Sensory neurons and fibers from multiple spinal cord levels innervate the rabbit lumbar disc.
OBJECTIVE
To establish the neurotransmission pathway from the lumbar L5/6 intervertebral disc (IVD) to the spinal cord in the rabbit.


METHODS
Fluorogold particles injected into the posterior portion of the rabbit L5/6 IVD were traced by examining gold-positive neurons and fibers in the dorsal root ganglion (DRG) and spinal cord at various root levels.


RESULTS
Fluorogold-labeled neurons were observed bilaterally in primary afferent DRG neurons from the L3 through L5 segments; a small number of gold-labeled neurons were found at the L1 level. Fluorogold-labeled neurons were predominantly present in the ipsilateral DRG (the side of the injection) at the L5 level, but they were more equally distributed (on both sides) at the L4 and L3 levels. In the posterior horn of the spinal cord, Fluorogold particles were found in nerve fibers as rostral as the T12 level.


CONCLUSIONS
Our study has shown that Fluorogold particles injected into the rabbit L5/6 IVD are taken up by primary sensory neurons in the DRGs and primary sensory fibers in the posterior horn of the spinal cord at multiple levels. This diffuse innervation pattern of the lumbar disc may help explain why discogenic back pain in humans is often poorly localized.
Zhang
Yejia
Y
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.
Kerns
James M
JM
Anderson
D Greg
DG
Lee
Young Sang
YS
Chen
Er-Yun
EY
Tannoury
Chadi
C
An
Howard S
HS
D000818:Animals; D004195:Disease Models, Animal; D005456:Fluorescent Dyes / Q000378:metabolism; D005727:Ganglia, Spinal / Q000378:metabolism / Q000502:physiology*; D007403:Intervertebral Disc / Q000294:innervation*; D017116:Low Back Pain / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000294:innervation*; D008297:Male; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology*; D011817:Rabbits; D013116:Spinal Cord; D009435:Synaptic Transmission; D013904:Thoracic Vertebrae
D005456:Fluorescent Dyes