The population of the dorsal root ganglion cells which have central processes in ventral root and their immunoreactivity

Xiu-bin, Fang

doi:10.1016/0006-8993(87)90053-9

Cited by 21 publications

(7 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One physiological consideration with respect to these data is that of ventral root afferents, which we propose played a minimal role, if any, in the development of allodynia in the present study. Ventral root afferents are largely unmyelinated or thinly myelinated (Coggeshall et al, 1973, Fang, 1987). While we cannot rule out the possibility that VRA induced some plasticity of small, unmyelinated afferents, our behavioral and immunohistochemical data strongly support the involvement of primarily large diameter myelinated afferents.…”

Section: A Motor Lesion Can Induce Sensory Plasticity Beyond the Levementioning

confidence: 99%

At-level neuropathic pain is induced by lumbosacral ventral root avulsion injury and ameliorated by root reimplantation into the spinal cord

Bigbee

Hoang

Havton

2007

Experimental Neurology

View full text Add to dashboard Cite

Neuropathic pain is common after traumatic injuries to the cauda equina/conus medullaris and brachial plexus. Clinically, this pain is difficult to treat and its mechanisms are not well understood. Lesions to the ventral roots are common in these injuries, but are rarely considered as potential contributors to pain. We examined whether a unilateral L6-S1 ventral root avulsion (VRA) injury in adult female rats might elicit pain within the dermatome projecting to the adjacent, uninjured L5 spinal segment. Additionally, a subset of subjects had the avulsed L6-S1 ventral roots reimplanted (VRA+Imp) into the lateral funiculus post-avulsion to determine whether this neural repair strategy elicits or ameliorates pain. Behavioral tests for mechanical allodynia and hyperalgesia were performed weekly over 7 weeks post-injury at the hind paw plantar surface. Allodynia developed early and persisted post-VRA, whereas VRA+Imp rats exhibited allodynia only at 1 week postoperatively. Hyperalgesia was not observed at any time in any experimental group. Quantitative immunohistochemistry showed increased levels of inflammatory markers in laminae III-V and in the dorsal funiculus of the L5 spinal cord of VRA, but not VRA+Imp rats, specific to areas that receive projections from mechanoreceptive, but not nociceptive, primary afferents. These data suggest that sustained at-level neuropathic pain can develop following a pure motor lesion, whereas the pain may be ameliorated by acute root reimplantation. We believe that our findings are of translational research interest, as root implantation surgery is emerging as a potentially useful strategy for the repair of cauda equina/conus medullaris injuries.

show abstract

Section: A Motor Lesion Can Induce Sensory Plasticity Beyond the Levementioning

confidence: 99%

At-level neuropathic pain is induced by lumbosacral ventral root avulsion injury and ameliorated by root reimplantation into the spinal cord

Bigbee

Hoang

Havton

2007

Experimental Neurology

View full text Add to dashboard Cite

show abstract

“…These neurons express tyrosine kinase receptor A, a tyrosine kinase-type of receptor for nerve growth factor (NGF) (Averill et al 1995), and are dependent on NGF for the expression of neuropeptides (Lindsay and Harmer 1989;. Previous studies in the rat indicate that in adults nearly 50% of DRG neurons contain CGRP (Fang 1987;Ju et al 1987). Another group of small DRG neurons binds to isolectin B4 (IB4) (Silverman and Kruger 1990), and is maintained by glial cell-line derived factor (GDNF) (Molliver et al 1997;Zwick et al 2002).…”

