CONTROL OF OSCILLATORY MEMBRANE POTENTIALS IN MOTOR NEURONS

在运动过程中，运动神经元动作电位的节律性爆发 取决于膜电位（Vm）的潜在振荡。 的 一项拟议的研究将检验N-甲基-D-天冬氨酸 脊髓运动神经元上的N-甲基-D-天冬氨酸（NMDA）受体控制着 哺乳动物的这种振荡。 两个具体目标是确定 如果NMDA受体：1）必须在Vm振荡之前被激活， 足以支持节律性放电; 2）调节节律性放电 左旋多巴和5-羟色胺对运动神经元的影响。 细胞内记录 来自新生小鼠的运动神经元将从急性腰骶 外植体以及来自腰椎的器官型（长期切片）共培养物 组织与肌肉。 第三个目标是确定是否运动神经元在 共培养物类似于急性脊髓外植体中的那些。 这将是 通过比较生理和形态学数据， 准备工作 两种制剂中的运动神经元均注射HRP， 因此可以获得全面的形态测量分析。 新 关于运动神经元中Vm振荡控制的信息将 大大推进了我们对运动节律表达方式的理解。 如果运动神经元的功能和结构有足够的相似性 在制备过程中，一个有价值的新的体外系统将被 为将来更详细的研究奠定了基础。 这项工作的第四个目标当然是招聘和培训 少数民族学生从事生物医学研究。 德州女子使命团 大学为培养妇女和少数民族意味着， 这项工作将对德克萨斯州的科学教育产生急需的影响。

During locomotion, rhythmic bursts of action potentials in motoneurons depend upon underlying oscillations in membrane potential (Vm). The proposed study will test the hypothesis that N-methyl-D-aspartic acid (NMDA) receptors on spinal motoneurons control the incidence and magnitude of such oscillations in mammals. Two specific objectives are to determine if NMDA receptors: 1) must be activated before Vm oscillations are sufficient to support rhythmic firing; and 2) regulate the rhythmogenic effects of L-DOPA and serotonin on motoneurons. Intracellular recordings from neonatal mouse motoneurons will be obtained from acute lumbosacral explants as well as from organotypic (long-term slice) cocultures of lumbar tissue with muscle. A third objective is to determine if motoneurons in cocultures resemble those in acute spinal explants. This will be accomplished by comparing both physiological and morphological data across preparations. Motoneurons in both preparations will be injected with HRP, so comprehensive morphometric analyses can be obtained. The new information on the control of Vm oscillations in motoneurons will significantly advance our understanding of how motor rhythms are expressed. If there is a sufficient resemblance in motoneuron function and structure across preparations, a valuable new in vitro system will have been established for future, more detailed studies. The fourth objective of this work is of course to recruit and train minority students in biomedical research. The mission Texas Woman's University has for training women and minorities means that the proposed work would carry a much needed impact upon science education in Texas.