Single cutaneous fibers were recorded in the median nerve of the deeply anesthetized rat and the receptor morphology in the forelimb glabrous skin was analyzed to establish a probable correlation between receptor anatomy and physiology. Receptor complexes in the glabrous skin of the rat forelimb were stained immunologically with antibodies NF-200 and PGP-9.5, confirming the presence of Meissner corpuscles and Merkel complexes within the dermal papilla similar to other mammals including primates. Both the Meissner corpuscles and Merkel cell complexes were sparse and located in the pyramidal-shaped palmer pads and the apex of the digit extremities. They were almost totally absent elsewhere in the glabrous skin. No Ruffini receptors or Pacinian corpuscles were found in our samples. A total of 92 cutaneous fibers were retained long enough for analysis. Thirty-five (38%) were characterized as rapidly adapting fibers (RA) and 57 (62%) were slowly adapting afferents (SA). Despite the very limited number of receptors at the tip of the digit, RA receptors outnumbered SA fibers 3.2/1.0. In contrast, SA fibers on the thenar pad outnumbered RA receptors by a ratio of 3–1. Despite the very limited number of low threshold mechanoreceptors in the glabrous skin of the rat forelimb, the prevalence of SA afferents in the palm and more frequent occurrence of RA afferents in the digit extremity suggest differences in functionality both for locomotion and object manipulation.

在深度麻醉的大鼠的正中神经中记录单皮纤维，并分析前肢无毛皮肤中的受体形态，以建立受体解剖学和生理学之间可能的相关性。用抗体 NF-200 和 PGP-9.5 对大鼠前肢无毛皮肤中的受体复合物进行免疫染色，证实与包括灵长类在内的其他哺乳动物相似，真皮乳头内存在迈斯纳小体和默克尔复合物。Meissner 小体和 Merkel 细胞复合体均稀疏且位于锥体状的掌垫和指端的顶点。在光滑的皮肤的其他地方几乎完全没有它们。在我们的样本中没有发现 Ruffini 受体或 Pacinian 小体。总共有 92 根皮肤纤维被保留足够长的时间用于分析。35 个 (38%) 被表征为快速适应纤维 (RA)，57 个 (62%) 被表征为缓慢适应传入纤维 (SA)。尽管指尖的受体数量非常有限，但 RA 受体的数量超过了 SA 纤维 3.2/1.0。相比之下，鱼际垫上的 SA 纤维以 3-1 的比例超过 RA 受体。尽管大鼠前肢无毛皮肤中的低阈值机械感受器数量非常有限，但手掌中 SA 传入神经的流行和指端 RA 传入神经的更频繁发生表明运动和物体操纵的功能存在差异。相比之下，鱼际垫上的 SA 纤维以 3-1 的比例超过 RA 受体。尽管大鼠前肢无毛皮肤中的低阈值机械感受器数量非常有限，但手掌中 SA 传入神经的流行和指端 RA 传入神经的更频繁发生表明运动和物体操纵的功能存在差异。相比之下，鱼际垫上的 SA 纤维以 3-1 的比例超过 RA 受体。尽管大鼠前肢无毛皮肤中的低阈值机械感受器数量非常有限，但手掌中 SA 传入神经的流行和指端 RA 传入神经的更频繁发生表明运动和物体操纵的功能存在差异。