THE SPINOMESENCEPHALIC TRACT--ANATOMY AND PHYSIOLOGY

脊髓中脑束（SMT）是由几个组成部分， 具有不同的起源部位、生理特性、脊柱轨迹 和中脑终止部位。 中脑区域与 SMT的终止可能涉及感觉、运动和自主神经 对不同刺激方式的反应，包括疼痛和 温度 正因为如此，它仍然是长期目标 与SMT相关的研究，以更好地了解 该投影系统的不同组件，以便更好地 了解它们在感觉的脊髓和脊髓上处理中的作用 来自皮肤、肌肉和内脏结构的信息。 的 本研究计划的具体目标包括评价： 上部颈髓中SMT细胞的起源和终止;（B） 三叉神经和脊髓对颈部SMT细胞的输入，包括会聚 来自硬脑膜、骨骼肌和心脏传入纤维;和（c） 脊髓本体通路对脊髓功能特性的贡献 宫颈表面贴壁细胞 顺行和逆行追踪技术将 用于研究SMT轴突的终止和起源。 这些研究将 包括对来自不同组织的终端投影的定量评估， 上颈髓的区域到整个 中脑的吻尾侧范围。 定量评价 细胞的层状和节段分布投射到特定的 还将实施中脑目标。 生理学鉴定 SMT单元将使用类似于以下的单单元记录技术进行研究： 在以前的研究中使用的。 三叉神经和脊髓的传入神经 由电、化学和自然刺激激活。 原嵴髓的 来自腰骶髓的通路将被兴奋和/或抑制， 自然和电刺激。 该研究计划涉及几个 与SMT元件组织相关的重要问题. 脊髓的不同水平。 这些研究的结果应该延伸到 基本了解涉及的脊柱和脊髓上的区域， 一般来说，感觉、运动和内脏信息的中枢处理， 特别是与颅面、肌肉和心脏疼痛有关的疼痛。 拟议研究的结果还应有助于 了解可能参与的中枢通路， 急性和慢性的多维情感和动机方面 痛苦

The spinomesencephalic tract (SMT) is made up of several components each with varying sites of origin, physiological properties, spinal trajectories and midbrain termination sites. Midbrain regions associated with the termination of the SMT may be involved in sensory, motor and autonomic responses to different modalities of stimulation, including pain and temperature. Because of this it continues to be the long range objective of research related to the SMT to gain a better understanding of the different components of this projection system in order to better understand their role in the spinal and supraspinal processing of sensory information derived from cutaneous, muscle and visceral structures. The specific aims of the present research plan include evaluation of: (a) the origin and termination of SMT cells in the upper cervical cord; (b) trigeminal and spinal inputs to cervical SMT cells, including convergence from dural, skeletal muscle and cardiac afferent fibers; and (c) the contribution of propriospinal pathways to the functional properties of cervical SMT cells. Anterograde and retrograde tracing techniques will be used to study the termination and origin of SMT axons. These studies will include a quantitative evaluation of the terminal projection from different regions of the upper cervical cord to structures throughout the rostrocaudal extent of the midbrain. A quantitative evaluation of the laminar and segmental distributions of cells projecting to specific midbrain targets will also be carried out. The physiology of identified SMT cells will be studied with single-unit recording techniques similar to those used in previous studies. Trigeminal and spinal afferents will be activated by electrical, chemical and natural stimuli. Propriospinal pathways from the lumbosacral cord will be excited and/or inhibited using natural and electrical stimulation. The research plan addresses several important questions related to the organization of SMT components at different levels of the cord. The results of these studies should extend the basic understanding of spinal and supraspinal regions involved in the central processing of sensory, motor and visceral information in general, and specifically that related to craniofacial, muscle and cardiac pain. The results of the proposed studies should also contribute to the understanding of central pathways that may be involved in the multidimensional affective and motivational aspects of acute and chronic pain.