EFFECTS OF 5-HT_1 RECEPTOR AGONIST ON THE EXCITABILITY OF MEDIAL VESTIBULAR NUCLEAR NEURONS

摘要

The aim of this study is to explore the action of 5-HTi receptor on spontaneous filing 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-HT_1 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-HT_(1A) 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-HTi receptors.