Sved A F, Ito S, Madden C J, Stocker S D, Yajima Y
Department of Neuroscience, University of Pittsburgh, 446 Crawford Hall, Pittsburgh, PA 15260, USA.
Ann N Y Acad Sci. 2001 Jun;940:247-58. doi: 10.1111/j.1749-6632.2001.tb03681.x.
The central neural circuit mediating baroreceptor control of sympathetic vasomotor outflow involves an excitatory projection from arterial baroreceptors to nucleus tractus solitarius, an excitatory projection from nucleus tractus solitarius to the caudal ventrolateral medulla, an inhibitory projection from the caudal ventrolateral medulla to the rostral ventrolateral medulla (RVLM), and an excitatory projection from the RVLM to sympathetic preganglionic neurons in the spinal cord. For this circuit to be operational, the relevant neurons in the RVLM must be tonically active. Indeed, numerous studies have demonstrated that RVLM vasomotor neurons are tonically active; however, little is known regarding the nature of the tonic excitatory drive to these neurons. We present a model in which RVLM vasomotor neurons are tonically excited by inputs to the RVLM that can be blocked by the excitatory amino acid receptor antagonist, kynurenic acid, as well as an input from the caudal ventrolateral medulla that is not sensitive to kynurenic acid.
介导压力感受器对交感缩血管神经传出控制的中枢神经回路，包括从动脉压力感受器到孤束核的兴奋性投射、从孤束核到延髓尾端腹外侧的兴奋性投射、从延髓尾端腹外侧到延髓头端腹外侧（RVLM）的抑制性投射，以及从RVLM到脊髓交感节前神经元的兴奋性投射。为使该神经回路发挥作用，RVLM中的相关神经元必须持续处于活动状态。事实上，大量研究已证实RVLM中的血管运动神经元持续处于活动状态；然而，对于这些神经元的持续性兴奋性驱动的本质却知之甚少。我们提出了一个模型，其中RVLM血管运动神经元受到可被兴奋性氨基酸受体拮抗剂犬尿氨酸阻断的RVLM输入以及对犬尿氨酸不敏感的延髓尾端腹外侧输入的持续性兴奋。