Section: Introductionmentioning

confidence: 98%

Differential development of TRPV1-expressing sensory nerves in peripheral organs

et al. 2005

View full text Add to dashboard Cite

In mouse ontogeny, neurons immunoreactive for transient receptor potential vanilloid receptor 1 (TRPV1) were observed primarily in the dorsal root ganglia (DRG) at embryonic day 13 (E13). In the embryonic period, the number of TRPV1(+) neurons decreased, but then gradually increased postnatally. Some of TRPV1(+) neurons were also immunoreactive for calcitonin gene-related peptide (CGRP). At postnatal day 7 (P7), 66% of CGRP(+) neurons were TRPV1(+), and 55% of TRPV1(+) neurons were also CGRP(+) in the L4 DRG. In the peripheral organs, TRPV1-immunorective nerve fibers were transiently observed in the skin at E14. They were also observed in the urinary tract at E14, and in the rectum at E15. Many TRPV1(+) nerve fibers in these organs were also CGRP(+). At P1, TRPV1(+) nerve fibers were observed in the respiratory organs, and to a lesser extent in the stomach, colon, skin, and skeletal muscles. The number of TRPV1(+) nerve fibers on each organ gradually increased postnatally. At P7, TRPV1(+) nerve fibers were also observed in the small intestine and kidneys. The percentage of total TRPV1(+) nerve fibers that co-localized with CGRP was greater in most organs at P7 than at P1. The present results indicate that TRPV1 expression on peripheral processes differs among organs. The differential time course of TRPV1 expression in the cell bodies might be related to the organs to which they project. Co-localization of TRPV1 with CGRP on nerve fibers also varies among organs. This suggests that the TRPV1-mediated neuropeptide release that occurs in certain pathophysiologic conditions also varies among organs.

show abstract

“…There is electrophysiological evidence for centrally bifurcating neurones projecting into both ventral and dorsal root (Kim, Shin & Chung, 1987). This finding has been supported by morphological experiments showing double-labelled ganglion cells after exposure of dorsal and ventral root to different fluorescent dyes (Chung & Kang, 1987;Fang, 1987).…”

mentioning

confidence: 74%

“…Double-labelling studies have provided conflicting results when fluorescent dyes were applied to ventral and dorsal roots of rats (Chung & Kang, 1987;Fang, 1987). The population of double-labelled dorsal root ganglion neurones would comprise trifurcating neurones (Fig.…”

Section: Some Ventral Root Afferents Do Enter the Spinal Cordmentioning

confidence: 99%

A quantitative study of the central projection patterns of unmyelinated ventral root afferents in the cat.

Häbler

Jänig

Koltzenburg

et al. 1990

The Journal of Physiology

View full text Add to dashboard Cite

1. The ventral roots of the spinal cord contain a large number of unmyelinated primary afferent neurones. There is some controversy, however, about the function of these fibres and the route of their central projection. Here we have used electrophysiological techniques to quantify the central projection patterns of these neurones in the segment S2 of adult chloralose-anaesthesized cats. 2. A total of 1185 single unmyelinated units were recorded in small filaments isolated from intact and de-efferented ventral roots or intact dorsal roots of the segment S2 in nineteen cats. The projection patterns of these neurones were tested using supramaximal electrical stimulation of the pelvic and pudendal nerve (the main tributaries of the spinal nerve of this segment) and of the segmental companion root (dorsal or ventral as appropriate). 3. The principal finding of this study is that 85% of unmyelinated afferent axons in the ventral root are direct and exclusive projections. They constitute a separate class of afferents which is only capable of transmitting information from the periphery via the ventral roots. However, the proportion of these fibres that enter the central nervous system is unknown and it seems likely that some of them peter out as they approach the spinal cord and end blindly. The functional role of such afferents remains obscure. 4. For the remaining 15% of unmyelinated ventral root afferents, a projection into the segmental dorsal root was found. The majority of those fibres (about two-thirds) are primary afferent neurones innervating the pia mater. Some of these units had a small spot-like receptive field and responded to mechanical stimuli such as pressure and stretch of the root. They did not have axon projections in a peripheral nerve. 5. A few (5%) unmyelinated ventral root fibres are collateral branches of normal primary afferents projecting through the dorsal root. These trifurcating neurones are a small population which make up only some 0.5% of all dorsal root ganglion cells. The functional significance of this population too is unknown. 6. For none of the fibres that projected into both dorsal and ventral root was there positive evidence for the existence of looping axons that merely make a detour into one of the roots. Although the existence of loops cannot completely be excluded, our evidence suggests that they can constitute at most 5% of the unmyelinated ventral root afferents.

show abstract

The population of the dorsal root ganglion cells which have central processes in ventral root and their immunoreactivity

Cited by 21 publications

References 24 publications

At-level neuropathic pain is induced by lumbosacral ventral root avulsion injury and ameliorated by root reimplantation into the spinal cord

At-level neuropathic pain is induced by lumbosacral ventral root avulsion injury and ameliorated by root reimplantation into the spinal cord

Differential development of TRPV1-expressing sensory nerves in peripheral organs

A quantitative study of the central projection patterns of unmyelinated ventral root afferents in the cat.

Contact Info

Product

Resources

About