Classification of motor units in flexor carpi radialis muscle of the cat.
Classification of motor units in flexor carpi radialis muscle of the cat.
复制标题
猫桡侧腕屈肌运动单位的分类。
DOI：
10.1152/jn.1985.54.3.676
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发表时间：
1985
影响因子：
2.5
通讯作者：
Gonyea,WJ
中科院分区：
文献类型：
--
作者：
Botterman,BR;Iwamoto,GA;Gonyea,WJ
猫桡侧腕屈肌（FCR）是两种主要腕屈肌之一，其运动单位分为三组：慢缩抗疲劳（S）、快缩抗疲劳（FR）和快缩疲劳敏感（FF）。分类是基于1）由40 pps的一系列刺激产生的紧张-时间面积与最大紧张-时间面积的比值（A40/Amax），和2）累积力指数（CFI），根据一系列列车计算（40 pps）CFI被定义为在刺激的最后2分钟中累积的力与刺激的前2分钟中累积的力之间的比率。分钟的刺激。A40/Amax值大于0.50的电机装置被归类为S型装置，小于0.50的电机装置被归类为F型装置。A40/Amax基本上等同于未融合破伤风的“下垂”曲线，其能够将单位分为“慢”和“快”收缩单位。在一般情况下，面积比小于0.50的单位抽搐收缩时间小于25毫秒，而面积比大于0.50的单位收缩时间大于25毫秒。F型单位分为两组的分离是基于CFI，与比例小于或等于0.75对应的FF型单位和大于0.75的FR型单位。S型装置的CFI也大于0.75。根据该分类方案，40.4%的FCR电机单元为S型，37.5%为FR型，22.1%为FF型。基于A40/Amax和CFI分布的三种运动单元类型的先验假设通过聚类分析进行评估。该分析支持运动单位的三个主要群体的假设。此外，当聚类形成进行到分析中仅剩下三个聚类的点时，这些聚类中的每一个仅由一种类型的单元组成（即，S、FR或FF）。分类方案的有效性进一步检验逐步判别分析。被分类为S、FR和FF型的单元预计将以100%的准确度进行分类。所有装置在其最初分类的组中具有组成员资格的概率（后验）较高（129个装置的P> 0.99; 7个装置的P> 0.90）。FR型和FF型单位的增强抽搐收缩的持续时间被认为是小于大多数人群的后肢单位的报告。（400字处截断摘要）
Motor units in the cat flexor carpi radialis (FCR) muscle, one of two primary wrist flexors, were classified into three groups: slow twitch, fatigue resistant (S); fast twitch, fatigue resistant (FR); and fast twitch, fatigue sensitive (FF). Classification was based on 1) the ratio of the tension-time area produced by a train of stimuli delivered at 40 pps and the maximum tension-time area (A40/Amax), and 2) the cumulative force index (CFI), calculated from a series of trains (40 pps) delivered intermittently for a period of 4 min. The CFI is defined as the ratio between the force accumulated in the last 2 min of stimulation to the first 2 min of stimulation. Motor units with values for A40/Amax greater than 0.50 were classified as type S units, and less than 0.50 as type F. A40/Amax is essentially equivalent to the "sag" profile of an unfused tetanus in its ability to separate units into "slow" and "fast" contracting units. In general, units with area ratios less than 0.50 had twitch contraction times less than 25 ms, whereas units with area ratios greater than 0.50 had contraction times greater than 25 ms. Separation of type F units into two groups was based on the CFI, with ratios less than or equal to 0.75 corresponding to type FF units and greater than 0.75 as type FR units. Type S units also had CFIs greater than 0.75. Based on this classification scheme, 40.4% of FCR motor units were type S, 37.5% type FR, and 22.1% type FF. The a priori assumption of three motor-unit types based on the distributions of A40/Amax and CFI was evaluated by cluster analysis. The analysis supported the assumption of three primary groups of motor units. Furthermore, when cluster formation proceeded to the point where only three clusters remained in the analysis, each of these clusters consisted exclusively of one type of unit (i.e., S, FR, or FF). The validity of the classification scheme was further tested by stepwise discriminant analysis. Units classified as types S, FR, and FF were predicted to be classified with 100% accuracy. All units had a high probability (a posteriori) of having group membership in their originally classified group (P greater than 0.99 for 129 units; P greater than 0.90 for 7 units). The duration of potentiated twitch contractions for type FR and FF units was found to be less than reported for most populations of hindlimb units.(ABSTRACT TRUNCATED AT 400 WORDS)