Biphasic reorganization of somatotopy in the primary motor cortex follows facial nerve lesions in adult rats

J. Toldi, Rainer Laskawi, Michael Landgrebe, Joachim R. Wolff

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Effects of facial nerve transection were studied on muscle responses evoked by electrical stimulation in the primary motor cortex (MI) of adult rats. In intact animals, activated muscles varied according to the somatotopic representation map, and responses were restricted to the contralateral side. Unilateral transection of the facial nerve extinguished contralateral vibrissal responses, while ipsilateral vibrissae began to respond within 4 min. This abnormal response (primary change) was transient and gradually disappeared within hours to days. Instead, contralateral movements of forepaw and eye/eyelid muscles could be evoked from increasing portions of the former vibrissal field (secondary change), in which many points became unresponsive. After 4 days, the former vibrissal field had shrunk to a small central part, where ipsilateral vibrissae responsiveness remained. The secondary modification was stable for at least 2 weeks. Since the primary change is rapid, transient and may be mimicked by picrotoxin, it may be based on disinhibition of commissural connections, while the secondary change is longlasting and therefore may include some form of reorganization of associational synapses.

Original languageEnglish
Pages (from-to)179-182
Number of pages4
JournalNeuroscience Letters
Volume203
Issue number3
DOIs
Publication statusPublished - Jan 26 1996

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Facial Nerve
Motor Cortex
Vibrissae
Muscles
Picrotoxin
Eyelids
Eye Movements
Synapses
Electric Stimulation

Keywords

  • Facial nerve lesion
  • Motor cortex
  • Neurophysiology
  • Neuroplasticity
  • Somatotopic representation

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Biphasic reorganization of somatotopy in the primary motor cortex follows facial nerve lesions in adult rats. / Toldi, J.; Laskawi, Rainer; Landgrebe, Michael; Wolff, Joachim R.

In: Neuroscience Letters, Vol. 203, No. 3, 26.01.1996, p. 179-182.

Research output: Contribution to journalArticle

Toldi, J. ; Laskawi, Rainer ; Landgrebe, Michael ; Wolff, Joachim R. / Biphasic reorganization of somatotopy in the primary motor cortex follows facial nerve lesions in adult rats. In: Neuroscience Letters. 1996 ; Vol. 203, No. 3. pp. 179-182.
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