Role of Posterior Thalamus in Nociception

丘脑后部在伤害感受中的作用

• 批准号: 6779225
• 负责人: GLENN JOSEPH GIESLER
• 金额: $ 24.69万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6779225
• 关键词: Macaca fascicularis; brain mapping; central neural pathway /tract; laboratory rat; neural information processing; pain; spinal nerves; thalamus

DESCRIPTION (provided by applicant): A number of recent findings have rekindled interest in the decades-old idea that neurons in the posterior region of the thalamus play important roles in nociception. For example, Craig et al. (94) have proposed that a nucleus that they have named VMpo is crucial in nociceptive and thermosensory processing. However, the evidence underlying Craig's proposal has recently been strongly criticized (Willis et al 2001). Indeed, Jones (2001), probably the leading authority on the thalamus, has questioned both the importance even the existence of VMpo. Thus, although substantial evidence exists for an important role for the region of the posterior thalamus in nociception, fundamental questions about the area remain unanswered. It is not clear what types of information spinothalamic tract axons carry to the posterior thalamus in rats and primates. It is also unclear which of the many nuclei within this region receive nociceptive spinal projections. In addition, the cortical regions that receive direct projections from nociceptive neurons in the posterior thalamus have not been determined. In the studies proposed in Specific Aim 1, spinal neurons that project to the posterior thalamus of rats will be identified using systematic micro-antidromic activation techniques. These studies will provide information on the specific nuclei within the posterior thalamus that receive a direct projection from the spinothalamic tract. The response characteristics of such neurons and the locations of their cell bodies within the spinal cord gray matter will also be determined. Our preliminary evidence suggests that a reasonable working hypothesis is that the triangular nucleus of the posterior thalamus is the primary recipient nucleus for nociceptive information in the region, not VMpo. In studies proposed in Specific Aim 2, somatic sensory neurons throughout the posterior thalamus of rats will be physiologically characterized and their precise cortical projections will be established. Based again on our preliminary data, our working hypothesis is that the triangular nucleus contains a large percentage of nociceptive neurons. These studies should reveal precisely the cortical areas that receive a direct nociceptive projection from the posterior thalamus. This would be strong evidence would provide new insights into the nature and locations of areas of nociceptive processing in cortex. In the studies proposed in Specific Aim 3, spinal neurons that project to the posterior thalamus will be examined in monkeys. The proposed studies will provide important information on the nature of spinal input to the posterior thalamus in primates and will reveal which area or areas in posterior thalamus of primates receive input through this large direct spinal projection.

描述（由申请人提供）：最近的一些发现重新点燃了人们对几十年前的观点的兴趣，即丘脑后部区域的神经元在伤害感受中起重要作用。例如，克雷格等人（94）提出，他们命名为VMpo的核团在伤害感受和温度感觉处理中至关重要。然而，支持克雷格提议的证据最近受到了强烈的批评（Willis et al 2001）。事实上，Jones（2001）可能是丘脑的主要权威，他对VMpo的重要性甚至存在都提出了质疑。因此，尽管有大量证据表明后丘脑区域在伤害性感受中发挥重要作用，但关于该区域的基本问题仍未得到解答。目前还不清楚大鼠和灵长类动物脊髓丘脑束轴突携带何种信息到后丘脑。也不清楚在这个区域内的许多核团中的哪一个接受伤害性脊髓投射。此外，接受来自后丘脑伤害性神经元的直接投射的皮质区域尚未确定。在具体目标1中提出的研究中，将使用系统性微逆向激活技术鉴定投射到大鼠后丘脑的脊髓神经元。这些研究将提供有关后丘脑内接受脊髓丘脑束直接投射的特定核团的信息。这些神经元的反应特征和它们的细胞体在脊髓灰质内的位置也将被确定。我们的初步证据表明，一个合理的工作假设是，后丘脑的三角核是该地区的伤害性信息的主要接受核，而不是VMPO。在特定目标2中提出的研究中，将对大鼠后丘脑的躯体感觉神经元进行生理学表征，并建立其精确的皮质投射。再次基于我们的初步数据，我们的工作假设是，三角核包含了很大比例的伤害性神经元。这些研究应该能准确地揭示接受来自后丘脑的直接伤害性投射的皮层区域。这将是强有力的证据，将提供新的见解的性质和区域的伤害性处理在皮层。在具体目标3中提出的研究中，将在猴子中检查投射到后丘脑的脊髓神经元。拟议的研究将提供重要的信息，在灵长类动物的后丘脑的脊髓输入的性质，并将揭示灵长类动物的后丘脑的区域或区域通过这个大的直接脊髓投射接收输入。