面神经后核内侧区微量注射不同氨基酸类递质对膈肌电活动的影响

Respiratory effects of microinjection of various amino acids neurotransmitters into medial areas of nucleus retrofacialis

观察了大鼠面神经后核内侧区（ｍＮＲＦ）微量注射两种不同氨基酸类递质对呼吸的影响。结果如下：１．ｍＲＮＦ区注射－氨基丁酸（ＧＡ－ＢＡ），呼吸频率和膈肌放电积分幅值下降，每分膈肌电活动减小，部分动物出现呼吸暂停。预先注射荷包牡丹硷（Ｂｉｃｕｃｕｌｉｎｅ）后，可拮抗由ＧＡ－ＢＡ所引起的呼吸抑制效应。２．ｍＮＲＦ注射Ｌ－谷氨酸单钠（Ｌ－ｇｌｕｔａｍａｔｅｍｏｎｏｓｏｄｉｕｍ），呼吸频率增加，每分隔肌电活动明显增加，ＡＰ－７可阻断谷氨酸的呼吸效应。此结果提示。

Experiments were performed on SD rats.The animals were anesthetized with urethane (1.0 g/kg,i.p.).The diaphragmatic electric activity and intratracheal pressure were monitored.The effects of microinjection of two kinds of amino acids,neurotransmitters,in the medial areas of the nucleus retrofacialis(mNRF) on respiration were observed.Microinjection of  aminobutyric acid(GABA)in mNRF induced a marked decrease in respiratory rate(RR),integrated diaphragmatic electric activity(IDEA)and minute diaphragmatic electric activity(MDA).Apnea could be induced in some animals.These depressant effects could be fully prevented by microinjection of bicuculline(a GABA A receptor antagonist) into mNRF in advance.Microinjection of L glutamate monosodium into mNRF,the RR was increased and MDA markedly increased.The respiratory effects were blocked by AP 7 in advance.These results suggest that GABA and glutamic acid may play a role of inhibitory or excitatory neurotransmitters in modulating respiration by acting on mNRF neurons.