Nimmerjahn Axel, Mukamel Eran A, Schnitzer Mark J
James H. Clark Center for Biomedical Engineering & Sciences, Stanford University, Stanford, CA 94305, USA.
Neuron. 2009 May 14;62(3):400-12. doi: 10.1016/j.neuron.2009.03.019.
Although it is firmly established that neuronal activity is a prime determinant of animal behavior, relationships between astrocytic excitation and animal behavior have remained opaque. Cerebellar Bergmann glia are radial astrocytes that are implicated in motor behavior and exhibit Ca(2+) excitation. However, Ca(2+) excitation in these cells has not previously been studied in behaving animals. Using two-photon microscopy we found that Bergmann glia exhibit three forms of Ca(2+) excitation in awake, behaving mice. Two of these are ongoing within the cerebellar vermis. During locomotor performance concerted Ca(2+) excitation arises in networks of at least hundreds of Bergmann glia extending across several hundred microns or more. Concerted Ca(2+) excitation was abolished by anesthesia or blockade of either neural activity or glutamatergic transmission. Thus, large networks of Bergmann glia can be activated by specific animal behaviors and undergo excitation of sufficient magnitude to potentially initiate macroscopic changes in brain dynamics or blood flow.
尽管神经元活动是动物行为的主要决定因素这一点已被确凿证实，但星形胶质细胞兴奋与动物行为之间的关系仍不明朗。小脑伯格曼胶质细胞是一种放射状星形胶质细胞，与运动行为有关，并表现出Ca(2+)兴奋。然而，此前尚未在行为动物中研究过这些细胞的Ca(2+)兴奋。利用双光子显微镜，我们发现伯格曼胶质细胞在清醒、行为活跃的小鼠中表现出三种形式的Ca(2+)兴奋。其中两种在小脑蚓部持续存在。在运动过程中，至少数百个伯格曼胶质细胞组成的网络会产生协同的Ca(2+)兴奋，这些网络延伸数百微米或更长。麻醉或阻断神经活动或谷氨酸能传递会消除协同的Ca(2+)兴奋。因此，大量的伯格曼胶质细胞网络可被特定的动物行为激活，并产生足以引发脑动力学或血流宏观变化的兴奋。
