Astrocytes: integrators of arousal state and sensory context

Abstract

The integration of external information with the internal state of the body is central to the survival of virtually every multicellular organism. However, a complete picture of the mechanisms that govern this process is lacking. In this opinion article, we synthesize evidence demonstrating that astrocytes sense the momentary arousal state - through neuromodulator release - as well as the sensory inputs - through local synaptic activity - and respond to them with changes in calcium (Ca²⁺) signaling. We hypothesize that astrocytes integrate sensory signals with the internal state and that this process is necessary to secure optimal behavior. Finally, we argue that dysfunctional astrocytic Ca²⁺ signaling could be an underlying factor in disorders characterized by disrupted sensory processing.

Keywords: calcium signaling; glial cells; internal state; neuromodulation; sensory processing.