Inhibition by Intravenously Administered Sodium Bicarbonate of Neuronal Activity in Medial Vestibular Nucleus Neurons

[摘要] References(5)Cited-By(5)The effects of 7% sodium bicarbonate on medial vestibular nucleus (MVN) neurons were examined to elucidate the mechanism underlying its antivertigo action, using α-chloralose-anesthetized cats. Intravenous injection of the drug at 1, 2 and 4 mI/kg every 10 min dose-dependently inhibited rotationand glutamate-induced firing of type I neurons, although a low dose of the drug enhanced firing in a few neurons. However, microiontophoretic application of bicarbonate ions did not inhibit rotation or glutamate-induced firing. After injection of the drug, the P02 level in arterial blood did not differ from previous levels, but the bicarbonate ion levels dose-dependently increased concomitantly with an increase in pH, as compared with previous levels. These results suggest that the intravenous injection of 7% sodium bicarbonate directly inhibits the neuronal activity of the MVN, although the lower dose may enhance neuronal activity by acting on the peripheral vestibule.

[学科分类] 药理学