Abstract |
To examine the relationship between neurosteroids and vertigo we performed electrophysiological studies to determine whether pregnenolone sulfate (PS) affects the activity of medial vestibular nucleus (MVN) neurons in alpha-chloralose-anesthetized cats. Single neuronal activities in the MVN were recorded extracellularly using a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette. 3 mM PS, 1 M glutamate and 3 mM NaCl were applied microiontophoretically in the immediate vicinity of the target neurons. The effects of these drugs were then examined on type I and type II neurons, identified by their responses to horizontal and sinusoidal rotations. The iontophoretic application of PS dose-dependently increased the spontaneous firing of both type I and type II neurons. The larger increase in firing was observed in type I neurons as compared with type II neurons following the PS application. These results suggest that PS excites types I and II neurons differentially, presumably resulting in a disturbance of harmony of the vestibulo-ocular reflex with ensuing development of vertigo.
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Authors | T Yamamoto, T Yamanaka, H Miyahara, T Matsunaga |
Journal | Acta oto-laryngologica. Supplementum
(Acta Otolaryngol Suppl)
Vol. 533
Pg. 22-5
( 1998)
ISSN: 0365-5237 [Print] Norway |
PMID | 9657306
(Publication Type: Journal Article)
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Chemical References |
- pregnenolone sulfate
- Glutamic Acid
- Sodium Chloride
- Pregnenolone
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Topics |
- Animals
- Cats
- Dose-Response Relationship, Drug
- Electrophysiology
- Glutamic Acid
(pharmacology)
- Neurons
(drug effects, physiology)
- Pregnenolone
(pharmacology)
- Sodium Chloride
(pharmacology)
- Vestibular Nuclei
(cytology, drug effects, physiology)
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