Dilation of cortical capillaries is not related to astrocyte calcium signaling.
Dilation of cortical capillaries is not related to astrocyte calcium signaling.
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作者：
Del Franco AP;Chiang PP;Newman EA
当神经元活动变化时，大脑需要足够的氧气和营养物质来维持正常的功能。这部分是通过神经血管耦合机制实现的，该机制通过小动脉和毛细血管的扩张介导局部血流增加。星形胶质细胞在介导这种功能性充血反应中的作用是有争议的。具体而言，星形胶质细胞Ca2+信号传导的功能尚不清楚。皮质小动脉在星形胶质细胞Ca2+信号的情况下扩张，但以前的工作表明，Ca2+的增加是毛细血管扩张所必需的。这个问题还没有完全解决在体内，但是，我们已经重新研究了星形胶质细胞的Ca2+信号在清醒，行为小鼠的桶皮质血管扩张的作用。我们记录了诱发血管扩张和星形胶质细胞Ca2+信号在响应晶须刺激。在WT和IP3R2 KO小鼠上进行实验，这是一种转基因模型，其中星形胶质细胞Ca2+信号传导显著降低。与WT小鼠相比，在休息时，Ca2+信号在星形胶质细胞endfeet接触毛细血管增加了240%时，胡须刺激诱发运行。相反，在IP3R2 KO小鼠中，Ca2+信号传导降低至WT值的9%。然而，在所有三种情况下，毛细血管扩张的幅度基本不变。此外，在大多数试验中，星形胶质细胞Ca2+信号传导的起始潜伏期落后于扩张起始，尽管发生了一个亚组的快速起始Ca2+事件，潜伏期短至0.15 s。总之，我们发现，胡须刺激诱发的毛细血管扩张发生独立的星形胶质细胞Ca2+的增加在大脑皮层。
The brain requires an adequate supply of oxygen and nutrients to maintain proper function as neuronal activity varies. This is achieved, in part, through neurovascular coupling mechanisms that mediate local increases in blood flow through the dilation of arterioles and capillaries. The role of astrocytes in mediating this functional hyperemia response is controversial. Specifically, the function of astrocyte Ca2+ signaling is unclear. Cortical arterioles dilate in the absence of astrocyte Ca2+ signaling, but previous work suggests that Ca2+ increases are necessary for capillary dilation. This question has not been fully addressed in vivo, however, and we have reexamined the role of astrocyte Ca2+ signaling in vessel dilation in the barrel cortex of awake, behaving mice. We recorded evoked vessel dilations and astrocyte Ca2+ signaling in response to whisker stimulation. Experiments were carried out on WT and IP3R2 KO mice, a transgenic model where astrocyte Ca2+ signaling is substantially reduced. Compared to WT mice at rest, Ca2+ signaling in astrocyte endfeet contacting capillaries increased by 240% when whisker stimulation evoked running. In contrast, Ca2+ signaling was reduced to 9% of WT values in IP3R2 KO mice. In all three conditions, however, the amplitude of capillary dilation was largely unchanged. In addition, the latency to the onset of astrocyte Ca2+ signaling lagged behind dilation onset in most trials, although a subset of rapid onset Ca2+ events with latencies as short as 0.15 s occurred. In summary, we found that whisker stimulation-evoked capillary dilations occurred independent of astrocyte Ca2+ increases in the cerebral cortex.
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DOI：
10.1073/pnas.1707702115
发表时间：
2018-06-19
影响因子：
11.1
作者：
Cai, Changsi;Fordsmann, Jonas C.;Lauritzen, Martin J.
通讯作者：
Lauritzen, Martin J.
影响因子：
6.2
作者：
Holtzclaw, LA;Pandhit, S;Russell, JT
通讯作者：
Russell, JT
影响因子：
5.3
作者：
Metea, MR;Newman, EA
通讯作者：
Newman, EA
影响因子：
7.1
作者：
Alarcon-Martinez, Luis;Yilmaz-Ozcan, Sinem;Dalkara, Turgay
通讯作者：
Dalkara, Turgay
周细胞变性导致神经血管解偶联并限制大脑的供氧
影响因子：
25
作者：
Kisler K;Nelson AR;Rege SV;Ramanathan A;Wang Y;Ahuja A;Lazic D;Tsai PS;Zhao Z;Zhou Y;Boas DA;Sakadžić S;Zlokovic BV
通讯作者：
Zlokovic BV