Cardiovascular and respiratory modulation of tactile afferents in the human finger pad
Cardiovascular and respiratory modulation of tactile afferents in the human finger pad
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DOI：
10.1113/eph8802548
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发表时间：
2003-09-01
影响因子：
2.7
通讯作者：
Macefield, VG
中科院分区：
文献类型：
--
作者：
Macefield, VG
人类指垫血管化程度很高，因此可以预期皮肤机械感受器附近持续的心脏搏动将反映在其自发或诱发的放电中。本研究的目的是检查指垫触觉传入的随机样本中这种潜在心律性的患病率。通过正中神经中的钨微电极，对 21 个快速（“快速”）适应（18 个 FA I；3 个 FA II）和 44 个缓慢适应（17 SA I；27 SA II）传入神经进行单一记录。测量对侧手指指腹的皮肤血流量；还记录了心电图活动、血压和呼吸。 44% 的传入神经表示心脏调制，表现为简单的脉搏节律或持续放电的调制。 18 个 FA I 单元中只有两个和三个 FA II 单元中只有两个表现出心律性，但它们与脉搏的时间耦合非常紧密。调节对于缓慢适应的传入神经 (57%) 更为常见，并且在 SA II (65%) 类别中比 SA I (47%) 类别更普遍。九个自发活动的 SA II 传入神经表现出呼吸节律，其背景放电在吸气期间下降。结论是，心脏调制对于两类缓慢适应的触觉传入神经来说很常见（但对于快速适应的传入神经则不太常见），这可能对触觉信息的感觉信号传导有影响。
The human finger pad is highly vascularized so it might be expected that the on-going cardiac pulsations in the vicinity of a cutaneous mechanoreceptor would be reflected in its spontaneous or evoked discharge. The purpose of this study was to examine the prevalence of this potential cardiac rhythmicity in a random sample of tactile afferents from the finger pad. Unitary recordings were made from 21 rapidly ('fast') adapting (18 FA I; 3 FA II) and 44 slowly adapting (17 SA I; 27 SA II) afferents via tungsten microelectrodes in the median nerve. Skin blood flow was measured over the pulp of a contralateral finger; ECG activity, blood pressure and respiration were also recorded. Cardiac modulation, present either as a simple pulse rhythm or as modulation of an on-going discharge, was expressed by 44 % of the afferents. Only two out of 18 FA I units, and two out of three FA II units, exhibited cardiac rhythmicity, but their temporal coupling to the pulse was very tight. Modulation was more common for the slowly adapting afferents (57 %), and more prevalent among the SA II (65 %) than the SA I (47 %) classes. Nine spontaneously active SA II afferents exhibited respiratory rhythmicity, their background discharge falling during inspiration. It is concluded that cardiac modulation is common for both classes of slowly adapting tactile afferents (but less common for the rapidly adapting afferents), which may have implications for the sensory signalling of tactile information.