Kochunov Peter, Wey Hsiao-Ying, Fox Peter T, Lancaster Jack L, Davis Michael D, Wang Danny J J, Lin Ai-Ling, Bastarrachea Raul A, Andrade Marcia C R, Mattern Vicki, Frost Patrice, Higgins Paul B, Comuzzie Anthony G, Voruganti Venkata S
Maryland Psychiatric Research Center, University of Maryland School of MedicineBaltimore, MA, USA; Research Imaging Institute, University of Texas Health Science Center at San AntonioSan Antonio, TX, USA; Southwest National Primate Research CenterSan Antonio, TX, USA.
Research Imaging Institute, University of Texas Health Science Center at San AntonioSan Antonio, TX, USA; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical SchoolCharlestown, MA, USA.
Front Neurosci. 2017 Feb 14;11:49. doi: 10.3389/fnins.2017.00049. eCollection 2017.
Changes in cerebral blood flow (CBF) during a hyperglycemic challenge were mapped, using perfusion-weighted MRI, in a group of non-human primates. Seven female baboons were fasted for 16 h prior to 1-h imaging experiment, performed under general anesthesia, that consisted of a 20-min baseline, followed by a bolus infusion of glucose (500 mg/kg). CBF maps were collected every 7 s and blood glucose and insulin levels were sampled at regular intervals. Blood glucose levels rose from 51.3 ± 10.9 to 203.9 ± 38.9 mg/dL and declined to 133.4 ± 22.0 mg/dL, at the end of the experiment. Regional CBF changes consisted of four clusters: cerebral cortex, thalamus, hypothalamus, and mesencephalon. Increases in the hypothalamic blood flow occurred concurrently with the regulatory response to systemic glucose change, whereas CBF declined for other clusters. The return to baseline of hypothalamic blood flow was observed while CBF was still increasing in other brain regions. The spatial pattern of extra-hypothalamic CBF changes was correlated with the patterns of several cerebral networks including the default mode network. These findings suggest that hypothalamic blood flow response to systemic glucose levels can potentially be explained by regulatory activity. The response of extra-hypothalamic clusters followed a different time course and its spatial pattern resembled that of the default-mode network.
利用灌注加权磁共振成像（MRI），绘制了一组非人类灵长类动物在高血糖刺激期间脑血流量（CBF）的变化情况。七只雌性狒狒在1小时成像实验前禁食16小时，该实验在全身麻醉下进行，包括20分钟的基线期，随后推注葡萄糖（500毫克/千克）。每7秒收集一次CBF图谱，并定期采集血糖和胰岛素水平样本。实验结束时，血糖水平从51.3±10.9毫克/分升升至203.9±38.9毫克/分升，然后降至133.4±22.0毫克/分升。局部CBF变化包括四个集群：大脑皮层、丘脑、下丘脑和中脑。下丘脑血流量的增加与对全身葡萄糖变化的调节反应同时发生，而其他集群的CBF则下降。当其他脑区的CBF仍在增加时，观察到下丘脑血流量恢复到基线水平。下丘脑外CBF变化的空间模式与包括默认模式网络在内的几个脑网络模式相关。这些发现表明，下丘脑对全身葡萄糖水平的血流反应可能由调节活动来解释。下丘脑外集群的反应遵循不同的时间进程，其空间模式类似于默认模式网络。
