Differentiation of autonomic reflex control begins with cellular mechanisms at the first synapse within the nucleus tractus solitarius
Differentiation of autonomic reflex control begins with cellular mechanisms at the first synapse within the nucleus tractus solitarius
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DOI：
10.1590/s0100-879x2004000400012
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发表时间：
2004-04-01
影响因子：
2.3
通讯作者：
Jin, Y.-H.
中科院分区：
文献类型：
--
作者：
Andresen, M.C.;Doyle, M.W.;Jin, Y.-H.
内脏传入神经通过颅神经将信息发送到孤束核（NTS）。NTS是信息处理的初始步骤，最终在稳态反射反应中达到高潮。最近的证据表明，在NTS的强传入突触反应最经常调制抑郁症，这形成了一个基本原则，中央整合这些自主神经通路。内脏传入突触是不常见的强大的NTS与大单一的反应幅度和抑郁症，而不是促进中高频激活。大量的信号抑制通过多种机制发生在第一个脑干突触到二级NTS神经元上。这篇综述强调了研究这些基本过程的新方法，包括NTS脑切片的膜片钳记录和荧光示踪的光学技术。香草素受体激动剂，辣椒素，区分两类二级神经元（辣椒素敏感或辣椒素抗性），似乎反映无髓鞘和有髓鞘传入途径。这两类NTS神经元的细胞特性的差异表明，在这些第一突触的突触前和突触后部分有明显的功能分化。由于它们在这些通路的最早阶段的位置，这种机制差异可能在整个反射通路的性能中赋予重要的差异。
Visceral afferents send information via cranial nerves to the nucleus tractus solitarius (NTS). The NTS is the initial step of information processing that culminates in homeostatic reflex responses. Recent evidence suggests that strong afferent synaptic responses in the NTS are most often modulated by depression and this forms a basic principle of central integration of these autonomic pathways. The visceral afferent synapse is uncommonly powerful at the NTS with large unitary response amplitudes and depression rather than facilitation at moderate to high frequencies of activation. Substantial signal depression occurs through multiple mechanisms at this very first brainstem synapse onto second order NTS neurons. This review highlights new approaches to the study of these basic processes featuring patch clamp recordings in NTS brain slices and optical techniques with fluorescent tracers. The vanilloid receptor agonist, capsaicin, distinguishes two classes of second order neurons (capsaicin sensitive or capsaicin resistant) that appear to reflect unmyelinated and myelinated afferent pathways. The differences in cellular properties of these two classes of NTS neurons indicate clear functional differentiation at both the pre- and postsynaptic portions of these first synapses. By virtue of their position at the earliest stage of these pathways, such mechanistic differences probably impart important differentiation in the performance over the entire reflex pathways.