SYNAPTIC ORGANIZATION IN SPINAL CORD AND THALAMUS

这项研究项目关注的是神经元和 哺乳动物体感丘脑的突触组织。 大脑的这一区域接受来自 提升的躯体感觉系统，并传递这一信息 到躯体感觉皮质。尽管丘脑经常 被称为“中继核”，很明显，有许多复杂的 在这个主要的间脑结构内进行信息处理。 丘脑的神经回路正在接受 几种实验技术：1)正交化输运 小麦胚凝集素--凝集素偶联微量注射 辣根过氧化物酶(WGA-HRP)被制成选定的区域 已知的投射到躯体感觉的神经轴 丘脑。利用一种新开发的方法，突触 从投射到丘脑的不同部位发出的 由电子显微镜揭示的及其精确分布 确定了丘脑神经元的表面。2) 生理特性的细胞内标记 体感丘脑神经元在某些情况下与 轴突运输方法学可以揭示突触群体 它们接触这些神经元，以及这些神经元的投影 生理特征上的特殊途径 体感神经元。这些神经元的突触输入是 然后使用计算机三维重建绘制地图 程序。3)免疫细胞化学方法用于描述 这些神经元和突触结构包含假定的 神经递质，如γ-氨基丁酸(GABA)， 5羟色胺、乙酰胆碱或去甲肾上腺素。据信， 其中一些递质改变了丘脑的放电模式 从而改变了信息通过 丘脑的单抗已经被用来对抗 来自体感丘脑和丘脑的突触体部分 随后对他们的活动进行了筛查。我们已经得到了六个 抗体(3,000多种)似乎有选择性地 标记躯体感觉丘脑中的特定元素。 将对这些抗体进行检查，以确定它们是否可以 用于识别特定类别的轴突终末 丘脑，为了进一步扩展我们的分析能力 丘脑回路。 现代解剖学与生理学的结合运用 本研究中使用的方法提供了一种强有力的手段 将神经元的结构和功能特性联系起来 构成神经系统的一个主要元素，与 各种体感机制，使动物和 人类能够检测和解释由皮肤和 身体的深层组织。

This research program is concerned with the neuronal and synaptic organization of the mammalian somatosensory thalamus. This region of the brain receives afferent information from ascending somatosensory systems and transmits this information to the somatosensory cortex. Although the thalamus is frequently termed a "relay nucleus", it is evident that there is much complex information processing within this major diencephalic structure. The neuronal circuitry of the thalamus is being examined by several experimental techniques: 1) orthograde transport of wheat germ lectin - microinjections of lectin conjugated to horseradish peroxidase (WGA-HRP) are made into selected regions of the neuraxis which are known to project to the somatosensory thalamus. Utilizing a newly developed methodology, the synapses arising from various sites which project to the thalamus can be revealed by electron microscopy and their precise distribution over the surfaces of thalamic neurons determined. 2) Intracellular labeling of physiologically characterized somatosensory thalamic neurons combined in some cases with the axon transport methodology can reveal the synaptic populations which contact these neurons, as well as the projections of particular pathways upon physiologically-characterized somatosensory neurons. The synaptic input to these neurons is then mapped using a three-dimensional computer reconstruction program. 3) Immunocytochemical methods are used to describe those neuronal and synaptic structures which contain putative neural transmitters, such as gamma-aminobutyric acid (GABA), serotonin, acetylcholine or norepinephrine. It is believed that some of these transmitters change the firing patterns of thalamic neurons and thus alter the transmission of information through the thalamus 4) Monoclonal antibodies have been raised against synaptosome fractions obtained from somatosensory thalamus and subsequently screened for their activity. We have obtained six antibodies (out of more than 3,000) which appear to selectively label particular elements within the somatosensory thalamus. These antibodies will be examined to determine whether they can be used to identify certain classes of axon terminals within the thalamus, in order to further expand our abilities to analyze thalamic circuitry. The combined use of modern anatomical and physiological methods to be used in this study provide a powerful means to relate structural and functional properties of neurons which constitute a major element of the nervous system concerned with a variety of somatosensory mechanisms, which allow animals and humans to detect and interpret stimuli arising from cutaneous and deep tissues of the body.