Motor Behavior Activates Bergmann Glial Networks

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 Ca2+ excitation. However, Ca2+ excitation in these cells has not previously been studied in behaving animals. Using twophoton microscopy we found that Bergmann glia exhibit three forms of Ca2+ excitation in awake, behaving mice. Two of these are ongoing within the cerebellar vermis. During locomotor performance concerted Ca2+ excitation arises in networks of at least hundreds of Bergmann glia extending across several hundred microns or more. Concerted Ca2+ 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.