試題詳解

6. For peripheral pain mechanisms and nociceptor sensitization, which one of the following statement is wrong?
(A) Sensory neurons commonly identified as nociceptors are those with myelinated (A-fiber) axons, big cell body diameters (＞ 50 μm), that terminate in the deep layers of the spinal cord dorsal horn.
(B) The presence or absence of certain markers (e.g., the tetrodotoxin (TTX)-resistant sodium channel NaV1.8, the transient receptor potential vanilloid receptor TRPV1) have been used to identify subsets of nociceptors.
(C) More recently, with the ability to analyze many genes expressed in a single cell, patterns of gene expression have been used to further define subpopulations of nociceptors.
(D) With respect to cell body size and myelination, it should be appreciated that there exist some large diameter cells with heavily myelinated and rapidly conducting axons that have been documented functionally to be nociceptors.
(E) Many non-nociceptors have unmyelinated axons, and thus, axon myelination or cell diameter cannot be applied as reliable criteria to define a nociceptor.