面神经核腹内侧区微量注射三种递质的呼吸效应

RESPIRATORY EFFECTS OF MICROINJECTION OF THREE KINDS OF NEUROTRANSMITTERS IN VENTROMEDIAL REGION OF NUCLEUS FACIALIS

实验用兔,在乌拉坦静脉麻醉、切断双侧颈迷走神经、自主呼吸条件下进行,以膈神经放电作呼吸指标。观察了面神经核腹内侧区(VMNF)微量注射三种递质对呼吸节律的影响。结果如下:(1)VMNF 区微量注射肾上腺素呼吸频率增加,膈神经吸气性放电的递增速度加快,积分幅度升高,VMNF 区微量注射妥拉苏林,呼吸频率下降且妥拉苏林可阻断肾上腺素的呼吸效应。(2)VMNF 区微量注射γ-氨基丁酸、甘氨酸导致呼吸频率下降,吸气时程、呼气时程延长。提示肾上腺素、γ-氨基丁酸、甘氨酸可能作为递质作用于 VMNF 区的神经元而发挥呼吸调节作用。

The effects of microinjection of three kinds of neurotransmitters in ventro-medial region of nucleus facialis(VMNF)on respiration were observed in vagoto-mized,spontaneously breathing rabbits anesthetized with urethane.Microin-jection of adrenaline in VMNF induced a marked increase in respiratory rate andamplitude of integrated phrenic activity associated with an increase in the ini-tial rate of rise of inspiratory activity.However,α-receptor antagonist tolazo-line elicited marked decreases in respiratory rate accompanied by little or nochanges in amplitude of integrated phrenic activity and initial rate of rise of inspira-tory activity.The respiratory effects of microinjection of adrenaline were blockedby previotus injection of tolazoline.Microinjection of GABA and glycine resultedin a decrease of respiratory frequency.These results suggest that adrenaline,GABAand glycine may modulate respiration by acting on VMNF neurons as neurotrans-mitters.