The Kölliker-Fuse (KF) nucleus is a part of the parabrachial complex, located in the dorsolateral pons. It is involved in the chemoreflex-evoked cardiovascular and respiratory changes, but the role of GABA and glutamate in cardiovascular chemoreflex has not been shown yet. This study was performed to determine the role of GABA, glutamate, and their interaction in the KF, in cardiovascular chemoreflex in anesthetized rat. The antagonists were microinjected into the KF, and arterial pressure, heart rate, and single-unit responses were recorded simultaneously. The chemoreflex was evoked by i.v. injection of KCN, consisted of a short pressor followed by long bradycardia responses. Both responses were significantly attenuated by injection of a synaptic blocker (CoCl₂) into the KF, confirming involvement of the KF in generating the reflex. Microinjection of AP5, an NMDA receptor antagonist, into the KF significantly attenuated the pressor and bradycardia responses, while blocking the AMPA receptors by CNQX had no significant effect. Blockade of GABA_A receptors by bicuculline methiodide (BMI) potentiated both responses. Co-injection of BMI and CNQX potentiated the responses too. Co-injection of BMI and AP5 had no significant effect on the pressor response but significantly attenuated the bradycardia response. In conclusion, the KF plays a role in generating cardiovascular chemoreflex via its glutamate NMDA but not AMPA receptors. GABA inhibits both components of this reflex through GABA_A receptors. There is an interaction between GABA_A and NMDA receptors in regulating the bradycardia response of the reflex. Single-unit results were also presented which were correlated with and supported the homodynamic findings.

Kölliker-Fuse（KF）核是臂旁复合物的一部分，位于背外侧桥。它与化学反射诱发的心血管和呼吸变化有关，但尚未显示GABA和谷氨酸在心血管化学反射中的作用。进行这项研究是为了确定GABA，谷氨酸及其在KF中的相互作用在麻醉大鼠的心血管化学反射中的作用。将拮抗剂微注射到KF中，并同时记录动脉压，心率和单单位反应。化学反射是通过静脉内注射KCN引起的，KCN包括短暂的升压和随后的长时间心动过缓反应。注射突触阻滞剂（CoCl ₂）进入KF，从而确认KF参与生成反射。将NMDA受体拮抗剂AP5微量注射到KF中可显着减弱升压和心动过缓反应，而CNQX阻断AMPA受体则无明显作用。_双小分子甲硫氨酸（BMI）阻滞GABA _A受体增强了这两种反应。BMI和CNQX的共同注射也增强了反应。BMI和AP5的共同注射对升压反应无明显影响，但可明显减轻心动过缓反应。总之，KF通过其谷氨酸NMDA而不是AMPA受体在产生心血管化学反射中起作用。GABA通过GABA _A受体抑制该反射的两个成分。GABA _A之间存在相互作用和NMDA受体在调节反射性心动过缓反应中。还提出了单单元结果，该结果与同系动力学结果相关并得到支持。