Karádi Z, Faludi B, Lénárd L, Czurkó A, Niedetzky C, Vida I, Nishino H
Neurophysiology Research Group, Hungarian Academy of Sciences, Pécs University, Medical School.
Brain Res Bull. 1995;37(2):157-62. doi: 10.1016/0361-9230(94)00268-6.
The globus pallidus (GP) is intimately involved in regulation of various aspects of hunger- and thirst-motivated behaviors. Our parallel neurochemical studies demonstrated the existence of GP neurons whose discharge rates are suppressed by glucose applied microelectrophoretically. In the present series of experiments, we aimed to provide complex, feeding-associated functional characterization--similar to that previously accomplished in the case of lateral hypothalamic and amygdaloid chemosensitive neurons--of these glucose-sensitive (GS) and the glucose-insensitive (GIS) pallidal cells. To do so, extracellular single neuron activity of the GP was recorded in anesthetized rats and anesthetized or awake rhesus monkeys by means of carbon fiber, multibarreled glass microelectrodes during: a) microelectrophoretic administration of chemicals, b) gustatory, and c) olfactory stimulations. In alert primates, activity changes were also recorded during presentation of food and nonfood objects as well as during the performance of a conditioned, high fixed-ratio bar-press feeding task. The half of pallidal cells examined showed firing rate changes during phases of the conditioned alimentary task. In both species, about 1/7 of all neurons tested proved to be GS, while the proportion of cells responding to gustatory and olfactory stimulations was 19% and 16%, respectively. Task-related and taste- and smell-responsive units were mainly found among the GS neurons of the pallidum. These data, along with previous findings, indicate that chemosensitive cells of the GP, in an apparent overlap with units of the central gustatory representation, are involved in a hierarchically organized glucose-monitoring neural network, through which pallidal neurons exert their integrative functions in the central feeding control.
苍白球（GP）密切参与饥饿和口渴动机行为各个方面的调节。我们的平行神经化学研究表明，存在一些苍白球神经元，其放电率会被微电泳施加的葡萄糖所抑制。在本系列实验中，我们旨在对这些葡萄糖敏感（GS）和葡萄糖不敏感（GIS）的苍白球细胞进行复杂的、与进食相关的功能表征，类似于先前在下丘脑外侧和杏仁核化学敏感神经元中所完成的那样。为此，在麻醉大鼠以及麻醉或清醒的恒河猴中，通过碳纤维、多管玻璃微电极记录苍白球的细胞外单神经元活动，记录过程如下：a）微电泳给药化学物质，b）味觉刺激，c）嗅觉刺激。在警觉的灵长类动物中，在呈现食物和非食物物体以及执行条件性高固定比率压杆进食任务期间，也记录活动变化。所检查的一半苍白球细胞在条件性进食任务阶段显示出放电率变化。在这两个物种中，所有测试神经元中约1/7被证明是葡萄糖敏感的，而对味觉和嗅觉刺激有反应的细胞比例分别为19%和16%。与任务相关以及对味觉和嗅觉有反应的单位主要在苍白球的葡萄糖敏感神经元中发现。这些数据与先前的发现一起表明，苍白球的化学敏感细胞与中枢味觉表征单位明显重叠，参与了一个层次组织的葡萄糖监测神经网络，通过该网络苍白球神经元在中枢进食控制中发挥其整合功能。
