taxa such as the snail Lurifax cf. japonicus and the limpet Pyropelta ryukyuensis, otherwise only known from distant vents in the Izu-Ogasawara Arc and Okinawa Trough off Japan, strengthens the hypothesis that serpentine seeps may function as dispersal stepping-stones across arc and back-arc systems.

ecology↗

bioRxiv2020

Resting-state functional connectivity predicts recovery from visually induced motion sickness

Movies depicting certain types of motion often provoke uncomfortable symptoms similar to motion sickness, termed visually induced motion sickness (VIMS). VIMS generally evolves slowly during the viewing of a motion stimulus and, when the stimulus is removed, the recovery proceeds over time. Recent human neuroimaging studies have provided new insights into the neural bases underlying the evolution of VIMS. In contrast, no study has investigated the neural bases underlying the recovery from VIMS. Study of the recovery process is critical for the development of a way to promote recovery and could provide further clues for understanding the mechanisms of VIMS. We thus investigated brain activity during the recovery from VIMS with functional connectivity (FC) magnetic resonance imaging. We found enhanced recovery-related FC patterns involving brain areas such as the insular, cingulate, and visual cortical regions, which have been suggested to play important roles in the emergence of VIMS. These regions also constituted large interactive networks. Furthermore, the increase in FC was correlated with the subjective awareness of recovery for the following 5 pairs of brain regions: insula-superior temporal gyrus, claustrum-left and right inferior parietal lobules, claustrum-superior temporal gyrus, and superior frontal gyrus-lentiform nucleus. Considering the previous findings on the functions of these regions and the present findings, it is suggested that the increase in FC may reflect brain processes such as enhanced interoceptive awareness to ones own bodily state, a neuroplastic change in visual processing circuits, and/or the maintenance of visual spatial memory.

neuroscience↗