Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada
Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
J Exp Biol. 2018 Sep 3;221(Pt 17):jeb168716. doi: 10.1242/jeb.168716.
The ability to modulate the function of muscle is integral to an animal's ability to function effectively in the face of widely disparate challenges. This modulation of function can manifest through short-term changes in neuromuscular control, but also through long-term changes in force profiles, fatiguability and architecture. However, the relative extent to which shorter-term modulation and longer-term plasticity govern locomotor flexibility remains unclear. Here, we obtain simultaneously recorded kinematic and muscle activity data of fin and body musculature of an amphibious fish, After examining swimming and walking behaviour in aquatically raised individuals, we show that walking behaviour is characterized by greater absolute duration of muscle activity in most muscles when compared with swimming, but that the magnitude of recruitment during walking is only increased in the secondary bursts of fin muscle and in the primary burst of the mid-body point. This localized increase in intensity suggests that walking in is powered in a few key locations on the fish, contrasting with the more distributed, low intensity muscle force that characterizes the stroke cycle during swimming. Finally, the increased intensity in secondary, but not primary, bursts of the fin muscles when walking probably underscores the importance of antagonistic muscle activity to prevent fin collapse, add stabilization and increase body support. Understanding the principles that underlie the flexibility of muscle function can provide key insights into the sources of animal functional and behavioural diversity.
调节肌肉功能的能力是动物在面对广泛不同挑战时有效发挥功能的关键。这种功能的调节可以通过神经肌肉控制的短期变化来体现，但也可以通过力廓、疲劳性和结构的长期变化来体现。然而，较短时间的调制和较长时间的塑性在多大程度上控制着运动灵活性仍不清楚。在这里，我们获得了两栖鱼类的鳍和身体肌肉的同时记录的运动学和肌肉活动数据。在检查了在水生环境中饲养的个体的游泳和行走行为后，我们表明，与游泳相比，行走行为的特征是大多数肌肉的肌肉活动绝对持续时间更长，但在鳍肌肉的次要爆发和中体点的主要爆发期间，行走时的募集幅度仅增加。这种强度的局部增加表明，在 中，行走是由鱼身上的几个关键部位提供动力的，与游泳时的划水周期中特征为分布广泛、强度较低的肌肉力量形成对比。最后，行走时鳍部的次级爆发而不是初级爆发的强度增加可能强调了拮抗肌活动的重要性，以防止鳍部塌陷、增加稳定性和增加身体支撑。了解肌肉功能灵活性的原理可以为动物功能和行为多样性的来源提供关键的见解。
