Characterization of motor units in behaving adult mice shows a wide primary range.
Characterization of motor units in behaving adult mice shows a wide primary range.
复制标题
行为成年小鼠运动单位的表征显示出广泛的主要范围。
DOI：
10.1152/jn.00108.2014
复制
发表时间：
2014
影响因子：
2.5
通讯作者：
Tysseling,VickiM
中科院分区：
文献类型：
--
作者：
Ritter,LauraK;Tresch,MatthewC;Heckman,CJ;Manuel,Marin;Tysseling,VickiM
The mouse is essential for genetic studies of motor function in both normal and pathological states. Thus it is important to consider whether the structure of motor output from the mouse is in fact analogous to that recorded in other animals. There is a striking difference in the basic electrical properties of mouse motoneurons compared with those in rats, cats, and humans. The firing evoked by injected currents produces a unique frequency-current (F-I) function that emphasizes recruitment of motor units at their maximum force. These F-I functions, however, were measured in anesthetized preparations that lacked two key components of normal synaptic input: high levels of synaptic noise and neuromodulatory inputs. Recent studies suggest that the alterations in the F-I function due to these two components are essential for recreating firing behavior of motor units in human subjects. In this study we provide the first data on firing patterns of motor units in the awake mouse, focusing on steady output in quiet stance. The resulting firing patterns did not match the predictions from the mouse F-I behaviors but instead revealed rate modulation across a remarkably wide range (10–60 Hz). The low end of the firing range may be due to changes in the F-I relation induced by synaptic noise and neuromodulatory inputs. The high end of the range may indicate that, unlike other species, quiet standing in the mouse involves recruitment of relatively fast-twitch motor units.
