In vivo visualization of subtle, transient, and local activity of astrocytes using an ultrasensitive Ca(2+) indicator

Cell Rep. 2014 Jul 10;8(1):311-8. doi: 10.1016/j.celrep.2014.05.056. Epub 2014 Jun 26.


Astrocytes generate local calcium (Ca(2+)) signals that are thought to regulate their functions. Visualization of these signals in the intact brain requires an imaging method with high spatiotemporal resolution. Here, we describe such a method using transgenic mice expressing the ultrasensitive ratiometric Ca(2+) indicator yellow Cameleon-Nano 50 (YC-Nano50) in astrocytes. In these mice, we detected a unique pattern of Ca(2+) signals. These occur spontaneously, predominantly in astrocytic fine processes, but not the cell body. Upon sensory stimulation, astrocytes initially responded with Ca(2+) signals at fine processes, which then propagated to the cell body. These observations suggest that astrocytic fine processes function as a high-sensitivity detector of neuronal activities. Thus, the method provides a useful tool for studying the activity of astrocytes in brain physiology and pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism*
  • Calcium Signaling*
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / metabolism*
  • Fluorescence Resonance Energy Transfer
  • Mice
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / metabolism*


  • Calcium-Binding Proteins
  • yellow cameleon