FUNCTIONAL ORGANIZATION OF CERVICAL SPINAL INTERNEURONS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 完成了我们研究5-羟色胺对行为猴脊髓神经元放电特性影响的数据收集。 新的数据证实了我们前几年在其他猴子身上的发现。 5-羟色胺和5-羟色胺受体拮抗剂麦角新碱施加到细胞外记录的神经元与组合的细胞外，离子电渗电极。 5-羟色胺引起显著百分比的脊髓神经元的活性的总体增加。 一小部分在5-羟色胺离子电渗疗法后表现出放电减少。 麦角新碱对大多数神经元有相反的作用。 其余的神经元不受血清素或其拮抗剂的影响。 在C6-T1节段的神经元的定向调谐确定多维手腕运动之前和之后的离子电渗应用的5-羟色胺和5-羟色胺拮抗剂。 阻断抑制对大多数神经元的定向调谐影响不大。 这些结果表明，5-羟色胺在调节许多脊髓神经元的兴奋性中起着重要作用，但不影响腕部运动在不同方向上的空间调谐。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Data collection was completed for our study of the effects of serotonin on the firing properties of neurons in the spinal cord of behaving monkeys. New data confirm our findings in other monkeys from previous years. Serotonin and the serotonin receptor antagonist methysergide were applied to extracellularly recorded neurons with a combined extracellular, iontophoresis electrode. Serotonin causes overall increase in activity of a significant percentage of spinal neurons. A small percentage exhibit decreased firing after iontophoresis of serotonin. Methysergide has the opposite effect for most of these neurons. The remaining neurons are not affected by either serotonin or its antagonist. The directional tuning of neurons in the C6-T1 segments was determined for multi-dimensional wrist movements before and after the iontophoretic application of serotonin and serotonin antagonists. Block of inhibition had little effect on the neurons' directional tuning for the majority of neurons. These results suggest that serotonin plays an important role in regulating excitability for many spinal neurons but does not affect spatial tuning for wrist movements in different directions.