Burhanudin R, McDonald F, Rowlerson A
Department of Orthodontics and Paediatric Dentistry, United Medical and Dental School, London, UK.
J Anat. 1996 Apr;188 ( Pt 2)(Pt 2):299-309.
The objectives of this study were to identify the exact location of spindles in jaw-closer muscles of the cat, to count the total number of spindles and to compare their distribution with the distribution of slow extrafusal fibres. The jaw-closer muscle group with all the skeletal attachments intact was fixed in a modified Carnoy solution, decalcified and processed through to wax. Complete series of sections were cut transverse, sagittal and perpendicular to the anterior temporalis muscle. At regular intervals, serial sections were stained by the Weigert-van Gieson method or immunostained for myosin isoforms. Spindle counts were made only from muscle areas where fibres were cut in transverse section, and the spindles were followed individually. The extrafusal fibres were identified by indirect immunoperoxidase staining with antibodies specific for the slow (type I) and fast (type IIM) isoforms of myosin found in jaw-closer muscles. The mean numbers and locations of spindles found were 13 in medial pterygoid (close to inferior border), 123 (one count only) in the deep anterior portion of the temporalis muscle (between the coronoid process of the mandible and the cranium), 50.5 in a small deep zone of superficial masseter anterior to the temporomandibular joint, and 50 in zygomaticomandibularis (the deepest portion of masseter). Most of the spindles were simple spindles. Spindle complexes (4 or more spindle units fused in parallel) were rare and were found only in zygomaticomandibularis and in masseter. Most parts of the jaw-closer muscles had no spindles and contained only fast fibres. Cosegregation of muscle spindles with slow fibres was found in most parts of this muscle group, but the distribution of spindles was more restricted than that of slow fibres.
本研究的目的是确定猫咬肌中肌梭的确切位置，计算肌梭的总数，并将其分布与慢肌梭外纤维的分布进行比较。将具有完整骨骼附着的咬肌肌群固定在改良的卡诺伊溶液中，脱钙并制成蜡块。从前颞肌切取完整的横切、矢状和垂直系列切片。每隔一定间隔，对连续切片进行魏格特 - 范吉森法染色或对肌球蛋白同工型进行免疫染色。仅在纤维横切的肌肉区域进行肌梭计数，并逐个追踪肌梭。通过间接免疫过氧化物酶染色，用针对咬肌中发现的肌球蛋白慢（I型）和快（IIM型）同工型的特异性抗体来识别梭外纤维。发现的肌梭平均数量和位置如下：翼内肌为13个（靠近下缘），颞肌深部前部（在下颌骨冠突和颅骨之间）为123个（仅一次计数），颞下颌关节前方浅层咬肌的一个小深部区域为50.5个，颧下颌肌（咬肌最深部）为50个。大多数肌梭为简单肌梭。肌梭复合体（4个或更多肌梭单位平行融合）很少见，仅在颧下颌肌和咬肌中发现。咬肌的大部分区域没有肌梭，仅含有快纤维。在该肌群的大部分区域发现肌梭与慢纤维共分离，但肌梭的分布比慢纤维更局限。
