【摘要】 在31只氯醛糖和氨基甲酸乙酯麻醉的猫,观察了选择性激活颈动脉压力和化学感受器对巨细胞旁外侧核(PGL)单位放电的影响。136个PGL自发放电单位中,有84个在激活颈动脉压力感受器(BA)(新福林,1—2μg/kg,iv)和/或激活颈动脉化学感受器(CA)(nicotine 5—20μg,溶于0.25—0.5ml生理盐水中,注入甲状腺动脉)时,放电频率有变化。在这些有反应的单位中,16个仅对CA起反应(11个兴奋、5个抑制);54个以各种组合方式对CA和BA都起反应,其中以CA引起兴奋反应而BA引起抑制反应的占比例最大;14个仅对BA起反应(7个兴奋,7个抑制)。在定位分布上,那些只对CA起反应的单位多位于PGL的腹侧部份;仅对BA起反应的单位则位于对CA起反应单位的较背侧;对BA和CA均起反应的单位介于上述两者之间或在较深区域。这些结果表明,颈动脉区压力和化学感受器活动传入到PGL,并会聚在其中一些神经元上。 在PGL内全部有反应的单位中,68个对激活颈动脉压力感受器起反应,其中兴奋的29个,抑制的39个(P>0.05);70个对激活颈动脉化学感受器起反应,其中48个兴奋,22个抑制(P<0.005)。这些结果提示,BA对PGL神经元引起兴奋和抑制两种效应,而CA则诱发兴奋为主的反应。更多还原

【Abstract】 The effects of selective activation of carotid baro- and chemoreceptor on thesingle unit activity of the nucleus paragigantocellularis lateralis (PGL) in ventrola-teral medulla were studied in 31 cats under α-chloralose and urethan anesthesia.Of the 136 units with spontaneous discharge in the PGL, 84 showed some changeof discharge frequency in response to the activation of carotid baroreceptor (phe-nylephrine, 1-2 μg/kg iv) (BA) and/or chemoreceptor (nicotine, 5--20 μg, injectedinto the thyroid artery (CA). Of these 84 units, 16 responded only to CA (11excited and 5 inhibited), 54 responded with various patterns to both CA and BA,in which majority of the units were excited by CA and inhibited by BA, and 14responded only to BA (7 excited, 7 inhibited). Topographically, the units responsiveonly to CA were primarily located in the ventral part of the PGL, the units responsiveonly to BA located dorsally, and the units responsive both to BA and CA located inthe middle or more dorsal part of the PGL. These results showed that the informa-tions from carotid baro- and chemoreceptor were conveyed to PGL and convergedon some neurones. In all responsive units of the PGL, 68 responded to baroreceptor activation, inwhich 29 were excited and 39 were inhibited (P>0.05), and 70 responded to chemo-receptor activation, in which 48 were excited and 22 were inhibited (P<0.005).These results suggested that the neurones in PGL were either activated or inactivatedby BA, but mainly activated by CA.更多还原