Unmasking of latent synaptic connections in the cortex of the rat, elicited by facial nerve transection

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Peripheral nerve injury elicits plastic changes in the cortex, resulting in reorganization of the somatotopic representation maps. These processes begin within minutes after nerve injury, and last for weeks. Although the mechanisms leading to these plastic changes are not known in a detail, a number of results suggest that the key element in the starting of these processes is a decrease in the function of the cortical GABAergic system, which allows the unmasking of pre-existing but normally silent synapses. The somatosensory and motor cortices of the rat brain are involved in strong and mutual interaction. This study of the early changes induced in this relationship by unilateral facial nerve transection (N7×) revealed that the disinhibition of associational and commissural connections caused by N7× allowed the appearance and enhancement of potentials in the motor cortices on both sides, evoked by right-side trigeminal stimulation, though these responses were strictly lateralized in normal animals. In response to the juxtacellular application of GABA and muscimol, reversal was observed in a small population of neurons (3 out of 84) tested with microelectrode recordings and pressure microinjections. These results suggest that a peripheral nerve injury (N7×) rapidly induces GABAA receptor-dependent disinhibition in the cortex.

Original languageEnglish
Pages (from-to)51-55
Number of pages5
JournalActa Biologica Szegediensis
Volume45
Issue number1-4
Publication statusPublished - 2001

Fingerprint

Peripheral Nerve Injuries
peripheral nerves
Facial Nerve
Motor Cortex
Rats
cortex
nerve tissue
plastics
Muscimol
Somatosensory Cortex
Microelectrodes
rats
Microinjections
GABA-A Receptors
synapse
Synapses
gamma-Aminobutyric Acid
Neurons
Brain
Animals

Keywords

  • Cortical disinhibition
  • Facial nerve
  • Nerve injury
  • Pressure microinjection
  • Unmasking of latent synapses

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Cell Biology
  • Applied Microbiology and Biotechnology
  • Neuroscience(all)

Cite this

@article{f799a6dff8fc42e5afe2c3371233fada,
title = "Unmasking of latent synaptic connections in the cortex of the rat, elicited by facial nerve transection",
abstract = "Peripheral nerve injury elicits plastic changes in the cortex, resulting in reorganization of the somatotopic representation maps. These processes begin within minutes after nerve injury, and last for weeks. Although the mechanisms leading to these plastic changes are not known in a detail, a number of results suggest that the key element in the starting of these processes is a decrease in the function of the cortical GABAergic system, which allows the unmasking of pre-existing but normally silent synapses. The somatosensory and motor cortices of the rat brain are involved in strong and mutual interaction. This study of the early changes induced in this relationship by unilateral facial nerve transection (N7×) revealed that the disinhibition of associational and commissural connections caused by N7× allowed the appearance and enhancement of potentials in the motor cortices on both sides, evoked by right-side trigeminal stimulation, though these responses were strictly lateralized in normal animals. In response to the juxtacellular application of GABA and muscimol, reversal was observed in a small population of neurons (3 out of 84) tested with microelectrode recordings and pressure microinjections. These results suggest that a peripheral nerve injury (N7×) rapidly induces GABAA receptor-dependent disinhibition in the cortex.",
keywords = "Cortical disinhibition, Facial nerve, Nerve injury, Pressure microinjection, Unmasking of latent synapses",
author = "T. Farkas and J. Toldi",
year = "2001",
language = "English",
volume = "45",
pages = "51--55",
journal = "Acta Biologica Szegediensis",
issn = "1588-385X",
publisher = "University of Szeged",
number = "1-4",

}

TY - JOUR

T1 - Unmasking of latent synaptic connections in the cortex of the rat, elicited by facial nerve transection

AU - Farkas, T.

AU - Toldi, J.

PY - 2001

Y1 - 2001

N2 - Peripheral nerve injury elicits plastic changes in the cortex, resulting in reorganization of the somatotopic representation maps. These processes begin within minutes after nerve injury, and last for weeks. Although the mechanisms leading to these plastic changes are not known in a detail, a number of results suggest that the key element in the starting of these processes is a decrease in the function of the cortical GABAergic system, which allows the unmasking of pre-existing but normally silent synapses. The somatosensory and motor cortices of the rat brain are involved in strong and mutual interaction. This study of the early changes induced in this relationship by unilateral facial nerve transection (N7×) revealed that the disinhibition of associational and commissural connections caused by N7× allowed the appearance and enhancement of potentials in the motor cortices on both sides, evoked by right-side trigeminal stimulation, though these responses were strictly lateralized in normal animals. In response to the juxtacellular application of GABA and muscimol, reversal was observed in a small population of neurons (3 out of 84) tested with microelectrode recordings and pressure microinjections. These results suggest that a peripheral nerve injury (N7×) rapidly induces GABAA receptor-dependent disinhibition in the cortex.

AB - Peripheral nerve injury elicits plastic changes in the cortex, resulting in reorganization of the somatotopic representation maps. These processes begin within minutes after nerve injury, and last for weeks. Although the mechanisms leading to these plastic changes are not known in a detail, a number of results suggest that the key element in the starting of these processes is a decrease in the function of the cortical GABAergic system, which allows the unmasking of pre-existing but normally silent synapses. The somatosensory and motor cortices of the rat brain are involved in strong and mutual interaction. This study of the early changes induced in this relationship by unilateral facial nerve transection (N7×) revealed that the disinhibition of associational and commissural connections caused by N7× allowed the appearance and enhancement of potentials in the motor cortices on both sides, evoked by right-side trigeminal stimulation, though these responses were strictly lateralized in normal animals. In response to the juxtacellular application of GABA and muscimol, reversal was observed in a small population of neurons (3 out of 84) tested with microelectrode recordings and pressure microinjections. These results suggest that a peripheral nerve injury (N7×) rapidly induces GABAA receptor-dependent disinhibition in the cortex.

KW - Cortical disinhibition

KW - Facial nerve

KW - Nerve injury

KW - Pressure microinjection

KW - Unmasking of latent synapses

UR - http://www.scopus.com/inward/record.url?scp=0035700760&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035700760&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0035700760

VL - 45

SP - 51

EP - 55

JO - Acta Biologica Szegediensis

JF - Acta Biologica Szegediensis

SN - 1588-385X

IS - 1-4

ER -