Data used in statistical analyses from The contractile patterns, anatomy and physiology of the hyoid musculature change longitudinally through infancy

All mammalian infants suckle, a fundamentally different process than drinking in adults. Infant mammal oropharyngeal anatomy is also anteroposteriorly compressed and becomes more elongate postnatally. While suckling and drinking require different patterns of muscle use and kinematics, little insight exists into how the neuromotor and anatomical systems change through the time that infants suckle. We measured the orientation, activity and contractile patterns of five muscles active during infant feeding from early infancy until weaning using a pig model. Muscles not aligned with the long axis of the body became less mediolaterally orientated with age. However, the timing of activation and the contractile patterns of those muscles exhibited little change, although variation was larger in younger infants than older infants. At both ages, there were differences in contractile patterns within muscles active during both sucking and swallowing, as well as variation among muscles during swallowing. The changes in anatomy, coupled with less variation closer to weaning and little change in muscle firing and shortening patterns suggest that the neuromotor system may be optimized to transition to solid foods. The lesser consequences of aspiration during feeding on an all-liquid diet may not necessitate the evolution of variation in neuromotor function through infancy.

所有哺乳动物幼崽均以吮吸方式进食，这与成年个体的饮水过程存在本质差异。哺乳动物幼崽的口咽部解剖结构呈前后向压缩状态，并在出生后逐渐伸长。尽管吮吸与饮水所需的肌肉活动模式及运动学特征各不相同，但目前学界对幼崽在整个吮吸发育阶段的神经运动与解剖系统如何发生变化仍知之甚少。本研究以家猪为模型，对幼崽从早期吮吸直至断奶阶段参与进食的5块肌肉的朝向、活动状态及收缩模式进行了测定。结果显示，未与身体长轴对齐的肌肉，其朝向随年龄增长愈发偏离内外侧方向；不过，这类肌肉的激活时序与收缩模式却几乎未发生改变，尽管幼崽年龄越小，相关参数的变异程度越大。在两个生长阶段中，同时参与吮吸与吞咽过程的肌肉，其内部收缩模式均存在差异；且不同肌肉在吞咽过程中的表现也各不相同。解剖结构的变化、断奶阶段变异程度的降低，以及肌肉激活与收缩模式几乎无改变的现象，共同提示神经运动系统或已朝着适应固体食物摄入的方向完成优化。全流质饮食条件下，进食时发生误吸的后果相对较轻，这或许无需幼崽在发育阶段演化出神经运动功能层面的变异特征。