Aβ-fiber nociceptive primary afferent neurons:: a review of incidence and properties in relation to other afferent A-fiber neurons in mammals
Aβ-fiber nociceptive primary afferent neurons:: a review of incidence and properties in relation to other afferent A-fiber neurons in mammals
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DOI：
10.1016/j.brainresrev.2004.07.015
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发表时间：
2004-10-01
影响因子：
--
通讯作者：
Lawson, SN
中科院分区：
文献类型：
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作者：
Djouhri, L;Lawson, SN
具有Abeta纤维的伤害感受器的存在经常被忽视，许多教科书支持所有伤害感受器都有C或Adelta纤维的观点。在这里，我们回顾证据从最早的描述A-纤维伤害性感受器，这清楚地表明，相当大比例的皮肤/躯体传入A-纤维伤害性感受器进行的Abeta传导速度（CV）范围内的所有物种中，CV仔细检查，包括小鼠，大鼠，豚鼠，猫和猴。A纤维伤害感受器与Abeta纤维的比例在不同物种中从18%至65%不等，在啮齿动物中通常>50%。在大鼠，大约20%的带有A α/β纤维的躯体传入神经元是伤害性的。A-纤维伤害感受器的CV分布通常呈现单峰，中值/峰值在较高的Δ CV范围或较低的Δ CV范围内。我们没有发现证据表明Adelta和Abeta伤害感受器的电生理学或细胞化学特性存在不连续的差异，而是与CV相关的逐渐变化。然而，已经报告了一些功能差异。在猫中，具有较低机械阈值的A纤维伤害感受器（中等压力感受器）倾向于具有更快的CV [P.R.伯吉斯，D. Petit，R.M.沃伦猫毛状皮肤中由有髓纤维供应的受体类型。神经生理学杂志。31（1968）833-848]。在灵长类动物（猴）中，对热有反应的A-纤维伤害感受器被分为具有较低机械和较高热阈值的I型A机械-热（AMH）单位（Adelta和Abeta CV），可能包括中等压力感受器，以及具有较高机械/较低热阈值的II型AMH单位（Adelta CV）。重要的是要认识到Abeta伤害感受器的存在，因为假设快速传导，大直径传入总是低阈值机械感受器可能导致/已经导致对数据的误解。(C)2004 Elsevier B. V.保留所有权利。
The existence of nociceptors with Abeta-fibers has often been overlooked, and many textbooks endorse the view that all nociceptors have either C- or Adelta-fibers. Here we review evidence starting from the earliest descriptions of A-fiber nociceptors, which clearly indicates that a substantial proportion of cutaneous/somatic afferent A-fiber nociceptors conduct in the Abeta conduction velocity (CV) range in all species in which CV was carefully examined, including mouse, rat, guinea pig, cat and monkey. Reported proportions of A-fiber nociceptors with Abeta -fibers vary from 18% to 65% in different species, usually >50% in rodents. In rat, about 20% of all somatic afferent neurons with Aalpha/beta-fibers were nociceptive. Distributions of CVs of A-fiber nociceptors usually appear unimodal, with a median/peak in the upper Adelta or lower Abeta CV range. We find no evidence to suggest discontinuous differences in electrophysiological or cytochemical properties of Adelta and Abeta nociceptors, rather there are gradual changes in relation to CV. However, some functional differences have been reported. In cat, A-fiber nociceptors with lower mechanical thresholds (moderate pressure receptors) tend to have faster CVs [P.R. Burgess, D. Petit, R.M. Warren. Receptor types in cat hairy skin supplied by myelinated fibers. J. Neurophysiol. 31 (1968) 833-848]. In primate (monkey) A-fiber nociceptors that responded to heat were divided into type I A mechano-heat (AMH) units (Adelta and Abeta CVs) with lower mechanical and higher heat thresholds and may include moderate pressure receptors, and type II AMH units (Adelta CVs) with higher mechanical/lower heat thresholds. It is important that the existence of Abeta nociceptors is recognised, because assumptions that fast conducting, large diameter afferents are always low threshold mechanoreceptors might lead/have led to misinterpretations of data. (C) 2004 Elsevier B.V. All rights reserved.