DORSAL COLUMN NUCLEI PROJECTIONS TO THE INFERIOR OLIVE

背柱核投射到下橄榄

• 批准号: 3416659
• 负责人: HELEN H MOLINARI
• 金额: $ 14.04万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3416659
• 关键词: antiantibody; biological signal transduction; brain mapping; cats; cell cell interaction; cerebellar nuclei; cerebellum; cerebral cortex; dorsal column; electron microscopy; gamma aminobutyrate; neuroanatomy; olivary body; radiotracer; somesthetic sensory cortex; spinal cord mapping; synapses

Lack of coordination results not only from lesions of structures such as the cerebellum, which ar generally thought to play an important role in controlling movement, but also from compromise of structures such as the dorsal columns and their relay, the dorsal column nuclei, that provide sensory information to the cerebellum. Information from the dorsal column nuclei reaches the cerebellum through a number of projections, most of which arise from widely scattered neurons that cannot be subjected to detailed experimental evaluation. Work from this laboratory has shown, however, that in cat the connection from the gracile portion of the dorsal column nuclei to the dorsal accessory subdivision of the inferior olive (DAO) constitutes not only a substantial source of somatosensory information for the cerebellum but one amenable to experimental manipulation. The DAO projection neurons in the gracile nucleus appear to preferentially signal contracts with external objects that occur at unexpected times during movement. The proposed electron microscopic experiments will investigate the anatomical substrates that underlie such signalling. The first experiment will determine the synaptic mechanisms through which the dorsal column fibers activated by external contact might interact with DAO projection neurons in the gracile nucleus. The DAO projection neurons will be identified with a retrograde tracer; synaptic inputs from the dorsal columns will be labeled with degeneration. Inhibitory elements that might regulate responsiveness of DAO projection neurons to these inputs will be identified using antibodies to the neurotransmitter GABA. The second experiment seeks to determine how inhibition of the DAO projection neurons might be achieved. This will be done by evaluating whether, and at what sites, putative GABAergic neurons adjacent to DAO projection neurons receive inputs that might signal the occurrence of either motor commands (the cerebral cortex) or contact with external objects (the dorsal columns). The data collected from these and other experiments in this laboratory will help determine how compromise of the dorsal columns and dorsal column nuclei might contribute to production of motor deficits and, ultimately, to a greater understanding of how sensory information is used to generate coordinated movement.

缺乏协调不仅是由于结构的损害， 小脑通常被认为在 控制运动，但也从妥协的结构，如 背柱及其中继，背柱核，提供 将感觉信息传递给小脑 来自背柱的信息 神经核通过许多投射到达小脑，大多数 它们来自广泛分散的神经元，这些神经元不能受到 详细的实验评估。 这个实验室的工作表明， 然而，在猫中，从背侧薄肌部分连接 下橄榄体背侧附属分部的柱核 (DAO)不仅构成了躯体感觉的重要来源， 小脑的信息，但一个适合实验 操纵 薄束核的DAO投射神经元似乎优先 信号合同与外部对象发生意外的时间 在运动过程中。 拟议的电子显微镜实验将 研究这种信号的解剖学基础。 的 第一个实验将确定突触机制， 外界接触激活的背柱纤维可能与DAO相互作用 薄束核投射神经元。 DAO投射神经元将 用逆行示踪剂识别;来自背侧的突触输入 列将被标记为退化。 抑制性因素可能 调节DAO投射神经元对这些输入的反应将是 用神经递质GABA的抗体来鉴定。 第二 实验试图确定DAO投射神经元的抑制是如何 可能实现。 这将通过评估是否，以及在什么情况下 位点，推定的GABA能神经元邻近DAO投射神经元 接收输入，该输入可以用信号通知电机命令的发生 (the大脑皮层）或与外部物体接触（背部 列）。 从这个实验室的这些和其他实验中收集的数据将 帮助确定背柱和背柱的损伤 核可能有助于产生运动缺陷，并最终， 更好地理解感官信息是如何被用来产生 协调的动作。