Regulation of Cortical Blood Flow by the Dorsal Raphe Nucleus: Topographic Organization of Cerebrovascular Regulatory Regions
Regulation of Cortical Blood Flow by the Dorsal Raphe Nucleus: Topographic Organization of Cerebrovascular Regulatory Regions
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DOI：
10.1038/jcbfm.1992.91
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发表时间：
1992-07
影响因子：
6.3
通讯作者：
M. Underwood;M. Bakalian;V. Arango;Robert W. Smith;J. Mann
中科院分区：
文献类型：
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作者：
M. Underwood;M. Bakalian;V. Arango;Robert W. Smith;J. Mann
我们在大鼠中检查：（1）电刺激中缝背核（DRN）后皮质血流（CoBF）变化的时间过程和幅度;（2）DRN损伤是否影响静息CoBF或脑血管对CO2的反应。将动物麻醉（氯醛糖）、麻痹和人工通气。检查刺激频率（1-200 Hz）和强度（10-100 μA）对动脉压、心率和CoBF的影响;电解损伤。使用激光多普勒流量计测量CoBF，探头放置在顶叶感觉运动皮层的硬膜外。DRN的计算机重建三维尼氏染色冠状面的电极位置的定位。短暂的刺激（8秒;n= 6）引起的频率和强度依赖性增加动脉压，心率，和CoBF。持续间断刺激头侧DRN（200 Hz; 1 s on/1 s off; 70 μA）引起CoBF下降（基线的85 ± 12%;n= 9）（p< 0.05），而刺激尾侧DRN导致CBF增加（基线的126 ± 13%;n= 9）。苯巴比妥（0.1-1 μg; i. v.; n= 8）增加的动脉压和CoBF小于由短暂DRN刺激引起的（p< 0.05）。DRN损伤不影响静息CoBF（损伤前140 ± 25灌注单位（PU）;损伤后127 ± 16 PU;p> 0.05，n = 5）或平均动脉压（损伤前127 ± 13;损伤后120 ± 11）;也不影响脑血管对动脉Pco 2变化的反应。持续间歇刺激DRN可以引起CoBF的增加或减少，这取决于解剖亚定位。DRN不维持静息CoBF，也不参与Pco 2变化的脑血管反应。
We examined in rat: (1) the time-course and magnitude of change in cortical blood flow (CoBF) following electrical stimulation of the dorsal raphe nucleus (DRN) and (2) whether DRN lesions affect resting CoBF or the cerebrovascular response to CO2. Animals were anesthetized (chloralose), paralyzed, and artificially ventilated. The effect of stimulus frequency (1–200 Hz) and intensity (10–100 μA) on arterial pressure, heart rate, and CoBF was examined; lesions were made electrolytically. CoBF was measured using a laser-Doppler flowmeter with the probe placed extradurally over the parietal sensorimotor cortex. The DRN was computer reconstructed in three dimensions from Nissl stained coronal sections for localization of electrode placements. Brief stimuli (8 s;n= 6) elicited frequency and intensity-dependent increases in arterial pressure, heart rate, and CoBF. Sustained intermittent trains of stimuli of rostral DRN (200 Hz; 1 s on/1 s off; 70 μA) elicited a decrease (85 ± 12% of baseline;n= 9) in CoBF (p< 0.05) while stimulation in caudal DRN resulted in increased CBF (126 ± 13% of baseline;n= 9). Phenylephrine infusion (0.1–1 μg; i.v.;n= 8) increased arterial pressure and CoBF less than that elicited by brief DRN stimulation (p< 0.05). DRN lesions did not affect resting CoBF (140 ± 25 perfusion units (PU) before; 127 ± 16 PU after DRN lesion;p> 0.05,n= 5) or mean arterial pressure (127 ± 13 before; 120 ± 11 after); nor did it affect the cerebrovascular response to change in arterial Pco2. Sustained intermittent stimulation of the DRN can evoke either increases or decreases in CoBF depending on the anatomical sublocalization. The DRN does not tonically maintain resting CoBF, nor participate in the cerebrovascular response to change in Pco2.