Effects of serotonin and noradrenaline on neuronal activities of the solitary tract nucleus and its alteration after ketanserin

摘要

Effects of serotonin(5-HT)and noradrenaline(NA)on neuronal activities of the sol-itary tract nucleus(NTS)were investigated in rat medullary slice preparations.After perfusingthe slice with 5-HT,the spontaneous discharge was significantly increased in 25(of 43,58.1%)NTS neurons,reduced in 13(30.2%)and not changed in 5(11.7%).After perfusingthe slice with NA,the spontaneous discharge was significantly reduced or even completelyceased in 27(62.8%)neurons,increased in 13(30.2%)and not changed in 3(7%).Therewere 38(88.4%)neurons responding to both 5-HT and NA.From the 38 neurons,21 wereselected for studying the effect of ketanserin.It was found that ketanserin potentiated the ef-fect of NA on spontaneous discharge in 10(47.6%)neurons and attenuated it in 4(19.0%)neurons.These results suggest that there is an interaction between 5-HT receptorand α-adrenoceptor at the NTS level.This interaction may be helpful in explaining themechanism of the central antihypertensive action of ketanserin.