Figure 1.

Microglia respond to changes in neural activity. In a resting state, microglia (blue) actively survey the neural environment, dynamically contacting synapses (presynaptic terminals in red, postsynaptic dendrites and spines in teal). Artificial manipulation of neural activity by pharmacological, chemogenetic, or optogenetic perturbation leads to robust changes in microglial calcium dynamics (shown in yellow), process motility, synaptic contact frequency, and transcription. Depriving mice of or exposing mice to sensory stimuli affect many of the same aspects of microglial function. These data are consistent with an important role for microglia in establishing and/or maintaining circuit stability and homeostasis.