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苍白球是基底神经节间接环路的重要核团,在机体运动功能调节中发挥重要作用。近年来,苍白球在基底神经节正常及异常功能调节中的重要性己日渐受到重视。然而,目前对苍白球内各种神经递质系统的功能活动了解较少。GABA是苍白球主要的神经递质。采用电生理记录、免疫组织化学及行为测试等实验方法,人们对大鼠苍白球GABA能神经传递系统的受体分布及功能活动有了新的认识。形态学研究揭示,苍白球存在GABAA受体及其苯二氮卓结合位点和GABAB受体。在亚细胞水平,GABAA受体主要位于对称性突触(GABA能突触)的突触后膜,而GABAB受体则位于对称性突触和非对称性突触(兴奋性突触)的突触前膜及突触后膜。功能学研究进一步揭示,激活苍白球突触前膜GABAB自身和异源性受体可分别减少GABA和谷氨酸释放;激活突触后膜GABAB受体,可引起苍白球神经元超极化。除GABAB受体外,激活苍白球GABAA受体苯二氮卓结合位点及阻断GABA重摄取可延长GABA电流持续时间,从而改变苍白球神经元兴奋性。与离体实验结果相一致,激活苍白球GABAB受体和苯二氮卓结合位点及阻断GABA重摄取可引起整体动物旋转行为。苍白球GABA神经递质系统与帕金森病病因学及癫痫发病有关。已证实,苍白球神经元放电频率的降低及簇状放电的产生与帕金森病运动减少 及静止?
Globus pallidus is an important nucleus of the indirect pathway of basal ganglia and plays an important role in the regulation of motor function. In recent years, the importance of globus pallidus in the regulation of normal and abnormal function of basal ganglia has been paid more and more attention. However, little is known about the functional activity of various neurotransmitter systems in the globus pallidus. GABA is the main neurotransmitter of globus pallidus. Using electrophysiological recordings, immunohistochemical and behavioral tests and other experimental methods, people have a new understanding of the receptor distribution and functional activity of the GABAergic neurotransmission system in the rat globus pallidus. Morphological studies revealed that GABAA receptor and its benzodiazepine binding site and GABAB receptor exist in globus pallidus. At the subcellular level, GABAA receptors are mainly located in the postsynaptic membrane of symmetric synapses (GABAergic synapses), whereas GABAB receptors are located in the synapses of symmetrical and asymmetric synapses (excitatory synapses) Pre-synaptic membrane and postsynaptic membrane. Functional studies further revealed that activation of the globus pallidus presynaptic membrane GABAB autoreceptors and heterologous receptors reduce GABA and glutamate release, respectively; activation of the postsynaptic membrane GABAB receptor can cause hyperpolarization of the globus pallidus neurons. In addition to the GABAB receptor, activation of the globus pallidum GABAA receptor benzodiazepine binding site and blockade of GABA reuptake can prolong GABA current duration, thereby changing the excitability of globus pallidus neurons. Consistent with in vitro results, activation of the globus pallidum GABAB receptor and benzodiazepine binding sites and blockade of GABA reuptake can cause global animal rotation behavior. The globus pallidus GABA neurotransmitter system is associated with the etiology of Parkinson’s disease and epilepsy. It has been demonstrated that the decrease in the firing rate of globus pallidus neurons and the generation of cluster discharges and Parkinson’s disease decrease and rest?