Reversible attenuation of neuropathic-like manifestations in rats by lesions or local blocks of the intralaminar or the medial thalamic nuclei

N. E. Saadé, Hassen Al Amin, S. Abdel Baki, S. Chalouhi, S. J. Jabbur, S. F. Atweh

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Background and aim: Thalamic somatosensory nuclei have been classified into medial and lateral systems based on their role in nociception. An imbalance between these two systems may result in abnormal somatic sensations and spontaneous pain. This study aims to investigate the effects of transient or permanent block of the medial and intralaminar nuclear groups on the neuropathic-like behavior in a rat model for mononeuropathy. Methods: Neuropathy was induced on one hind paw in different groups of rats following the spared nerve injury model. When the resulting hyperalgesia and allodynia (tactile and cold) reached a maximum plateau, the rats received either chemical or electrolytic lesion or lidocaine (2%) microperfusion, placed in the various thalamic nuclear groups. Results: All procedures produced transient but significant decrease of neuropathic manifestations. The magnitude and duration of decrease depended on the type and the site of the block. These effects can be ranked in increasing order as follows, electrolytic < chemical < lidocaine micro-perfusion according to the procedure, and as rostro-medial < ventro-median < parafascicular nuclei, according to the site of the block. Thermal hyperalgesia was the most affected while cold allodynia showed the least attenuation. Neuropathic manifestations returned to their pre-lesion levels after 2-3 weeks, along with frequently observed delayed hyper-responsiveness to the hotplate test. Conclusion: The observed results demonstrate the involvement of the medial and intralaminar thalamic nuclei in the processing of neuropathic-like manifestations, and the reversibility of the effects suggests the flexibility of the neural network involved in supraspinal processing of nociceptive information.

Original languageEnglish
Pages (from-to)205-219
Number of pages15
JournalExperimental Neurology
Volume204
Issue number1
DOIs
Publication statusPublished - Mar 2007
Externally publishedYes

Fingerprint

Mediodorsal Thalamic Nucleus
Hyperalgesia
Intralaminar Thalamic Nuclei
Lidocaine
Mononeuropathies
Thalamic Nuclei
Nociception
Automatic Data Processing
Perfusion
Pain
Wounds and Injuries

Keywords

  • Hyperalgesia allodynia
  • Nerve injury
  • Pain pathways
  • Thalamic pain
  • Thalamotomy

ASJC Scopus subject areas

  • Neurology
  • Neuroscience(all)

Cite this

Reversible attenuation of neuropathic-like manifestations in rats by lesions or local blocks of the intralaminar or the medial thalamic nuclei. / Saadé, N. E.; Al Amin, Hassen; Abdel Baki, S.; Chalouhi, S.; Jabbur, S. J.; Atweh, S. F.

In: Experimental Neurology, Vol. 204, No. 1, 03.2007, p. 205-219.

Research output: Contribution to journalArticle

Saadé, N. E. ; Al Amin, Hassen ; Abdel Baki, S. ; Chalouhi, S. ; Jabbur, S. J. ; Atweh, S. F. / Reversible attenuation of neuropathic-like manifestations in rats by lesions or local blocks of the intralaminar or the medial thalamic nuclei. In: Experimental Neurology. 2007 ; Vol. 204, No. 1. pp. 205-219.
@article{982ba7fdf538448b979346facc74318c,
title = "Reversible attenuation of neuropathic-like manifestations in rats by lesions or local blocks of the intralaminar or the medial thalamic nuclei",
abstract = "Background and aim: Thalamic somatosensory nuclei have been classified into medial and lateral systems based on their role in nociception. An imbalance between these two systems may result in abnormal somatic sensations and spontaneous pain. This study aims to investigate the effects of transient or permanent block of the medial and intralaminar nuclear groups on the neuropathic-like behavior in a rat model for mononeuropathy. Methods: Neuropathy was induced on one hind paw in different groups of rats following the spared nerve injury model. When the resulting hyperalgesia and allodynia (tactile and cold) reached a maximum plateau, the rats received either chemical or electrolytic lesion or lidocaine (2{\%}) microperfusion, placed in the various thalamic nuclear groups. Results: All procedures produced transient but significant decrease of neuropathic manifestations. The magnitude and duration of decrease depended on the type and the site of the block. These effects can be ranked in increasing order as follows, electrolytic < chemical < lidocaine micro-perfusion according to the procedure, and as rostro-medial < ventro-median < parafascicular nuclei, according to the site of the block. Thermal hyperalgesia was the most affected while cold allodynia showed the least attenuation. Neuropathic manifestations returned to their pre-lesion levels after 2-3 weeks, along with frequently observed delayed hyper-responsiveness to the hotplate test. Conclusion: The observed results demonstrate the involvement of the medial and intralaminar thalamic nuclei in the processing of neuropathic-like manifestations, and the reversibility of the effects suggests the flexibility of the neural network involved in supraspinal processing of nociceptive information.",
keywords = "Hyperalgesia allodynia, Nerve injury, Pain pathways, Thalamic pain, Thalamotomy",
author = "Saad{\'e}, {N. E.} and {Al Amin}, Hassen and {Abdel Baki}, S. and S. Chalouhi and Jabbur, {S. J.} and Atweh, {S. F.}",
year = "2007",
month = "3",
doi = "10.1016/j.expneurol.2006.10.009",
language = "English",
volume = "204",
pages = "205--219",
journal = "Experimental Neurology",
issn = "0014-4886",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Reversible attenuation of neuropathic-like manifestations in rats by lesions or local blocks of the intralaminar or the medial thalamic nuclei

