@article{8758f466d6da407a8bc517dcd9e0cdbd,
title = "Long ascending unmyelinated primary afferent axons in the rat dorsal column: Immunohistochemical localizations",
abstract = "The present study demonstrates a significant number of calcitonin gene-related peptide (CGRP) immunolabeled unmyelinated axons in the C3 fasciculus gracilis of the rat. Approximately 88% of these axons are lost following dorsal rhizotomies from midthoracic levels caudally. Assuming that CGRP labels primary afferent axons, these findings support the hypothesis that there are significant numbers of long ascending unmyelinated primary afferent axons in the dorsal columns of the rat. If these findings can be generalized, they may have clinical import.",
keywords = "Calcitonin gene-related peptide, Dorsal column, Primary afferent, Unmyelinated axon",
author = "Patterson, {J. T.} and Coggeshall, {R. E.} and Lee, {W. T.} and K. Chung",
note = "Funding Information: Unmyelinated primary afferent axons are often associated with the transmission of noxious information [12]. If this is the case, these fibers might explain the failures of anterior cordotomy to relieve pain and also might explain the deep boring pain following intense stimulation of the dorsal column (e.g. ref. 1 1). Of interest in this regard is the observation of CGRP immunolabeled unmyelinated axons in the dorsal funiculi of humans [1]. Clearly, however, physiological data must be obtained before these speculations can be accepted. Finally, the question as to the termination of the unmyelinated dorsal column primary afferents is of interest. The two probable sites, not mutually exclusive, are (1) the dorsal horn of Ci and C2 where many spinothalamic cells are located in the rat [7, 8] and (2) the nucleus gracilis. We have found CGRP presynaptic terminals on dendrites in the nucleus gracilis, but this is not proof that unmyelinated afferents are terminating here because there are also myelinated CGRP containing primary afferent fibers. Thus, further work on the synaptic terminations of the unmyelinated dorsal column fibers is necessary. This study is supported by NIH Grants NS10161 and NSi2255 and the Bristol-Myers Company.",
year = "1990",
month = jan,
day = "1",
doi = "10.1016/0304-3940(90)90697-8",
language = "English (US)",
volume = "108",
pages = "6--10",
journal = "Neuroscience Letters",
issn = "0304-3940",
publisher = "Elsevier Ireland Ltd",
number = "1-2",
}