ORGANIZATION OF THE LAMINA I STT PROJECTION

本研究项目基于背侧椎板I的概念 角是疼痛的中枢表征的一个组成部分， 温度敏感度。只有椎板I接受小径初级椎板 来自身体所有组织的传入输入，并包含特定的 伤害性和温度感受性神经元的集中。I层神经元 形成脊髓丘脑束(STT)的一半，其上升轴突是 集中在疼痛和体温感的关键部位。 椎板投射的功能和解剖组织需要 有待澄清。在之前的授权期内，我们认同 解剖学、免疫组织化学和生理学方法 丘脑I板层STT丘脑中继核(VMPO) 在猕猴和人类身上的感觉，我们展示了板层I 本脊髓和脑干投射可以提供基础 伤害性和热性躯体自主神经反射。在猫身上，我们也 鉴定了I层STT的三个主要生理/形态分类 细胞，表明它们有选择性的丘脑投射，并且 证明了丘脑-大脑皮层整合的简单模型 这些板层STT感觉通道的活动可以解释热 烧烤的错觉和寒冷的灼痛。 拟议的实验涉及椎板I的功能解剖。 灵长类动物的脊髓-丘脑-皮质通路。我们将(I)确定是否 主要椎板I层的皮质投影STT投射靶点 我们已经在猴子中确定了(VMPO、VPI和MDVC)对应于 在人类PET研究中，疼痛激活的主要皮质区域，(2)确定 不同形态的I板层STT神经元 在猫身上发现的是猴子和投射中的区别 不同的是，(3)检查VMPO和邻近结构是否在 猴和人丘脑是化学结构组织的，(4) 定量地确定生理上不同类别的 猴子体内存在I层STT细胞，与猫中发现的细胞相似， 以及(5)定量确定VMPO神经元是否维持 I型板层反应类型的生理特异性或表现为 板层I STT输入的综合收敛。暖气烤架和 瘙痒诱导剂组胺也将被用来检查 推测在VMpo中存在I层STT活性的整合。 这些实验测试了描绘积分的特定假设 特定疼痛和温度的中心底物的成分 猴子和人类的敏感性。我们认为假设的模型 丘脑-皮质整合的I层感觉通道可以提供 伤寒止痛、燥热止痛 描述典型的(中枢性中风后)丘脑疼痛综合征。

This research project is based on the concept that lamina I of the dorsal horn is an integral component of the central representation of pain and temperature sensibility. Only lamina I receives small-diameter primary afferent input from all tissues of the body and contains a specific concentration of nociceptive and thermoreceptive neurons. Lamina I neurons form half of the spinothalamic tract (STT), and their ascending axons are concentrated in the critical location for pain and temperature sensation. The functional and anatomical organization of lamina I projections needs to be elucidated. In the preceding grant period, we identified with anatomical, immunohistochemical and physiological methods a specific lamina I STT thalamic relay nucleus (VMpo) for pain and temperature sensation in macaques and humans, and we demonstrated lamina I propriospinal and brainstem projections that could provide the basis for noxious and thermal somato-autonomic reflexes. In cats, we also identified three major physiological/morphological classes of lamina I STT cells, showed that they have selective thalamic projections, and demonstrated that a simple model of thalamo-cortical integration of the activity of these lamina I STT sensory channels can explain the thermal grill illusion and the burn of cold pain. The proposed experiments address the functional anatomy of the lamina I spino-thalamo-cortical pathway in primates. We will (i) determine whether the cortical projections of the major lamina I STT projection targets that we have identified (VMpo, VPI, and MDvc) in the monkey correspond with the major cortical areas activated by pain in human PET studies, (2) determine whether the different morphological classes of lamina I STT neurons identified in the cat are distinguishable in the monkey and project differentially, (3) examine whether VMpo and neighboring structures in monkey and human thalamus are chemoarchitectonically organized, (4) quantitatively determine whether physiologically distinct classes of lamina I STT cells exist in the monkey like those identified in the cat, and (5) quantitatively determine whether VMpo neurons maintain the physiological specificity of lamina I response classes or show evidence of integrative convergence of lamina I STT inputs. The thermal grill and the itch-inducing agent histamine will also be used to examine whether the postulated integration of lamina I STT activity occurs in VMpo. These experiments test specific hypotheses that delineate integral components of the central substrates of specific pain and temperature sensibility in monkeys and humans. We believe that the postulated model of thalamo-cortical integration of lamina I sensory channels could provide a basis for the cold allodynia and burning dysesthetic pain that characterize the classic (central post-stroke) thalamic pain syndrome.