Triggering genetically-expressed transneuronal tracers by peripheral axotomy reveals convergent and segregated sensory neuron-spinal cord connectivity.
Triggering genetically-expressed transneuronal tracers by peripheral axotomy reveals convergent and segregated sensory neuron-spinal cord connectivity.
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通过周围轴切开术触发遗传表达的跨神经元示踪剂，揭示了收敛性和隔离的感觉神经脊髓连接性。
DOI：
10.1016/j.neuroscience.2009.07.051
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发表时间：
2009-11-10
期刊：
影响因子：
3.3
通讯作者：
Basbaum, A. I.
中科院分区：
文献类型：
--
作者：
Braz, J. M.;Basbaum, A. I.
为了更好地理解非痛苦刺激和痛苦刺激唤起行为的机制，需要新的资源来剖析初级传入神经元亚群参与的复杂电路。这对于理解损伤的后果尤其正确，因为中枢神经系统回路的重组可能有助于疼痛的持续。在这里，我们描述了一个转基因小鼠品系(ZWX)，在该品系中，一种依赖于Cre重组酶的跨神经元示踪物小麦胚凝集素(WGA)在初级躯体或内脏传入神经元中表达，但仅在它们的外周轴突横断后表达。后一项要求允许示踪剂表达的区域和时间控制，即使在成人中也是如此。使用不同的CRE系将WGA转运到感觉神经元的亚群，在这里，我们展示了有髓和无髓“痛”纤维(伤害性感受器)参与不同脊髓回路的程度。我们发现无髓传入(包括TRPV1表达的亚群)和有髓传入与表达NK1受体的I层神经元有显著的趋同(即WGA-跨神经元标记)。相比之下，内层II的PKCγ中间神经元只接受有髓传入。WGA标记在脊髓中的这种不同分布表明，有髓感觉神经元和无髓感觉神经元针对不同的空间分离的突触后神经元群体。另一方面，我们发现较深板层(III-V)的神经元从有髓传入接受直接(即单突触)输入，从无髓传入接受多突触输入。综上所述，我们的结果表明，外周感觉信息通过分离和汇聚两种途径传递到中枢神经。
To better understand the mechanisms through which non-painful and painful stimuli evoke behavior, new resources to dissect the complex circuits engaged by subsets of primary afferent neurons are required. This is especially true to understand the consequences of injury, when reorganization of CNS circuits likely contributes to the persistence of pain. Here we describe a transgenic mouse line (ZWX) in which there is Cre-recombinase-dependent expression of a transneuronal tracer, wheat germ agglutinin (WGA), in primary somatic or visceral afferent neurons, but only after transection of their peripheral axons. The latter requirement allows for both regional and temporal control of tracer expression, even in the adult. Using a variety of Cre lines to target WGA transport to subpopulations of sensory neurons, here we demonstrate the extent to which myelinated and unmyelinated “pain” fibers (nociceptors) engage different spinal cord circuits. We found significant convergence (i.e. manifest as WGA-transneuronal labeling) of unmyelinated afferents, including the TRPV1-expressing subset, and myelinated afferents to NK1 receptor expressing neurons of lamina I. By contrast, PKCγ interneurons of inner lamina II only receive a myelinated afferent input. This differential distribution of WGA labeling in the spinal cord indicates that myelinated and unmyelinated sensory neurons target different and spatially segregated populations of postsynaptic neurons. On the other hand, we show that neurons of deeper laminae (III-V) receive direct (i.e. monosynaptic) inputs from myelinated afferents and polysynaptic input from unmyelinated afferents. Taken together, our results indicate that peripheral sensory information is transmitted to the CNS both through segregated and convergent pathways.
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影响因子：
5.5
作者：
Andrew, D;Craig, AD
通讯作者：
Craig, AD
影响因子：
56.9
作者：
MELZACK, R;WALL, PD
通讯作者：
WALL, PD
DOI：
10.1073/pnas.222546999
发表时间：
2002-11-12
影响因子：
11.1
作者：
Braz, JM;Rico, B;Basbaum, AI
通讯作者：
Basbaum, AI
影响因子：
56.9
作者：
DeFalco, J;Tomishima, M;Friedman, JM
通讯作者：
Friedman, JM
影响因子：
2.5
作者：
Eckert, WA;McNaughton, KK;Light, AR
通讯作者：
Light, AR