AU - Saadé, N. E.

AU - Al Amin, Hassen

AU - Abdel Baki, S.

AU - Chalouhi, S.

AU - Jabbur, S. J.

AU - Atweh, S. F.

PY - 2007/3

Y1 - 2007/3

N2 - Background and aim: Thalamic somatosensory nuclei have been classified into medial and lateral systems based on their role in nociception. An imbalance between these two systems may result in abnormal somatic sensations and spontaneous pain. This study aims to investigate the effects of transient or permanent block of the medial and intralaminar nuclear groups on the neuropathic-like behavior in a rat model for mononeuropathy. Methods: Neuropathy was induced on one hind paw in different groups of rats following the spared nerve injury model. When the resulting hyperalgesia and allodynia (tactile and cold) reached a maximum plateau, the rats received either chemical or electrolytic lesion or lidocaine (2%) microperfusion, placed in the various thalamic nuclear groups. Results: All procedures produced transient but significant decrease of neuropathic manifestations. The magnitude and duration of decrease depended on the type and the site of the block. These effects can be ranked in increasing order as follows, electrolytic < chemical < lidocaine micro-perfusion according to the procedure, and as rostro-medial < ventro-median < parafascicular nuclei, according to the site of the block. Thermal hyperalgesia was the most affected while cold allodynia showed the least attenuation. Neuropathic manifestations returned to their pre-lesion levels after 2-3 weeks, along with frequently observed delayed hyper-responsiveness to the hotplate test. Conclusion: The observed results demonstrate the involvement of the medial and intralaminar thalamic nuclei in the processing of neuropathic-like manifestations, and the reversibility of the effects suggests the flexibility of the neural network involved in supraspinal processing of nociceptive information.

AB - Background and aim: Thalamic somatosensory nuclei have been classified into medial and lateral systems based on their role in nociception. An imbalance between these two systems may result in abnormal somatic sensations and spontaneous pain. This study aims to investigate the effects of transient or permanent block of the medial and intralaminar nuclear groups on the neuropathic-like behavior in a rat model for mononeuropathy. Methods: Neuropathy was induced on one hind paw in different groups of rats following the spared nerve injury model. When the resulting hyperalgesia and allodynia (tactile and cold) reached a maximum plateau, the rats received either chemical or electrolytic lesion or lidocaine (2%) microperfusion, placed in the various thalamic nuclear groups. Results: All procedures produced transient but significant decrease of neuropathic manifestations. The magnitude and duration of decrease depended on the type and the site of the block. These effects can be ranked in increasing order as follows, electrolytic < chemical < lidocaine micro-perfusion according to the procedure, and as rostro-medial < ventro-median < parafascicular nuclei, according to the site of the block. Thermal hyperalgesia was the most affected while cold allodynia showed the least attenuation. Neuropathic manifestations returned to their pre-lesion levels after 2-3 weeks, along with frequently observed delayed hyper-responsiveness to the hotplate test. Conclusion: The observed results demonstrate the involvement of the medial and intralaminar thalamic nuclei in the processing of neuropathic-like manifestations, and the reversibility of the effects suggests the flexibility of the neural network involved in supraspinal processing of nociceptive information.

KW - Hyperalgesia allodynia

KW - Nerve injury

KW - Pain pathways

KW - Thalamic pain

KW - Thalamotomy

UR - http://www.scopus.com/inward/record.url?scp=33847290776&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33847290776&partnerID=8YFLogxK

U2 - 10.1016/j.expneurol.2006.10.009

DO - 10.1016/j.expneurol.2006.10.009

M3 - Article

VL - 204

SP - 205

EP - 219

JO - Experimental Neurology

JF - Experimental Neurology

SN - 0014-4886

IS - 1

ER -