Laser Speckled Contrast Imaging to measure blood flow to microvasculature

***皮肤机械感受器的激活调节上肢和下肢的肌肉活动来调节运动。某些机械感受器类别，特别是快速适应（FAI），与运动神经元有很强的耦合，表明它们在平衡控制中起着重要作用。本特博士最近的研究进展揭示了血液流动和皮肤传入放电模式之间关系的潜在混淆因素。在微神经摄影的单单位记录中，脚底的冷却显示皮肤传入神经对负荷的反应发生了显著变化，这些变化被认为与血流调节有关。据称，血流会改变皮肤特性，包括血管诱导的皮肤硬度，以及影响机械感受器本身的机械特性。外力对机械感受器末端器官的传导受到皮肤环境的这些机械特性（包括硬度和刚度）的影响，导致传入神经的放电能力发生改变。这影响了负荷转化为传入射击的能力，并导致运动控制的缺陷。因此，不仅传入输入的数量，而且传入输入的质量都随着血流的变化而改变。******血流量也是理解中枢致敏机制的关键。中枢敏化（CS）是一种神经系统的不适应状态，对骨骼肌的结构和功能有重要影响。虽然疼痛无处不在，但我们目前还不了解导致肌肉症状表现的机制，例如触发点，导致功能改变。Srbely博士的研究项目的目的是探索CS与肌肉功能的时间和剂量反应关系。然而，为了评估CS的变化，有必要能够测量它。传统上使用的是主观度量，这限制了量化变化的能力。为了解决这一知识差距，Srbely博士需要一种能够客观测量中枢致敏变化的工具，这将使未来的工作能够推进和评估剂量依赖性反应和干预措施。对疼痛的自主反应改变了血流量，这是一种机制，可以将周围皮肤微血管灌注作为CS的可行客观生物标志物。通过量化脊柱水平的疼痛，这将使该领域取得重大进展。******本拨款提案是申请资金购买激光散斑对比成像（LSCI）相机能够测量血液流向毛细血管。该设备将直接支持NSERC资助的两个研究项目，目前培训了20名HQP。摄像机的采购将大大增加HQP在各级培训中的机会，并通过提供多层调查（血管，神经，全身）扩大开发高质量研究目标的能力。*****

***Activation of cutaneous mechanoreceptors modulates muscle activity in the upper and lower limbs to regulate movement. Select mechanoreceptor classes, in particular Fast Adapting (FAI), have strong coupling to motor neurones suggesting they have a large role in balance control. Recent advancements in Dr. Bent's work have revealed potential confounding factors in the relationship between blood flow and cutaneous afferent firing patterns. During single unit recordings in microneurography, cooling of the foot sole has shown significant changes in the behaviour of cutaneous afferents in response to load, changes believed to relate to modulation of blood flow. Blood flow purportedly changes skin properties, including vascular induced skin stiffness, as well as impacting the mechanical properties of the mechanoreceptors themselves. Transduction of external forces to the mechanoreceptor end organ is impacted by these mechanical properties of the skin environment, including hardness and stiffness, resulting in altered capability of the afferents to discharge. This affects the ability of load to translate into afferent firing, and results in deficits in movement control. As such, not only the quantity, but the quality of the afferent input is altered with variable blood flow. ******Blood flow is also critical to understand mechanisms behind central sensitization. Central Sensitization (CS) is a maladaptive state of the nervous system with significant implications to skeletal muscle structure and function. While pain is ubiquitous, we do not currently understand the mechanisms that lead to manifestation of symptoms in muscle, such as trigger points, which lead to altered function. The objective of Dr. Srbely's research program is to explore both the temporal and dose-response relationship of CS with muscle function. However, to assess changes in CS, it is necessary to be able to measure it. Traditionally subjective measures have been used, which limit the ability to quantify change. To address this knowledge gap Dr. Srbely requires a tool able to objectively measure changes in central sensitization, which will allow future work to push forward and evaluate dose dependent responses and interventions. Autonomic responses to pain alter blood flow and are mechanisms that will enable the use of peripheral cutaneous microvascular perfusion as a viable objective biomarker for CS. This will allow significant advancements in the field by quantifying pain at the spinal level. ******This grant proposal is to request funds for the purchase of a Laser Speckle Contrast Imaging (LSCI) Camera capable of measuring blood flow to capillaries. The equipment will directly support two NSERC funded research programs, which currently train 20 HQP. Procurement of the camera will vastly increase the opportunities for HQP across all levels of training and expand the capacity to develop high quality research goals by providing multiple tiers of investigation (vascular, nerve, whole body).*****