Transneuronal tracing of neural pathways that regulate hindlimb muscle blood flow
Transneuronal tracing of neural pathways that regulate hindlimb muscle blood flow
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DOI：
10.1152/ajpregu.00633.2006
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发表时间：
2007-04-01
影响因子：
2.8
通讯作者：
Yates, B. J.
中科院分区：
文献类型：
--
作者：
Lee, T-K.;Lois, J. H.;Yates, B. J.
尽管对调节肌肉血流量的神经机制有相当大的兴趣，但控制交感神经流出到骨骼肌的下行通路还没有得到充分的理解。本研究通过将两种重组伪狂犬病病毒（PRV）株注射到大鼠左后肢和右后肢腓肠肌中：PRV-152和PRV-BaBlu的跨神经转运来绘制这些途径。为了防止PRV通过运动回路传播到脑干，在L2节段下方进行了脊髓横断。感染的神经元被观察到双边在所有的大脑区域，以前已被证明有助于调节交感神经流出：延髓中缝核，头端腹外侧延髓（RVLM），头端腹内侧延髓，A5肾上腺素能细胞群区域，蓝斑，蓝斑下核，和室旁核的下丘脑。RVLM是脑干区域，通常被认为在调节肌肉血流量方面发挥最大作用，其包含的神经元在接种后存活时间最短。大约一半的感染RVLM神经元酪氨酸羟化酶免疫阳性，表明他们是儿茶酚胺。许多（47%）的RVLM神经元双重感染的PRV重组体注射到左，右后肢，表明中枢神经系统具有有限的能力，独立调节血液流向左，右后肢肌肉。
Despite considerable interest in the neural mechanisms that regulate muscle blood flow, the descending pathways that control sympathetic outflow to skeletal muscles are not adequately understood. The present study mapped these pathways through the transneuronal transport of two recombinant strains of pseudorabies virus (PRV) injected into the gastrocnemius muscles in the left and right hindlimbs of rats: PRV-152 and PRV-BaBlu. To prevent PRV from being transmitted to the brain stem via motor circuitry, a spinal transection was performed just below the L2 level. Infected neurons were observed bilaterally in all of the areas of the brain that have previously been shown to contribute to regulating sympathetic outflow: the medullary raphe nuclei, rostral ventrolateral medulla (RVLM), rostral ventromedial medulla, A5 adrenergic cell group region, locus coeruleus, nucleus subcoeruleus, and the paraventricular nucleus of the hypothalamus. The RVLM, the brain stem region typically considered to play the largest role in regulating muscle blood flow, contained neurons infected following the shortest postinoculation survival times. Approximately half of the infected RVLM neurons were immunopositive for tyrosine hydroxylase, indicating that they were catecholaminergic. Many (47%) of the RVLM neurons were dually infected by the recombinants of PRV injected into the left and right hindlimb, suggesting that the central nervous system has a limited capacity to independently regulate blood flow to left and right hindlimb muscles.