Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan.
Research Centre for Environmental and Developmental Medical Sciences, Kyushu University, Fukuoka, Japan.
Sci Rep. 2018 Jan 8;8(1):27. doi: 10.1038/s41598-017-18384-w.
The ontogeny associated with the arm-hanging posture, which is considered ape-specific, remains unknown. To examine its ontogeny, we measured foetal movements of 62 human foetuses aged 10-20 gestation weeks using four-dimensional sonography. We observed that the first-trimester foetuses show this particular species-specific posture. After 11 weeks of gestation, all foetuses showed the arm-hanging posture, and the posture was most frequently observed at 14-16 weeks of gestation. Moreover, this posture often involved extension of both arms and both legs, indicating that it is not myogenic but neurogenic. Furthermore, early ontogeny suggests that it originates because of subcortical activity. Such posture extension bias and persistence indicates that vestibulospinal tract maturation involves the ontogeny of arm-hanging posture during 14-16 weeks of gestation.
与被认为是类人猿特有的悬挂手臂姿势相关的发生过程尚不清楚。为了研究其发生过程，我们使用四维超声对 62 名妊娠 10-20 周的人类胎儿的胎儿运动进行了测量。我们观察到，在妊娠第一期中胎儿就表现出这种特定的种特异性姿势。在妊娠 11 周后，所有胎儿都表现出悬挂手臂的姿势，而在妊娠 14-16 周时最常观察到这种姿势。此外，这种姿势经常涉及到双臂和双腿的伸展，表明它不是肌源性的，而是神经源性的。此外，早期发生过程表明它起源于皮质下活动。这种姿势伸展的偏向和持续表明，前庭脊髓束的成熟涉及到妊娠 14-16 周期间悬挂手臂姿势的发生过程。
