The degenerated lumbar intervertebral disc is innervated primarily by peptide-containing sensory nerve fibers in humans.
METHODS
Immunohistochemical study of the sensory innervation of the human lumbar intervertebral disc.


OBJECTIVE
To determine the type of sensory fibers innervating human degenerated lumbar intervertebral discs.


BACKGROUND
Sensory neurons involved in pain perception related to inflammation in rats are typically small, peptide-containing neurons immunoreactive for calcitonin gene-related peptide (CGRP). Small non-peptide-containing neurons binding to isolectin B4 (IB4) may also be involved in pain states, such as nerve injury pain. The character of such sensory neurons in humans has not been clarified.


METHODS
A degenerated, painful lumbar intervertebral disc was harvested from each of 8 patients during surgery. Sections were immunostained for protein gene product 9.5 (PGP 9.5, a general neuronal marker), CGRP, and IB4. The numbers of PGP 9.5- and CGRP-immunoreactive, and IB4-binding nerve fibers in the discs were counted.


RESULTS
PGP 9.5-immunoreactive fibers were observed in all discs. Nerve fibers immunoreactive for CGRP were also observed in 6 of 8 cases. IB4-binding nerve fibers were not found in any case.


CONCLUSIONS
Almost all of the nociceptive nerve fibers in the human intervertebral disc are peptide-containing nerve fibers, similar to the rat disc, suggesting that nerve fibers related to inflammation may transmit pain originating from human degenerated intervertebral discs.
Ozawa
Tomoyuki
T
From the Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. tomokun@wg7.so-net.ne.jp
Ohtori
Seiji
S
Inoue
Gen
G
Aoki
Yasuchika
Y
Moriya
Hideshige
H
Takahashi
Kazuhisa
K
D000328:Adult; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000737:chemistry* / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000737:chemistry* / Q000294:innervation* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000737:chemistry* / Q000473:pathology; D009475:Neurons, Afferent / Q000737:chemistry* / Q000473:pathology; D009479:Neuropeptides / Q000032:analysis* / Q000378:metabolism; D013122:Spinal Diseases / Q000473:pathology
D009479:Neuropeptides