Does Norepinephrine Influence Pain Behavior Mediated by Dorsal Root Ganglia?: A Pilot Study

Tanimoto, Katsumasa; Takebayashi, Toru; Kobayashi, Takeshi; Tohse, Noritsugu; Yamashita, Toshihiko

doi:10.1007/s11999-011-1798-x

Cited by 9 publications

(17 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Investigators blinded to the surgical protocol of each rat performed these behavioural tests. 1,3,4,23 …”

Section: Methodsmentioning

confidence: 99%

“…1-6 Patients with lumbar radicular pain are usually treated with oral medication, epidural block or surgery; however, some patients are difficult to treat using these methods and are afflicted with chronic pain. Previous studies have suggested that the sympathetic nervous system plays an important role in generating chronic neuropathic pain.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies have suggested that the sympathetic nervous system plays an important role in generating chronic neuropathic pain. 1-3,7-11 However, it does not generate pain under normal circumstances. In neuropathic pain, an abnormal sympathetic-somatosensory interaction is formed that leads to sympathetically maintained pain.…”

Section: Introductionmentioning

confidence: 99%

“…It has been reported that sympathetic nerve fibres sprout in the dorsal root ganglion (DRG) after nerve injury, 1,7,11,13-16 and that sympathectomy can relieve mechanical allodynia and thermal hyperalgesia in peripheral nerve injury models. 2,8,13,14,17 In contrast, some animal studies have reported that sympathectomy does not reduce allodynia and hyperalgesia.…”

Section: Introductionmentioning

confidence: 99%

“…1,3 Immunohistochemical analysis showed that sympathetic nerve fibres were more abundant on the constriction side of the DRG than on the contralateral side. 3 Norepinephrine (NE), a neurotransmitter of the sympathetic nervous system, enhances the excitability of the DRG neurons, 1 suggesting that the sympathetic nervous system is closely related to lumbar radicular pain.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

Iwase

Takebayashi

Tanimoto

et al. 2012

Bone & Joint Research

View full text Add to dashboard Cite

ObjectivesIn order to elucidate the influence of sympathetic nerves on lumbar radiculopathy, we investigated whether sympathectomy attenuated pain behaviour and altered the electrical properties of the dorsal root ganglion (DRG) neurons in a rat model of lumbar root constriction.MethodsSprague-Dawley rats were divided into three experimental groups. In the root constriction group, the left L5 spinal nerve root was ligated proximal to the DRG as a lumbar radiculopathy model. In the root constriction + sympathectomy group, sympathectomy was performed after the root constriction procedure. In the control group, no procedures were performed. In order to evaluate the pain relief effect of sympathectomy, behavioural analysis using mechanical and thermal stimulation was performed. In order to evaluate the excitability of the DRG neurons, we recorded action potentials of the isolated single DRG neuron by the whole-cell patch-clamp method.ResultsIn behavioural analysis, sympathectomy attenuated the mechanical allodynia and thermal hyperalgesia caused by lumbar root constriction. In electrophysiological analysis, single isolated DRG neurons with root constriction exhibited lower threshold current, more depolarised resting membrane potential, prolonged action potential duration, and more depolarisation frequency. These hyperexcitable alterations caused by root constriction were significantly attenuated in rats treated with surgical sympathectomy.ConclusionThe present results suggest that sympathectomy attenuates lumbar radicular pain resulting from root constriction by altering the electrical property of the DRG neuron itself. Thus, the sympathetic nervous system was closely associated with lumbar radicular pain, and suppressing the activity of the sympathetic nervous system may therefore lead to pain relief.

show abstract

“…Investigators blinded to the surgical protocol of each rat performed these behavioural tests. 1,3,4,23 …”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

Iwase

Takebayashi

Tanimoto

et al. 2012

Bone & Joint Research

View full text Add to dashboard Cite

show abstract

Attenuation of pain behaviour by local administration of alpha‐2 adrenoceptor antagonists to dorsal root ganglia in a rat radiculopathy model

Ogon

Takebayashi

Miyakawa

et al. 2015

European Journal of Pain

View full text Add to dashboard Cite

show abstract

Differential expression of alpha-adrenoceptor subtypes in rat dorsal root ganglion after chronic constriction injury

Cheng

et al. 2014

J. Huazhong Univ. Sci. Technol. [Med. Sci.]

View full text Add to dashboard Cite

mRNAs of alpha-adrenoceptor (α-AR) subtypes are found in neurons in dorsal root ganglion (DRG) and change after peripheral nerve injury. In this study, the distribution of α-AR subtype proteins was studied in L5 DRG of normal rats and rats with chronic constriction injury of sciatic nerve (CCI). Using immunofluorescence technique, it was found that α1A-, α1B-, and α2A-AR proteins were expressed in large, medium, and small size neurons in normal DRG, and significantly increased in all size neurons 14 days after CCI. α1D- and α2C-AR was also expressed in all size neurons in normal DRG. However, α1D-AR was significantly increased and α2C-AR was decreased in small size neurons 14 days post CCI. α2B-AR neurons were not detectable in normal and CCI DRG. Co-expression of α1A- and α2A-AR in the same neuron was observed in normal DRG and increased post CCI. Collectively, these results indicated that there is distinct distribution of α-AR subtypes in DRG neurons, and the distribution and levels of expression of α-AR subtypes change differently after CCI. The up-regulation of α-AR subtypes in DRG neurons may play an important role in the process of generating and transmitting neuropathic pain.

show abstract

Does Norepinephrine Influence Pain Behavior Mediated by Dorsal Root Ganglia?: A Pilot Study

Abstract: An α(2)-antagonist may be an appropriate agent for trials to treat lumbar radicular pain.

Cited by 9 publications

References 51 publications

Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

Attenuation of pain behaviour by local administration of alpha‐2 adrenoceptor antagonists to dorsal root ganglia in a rat radiculopathy model

Differential expression of alpha-adrenoceptor subtypes in rat dorsal root ganglion after chronic constriction injury

Contact Info

Product

Resources

About