Temporal changes in neuronal activity of the bilateral medial vestibular nuclei following unilateral labyrinthectomy in rats
The Korean Journal of Physiology and Pharmacology
;
: 481-490, 1999.
Article
Dans Anglais
| WPRIM
| ID: wpr-727846
ABSTRACT
To investigate the changes in the responses of vestibular neurons with time during vestibular compensation, the resting activity and dynamic responses of type I and II neurons in the medial vestibular nuclei to sinusoidal angular acceleration were recorded following unilateral labyrinthectomy (ULX) in Sprague-Dawley rats. The unitary extracellular neuronal activity was recorded from the bilateral medial vestibular nuclei with stainless steel microelectrodes of 3~5 MOMEGA before ULX, and 6, 24, 48, 72 hours, and I week after ULX under pentobarbital sodium anesthesia (30 mg/kg, i.p.). Gain (spikes/s/deg/s) and phase (in degrees) were determined from the neuronal activity induced by sinusoidal head rotation with 0.05, 0.1, 0.2, and 0.4 Hz. The mean resting activity before ULX was 16.7+/-8.6 spikes/s in type I neurons (n=67, M+-SD) and 14.5+/-8.4 spikes/s in type II neurons (n=43). The activities of ipsilateral type I and contralateral type 11 neurons to the lesion side decreased markedly till 24 hr post-op, and a significant difference between ipsilateral and contralateral type I neurons sustained till 24 hr post-op. The gain at 4 different frequencies of sinusoidal rotation was depressed in all neurons till 6 or 24 hr post-op and then increased with time. The rate of decrease in gain was more prominent in ipsilateral type I and contralateral type 11 neurons immediately after ULX. Although the gain of those neurons increased gradually after 24 hours, it remained below normal levels. The phase was significantly advanced in all neurons following ULX. These results suggest that a depression of activities in ipsilateral type I and contralateral type II neurons is closely related with the occurrence of vestibular symptoms and restoration of activities in those neurons ameliorates the vestibular symptoms.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Pentobarbital
/
Acier inoxydable
/
Noyaux vestibulaires
/
Rat Sprague-Dawley
/
Indemnités compensatoires
/
Dépression
/
Accélération
/
Tête
/
Anesthésie
/
Microélectrodes
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
The Korean Journal of Physiology and Pharmacology
Année:
1999
Type:
Article
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