Neura, nerves, nerve fibers, neurofibrils, microtubules: Multidimensional routes of pain, pleasure, and voluntary action in images across the ages.

Available records indicate that the human body has always been conceived, in different periods and cultures, as spanned by multiple channels for internal communication and coherent functioning as a unit-"meridians" in treatises of Chinese medicine, metu in Egyptian papyri, srotas in Ayurvedic Indian texts, and neura in the Western scientific heritage from ancient Greece. Unfortunately, the earliest extant figurative depictions of such pathways of general control, complementary to the blood vessels, are late medieval copies of old crude sketches that attempted to show the main anatomico-physiological systems. The scarcity of adequate illustrations was more than compensated in the Renaissance, when the efforts of both artists and anatomists for the first time produced basically correct renditions of the human nervous system and many other bodily structures. As attention was next focused on microscopic structure as a requisite to understand physiological mechanisms, during the Enlightenment the nerves were revealed to consist of numerous thin tubes or fibers aligned in parallel. Improved microscopy techniques in the nineteenth century led to discovering and delineating still finer fibrils coursing along the cores of the nerve fibers themselves. Electron microscopy, developed throughout the twentieth century, recognized some of these fibrils within nerve fibers as being also tubular. All the progressive stages in understanding nerve construction, at increasingly more detailed scales, have been accompanied by technological advances and by debate about the structure and function relationship. And every step has been a source of amazing imagery.
© 2013 Elsevier B.V. All rights reserved.
KEYWORDS:
Renaissance art, acupuncture, anatomical illustration, anatomy, history of medicine, microscopy, nervous system, neuroanatomy

PMID: 24041279