CONVERGENCE OF SENSORY INFORMATION FROM ABDOMINAL VISCERA IN THE RAT-BRAIN STEM
CONVERGENCE OF SENSORY INFORMATION FROM ABDOMINAL VISCERA IN THE RAT-BRAIN STEM
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DOI：
10.1152/ajpgi.1986.251.2.g169
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发表时间：
1986-08-01
影响因子：
--
通讯作者：
WINGATE, DL
中科院分区：
文献类型：
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作者：
APPIA, F;EWART, WR;WINGATE, DL
本研究的目的是确定胃机械感受器和肝葡萄糖感受器的生理激活所刺激的大鼠脑干中是否存在感觉信息的收敛。细胞外记录是由迷走神经背核和髓质孤束核区域的单个神经元进行的。研究了这些神经元对胃扩张、等渗D-葡萄糖的肝门静脉灌注和等渗盐水的肝门静脉灌注的反应。研究了 56 个神经元；结果发现，与对任何一种形式的肝脏刺激做出反应的神经元数量相比，对胃扩张作出反应的神经元比例没有显着差异。在 20 个神经元中（所有 3 种类型的刺激均在同一神经元上进行测试），两种形式的内脏刺激均观察到兴奋和抑制。在对肝门静脉输注做出反应的七个神经元中，其中四个也有来自胃机械感受器的输入。只有三个神经元对肝脏葡萄糖灌注有反应；在其余部分中，反应的一个组成部分是由于体积本身的输注。这些实验的结果表明，肝脏迷走神经传入神经所携带的功能性突触投射明显较弱，特别是那些对门静脉葡萄糖浓度变化做出反应的突触投射，这可能表明肝脏中存在相当分散和非特异性的感觉系统。这些结果还证明来自胃和肝肠感受器的信息会汇聚到脑干中的神经元上。大脑这一水平的收敛可能有助于协调对食物摄入的反应，这是胃肠道分泌和运动反射的一部分，旨在最大限度地提高从食物摄入中获得的营养价值。
This study was carried out to establish whether there was convergence of sensory information in the rat brain stem stimulated by physiological activation of gastric mechanoreceptors and hepatic glucoreceptors. Extracellular recordings were made from single neurons in the region of the dorsal vagal nucleus and nucleus of the solitary tract in the medulla. The responses of these neurons to gastric distension, hepatic portal vein perfusion of isotonic D-glucose, and hepatic portal vein infusion of isotonic saline were studied. Fifty-six neurons were studied; it was found that there was no significant difference in the proportion of neurons responding to gastric distension compared with the number responding to either form of hepatic stimulation. In 20 neurons (all 3 types of stimulation were tested on the same neuron), both excitation and inhibition were observed with both forms of visceral stimulation. Of the seven of these neurons that responded to hepatic portal vein infusion, four of them also had an input from gastric mechanoreceptors. Only three of the neurons that responded to hepatic glucose perfusion; in the remainder a component of the response was due to the infusion of the volume itself. The results from these experiments have demonstrated an apparently weak functional synaptic projection carried by hepatic vagal afferents, particularly those responding to changes in portal glucose concentration, which may indicate a rather diffuse and nonspecific sensory system in the liver. These results have also demonstrated the convergence onto neurons in the brain stem of information from gastric and hepatic enteroceptors. Convergence at this level of the brain could contribute to the coordination of responses to food intake that are part of gastrointestinal secretory and motor reflexes designed to maximize the nutrient value obtained from food ingestion.