Physiological analyzes of synaptic mechanisms underlying the central compensation in crayfish using simultaneous intracellular recording techniques

当甲壳动物的平衡器官部分失灵时，眼柄首先采取双侧不对称的姿势，但在几周内逐渐恢复到原来的对称姿势。虽然这一恢复过程长期以来一直被认为是行为水平的中枢补偿，但在神经元水平上，为其服务的生理过程在很大程度上仍然未知。在这项研究中，我们用细胞内记录和染色技术研究了小龙虾单侧状石去除后眼柄姿势中枢代偿的突触机制。对在控制眼柄姿势的感觉-运动信号传递中起关键作用的非棘突巨细胞树突膜特性和突触活动的生理学分析表明，在代偿p-…过程中，不仅它们的被动膜特性发生了显着变化，而且自发突触活动也发生了显著变化。更多的岩石流。单侧鼻石摘除后的输入阻力和膜时间常数随手术侧的不同而增加或减少，这清楚地表明NGIS是导致中枢代偿的改变部位。然而，由于NGIS的自发突触活动反映了与NGIS有关的突触前细胞的放电活动，因此这些突触前中间神经元在中枢代偿中也起着重要作用。通过细胞内同步记录，发现许多局部中间神经元与NGIS发生单突触或多突触联系。这些局部中间神经元的树突分支大多投射到中脑的副嗅叶，在那里他汀囊传入也直接投射到NGIS的树突所在的前脑，从而将他汀囊信息传递给NGIS。结论：中枢代偿过程是基于脑内多个部位的活动变化，包括本研究中确定的NGIS及其突触前细胞。较少

When the equilibrium organ of crustaceans is partially disabled, the eyestalks first take bilaterally asymmetrical posture, but they gradually recover the original symmetrical posture in a few weeks. Although this recovery process has long been known as the central compensation at the behavioral level, the physiological process subserving it largely remains unknown at the neuronal level. In this study, the synaptic mechanisms underlying the central compensation of the eyestalk posture following unilateral statolith removal have been investigated using intracellular recording and staining techniques in crayfish. Physiological analyzes of the dendritic membrane properties and synaptic activities of nonspiking giant interneurons (NGIs) that play a crucial role in the sensori-motor signal transmission for controlling the eyestalk posture revealed that not only their passive membrane properties but also the spontaneous synaptic activities showed significant changes during the compensation p … More rocess. The finding that the input resistance and membrane time constant increased or decreased after unilateral statolith removal, depending on the side of operation, clearly demonstrated that NGIs are the site of changes leading to the central compensation. However, since the spontaneous synaptic activity of NGIs reflects the spike activity of those cells that are presynaptic to NGIs, it was suggested that those presynaptic interneurons also play important roles in the central compensation. Many local interneurons that made either monosynaptic or polysynaptic connection with NGIs were identified by simultaneous intracellular recording from them. Most of these local interneurons projected dendritic branches onto the parolfactory lobe of the deutocerebrum where statocyst afferents also project directly as well as onto the protocerebrum where dendrites of NGIs are located, thus mediating statocyst information to NGIs. It is concluded that the central compensation process is based on activity changes at multiple sites in the brain including NGIs and their presynaptic cells identified in this study. Less