Ⅱ组代谢性谷氨酸受体参与新生鼠离体延髓脑片呼吸节律性放电的调节

目的 探讨Ⅱ组代谢性谷氨酸受体在延髓离体脑片基本节律性呼吸放电调节中的作用.方法 以改良Kreb'S液恒温灌流新生Sprague-Dawley大鼠(0～3d)离体延髓脑片标本,稳定记录与之相连的舌下神经根的呼吸节律性放电活动(RRDA)后,第一组分别给予不同浓度Ⅱ组代谢性谷氨酸受体的特异性激动剂2R,4R-4-aminopyrrolidine-2,4-dicarboxylate(APDC)(10、20、50 μmol/L),观察各浓度舌下神经根RRDA的变化;第二组给予特异性拮抗剂(2S)-α-ethyiglutamic acid(EGLU)(300μmol/L),观察舌下神经根RRDA的变化;第三组先给予50μmol/L APDC持续灌流10 min后再给予50μmol/L APDC+300 μmol/L EGLU灌流10 mm,观察各时间点舌下神经根RRDA的变化.结果 单独给予APDC后,呼吸周期和呼气时程延长、吸气时程缩短、吸气放电积分幅度降低,且有浓度依赖性;单独给予EGLU后,呼吸周期及呼气时程缩短,对吸气时程和放电积分幅度没有影响,且APDC的作用可以被EGLU部分逆转.结论 Ⅱ组代谢性谷氨酸受体参与了哺乳动物基本呼吸节律的调节.

Group II metabotropic glutamate receptors is involved in the modulation of respiratory rhythmical discharge activity in neonatal rat medullary brain slices

Objective To explore the role of group II metabotropic glutamate receptors in the modulation of basic respiratory rhythm. Methods Neonatal (0-3 days) SD rats of either sex were used. The medulla oblongata brain slice containing the medial region of the nucleus retrofacialis (mNRF) and the hypoglossal nerve rootlets was prepared, and the surgical procedure was performed in the modified Kreb's solution (MKS) with continuous carbogen (95% O2 and 5% CO2) within 3 min. The brain slices were quickly transferred t...