The Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, 75080, USA.
Rare Brain Disorders Program, Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Mail Code 8813, Dallas, TX, 75390-8813, USA.
Sci Rep. 2023 Aug 25;13(1):13942. doi: 10.1038/s41598-023-39344-7.
Selective vascular access to the brain is desirable in metabolic tracer, pharmacological and other studies aimed to characterize neural properties in isolation from somatic influences from chest, abdomen or limbs. However, current methods for artificial control of cerebral circulation can abolish pulsatility-dependent vascular signaling or neural network phenomena such as the electrocorticogram even while preserving individual neuronal activity. Thus, we set out to mechanically render cerebral hemodynamics fully regulable to replicate or modify native pig brain perfusion. To this end, blood flow to the head was surgically separated from the systemic circulation and full extracorporeal pulsatile circulatory control (EPCC) was delivered via a modified aorta or brachiocephalic artery. This control relied on a computerized algorithm that maintained, for several hours, blood pressure, flow and pulsatility at near-native values individually measured before EPCC. Continuous electrocorticography and brain depth electrode recordings were used to evaluate brain activity relative to the standard offered by awake human electrocorticography. Under EPCC, this activity remained unaltered or minimally perturbed compared to the native circulation state, as did cerebral oxygenation, pressure, temperature and microscopic structure. Thus, our approach enables the study of neural activity and its circulatory manipulation in independence of most of the rest of the organism.
选择性的血管通路进入大脑是可取的，在代谢示踪剂，药理学和其他研究旨在从胸部，腹部或四肢的躯体影响中分离出神经特性。然而，目前用于人工控制脑循环的方法可以消除与脉动相关的血管信号或神经网络现象，如脑电图，即使在保持单个神经元活动的情况下也是如此。因此，我们着手通过机械方式使脑血液动力学完全可调节，以复制或修饰天然猪脑灌注。为此，头部的血流通过手术与全身循环分离，并通过改良的主动脉或头臂动脉提供完全体外脉动循环控制（EPCC）。这种控制依赖于一种计算机算法，该算法可在 EPCC 之前单独测量近自然值的血压，流量和脉动，以维持数小时。连续脑电图和脑深部电极记录用于评估相对于清醒人类脑电图提供的标准的脑活动。在 EPCC 下，与天然循环状态相比，这种活动保持不变或仅受到轻微干扰，脑氧合，压力，温度和微观结构也是如此。因此，我们的方法能够在不依赖于大多数其他器官的情况下研究神经活动及其循环操纵。
