Cottrell D F, Iggo A
J Physiol. 1984 Sep;354:457-75. doi: 10.1113/jphysiol.1984.sp015388.
Single-unit afferent activity was recorded from the hepatic-duodenal branch of the vagus nerve of chloralose-anaesthetized sheep during acute electrophysiological experiments. The impulse activity of sixty-seven slowly adapting mechanoreceptors situated in the muscularis externa of the proximal duodenum and pyloric sphincter was synchronous with alterations in electromyographic and tension records. Afferent units were excited during passive distension, compression and drug-induced increases in muscle tension, thus satisfying the criteria for 'in series' tension receptors (Iggo, 1955). From the responses to compression some evidence was found for the existence of separate populations of tension receptors with different mechanical thresholds. Two fibre populations were found: non-myelinated (0.70 +/- 0.26 S.D. ms-1) and myelinated (7.6 +/- 1.6 S.D. m s-1). Mucosal application of solutions of hydrochloric acid, volatile fatty acids, alkali and amino acids, and mucosal probing modified the activity of most units. These changes were reduced by anaesthesia of the mucosa. It is concluded that tension receptors in the sheep duodenum occupy a position 'in series' with longitudinal muscle, and that their activity can be modified by the particulate and chemical composition of chyme by a mechanism involving local nerve plexuses. The activity of tension receptors is compared with that of two other mechanoreceptor classes located serosally (five units) and in the lesser omentum (eleven units). Receptors in neither of these two classes were directly excited by active contraction of the duodenum.
在急性电生理实验中，从水合氯醛麻醉的绵羊迷走神经肝十二指肠分支记录单单位传入活动。位于十二指肠近端和幽门括约肌外肌层的67个慢适应性机械感受器的冲动活动与肌电图和张力记录的变化同步。在被动扩张、压迫以及药物诱导的肌肉张力增加期间，传入单位被兴奋，因此符合“串联”张力感受器的标准（伊戈，1955年）。从对压迫的反应中发现了一些证据，表明存在具有不同机械阈值的不同张力感受器群体。发现了两种纤维群体：无髓鞘的（0.70±0.26标准差毫秒-1）和有髓鞘的（7.6±1.6标准差米秒-1）。向黏膜施加盐酸、挥发性脂肪酸、碱和氨基酸溶液以及对黏膜进行探查会改变大多数单位的活动。黏膜麻醉可减少这些变化。得出的结论是，绵羊十二指肠中的张力感受器与纵肌处于“串联”位置，并且它们的活动可通过涉及局部神经丛的机制被食糜的颗粒和化学成分改变。将张力感受器的活动与另外两类位于浆膜（5个单位）和小网膜（11个单位）的机械感受器的活动进行了比较。十二指肠的主动收缩均未直接兴奋这两类感受器中的任何一类感受器。
