Effects of 5‐HT1 receptor agonist on the excitability of medial vestibular nuclear neurons

Abstract

AbstractThe aim of this study is to explore the action of 5‐HT1 receptor on spontaneous firing activity of the rat medial vestibular nuclear neurons by patch clamp experiments. The spontaneous firing was increased in 45.5% and decreased in 54.5% of the neurons tested with 5‐carboxamidotryptamine, non‐selective 5‐HT1 receptor agonist. And the whole potassium currents of medial vestibular nuclear neurons was decreased in 64% and increased in 36% of cells tested with 5‐carboxamidotryptamine. The spontaneous firing rate was increased by 8‐OH‐DPAT, selective 5‐HT1A receptor agonist in 73.3% and was not changed in 26.7%. Whole potassium currents were decreased in 84.2% and was not affected in 15.8% by 8‐OH‐DPAT. These results suggest that 5‐HTIA receptor of the medial vestibular nuclear neurons mediates excitatory effects whereas inhibitory effects are mediated by other 5‐HT1 receptors.