Drye R G, Baisden R H, Whittington D L, Woodruff M L
Department of Anatomy, James H. Quillen College of Medicine, East Tennessee State University, Johnson City 37614.
Brain Res Bull. 1990 Jan;24(1):33-9. doi: 10.1016/0361-9230(90)90286-9.
The effects of stimulation of the A5 cell group of the caudal ventrolateral pons electrically or with L-glutamate on heart rate and blood pressure were determined in rabbits. Electrical stimulation caused blood pressure increases and reflex bradycardia. L-glutamate caused decreases in blood pressure and heart rate which were blocked by the L-glutamate antagonist aminophosphoheptanoic acid. Transection of the brainstem at the level of the midbrain did not alter the effects of either electrical or chemical stimulation. Lesions of the nucleus and tractus solitarius (NTS) attenuated the effects of L-glutamate, but did not change the effectiveness of electrical stimulation. Injections of 6-hydroxydopamine three to four weeks before the experiments blocked the effects of electrical stimulation but only reduced the effects of L-glutamate injection. The A5 group may have two functional subdivisions. Some A5 cells may produce blood pressure depressor and bradycardic effects by means of projections to the NTS and the spinal cord. Other A5 cells may produce blood pressure pressor effects by means of projections to the spinal cord.
在兔身上确定了电刺激或用L-谷氨酸刺激脑桥尾端腹外侧A5细胞群对心率和血压的影响。电刺激导致血压升高和反射性心动过缓。L-谷氨酸导致血压和心率降低，而L-谷氨酸拮抗剂氨基磷酸庚酸可阻断这种作用。在中脑水平横断脑干并不改变电刺激或化学刺激的效应。孤束核和孤束（NTS）损伤减弱了L-谷氨酸的效应，但并未改变电刺激的效果。在实验前三到四周注射6-羟基多巴胺可阻断电刺激的效应，但仅降低L-谷氨酸注射的效应。A5组可能有两个功能亚群。一些A5细胞可能通过投射到NTS和脊髓产生降压和心动过缓效应。其他A5细胞可能通过投射到脊髓产生升压效应。
